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Sample records for atrofia cortical posterior

  1. Atrofia cortical posterior

    OpenAIRE

    Delgado D,Carolina; Donoso S,Archibaldo

    2009-01-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome, usually due to Alzheimer's disease. The first symptoms are progressive impairment of visuo spatial (Balint's and Gertsmann's syndromes) or visuo perceptive (visual agnosia, alexia) function. Episodic memory and executive function are spared until later stages. We report two males aged 51 and 55years and three females aged 50, 54 and 56 years, with posterior cortical atrophy. Ophthalmologic study was normal in all. Presenting si...

  2. Progressive posterior cortical dysfunction

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    Fábio Henrique de Gobbi Porto

    Full Text Available Abstract Progressive posterior cortical dysfunction (PPCD is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal and ventral (occipito-temporal pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction, complete Balint's syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right . Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD.

  3. Posterior cortical atrophy.

    Science.gov (United States)

    Zakzanis, K K; Boulos, M I

    2001-11-01

    The term posterior cortical atrophy (PCA) was introduced in 1988 to describe five patients with fairly homogeneous, but otherwise unclassified, symptoms. These patients showed signs of a slowly progressive dementia bearing behavioral and physiologic similarities to Alzheimer's disease, but with notable distinctions. Specifically, PCA is characterized by an early onset of visual agnosia, followed by some or all components of Balint's syndrome, Gerstmann's syndrome, and transcortical sensory aphasia. In this review, the history, epidemiology, pathophysiology, neurobehavioral aspects, assessment (including neurologic and neuropsychologic), differential diagnosis, and treatment recommendations for this disorder are reviewed. As originally defined, PCA appears to be a clinically homogeneous syndrome. The cluster of symptoms that are common to virtually all examined cases evidences this. Although the behavioral and cognitive properties of the disorder are well established, many aspects of PCA remain unclear. Specifically, available research and understanding of PCA epidemiology and treatment are highly inadequate. In fact, the majority of such information regarding PCA is derived from studies of Alzheimer's disease. To a lesser extent, Pick's disease and Creutzfeldt-Jakob disease research have also provided insight into the underpinnings of PCA. Until PCA is categorically defined as a variant or subgroup of these other neurodegenerative disorders, however, such derivations are merely speculations.

  4. Frontoparietal cortical atrophy with gliosis in the gray matter of cerebral cortex: case report Atrofia cortical frontoparietal com gliose na substância cinzenta do córtex cerebral: relato de caso

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    Paulo Roberto de Brito-Marques

    2002-06-01

    região periventricular, centro semi-oval bilateral, e alta hiperintensidade de sinal na região da cápsula interna esquerda, além de leve atrofia bilateral nos lobos frontoparietais. Tomografia cerebral por emissão de fóton único revelou hipoperfusão de intensidade moderada nos lobos frontais e severa nos parietais, especialmente à esquerda. Os achados de necrópsia evidenciaram atrofia cortical, sendo severa nos lobos frontais, moderada nos parietais e leve no terço posterior dos temporais. Havia também leve atrofia no neostriado. Do ponto de vista histopatológico, existia na camada cortical severa perda neuronal com intensa gliose gemioscítica e grau variável de status spongiosus. As colorações por hematoxilina-eosina e Bielschowsky não revelaram células baloniformes (células de Pick e corpúsculos argirofílicos (corpos de Pick, degeneração neurofibrilar ou placa senil. As reações imuno-histoquímicas foram negativas para anti-ubiquitina, anti-tau, anti-beta amilóide e proteína anti-prion.

  5. [Posterior cortical atrophy. Report of five cases].

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    Delgado D, Carolina; Donoso S, Archibaldo

    2009-11-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome, usually due to Alzheimer's disease. The first symptoms are progressive impairment of visuo spatial (Balint's and Gertsmann's syndromes) or visuo perceptive (visual agnosia, alexia) function. Episodic memory and executive function are spared until later stages. We report two males aged 51 and 55years and three females aged 50, 54 and 56 years, with posterior cortical atrophy. Ophthalmologic study was normal in all. Presenting signs and symptoms were visual ataxia, simultagnosia, agraphia, acalculia, spatial disorientation and unilateral neglect (Balint's and Gerstmann's syndromes). Apperceptive visual agnosia, aphasia, apraxia and alexia were also observed. One female had cortical blindness. Structural images were inconclusive, but PET scan and SPECT disclosed functional impairments in occipitotemporal or occipitoparietal areas.

  6. Visual Dysfunction in Posterior Cortical Atrophy

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    Maia da Silva, Mari N.; Millington, Rebecca S.; Bridge, Holly; James-Galton, Merle; Plant, Gordon T.

    2017-01-01

    Posterior cortical atrophy (PCA) is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical) visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed. Emphasis is given to the visual dysfunction that defines the disorder, and the classical deficits, such as simultanagnosia and visual agnosia, as well as the more recently recognized visual field defects, are reviewed, along with the evidence on their neural correlates. The latest developments on the imaging of PCA are summarized, with special attention to its role on the differential diagnosis with related conditions. PMID:28861031

  7. Visual Dysfunction in Posterior Cortical Atrophy.

    Science.gov (United States)

    Maia da Silva, Mari N; Millington, Rebecca S; Bridge, Holly; James-Galton, Merle; Plant, Gordon T

    2017-01-01

    Posterior cortical atrophy (PCA) is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical) visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed. Emphasis is given to the visual dysfunction that defines the disorder, and the classical deficits, such as simultanagnosia and visual agnosia, as well as the more recently recognized visual field defects, are reviewed, along with the evidence on their neural correlates. The latest developments on the imaging of PCA are summarized, with special attention to its role on the differential diagnosis with related conditions.

  8. Visual Dysfunction in Posterior Cortical Atrophy

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    Mari N. Maia da Silva

    2017-08-01

    Full Text Available Posterior cortical atrophy (PCA is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed. Emphasis is given to the visual dysfunction that defines the disorder, and the classical deficits, such as simultanagnosia and visual agnosia, as well as the more recently recognized visual field defects, are reviewed, along with the evidence on their neural correlates. The latest developments on the imaging of PCA are summarized, with special attention to its role on the differential diagnosis with related conditions.

  9. Bilateral cortical atrophy after severe brain trauma and extradural homatoma Atrofia cortical bilateral após traumatismo cranioencefálico grave e hematoma extradural

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    Paulo Roberto Louzada

    2007-12-01

    Full Text Available We report the case of a severe head injured 43-year old male patient with a large extradural hematoma, Glasgow Coma Scale 3 and dilated fixed pupils. Patient was promptly submitted to surgical evacuation of the lesion, but remained in persistent vegetative state in the post-operative time. Head computed tomography scans performed before surgery, and at early and late post-operative periods comparatively revealed extreme bilateral cortical atrophy. Late consequences of severe head trauma drastically affect the prognosis of patients, being its prevention, and neuroprotection against secondary injury still a therapeutical challenge for neurosurgeons.Relatamos o caso de um paciente de 43 anos, com traumatismo cranioencefálico grave, com grande hematoma extradural, Escala de Coma de Glasgow 3 e pupilas fixas e dilatadas. O paciente foi prontamente submetido à evacuação cirúrgica da lesão mas permaneceu em estado vegetativo persistente no período pós-operatório. As TC de crânio realizadas antes da cirurgia e nos períodos pós-operatórios precoce e tardio revelaram comparativamente extrema atrofia cerebral bilateral. As conseqüências tardias do traumatismo craniano grave afetam drasticamente o prognóstico dos pacientes, sendo sua prevenção, e a neuroproteção contra a injúria secundária ainda um desafio terapêutico para os neurocirurgiões.

  10. [Homonymous hemianopia and posterior cortical atrophy].

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    Formaglio, M; Krolak-Salmon, P; Tilikete, C; Bernard, M; Croisile, B; Vighetto, A

    2009-03-01

    Posterior cortical atrophy (PCA) is a clinically and radiologically defined syndrome, in which predominant symptoms focus on higher visual dysfunction with progressive course and association with cortical atrophy or hypometabolism that predominates in the posterior part of the hemispheres. Homonymous hemianopia (HH) has rarely been described in this syndrome. We report on six patients (four females, two males, aged 63 to 80) referred for visual disorder which led to demonstration of HH using perimetry testing. These patients were followed for 1 to 5 years after discovery of HH. Brain imaging with MRI or CT scan was obtained in the six cases and a SPECT scan was performed in four cases. HH was left-sided in four cases and right-sided in two cases. Associated symptoms related to higher visual dysfunction were simultagnosia, alone or as part of a full Balint's syndrome, alexia, constructional apraxia, dressing apraxia, visual form agnosia, prosopagnosia and hemispatial neglect. These symptoms were mild at onset but invariably worsened with disease progression. Dementia eventually developed in all cases. The clinical diagnosis was probable Alzheimer's disease in five cases and corticobasal degeneration in one case. Radiology showed posterior cortex atrophy in all cases as well as reduced cerebral blood flow in the same region, with an asymmetrical pattern compatible with the side of HH. Elementary cortical lesions in PCA can develop mainly in the associative visual areas and even in the primary visual area, resulting in HH. HH has rarely been documented in PCA, but its prevalence would probably be higher if systematic search was conducted. Apparently isolated HH of insidious onset should suggest PCA and lead to neuropsychological testing and search for discrete atrophic changes of the posterior cortex on MRI as well as for metabolic alterations with SPECT or PET.

  11. [Posterior cortical atrophy with progressive visual agnosia].

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    Zarranz, J J; Lasa, A; Fernández, M; Lezcano, E; Pérez Bas, M; Varona, L; Ruiz, J; Beristain, X

    1995-03-01

    Interest in progressive focal cerebral syndromes associated with classical degenerative diseases has increased in recent years. Descriptions of posterior cortical atrophy with progressive visual agnosia are relatively rare. We present 5 patients (2 women) ranging in age between 57 and 72 years old. In all cases symptoms began and progressed with no known etiology. All cases were sporadic. The main clinical signs are difficulty in recognizing objects, colors, persons or places; topographical disorientation and visual memory alterations; alexia, simultagnosia, loss of ocular fixing and optic ataxia. Some patients presented other disturbances of praxis or memory and 2 progressed to global dementia. Language function was preserved and behavioral disturbances did not develop. The amplitude of the P100 visual evoked potential was low but latency was normal in 4 patients and prolonged in 1. Brain images showed atrophy and hypoperfusion in the parieto-occipital area. The neuropathology status of these patients is unknown.

  12. Facilitating text reading in posterior cortical atrophy.

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    Yong, Keir X X; Rajdev, Kishan; Shakespeare, Timothy J; Leff, Alexander P; Crutch, Sebastian J

    2015-07-28

    We report (1) the quantitative investigation of text reading in posterior cortical atrophy (PCA), and (2) the effects of 2 novel software-based reading aids that result in dramatic improvements in the reading ability of patients with PCA. Reading performance, eye movements, and fixations were assessed in patients with PCA and typical Alzheimer disease and in healthy controls (experiment 1). Two reading aids (single- and double-word) were evaluated based on the notion that reducing the spatial and oculomotor demands of text reading might support reading in PCA (experiment 2). Mean reading accuracy in patients with PCA was significantly worse (57%) compared with both patients with typical Alzheimer disease (98%) and healthy controls (99%); spatial aspects of passages were the primary determinants of text reading ability in PCA. Both aids led to considerable gains in reading accuracy (PCA mean reading accuracy: single-word reading aid = 96%; individual patient improvement range: 6%-270%) and self-rated measures of reading. Data suggest a greater efficiency of fixations and eye movements under the single-word reading aid in patients with PCA. These findings demonstrate how neurologic characterization of a neurodegenerative syndrome (PCA) and detailed cognitive analysis of an important everyday skill (reading) can combine to yield aids capable of supporting important everyday functional abilities. This study provides Class III evidence that for patients with PCA, 2 software-based reading aids (single-word and double-word) improve reading accuracy. © 2015 American Academy of Neurology.

  13. Relación entre atrofia cortical difusa y desempeño cognitivo : estudio en población mayor de 60 años en un hospital universitario en la ciudad de Bogotá

    OpenAIRE

    Cogollos, Jenny Natalia; Piedrahita, Paula Viviana; Urquijo, Paula Andrea

    2016-01-01

    El presente trabajo tuvo como objetivo evaluar la existencia de la relación entre la atrofia cortical difusa objetivada por neuroimagenes cerebrales y desempeños cognitivos determinados mediante la aplicación de pruebas neuropsicológicas que evalúan memoria de trabajo, razonamiento simbólico verbal y memoria anterógrada declarativa. Participaron 114 sujetos reclutados en el Hospital Universitario Mayor Méderi de la ciudad de Bogotá mediante muestreo de conveniencia. Los resultados arrojaron...

  14. Endarterectomia e atrofia cortical cerebral

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    Luis Eduardo Belini Soares

    2016-01-01

    Resumo: O acidente vascular cerebral isquêmico (AVCi) é uma das principais causas de morte no Brasil e no mundo. Dentre as principais causas destaca-se a doença aterosclerótica, em especial, a formada do bulbo carotídeo. A mesma pode ser considerada sintomática quando é causadora de AVCi ou ataque isquêmico transitório. Todavia, sabe-se que as estenoses ditas assintomáticas, também levam a diminuição de fluxo sanguíneo cerebral. Idosos acima de 80 anos prevalência das estenoses assintomáticas...

  15. Clinical, FDG and amyloid PET imaging in posterior cortical atrophy

    OpenAIRE

    Singh, Tarun D.; Josephs, Keith A.; Machulda, Mary M.; Drubach, Daniel A.; Apostolova, Liana G.; Lowe, Val J.; Whitwell, Jennifer L.

    2015-01-01

    The purpose of this study was to identify the clinical, [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) and amyloid-PET findings in a large cohort of posterior cortical atrophy (PCA) patients, to examine the neural correlates of the classic features of PCA, and to better understand the features associated with early PCA. We prospectively recruited 25 patients who presented to the Mayo Clinic between March 2013 and August 2014 and met diagnostic criteria for PCA. All patients u...

  16. The evolution of alexia and simultanagnosia in posterior cortical atrophy.

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    Mendez, M F; Cherrier, M M

    1998-04-01

    Early alexia and higher visual impairments characterize Posterior cortical atrophy (PCA), a progressive dementing syndrome most often caused by Alzheimer disease. Posterior cortical atrophy is rare, and the nature of the visual impairments in PCA are unclear. The authors observed two patients who had an insidiously progressive reading difficulty characterized by letter-by-letter reading and otherwise intact cognitive functions. Over time, these patients developed "ventral simultanagnosia" with preserved detection of multiple stimuli but inability to interpret whole scenes. Subsequently, they progressed to Balint syndrome with "dorsal simultanagnosia," optic ataxia, and oculomotor apraxia. Structural imaging was normal, but functional imaging revealed posterior cortical dysfunction. On a letter reading task, both patients had a word superiority effect, and on a whole word reading task, they could not read most words with missing or crosshatched letters. An inability to assess whole scenes progressed to an inability to detect more than one stimulus in an array. These findings suggest an evolution of PCA with progressive difficulty in visual integration beginning with letters, progressing to whole scenes, and culminating in Balint syndrome. These changes may reflect an extension of the pathophysiology of PCA from the extrastriate visual cortex to its occipitotemporal and occipitoparietal connections.

  17. Late-onset Alzheimer disease genetic variants in posterior cortical atrophy and posterior AD.

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    Carrasquillo, Minerva M; Khan, Qurat ul Ain; Murray, Melissa E; Krishnan, Siddharth; Aakre, Jeremiah; Pankratz, V Shane; Nguyen, Thuy; Ma, Li; Bisceglio, Gina; Petersen, Ronald C; Younkin, Steven G; Dickson, Dennis W; Boeve, Bradley F; Graff-Radford, Neill R; Ertekin-Taner, Nilüfer

    2014-04-22

    To investigate association of genetic risk factors for late-onset Alzheimer disease (LOAD) with risk of posterior cortical atrophy (PCA), a syndrome of visual impairment with predominant Alzheimer disease (AD) pathology in posterior cortical regions, and with risk of "posterior AD" neuropathology. We assessed 81 participants with PCA diagnosed clinically and 54 with neuropathologic diagnosis of posterior AD vs 2,523 controls for association with 11 significant single nucleotide polymorphisms (SNPs) from published LOAD risk genome-wide association studies. There was highly significant association with APOE ε4 and increased risk of PCA (p = 0.0003, odds ratio [OR] = 3.17) and posterior AD (p = 1.11 × 10(-17), OR = 6.43). No other locus was significant after corrections for multiple testing, although rs11136000 near CLU (p = 0.019, OR = 0.60) and rs744373 near BIN1 (p = 0.025, OR = 1. 63) associated nominally significantly with posterior AD, and rs3851179 at the PICALM locus had significant association with PCA (p = 0.0003, OR = 2.84). ABCA7 locus SNP rs3764650, which was also tested under the recessive model because of Hardy-Weinberg disequilibrium, also had nominally significant association with PCA risk. The direction of association at APOE, CLU, and BIN1 loci was the same for participants with PCA and posterior AD. The effects for all SNPs, except rs3851179, were consistent with those for LOAD risk. We identified a significant effect for APOE and nominate CLU, BIN1, and ABCA7 as additional risk loci for PCA and posterior AD. Our findings suggest that at least some of the genetic risk factors for LOAD are shared with these atypical conditions and provide effect-size estimates for their future genetic studies.

  18. Atrofia muscular proximal familiar

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    José Antonio Levy

    1962-09-01

    Full Text Available Os autores relatam dois casos de atrofia muscular proximal familiar, moléstia caracterizada por déficit motor e atrofias musculares de distribuição proximal, secundárias a lesão de neurônios periféricos. Assim, como em outros casos descritos na literatura, foi feito inicialmente o diagnóstico de distrofia muscular progressiva. O diagnóstico correto foi conseguido com auxílio da eletromiografia e da biopsia muscular.

  19. Functional neural substrates of posterior cortical atrophy patients.

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    Shames, H; Raz, N; Levin, Netta

    2015-07-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome in which the most pronounced pathologic involvement is in the occipito-parietal visual regions. Herein, we aimed to better define the cortical reflection of this unique syndrome using a thorough battery of behavioral and functional MRI (fMRI) tests. Eight PCA patients underwent extensive testing to map their visual deficits. Assessments included visual functions associated with lower and higher components of the cortical hierarchy, as well as dorsal- and ventral-related cortical functions. fMRI was performed on five patients to examine the neuronal substrate of their visual functions. The PCA patient cohort exhibited stereopsis, saccadic eye movements and higher dorsal stream-related functional impairments, including simultant perception, image orientation, figure-from-ground segregation, closure and spatial orientation. In accordance with the behavioral findings, fMRI revealed intact activation in the ventral visual regions of face and object perception while more dorsal aspects of perception, including motion and gestalt perception, revealed impaired patterns of activity. In most of the patients, there was a lack of activity in the word form area, which is known to be linked to reading disorders. Finally, there was evidence of reduced cortical representation of the peripheral visual field, corresponding to the behaviorally assessed peripheral visual deficit. The findings are discussed in the context of networks extending from parietal regions, which mediate navigationally related processing, visually guided actions, eye movement control and working memory, suggesting that damage to these networks might explain the wide range of deficits in PCA patients.

  20. Clinical, FDG and amyloid PET imaging in posterior cortical atrophy.

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    Singh, Tarun D; Josephs, Keith A; Machulda, Mary M; Drubach, Daniel A; Apostolova, Liana G; Lowe, Val J; Whitwell, Jennifer L

    2015-06-01

    The purpose of this study was to identify the clinical, [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) and amyloid-PET findings in a large cohort of posterior cortical atrophy (PCA) patients, to examine the neural correlates of the classic features of PCA, and to better understand the features associated with early PCA. We prospectively recruited 25 patients who presented to the Mayo Clinic between March 2013 and August 2014 and met diagnostic criteria for PCA. All patients underwent a standardized set of tests and amyloid imaging with [(11)C] Pittsburg compound B (PiB). Seventeen (68 %) underwent FDG-PET scanning. We divided the cohort at the median disease duration of 4 years in order to assess clinical and FDG-PET correlates of early PCA (n = 13). The most common clinical features were simultanagnosia (92 %), dysgraphia (68 %), poly-mini-myoclonus (64 %) and oculomotor apraxia (56.5 %). On FDG-PET, hypometabolism was observed bilaterally in the lateral and medial parietal and occipital lobes. Simultanagnosia was associated with hypometabolism in the right occipital lobe and posterior cingulum, optic ataxia with hypometabolism in left occipital lobe, and oculomotor apraxia with hypometabolism in the left parietal lobe and posterior cingulate gyrus. All 25 PCA patients were amyloid positive. Simultanagnosia was the only feature present in 85 % of early PCA patients. The syndrome of PCA is associated with posterior hemisphere hypometabolism and with amyloid deposition. Many of the classic features of PCA show associated focal, but not widespread, areas of involvement of these posterior hemispheric regions. Simultanagnosia appears to be the most common and hence sensitive feature of early PCA.

  1. Effect of age at onset on cortical thickness and cognition in posterior cortical atrophy.

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    Suárez-González, Aida; Lehmann, Manja; Shakespeare, Timothy J; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Foulkes, Alexander J M; Rabinovici, Gil D; Gil-Néciga, Eulogio; Roldán-Lora, Florinda; Schott, Jonathan M; Fox, Nick C; Crutch, Sebastian J

    2016-08-01

    Age at onset (AAO) has been shown to influence the phenotype of Alzheimer's disease (AD), but how it affects atypical presentations of AD remains unknown. Posterior cortical atrophy (PCA) is the most common form of atypical AD. In this study, we aimed to investigate the effect of AAO on cortical thickness and cognitive function in 98 PCA patients. We used Freesurfer (v5.3.0) to compare cortical thickness with AAO both as a continuous variable, and by dichotomizing the groups based on median age (58 years). In both the continuous and dichotomized analyses, we found a pattern suggestive of thinner cortex in precuneus and parietal areas in earlier-onset PCA, and lower cortical thickness in anterior cingulate and prefrontal cortex in later-onset PCA. These cortical thickness differences between PCA subgroups were consistent with earlier-onset PCA patients performing worse on cognitive tests involving parietal functions. Our results provide a suggestion that AAO may not only affect the clinico-anatomical characteristics in AD but may also affect atrophy patterns and cognition within atypical AD phenotypes. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Picture agnosia as a characteristic of posterior cortical atrophy.

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    Sugimoto, Azusa; Midorikawa, Akira; Koyama, Shinichi; Futamura, Akinori; Hieda, Sotaro; Kawamura, Mitsuru

    2012-01-01

    Posterior cortical atrophy (PCA) is a degenerative disease characterized by progressive visual agnosia with posterior cerebral atrophy. We examine the role of the picture naming test and make a number of suggestions with regard to diagnosing PCA as atypical dementia. We investigated 3 cases of early-stage PCA with 7 control cases of Alzheimer disease (AD). The patients and controls underwent a naming test with real objects and colored photographs of familiar objects. We then compared rates of correct answers. Patients with early-stage PCA showed significant inability to recognize photographs compared to real objects (F = 196.284, p = 0.0000) as measured by analysis of variants. This difficulty was also significant to AD controls (F = 58.717, p = 0.0000). Picture agnosia is a characteristic symptom of early-stage PCA, and the picture naming test is useful for the diagnosis of PCA as atypical dementia at an early stage. Copyright © 2012 S. Karger AG, Basel.

  3. [Posterior cortical atrophy with incomplete Bálint's syndrome].

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    Iizuka, O; Soma, Y; Otsuki, M; Endo, K; Tanno, Y; Tsuji, S

    1997-09-01

    We report a patient of posterior cortical atrophy (PCA) with progressive memory disturbance and incomplete Bálint's syndrome consisting of optic ataxie (ataxie optique type) and visual inattention without psychic paralysis of fixation of gaze. The patients is a 58-year-old woman who noticed memory disturbance at 53 years old. Neurological deficit at 54 years old was detected only in the domain of memory, and mild diffuse brain atrophy was revealed on MRI. Memory disturbance progressed gradually, and at the age of 58 she was noticed to have visual disorder. Neuropsychological examination revealed severe memory disorder, incomplete Bálint's syndrome, transcortical sensory aphasia, mild ideational apraxia, and severe constructional apraxia. Visual inattention was too severe to evaluate visual acuity and visual field. MRI showed moderate dilatation of bilateral lateral ventricles, especially in their posterior horns, with atrophy of bilateral temporo-parieto-occipital lobes and hippocampus. IMP-SPECT revealed a diffuse decrease of cerebral blood flow in the bilateral temporo-parieto-occipital region, predominantly in the parietal regions. We believe that she is still in the early phase of PCA, and that psychic paralysis of fixation of gaze, visual agnosia will be noted in several years. Our patient represents an example of early stage PCA from neuropsychological and MRI findings.

  4. Ruptura del ligamento cruzado posterior. Fijacion cortical retrógrada. [Rupture of posterior cruciate ligament. Retrograde cortical tibial fixation

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    Rodolfo Horacio Alonso

    2015-11-01

    Full Text Available Introducción Presentamos las dificultades propias de cada una de las técnicas empleadas en la reconstrucción del Ligamento Cruzado Posterior (LCP, el objetivo es analizar retrospectivamente si hemos mejorado el resultado final con la técnica actual de fijación cortical tibial retrógrada. Material y Método Sobre 106 pacientes operados con distintas técnicas de fijación artroscópica en rupturas del LCP, tipo II y III se incluyen 96 reconstrucciones en las cuales evaluamos retrospectivamente el cajón posterior (CP radiográfico al alta.   Se excluyeron 8 pacientes que no están de alta o se perdieron durante el tratamiento y dos pacientes operados con injerto de tendón cuadricipital, que por el escaso número no tienen relevancia estadística y cuyo CP al alta fue similar a nuestras primeras cirugías. Resultados El CP radiográfico al alta tuvo diferencias estadísticamente significativas entre la técnica actual y las otras realizadas anteriormente. Conclusión La reconstrucción del LCP con esta técnica, objetivamente ha mejorado el CP final radiográfico.

  5. Posterior cortical dementia with alexia: neurobehavioural, MRI, and PET findings.

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    Freedman, L; Selchen, D H; Black, S E; Kaplan, R; Garnett, E S; Nahmias, C

    1991-05-01

    A progressive disorder of relatively focal but asymmetric biposterior dysfunction is described in a 54 year old right handed male. Initial clinical features included letter-by-letter alexia, visual anomia, acalculia, mild agraphia, constructional apraxia, and visuospatial compromise. Serial testing demonstrated relentless deterioration with additional development of transcortical sensory aphasia, Gerstmann's tetrad, and severe visuoperceptual impairment. Amnesia was not an early clinical feature. Judgment, personality, insight, and awareness remained preserved throughout most of the clinical course. Extinction in the right visual field to bilateral stimulation was the sole neurological abnormality. Early CT was normal and late MRI showed asymmetrical bioccipitoparietal atrophy with greater involvement of the left hemisphere. Results from positron emission tomography (PET) showed bilaterally asymmetric (left greater than right) occipitotemporoparietal hypometabolism. The metabolic decrement was strikingly asymmetric with a 50% reduction in glucose consumption confined to the left occipital cortex. The picture of occipitotemporoparietal compromise verified by MRI, PET, and neurobehavioural testing would be unusual for such degenerative dementias as Alzheimer's (AD) and Pick's disease, although atypical AD with predominant occipital lobe involvement cannot be excluded. This case supports the concepts of posterior cortical dementia (PCD) as a clinically distinct entity and for the first time documents its corresponding metabolic deficit using PET.

  6. The Progression of Posterior Cortical Atrophy to Corticobasal Syndrome: Lumping or Splitting Neurodegenerative Diseases?

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    Maurizio Giorelli

    2014-06-01

    Full Text Available Background: Posterior cortical atrophy is a clinical syndrome that is characterized by the progressive loss of visuospatial integration and is associated with neurodegenerative conditions.Case Report: We describe a 60‐year‐old female with simultanagnosia, oculomotor apraxia, and optic ataxia for which she received an initial clinical diagnosis of posterior cortical atrophy. Three years later, she developed Balint's syndrome, Gerstmann's syndrome, left alien hand syndrome, smooth asymmetric (left rigidity, cortical sensory loss, and spontaneous myoclonic jerks of the left arm, which suggested a final diagnosis of corticobasal syndrome.Discussion: This case report indicates that corticobasal syndrome may present with visuospatial deficits.

  7. The progression of posterior cortical atrophy to corticobasal syndrome: lumping or splitting neurodegenerative diseases?

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    Giorelli, Maurizio; Losignore, Nunzia Alessandra; Bagnoli, Junia; Difazio, Pasquale; Zimatore, Giovanni Bosco

    2014-01-01

    Posterior cortical atrophy is a clinical syndrome that is characterized by the progressive loss of visuospatial integration and is associated with neurodegenerative conditions. We describe a 60-year-old female with simultanagnosia, oculomotor apraxia, and optic ataxia for which she received an initial clinical diagnosis of posterior cortical atrophy. Three years later, she developed Balint's syndrome, Gerstmann's syndrome, left alien hand syndrome, smooth asymmetric (left) rigidity, cortical sensory loss, and spontaneous myoclonic jerks of the left arm, which suggested a final diagnosis of corticobasal syndrome. This case report indicates that corticobasal syndrome may present with visuospatial deficits.

  8. [Surgery for pediatric intractable epilepsy due to posterior quadrantic cortical dysplasia].

    Science.gov (United States)

    Liu, Qing-Zhu; Cai, Li-Xin; Liu, Xiao-Yan; Jiang, Yu-Wu; Wang, Shuang; Ji, Tao-Yun; Wang, Wen; Cheng, Wei-Ke; Wang, Ruo-Fan

    2017-03-01

    To investigate the clinical features and surgical strategy for pediatric intractable epilepsy due to posterior quadrantic cortical dysplasia and to assess the surgical outcomes. The clinical features and preoperative evaluation results of 14 children with intractable epilepsy due to posterior quadrantic cortical dysplasia were retrospectively analyzed. The localization values of video-electroencephalography and intraoperative monitoring and the indications, advantages and disadvantages of temporoparietooccipital disconnection were evaluated. The 14 children had different seizure types, of which spasm was the most common one. The lesions of cortical dysplasia involved the central cerebral region in 2 cases. After temporoparietooccipital disconnection in 14 patients, 13 cases were seizure-free; only one case still had seizures, but the frequency dropped by more than 50%. Temporoparietooccipital disconnection is a safe and effective surgical procedure for children with intractable epilepsy due to posterior quadrantic cortical dysplasia.

  9. Comparing the influence of crestal cortical bone and sinus floor cortical bone in posterior maxilla bi-cortical dental implantation: a three-dimensional finite element analysis.

    Science.gov (United States)

    Yan, Xu; Zhang, Xinwen; Chi, Weichao; Ai, Hongjun; Wu, Lin

    2015-05-01

    This study aimed to compare the influence of alveolar ridge cortical bone and sinus floor cortical bone in sinus areabi-cortical dental implantation by means of 3D finite element analysis. Three-dimensional finite element (FE) models in a posterior maxillary region with sinus membrane and the same height of alveolar ridge of 10 mm were generated according to the anatomical data of the sinus area. They were either with fixed thickness of crestal cortical bone and variable thickness of sinus floor cortical bone or vice versa. Ten models were assumed to be under immediate loading or conventional loading. The standard implant model based on the Nobel Biocare implant system was created via computer-aided design software. All materials were assumed to be isotropic and linearly elastic. An inclined force of 129 N was applied. Von Mises stress mainly concentrated on the surface of crestal cortical bone around the implant neck. For all the models, both the axial and buccolingual resonance frequencies of conventional loading were higher than those of immediate loading; however, the difference is less than 5%. The results showed that bi-cortical implant in sinus area increased the stability of the implant, especially for immediately loading implantation. The thickness of both crestal cortical bone and sinus floor cortical bone influenced implant micromotion and stress distribution; however, crestal cortical bone may be more important than sinus floor cortical bone.

  10. Cortical blindness and posterior reversible encephalopathy syndrome in an older patient

    Science.gov (United States)

    Ait, Sabrina; Gilbert, Thomas; Cotton, Francois; Bonnefoy, Marc

    2012-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological entity. It associates, to varying extents, neurological symptoms such as headaches, confusion, seizures and visual alterations from haemianopsia to cortical blindness. The diagnosis relies on brain MRI, showing signs of subcortical and cortical oedema in the posterior regions of the brain, with hypersignals in T2/fluid attenuated inversion recovery (FLAIR) or diffusion sequences. With early diagnosis and control of the causal factors, the symptoms and radiological signs can be – as the name implies – totally regressive. PRES can be caused by various heterogeneous factors, such as hypertension, side effect of drug therapies, eclampsia, sepsis or autoimmune diseases. The authors report here the case of an 86-year-old woman, presenting totally regressive cortical blindness and seizures, with compatible imaging. PMID:22669215

  11. Cortical damage in the posterior visual pathway in patients with sialidosis type 1.

    Science.gov (United States)

    Lu, Chin-Song; Ng, Shu-Hang; Lai, Szu-Chia; Kao, Ling-Yuh; Liu, Laura; Lin, Wey-Yil; Wu, Yi-Ming; Chen, Yao-Liang; Wang, Jiun-Jie

    2017-02-01

    In order to identify the cortical changes in patients with Sialidosis type 1, diffusion tensor imaging and resting state fMRI were acquired from 11 patients and 11 sex/age matched normal controls after clinical evaluations. The neuroimages from each participant were normalized and parcellated according to the Automatic Anatomical Labeling. Both the mean diffusivity and the corresponding functional connectivity were calculated from each cortical region. The white matter tract integrity was examined. The difference between patients and controls was examined using Student's t-test and between patients with either homozygous or heterozygous mutations by Mann-Whitney U test, both at a threshold of 0.05. Increased mean diffusivity throughout the brain can be noticed in the patients, together with a compromised white matter tracts integrity. The most severely affected cortical regions are in the occipital lobe. Decreased functional connectivity was from the temporal and occipital lobes to the hippocampus and parahippocampus. In contrast, connectivity from thalamus was enhanced. Diffused cortical atrophy with posterior focal lesions was noticed. We concluded that MRI observed functional changes in the posterior cortical pathways in the patients with Sialidosis. The observation might be related to the cortical blindness due to an altered neural network and a compromised visual pathway in the patients.

  12. [Familial posterior cortical atrophy with visual agnosia and Bálint's syndrome].

    Science.gov (United States)

    Otsuki, M; Soma, Y; Tanaka, M; Tanaka, K; Tanno, Y; Uesugi, Y; Tsuji, S

    1995-12-01

    We report a patient of posterior cortical atrophy with progressive visual agnosia, Bálint's syndrome and dementia in which posterior cortical atrophy with similar characteristics on CT and progressive dementia were found in a sister. The patient was a 75-year-old woman who noted the onset of a progressive visual disorder at the age of 70, and whose family first noticed disoriented behavior at around the same period. Ophthalmologic examinations revealed mild cataract but no evidence of peripheral optic nerve or retinal lesions. Neuropsychological examination showed right homonymous hemianopia, visual agnosia, Bálint's syndrome, mild transcortical sensory aphasia, Gerstmann's syndrome, constructional apraxia, mild ideomotor apraxia and memory disorder. MRI showed marked dilatation of both lateral ventricles, especially the posterior horns, and severe atrophy of the occipital lobes, hippocampus, and the parahippocampal gyrus. Assessment of regional cerebral blood flow by IMP-SPECT revealed a generalized decrease in the temporo-parieto-occipital region bilaterally. The patient's sister began to show evidence of progressive dementia at 80 years of age and CT of the brain revealed marked atrophy, predominantly in the occipital lobes, similar to that of the patient. We believe this to be the first report of posterior cortical atrophy with a positive family history, suggesting the possibility of a hereditary syndrome.

  13. Control of Somatosensory Cortical Processing by Thalamic Posterior Medial Nucleus: A New Role of Thalamus in Cortical Function.

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    Carlos Castejon

    Full Text Available Current knowledge of thalamocortical interaction comes mainly from studying lemniscal thalamic systems. Less is known about paralemniscal thalamic nuclei function. In the vibrissae system, the posterior medial nucleus (POm is the corresponding paralemniscal nucleus. POm neurons project to L1 and L5A of the primary somatosensory cortex (S1 in the rat brain. It is known that L1 modifies sensory-evoked responses through control of intracortical excitability suggesting that L1 exerts an influence on whisker responses. Therefore, thalamocortical pathways targeting L1 could modulate cortical firing. Here, using a combination of electrophysiology and pharmacology in vivo, we have sought to determine how POm influences cortical processing. In our experiments, single unit recordings performed in urethane-anesthetized rats showed that POm imposes precise control on the magnitude and duration of supra- and infragranular barrel cortex whisker responses. Our findings demonstrated that L1 inputs from POm imposed a time and intensity dependent regulation on cortical sensory processing. Moreover, we found that blocking L1 GABAergic inhibition or blocking P/Q-type Ca2+ channels in L1 prevents POm adjustment of whisker responses in the barrel cortex. Additionally, we found that POm was also controlling the sensory processing in S2 and this regulation was modulated by corticofugal activity from L5 in S1. Taken together, our data demonstrate the determinant role exerted by the POm in the adjustment of somatosensory cortical processing and in the regulation of cortical processing between S1 and S2. We propose that this adjustment could be a thalamocortical gain regulation mechanism also present in the processing of information between cortical areas.

  14. Neuro-cognitive mechanisms of simultanagnosia in patients with posterior cortical atrophy.

    Science.gov (United States)

    Neitzel, Julia; Ortner, Marion; Haupt, Marleen; Redel, Petra; Grimmer, Timo; Yakushev, Igor; Drzezga, Alexander; Bublak, Peter; Preul, Christoph; Sorg, Christian; Finke, Kathrin

    2016-12-01

    Posterior cortical atrophy is dominated by progressive degradation of parieto-occipital grey and white matter, and represents in most cases a variant of Alzheimer's disease. Patients with posterior cortical atrophy are characterized by increasing higher visual and visuo-spatial impairments. In particular, a key symptom of posterior cortical atrophy is simultanagnosia i.e. the inability to perceive multiple visual objects at the same time. Two neuro-cognitive mechanisms have been suggested to underlie simultanagnosia, either reduced visual short-term memory capacity or decreased visual processing speed possibly resulting from white matter impairments over and above damage to cortical brain areas. To test these distinct hypotheses, we investigated a group of 12 patients suffering from posterior cortical atrophy with homogenous lesion sides in parieto-occipital cortices and varying severity of grey and white matter loss. More specifically, we (i) tested whether impaired short-term memory capacity or processing speed underlie symptoms of simultanagnosia; (ii) assessed the link to grey and white matter damage; and (iii) integrated those findings into a neuro-cognitive model of simultanagnosia in patients with posterior cortical atrophy. To this end, simultaneous perception of multiple visual objects was tested in patients with posterior cortical atrophy mostly with positive Alzheimer's disease biomarkers and healthy age-matched controls. Critical outcome measures were identification of overlapping relative to non-overlapping figures and visuo-spatial performance in tests sensitive to simultanagnosia. Using whole report of briefly presented letter arrays based on the mathematically formulated 'Theory of Visual Attention', we furthermore quantified parameters of visual short-term memory capacity and visual processing speed. Grey and white matter atrophy was assessed by voxel-based morphometry analyses of structural magnetic resonance data. All patients showed severe

  15. Towards an earlier diagnosis of Alzheimer's disease presenting with visuospatial disorders (posterior cortical atrophy).

    Science.gov (United States)

    Vighetto, A

    2013-10-01

    Progressive visual complaints related to visuospatial disorders, and less often to visuoperceptual disorders, may be the presenting and isolated manifestation of a focal degeneration in the posterior cortical areas, called posterior cortical atrophy (PCA). PCA is a clinical syndrome corresponding to a focal variant of Alzheimer's disease in 80% of cases. The predominant dysfunction in the occipitoparietal pathways results in predominant visuospatial disorders, manifesting primarily as dorsal simultanagnosia, alone or associated with other symptoms of Balint's syndrome. PCA is rare and affects young patients who are fully aware of their deficits. Diagnosis of PCA is often delayed, due to insidious onset and development of symptoms, and to poor awareness of the condition in the medical community. An earlier diagnosis requires both better knowledge of PCA among ophthalmologists and neurologists and better recognition of visual complaints, leading to simple bedside tasks that can tackle the syndrome. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  16. [Visuo-constructional disorders and alexia-agraphia associated with posterior cortical atrophy].

    Science.gov (United States)

    Croisile, B; Trillet, M; Hibert, O; Cinotti, L; Le Bars, D; Mauguière, F; Aimard, G

    1991-01-01

    A 57 year-old woman developed a slowly progressive environmental agnosia and dressing apraxia without disturbances of language, memory, orientation and social activities. Two years later, alexia, agraphia, visual agnosia, constructional apraxia, simultagnosia and imitation apraxia of nonsymbolic gestures were also noted. Ophthalmic examination demonstrated a left inferior quadranopsia. Oral comprehension was normal. There was no loss of insight, and behavioral response was appropriately concerned. Computed tomography and magnetic resonance imaging revealed bilateral cortical atrophy in parieto-occipital areas, most pronounced on the right side, with enlargement of the ventricles. Positron emission tomography demonstrated low flow and metabolism values in the right parietal, temporal and occipital regions. This case is very similar to those of posterior cortical atrophy recently reported by Benson et al. (1988). It suggests a selectively degenerative dysfunction of posterior association cortex, sparing oral language and verbal memory.

  17. Quantitative regional validation of the visual rating scale for posterior cortical atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Christiane; Benedictus, Marije R.; Koedam, Esther L.G.M.; Scheltens, Philip [VU University Medical Center, Alzheimer Center and Department of Neurology, Neuroscience Campus Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); Flier, Wiesje M. van der [VU University Medical Center, Alzheimer Center and Department of Neurology, Neuroscience Campus Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); VU University Medical Center, Department of Epidemiology and Biostatistics, Neuroscience Campus Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); Versteeg, Adriaan; Wattjes, Mike P.; Barkhof, Frederik [VU University Medical Center, Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); Vrenken, Hugo [VU University Medical Center, Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); VU University Medical Center, Department of Physics and Medical Technology, Neuroscience Campus Amsterdam, P.O. Box 7057, Amsterdam (Netherlands)

    2014-02-15

    Validate the four-point visual rating scale for posterior cortical atrophy (PCA) on magnetic resonance images (MRI) through quantitative grey matter (GM) volumetry and voxel-based morphometry (VBM) to justify its use in clinical practice. Two hundred twenty-nine patients with probable Alzheimer's disease and 128 with subjective memory complaints underwent 3T MRI. PCA was rated according to the visual rating scale. GM volumes of six posterior structures and the total posterior region were extracted using IBASPM and compared among PCA groups. To determine which anatomical regions contributed most to the visual scores, we used binary logistic regression. VBM compared local GM density among groups. Patients were categorised according to their PCA scores: PCA-0 (n = 122), PCA-1 (n = 143), PCA-2 (n = 79), and PCA-3 (n = 13). All structures except the posterior cingulate differed significantly among groups. The inferior parietal gyrus volume discriminated the most between rating scale levels. VBM showed that PCA-1 had a lower GM volume than PCA-0 in the parietal region and other brain regions, whereas between PCA-1 and PCA-2/3 GM atrophy was mostly restricted to posterior regions. The visual PCA rating scale is quantitatively validated and reliably reflects GM atrophy in parietal regions, making it a valuable tool for the daily radiological assessment of dementia. (orig.)

  18. Different levels of implicit emotional recognition in posterior cortical atrophy (PCA).

    Science.gov (United States)

    Gonzalez-Gadea, María Luz; Ibanez, Agustín; Damm, Juliane; Ramirez Romero, Diana Andrea; Abrevaya, Sofia; Manes, Facundo; Richly, Pablo; Roca, Maria

    2015-01-01

    Previous single-case reports in posterior cortical atrophy (PCA) have shown preserved nonconscious visual recognition despite the absence of explicit recognition. In this study, we investigated three levels of visual recognition in both a female patient with PCA and a control group during the presentation of neutral, positive, and negative affective stimuli. Our results confirmed the profile of impaired explicit recognition and intact psychophysiological responses in the patient. In addition, she was able to implicitly recognize the valence and intensity of arousal of these stimuli. We suggest that implicit emotional awareness may mediates explicit and psychophysiological recognition in PCA.

  19. Conduction aphasia in a 3-year-old with a left posterior cortical/subcortical abscess.

    Science.gov (United States)

    Nass, R; Leventhal, F; Levine, B; Lebron, D; Maxfield, C; McCaul, P; George, A; Allen, J

    1998-03-01

    A 3-year-old, right-handed girl developed a conduction-type aphasia following a second generalized seizure in the setting of a developing abscess involving left subcortical and cortical angular gyrus and arcuate fasciculus, and the posterior corpus callosum. The language disorder was fluent, characterized by age appropriate mean length of utterance and syntax, but with markedly reduced spontaneity of output, rapid rate of speech and mild dysarthria. Comprehension was relatively, but not completely spared. Naming, repetition, and reading (letters) were initially markedly impaired. Improvements in naming and repetition were associated with both literal and semantic paraphasias. Writing skills in the form of drawing were spared, but a mild apraxia to verbal command and imitation was initially present. Despite her young age, this child's fluent conduction aphasia and lesion localization were adult-like. Multimodal memory difficulties appeared to underlie what is best described as conduction aphasia.

  20. Temporary interference over the posterior parietal cortices disrupts thermoregulatory control in humans.

    Directory of Open Access Journals (Sweden)

    Alberto Gallace

    Full Text Available The suggestion has recently been made that certain higher-order cortical areas involved in supporting multisensory representations of the body, and of the space around it, might also play a role in controlling thermoregulatory functions. Here we demonstrate that temporary interference with the function of one of these areas, the posterior parietal cortex, by repetitive transcranial magnetic stimulation, results in a decrease in limb temperature. By contrast, interference with the activity of a sensory-specific area (the primary somatosensory cortex had no effect on temperature. The results of this experiment suggest that associative multisensory brain areas might exert a top-down modulation over basic physiological control. Such a function might be part of a larger neural circuit responsible for maintaining the integrity of the body at both a homeostatic and a psychological level.

  1. Hiding in plain sight: a closer look at posterior cortical atrophy.

    Science.gov (United States)

    Beh, Shin C; Muthusamy, Brinda; Calabresi, Peter; Hart, John; Zee, David; Patel, Vivek; Frohman, Elliot

    2015-02-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome dominated by deterioration of higher visual function (particularly visuospatial and visuoperceptual abilities). It is most commonly due to Alzheimer's disease pathology, but may also be caused by dementia with Lewy bodies, corticobasal degeneration or Creutzfeldt-Jakob disease. Patients often present to optometrists, ophthalmologists and/or neurologists with non-specific visual complaints, and unless clinicians seek the specific symptoms and signs of PCA (beyond that of the 'standard' neurological examination), this infrequent disorder is easily missed, delaying its diagnosis and treatment. We review the clinical features of PCA, focusing on its visual manifestations, to help neurologists recognise this important syndrome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  2. Scene perception in posterior cortical atrophy: categorization, description and fixation patterns.

    Science.gov (United States)

    Shakespeare, Timothy J; Yong, Keir X X; Frost, Chris; Kim, Lois G; Warrington, Elizabeth K; Crutch, Sebastian J

    2013-01-01

    Partial or complete Balint's syndrome is a core feature of the clinico-radiological syndrome of posterior cortical atrophy (PCA), in which individuals experience a progressive deterioration of cortical vision. Although multi-object arrays are frequently used to detect simultanagnosia in the clinical assessment and diagnosis of PCA, to date there have been no group studies of scene perception in patients with the syndrome. The current study involved three linked experiments conducted in PCA patients and healthy controls. Experiment 1 evaluated the accuracy and latency of complex scene perception relative to individual faces and objects (color and grayscale) using a categorization paradigm. PCA patients were both less accurate (faces < scenes < objects) and slower (scenes < objects < faces) than controls on all categories, with performance strongly associated with their level of basic visual processing impairment; patients also showed a small advantage for color over grayscale stimuli. Experiment 2 involved free description of real world scenes. PCA patients generated fewer features and more misperceptions than controls, though perceptual errors were always consistent with the patient's global understanding of the scene (whether correct or not). Experiment 3 used eye tracking measures to compare patient and control eye movements over initial and subsequent fixations of scenes. Patients' fixation patterns were significantly different to those of young and age-matched controls, with comparable group differences for both initial and subsequent fixations. Overall, these findings describe the variability in everyday scene perception exhibited by individuals with PCA, and indicate the importance of exposure duration in the perception of complex scenes.

  3. Visuo-Spatial Imagery Impairment in Posterior Cortical Atrophy: A Cognitive and SPECT Study

    Directory of Open Access Journals (Sweden)

    Simona Gardini

    2011-01-01

    Full Text Available This study investigated the cognitive profile and the cerebral perfusion pattern in a highly educated 70 year old gentleman with posterior cortical atrophy (PCA. Visuo-perceptual abilities, spatial memory, spatial representation and navigation, visuo-spatial mental imagery, semantic and episodic-autobiographical memory were assessed. Regional cerebral blood flow (rCBF was imaged with SPECT. Cognitive testing showed visual-perceptual impairment, apperceptive visual and landmark agnosia, topographical disorientation with way-finding deficits, impaired map learning and poor mental image generation. Semantic memory was normal, while episodic-autobiographical memory was impaired. Reduced rCBF was found mainly in the right hemisphere, in the precentral gyrus, posterior cingulate and middle temporal gyri, cuneus and precuneus, in the left superior temporal and lingual gyri and in the parahippocampus bilaterally. Hypoperfusion in occipito-parietal regions was associated with visuo-spatial deficits, whereas deficits in visuo-spatial mental imagery might reflect dysfunction related to hypoperfusion in the parahippocampus and precuneus, structures which are responsible for spatial and imagery processing. Dissociating performance between preserved semantic memory and poor episodic-autobiographical recall is consistent with a pattern of normal perfusion in frontal and anterior temporal regions but abnormal rCBF in the parahippocampi. The present findings indicate that PCA involves visuo-spatial imagery deficits and provide further validation to current neuro-cognitive models of spatial representation and topographical disorientation.

  4. Scene perception in Posterior Cortical Atrophy: categorisation, description and fixation patterns

    Directory of Open Access Journals (Sweden)

    Timothy J Shakespeare

    2013-10-01

    Full Text Available Partial or complete Balint’s syndrome is a core feature of the clinico-radiological syndrome of posterior cortical atrophy (PCA, in which individuals experience a progressive deterioration of cortical vision. Although multi-object arrays are frequently used to detect simultanagnosia in the clinical assessment and diagnosis of PCA, to date there have been no group studies of scene perception in patients with the syndrome. The current study involved three linked experiments conducted in PCA patients and healthy controls. Experiment 1 evaluated the accuracy and latency of complex scene perception relative to individual faces and objects (colour and greyscale using a categorisation paradigm. PCA patients were both less accurate (faces

  5. Posterior cortical atrophy: An investigation of scan paths generated during Face Matching tasks.

    Directory of Open Access Journals (Sweden)

    Benjamin P Meek

    2013-06-01

    Full Text Available When viewing a face, healthy individuals focus more on the area containing the eyes and upper nose in order to retrieve important featural and configural information. In contrast, individuals with face blindness (prosopagnosia tend to direct fixations towards individual facial features – particularly the mouth. Presented here is an examination of face perception deficits in individuals with Posterior Cortical Atrophy (PCA. PCA is a rare progressive neurodegenerative disorder that is characterized by atrophy in occipito-parietal and occipito-temporal cortices. PCA primarily affects higher visual processing, while memory, reasoning, and insight remain relatively intact. A common symptom of PCA is a decreased effective field of vision caused by the inability to ‘see the whole picture’. Individuals with PCA and healthy control participants completed a same/different discrimination task in which images of faces were presented as cue-target pairs. Eye-tracking equipment and a novel computer-based perceptual task – the Viewing Window paradigm – were used to investigate scan patterns when faces were presented in open view or through a restricted-view, respectively. In contrast to previous prosopagnosia research, individuals with PCA each produced unique scan paths that focused on non-diagnostically useful locations. This focus on non-diagnostically useful locations was also present when using a restricted viewing aperture, suggesting that individuals with PCA have difficulty processing the face at either the featural or configural level. In fact, it appears that the decreased effective field of view in PCA patients is so severe that it results in an extreme dependence on local processing, such that a feature-based approach is not even possible.

  6. Somatosensory-motor adaptation of orofacial actions in posterior parietal and ventral premotor cortices.

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    Krystyna Grabski

    Full Text Available Recent studies have provided evidence for sensory-motor adaptive changes and action goal coding of visually guided manual action in premotor and posterior parietal cortices. To extend these results to orofacial actions, devoid of auditory and visual feedback, we used a repetition suppression paradigm while measuring neural activity with functional magnetic resonance imaging during repeated intransitive and silent lip, jaw and tongue movements. In the motor domain, this paradigm refers to decreased activity in specific neural populations due to repeated motor acts and has been proposed to reflect sensory-motor adaptation. Orofacial movements activated a set of largely overlapping, common brain areas forming a core neural network classically involved in orofacial motor control. Crucially, suppressed neural responses during repeated orofacial actions were specifically observed in the left ventral premotor cortex, the intraparietal sulcus, the inferior parietal lobule and the superior parietal lobule. Since no visual and auditory feedback were provided during orofacial actions, these results suggest somatosensory-motor adaptive control of intransitive and silent orofacial actions in these premotor and parietal regions.

  7. Somatosensory-Motor Adaptation of Orofacial Actions in Posterior Parietal and Ventral Premotor Cortices

    Science.gov (United States)

    Grabski, Krystyna; Lamalle, Laurent; Sato, Marc

    2012-01-01

    Recent studies have provided evidence for sensory-motor adaptive changes and action goal coding of visually guided manual action in premotor and posterior parietal cortices. To extend these results to orofacial actions, devoid of auditory and visual feedback, we used a repetition suppression paradigm while measuring neural activity with functional magnetic resonance imaging during repeated intransitive and silent lip, jaw and tongue movements. In the motor domain, this paradigm refers to decreased activity in specific neural populations due to repeated motor acts and has been proposed to reflect sensory-motor adaptation. Orofacial movements activated a set of largely overlapping, common brain areas forming a core neural network classically involved in orofacial motor control. Crucially, suppressed neural responses during repeated orofacial actions were specifically observed in the left ventral premotor cortex, the intraparietal sulcus, the inferior parietal lobule and the superior parietal lobule. Since no visual and auditory feedback were provided during orofacial actions, these results suggest somatosensory-motor adaptive control of intransitive and silent orofacial actions in these premotor and parietal regions. PMID:23185300

  8. [Posterior cortical atrophy. Pathology, diagnosis and treatment of a rare form of dementia].

    Science.gov (United States)

    Ortner, M; Kurz, A

    2015-07-01

    The syndrome of posterior cortical atrophy (PCA) is a rare clinical manifestation of several neurodegenerative diseases which affect the parieto-occipital cortex. The most frequent underlying pathology is Alzheimer's disease but some cases are caused by Lewy body disease, progressive subcortical gliosis, corticobasal degeneration or prion diseases. The most prominent clinical feature of PCA is complex visual disturbances including object agnosia, simultanagnosia, optical ataxia and oculomotor apraxia while basic visual functions remain intact. These deficits lead to multiple impairments in activities of daily living that require visual control. On progression of the disease amnestic, apraxic and dysexecutive symptoms occur so that a global dementia gradually emerges. At the core of the diagnostic work-up are a detailed patient history, accurate analysis of behavior and neuropsychological testing. Structural and functional brain imaging are suitable to demonstrate the localization of the disease process. Measurement of cerebrospinal fluid proteins (e.g. beta amyloid, tau, phospho-tau and 14-3-3) serves to confirm or exclude Alzheimer's disease or prion diseases. The mainstay of treatment are non-pharmacological interventions to support activities of daily living and personal independence. These treatments include cognitive training and compensatory strategies which can be prescribed as neuropsychological treatment or occupational therapy. If Alzheimer's disease or Lewy body disease is the likely cause, a treatment with cholinesterase inhibitor may be tried. Caregiver education and support are another essential part of the treatment regimen as with all forms of dementia.

  9. Genetic risk factors for the posterior cortical atrophy variant of Alzheimer's disease.

    Science.gov (United States)

    Schott, Jonathan M; Crutch, Sebastian J; Carrasquillo, Minerva M; Uphill, James; Shakespeare, Tim J; Ryan, Natalie S; Yong, Keir X; Lehmann, Manja; Ertekin-Taner, Nilufer; Graff-Radford, Neill R; Boeve, Bradley F; Murray, Melissa E; Khan, Qurat Ul Ain; Petersen, Ronald C; Dickson, Dennis W; Knopman, David S; Rabinovici, Gil D; Miller, Bruce L; González, Aida Suárez; Gil-Néciga, Eulogio; Snowden, Julie S; Harris, Jenny; Pickering-Brown, Stuart M; Louwersheimer, Eva; van der Flier, Wiesje M; Scheltens, Philip; Pijnenburg, Yolande A; Galasko, Douglas; Sarazin, Marie; Dubois, Bruno; Magnin, Eloi; Galimberti, Daniela; Scarpini, Elio; Cappa, Stefano F; Hodges, John R; Halliday, Glenda M; Bartley, Lauren; Carrillo, Maria C; Bras, Jose T; Hardy, John; Rossor, Martin N; Collinge, John; Fox, Nick C; Mead, Simon

    2016-08-01

    The genetics underlying posterior cortical atrophy (PCA), typically a rare variant of Alzheimer's disease (AD), remain uncertain. We genotyped 302 PCA patients from 11 centers, calculated risk at 24 loci for AD/DLB and performed an exploratory genome-wide association study. We confirm that variation in/near APOE/TOMM40 (P = 6 × 10(-14)) alters PCA risk, but with smaller effect than for typical AD (PCA: odds ratio [OR] = 2.03, typical AD: OR = 2.83, P = .0007). We found evidence for risk in/near CR1 (P = 7 × 10(-4)), ABCA7 (P = .02) and BIN1 (P = .04). ORs at variants near INPP5D and NME8 did not overlap between PCA and typical AD. Exploratory genome-wide association studies confirmed APOE and identified three novel loci: rs76854344 near CNTNAP5 (P = 8 × 10(-10) OR = 1.9 [1.5-2.3]); rs72907046 near FAM46A (P = 1 × 10(-9) OR = 3.2 [2.1-4.9]); and rs2525776 near SEMA3C (P = 1 × 10(-8), OR = 3.3 [2.1-5.1]). We provide evidence for genetic risk factors specifically related to PCA. We identify three candidate loci that, if replicated, may provide insights into selective vulnerability and phenotypic diversity in AD. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Counting or chunking? Mathematical and heuristic abilities in patients with corticobasal syndrome and posterior cortical atrophy.

    Science.gov (United States)

    Spotorno, Nicola; McMillan, Corey T; Powers, John P; Clark, Robin; Grossman, Murray

    2014-11-01

    A growing amount of empirical data is showing that the ability to manipulate quantities in a precise and efficient fashion is rooted in cognitive mechanisms devoted to specific aspects of numbers processing. The analog number system (ANS) has a reasonable representation of quantities up to about 4, and represents larger quantities on the basis of a numerical ratio between quantities. In order to represent the precise cardinality of a number, the ANS may be supported by external algorithms such as language, leading to a "precise number system". In the setting of limited language, other number-related systems can appear. For example the parallel individuation system (PIS) supports a "chunking mechanism" that clusters units of larger numerosities into smaller subsets. In the present study we investigated number processing in non-aphasic patients with corticobasal syndrome (CBS) and posterior cortical atrophy (PCA), two neurodegenerative conditions that are associated with progressive parietal atrophy. The present study investigated these number systems in CBS and PCA by assessing the property of the ANS associated with smaller and larger numerosities, and the chunking property of the PIS. The results revealed that CBS/PCA patients are impaired in simple calculations (e.g., addition and subtraction) and that their performance strongly correlates with the size of the numbers involved in these calculations, revealing a clear magnitude effect. This magnitude effect was correlated with gray matter atrophy in parietal regions. Moreover, a numeral-dots transcoding task showed that CBS/PCA patients were able to take advantage of clustering in the spatial distribution of the dots of the array. The relative advantage associated with chunking compared to a random spatial distribution correlated with both parietal and prefrontal regions. These results shed light on the properties of systems for representing number knowledge in non-aphasic patients with CBS and PCA. Copyright

  11. (Con)text-specific effects of visual dysfunction on reading in posterior cortical atrophy.

    Science.gov (United States)

    Yong, Keir X X; Shakespeare, Timothy J; Cash, Dave; Henley, Susie M D; Warren, Jason D; Crutch, Sebastian J

    2014-08-01

    Reading deficits are a common early feature of the degenerative syndrome posterior cortical atrophy (PCA) but are poorly understood even at the single word level. The current study evaluated the reading accuracy and speed of 26 PCA patients, 17 typical Alzheimer's disease (tAD) patients and 14 healthy controls on a corpus of 192 single words in which the following perceptual properties were manipulated systematically: inter-letter spacing, font size, length, font type, case and confusability. PCA reading was significantly less accurate and slower than tAD patients and controls, with performance significantly adversely affected by increased letter spacing, size, length and font (cursive reading speed in the same direction as controls, and, in contrast to PCA patients, control reading was faster for larger font sizes. The inverse size effect in PCA (less accurate reading of large than small font size print) was associated with lower grey matter volume in the right superior parietal lobule. Reading accuracy was associated with impairments of early visual (especially crowding), visuoperceptual and visuospatial processes. However, these deficits were not causally related to a universal impairment of reading as some patients showed preserved reading for small, unspaced words despite grave visual deficits. Rather, the impact of specific types of visual dysfunction on reading was found to be (con)text specific, being particularly evident for large, spaced, lengthy words. These findings improve the characterisation of dyslexia in PCA, shed light on the causative and associative factors, and provide clear direction for the development of reading aids and strategies to maximise and sustain reading ability in the early stages of disease. Copyright © 2014. Published by Elsevier Ltd.

  12. The oral spelling profile of posterior cortical atrophy and the nature of the graphemic representation.

    Science.gov (United States)

    Primativo, Silvia; Yong, Keir X X; Shakespeare, Timothy J; Crutch, Sebastian J

    2017-01-08

    Spelling is a complex cognitive task where central and peripheral components are involved in engaging resources from many different cognitive processes. The present paper aims to both characterize the oral spelling deficit in a population of patients affected by a neurodegenerative condition and to clarify the nature of the graphemic representation within the currently available spelling models. Indeed, the nature of graphemic representation as a linear or multi-componential structure is still debated. Different hypotheses have been raised about its nature in the orthographic lexicon, with one positing that graphemes are complex objects whereby quantity and identity are separately represented in orthographic representations and can thus be selectively impaired. Posterior cortical atrophy (PCA) is a neurodegenerative condition that mainly affects visuoperceptual and visuospatial functions. Spelling impairments are considered part of the disease. Nonetheless the spelling deficit has received little attention so far and often it has been interpreted in relation to peripheral impairments such as writing difficulties associated with visuoperceptual and visuospatial deficits. In the present study we provide a detailed characterization of the oral spelling profile in PCA. The data suggest that multiple deficits underpin oral spelling problems in PCA, with elements of surface and phonological dysgraphia but also suggesting the involvement of the graphemic buffer. A large phenotypic individual variability is reported. Moreover, the larger proportion and the specific nature of errors involving geminate (i.e., double) as compared to non-geminate (i.e., non-double) letters suggest that a further central impairment might be associated with the abstract graphemic representation of letter numerosity. The present study contributes to the clinical characterization of PCA and to the current debate in the cognitive literature on spelling models; findings, despite not definitive

  13. Elizabeth Warrington Prize Lecture. Seeing why they cannot see: understanding the syndrome and causes of posterior cortical atrophy.

    Science.gov (United States)

    Crutch, Sebastian J

    2014-09-01

    Posterior cortical atrophy (PCA) is a syndrome defined by focal neurodegeneration of the parietal, occipital, and occipito-temporal cortices and associated with progressive dysfunction of visual processing, praxis, numeracy and reading. The condition is most commonly caused by (and viewed as an atypical presentation of) Alzheimer's disease, although can also be caused by other degenerative diseases. The current paper examines the relationship of PCA to other degenerative syndromes, and considers what comparisons of these syndromes and disease phenotypes can tell us about underlying disease mechanisms. The focus then turns to neuropsychological investigations of the cognitive basis of symptoms which, although unusual in the broader context of a dementia clinic, are particularly characteristic of the PCA syndrome, before exploring implications for clinical management and patient and carer support. © 2013 The British Psychological Society.

  14. Tau-PET Binding Distinguishes Patients With Early-stage Posterior Cortical Atrophy From Amnestic Alzheimer Disease Dementia.

    Science.gov (United States)

    Day, Gregory S; Gordon, Brian A; Jackson, Kelley; Christensen, Jon J; Rosana Ponisio, Maria; Su, Yi; Ances, Beau M; Benzinger, Tammie L S; Morris, John C

    2017-01-01

    Flortaucipir (tau) positron emission tomography (PET) binding distinguishes individuals with clinically well-established posterior cortical atrophy (PCA) due to Alzheimer disease (AD) from cognitively normal (CN) controls. However, it is not known whether tau-PET binding patterns differentiate individuals with PCA from those with amnestic AD, particularly early in the symptomatic stages of disease. Flortaucipir and florbetapir (β-amyloid) PET imaging were performed in individuals with early-stage PCA (N=5), amnestic AD dementia (N=22), and CN controls (N=47). Average tau and β-amyloid deposition were quantified using standard uptake value ratios and compared at a voxelwise level, controlling for age. PCA patients [median age-at-onset, 59 (51 to 61) years] were younger at symptom onset than similarly staged individuals with amnestic AD [75 (60 to 85) years] or CN controls [73 (61 to 90) years; P=0.002]. Flortaucipir uptake was higher in individuals with early-stage symptomatic PCA versus those with early-stage amnestic AD or CN controls, and greatest in posterior regions. Regional elevations in florbetapir were observed in areas of greatest tau deposition in PCA patients. Flortaucipir uptake distinguished individuals with PCA and amnestic AD dementia early in the symptomatic course. The posterior brain regions appear to be uniquely vulnerable to tau deposition in PCA, aligning with clinical deficits that define this disease subtype.

  15. Interconnected Cortical Networks Between Primary Somatosensory Cortex Septal Columns and Posterior Parietal Cortex in Rat

    NARCIS (Netherlands)

    Lee, Taehee; Alloway, Kevin D.; Kim, Uhnoh

    2011-01-01

    Visual and somesthetic cues are used for spatial processing in the posterior parietal cortex (PPC) of the mammalian brain. In rats, somatic information collected by the mystacial whiskers is critically involved in constructing a neural representation of the external space. Here, we delineated the

  16. Diagnostic value of 18F-FDG PET and 11C-PIB PET on early stage posterior cortical atrophy

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    Shuai LIU

    2015-08-01

    Full Text Available Background  Posterior cortical atrophy (PCA is a kind of progressive neurodegenerative disease with cortical visual impairment as the first symptom. Because of rare clinical incidence, early onset age, special clinical symptoms and unobvious MRI abnormality, the definitive diagnosis of PCA is difficult. This study used 18F-fluoro-2-deoxy-D-glucose (18F-FDG PET and 11C-Pittsburgh compound B (11C-PIB PET for PCA patients with unobvious MRI abnormality, so as to discuss the value of PET in the early diagnosis of PCA.  Methods  Five patients diagnosed as PCA in our hospital between April 2012 and March 2015 were enrolled in this study. Cognitive function was measured by Mini-Mental State Examination (MMSE, Montreal Cognitive Assessment (MoCA, Activities of Daily Living (ADL and Clock Drawing Test (CDT. Brain MRI, 18F-FDG PET and 11C-PIB PET were performed to analyze glucose metabolism and perfusion of posterior cortex.  Results Neuropsychological tests revealed that the ability of writing, calculating, visuospatial and executive function of all these patients were impaired. Color vision tests showed abnormal results. MRI showed that the posterior atrophy (PA scores were 0-2 (average 1 on the left side and 0-1 (average 0.80 on the right side. The medial temporal atrophy (MTA scores were 1-3 (average 1.80 on the left side and 1-4 (average 2 on the right side. The ventricular enlargement (VE scores were 1-2 (average 1.80 on the left side and 1-2 (average 1.60 on the right side. 18F-FDG PET showed glucose metabolism decreased obviously on bilateral temporo-parieto-occipital cortex, precuneus and cingulate gyrus, and slightly on frontal lobes and subcortical structure. 11C-PIB PET showed radioactive 11C-PIB deposition on bilateral frontal, temporal, parietal and occipital cortex, and the outline of cerebellar cortex was clear.  Conclusions  For PCA patients whose parietal and occipital cortical atrophy is not obvious on MRI, 18F-FDG PET

  17. Posterior cortical atrophy - a prototypical case of dementia beginning with visual symptoms: case report

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    Leonardo Ferreira Caixeta

    2013-10-01

    Full Text Available Dementia presenting with prominent higher order visual symptoms may be observed in a range of neurodegenerative conditions and is often challenging to diagnose. We describe a case of progressive dementia presenting with prominent visual cortical symptoms. A 55-year-old, right-handed, woman with early onset of visual impairment not associated with anterior visual pathology, presenting with dyslexia, visual agnosia, Balint's syndrome, and spatial disorientation. Ophthalmologists should consider this condition especially in presenile patients with slowly progressive higher-order visual symptoms. Although described in association with different conditions, it may also occur in Alzheimer disease.

  18. Posterior lumbar interbody fusion with cortical bone trajectory screw fixation versus posterior lumbar interbody fusion using traditional pedicle screw fixation for degenerative lumbar spondylolisthesis: a comparative study.

    Science.gov (United States)

    Sakaura, Hironobu; Miwa, Toshitada; Yamashita, Tomoya; Kuroda, Yusuke; Ohwada, Tetsuo

    2016-11-01

    OBJECTIVE Several biomechanical studies have demonstrated the favorable mechanical properties of the cortical bone trajectory (CBT) screw. However, no reports have examined surgical outcomes of posterior lumbar interbody fusion (PLIF) with CBT screw fixation for degenerative spondylolisthesis (DS) compared with those after PLIF using traditional pedicle screw (PS) fixation. The purposes of this study were thus to elucidate surgical outcomes after PLIF with CBT screw fixation for DS and to compare these results with those after PLIF using traditional PS fixation. METHODS Ninety-five consecutive patients underwent PLIF with CBT screw fixation for DS (CBT group; mean followup 35 months). A historical control group consisted of 82 consecutive patients who underwent PLIF with traditional PS fixation (PS group; mean follow-up 40 months). Clinical status was assessed using the Japanese Orthopaedic Association (JOA) scale score. Fusion status was assessed by dynamic plain radiographs and CT. The need for additional surgery and surgery-related complications was also evaluated. RESULTS The mean JOA score improved significantly from 13.7 points before surgery to 23.3 points at the latest follow-up in the CBT group (mean recovery rate 64.4%), compared with 14.4 points preoperatively to 22.7 points at final follow-up in the PS group (mean recovery rate 55.8%; p 0.05). Symptomatic adjacent-segment disease developed in 3 patients from the CBT group (3.2%) compared with 9 patients from the PS group (11.0%, p < 0.05). CONCLUSIONS PLIF with CBT screw fixation for DS provided comparable improvement of clinical symptoms with PLIF using traditional PS fixation. However, the successful fusion rate tended to be lower in the CBT group than in the PS group, although the difference was not statistically significant between the 2 groups.

  19. The syndrome of progressive posterior cortical dysfunction: A multiple case study and review

    Directory of Open Access Journals (Sweden)

    Renata Areza-Fegyveres

    Full Text Available Abstract Dementia presenting with prominent higher order visual symptoms may be observed in a range of neurodegenerative conditions and is often challenging to diagnose. Objectives: To describe cases of progressive dementia presenting with prominent visual cortical symptoms. Methods: We conducted a retrospective search of cases of progressive dementia with predominant visual symptoms, seen at our dementia unit from 1996 to 2006. Results: Twelve patients (5 men, 7 women were identified, with ages ranging from 49 to 67 years. At the first examination, the duration of the symptoms ranged from one to ten years and the Mini-Mental State Examination scores from 7 to 27. Eleven patients presented with predominant visuospatial symptoms (partial or complete Balint syndrome and one with visuoperceptive impairment. Other reported manifestations were: constructional apraxia in 11 patients, partial or complete Gerstmann syndrome in ten, ideomotor apraxia in nine, hemineglect or extinction in four patients, alien hand phenomenon in three, and prosopagnosia in one patient. Memory loss was reported by ten patients, but was not the main complaint in any of these cases. Insight was relatively preserved in five patients even after a long period following the onset of symptoms. Six patients developed parkinsonism during evolution. Clinical diagnoses were possible or probable AD in seven patients, cortico-basal degeneration in four, and dementia with Lewy body in one. Conclusions: Clinicians should consider this condition especially in presenile patients with slowly progressive higher-order visual symptoms. Although described in association with different conditions, it may also occur in Alzheimer disease.

  20. Altered posterior cingulate cortical cyctoarchitecture, but normal density of neurons and interneurons in the posterior cingulate cortex and fusiform gyrus in autism.

    Science.gov (United States)

    Oblak, Adrian L; Rosene, Douglas L; Kemper, Thomas L; Bauman, Margaret L; Blatt, Gene J

    2011-06-01

    Autism is a developmental disorder with prenatal origins, currently estimated to affect 1 in 91 children in the United States. Social-emotional deficits are a hallmark of autism and early neuropathology studies have indicated involvement of the limbic system. Imaging studies demonstrate abnormal activation of the posterior cingulate cortex (PCC), a component of the limbic system. Abnormal activation has also been noted in the fusiform gyrus (FFG), a region important for facial recognition and a key element in social interaction. A potential imbalance between excitatory and inhibitory interneurons in the cortex may contribute to altered information processing in autism. Furthermore, reduced numbers of GABA receptors have previously been reported in the autistic brain. Thionin-stained sections were used to qualitatively assess cytoarchitectonic patterning and quantitatively determine the density of neurons and immunohistochemistry was used to determine the densities of a subset of GABAergic interneurons utilizing parvalbumin-and calbindin-immunoreactivity. In autism, the PCC displayed altered cytoarchitecture with irregularly distributed neurons, poorly demarcated layers IV and V, and increased presence of white matter neurons. In contrast, no neuropathology was observed in the FFG. There was no significant difference in the density of thionin, parvalbumin, or calbindin interneurons in either region and there was a trend towards a reduced density of calbindin neurons in the PCC. This study highlights the presence of abnormal findings in the PCC, which appear to be developmental in nature and could affect the local processing of social-emotional behaviors as well as functioning of interrelated areas. Copyright © 2011, International Society for Autism Research, Wiley Periodicals, Inc.

  1. The Pattern of Brain Amyloid Load in Posterior Cortical Atrophy Using 18F-AV45: Is Amyloid the Principal Actor in the Disease

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    Emilie Beaufils

    2014-11-01

    Full Text Available Background: Posterior cortical atrophy (PCA is characterized by progressive higher-order visuoperceptual dysfunction and praxis declines. This syndrome is related to a number of underlying diseases, including, in most cases, Alzheimer's disease (AD. The aim of this study was to compare the amyloid load with 18F-AV45 positron emission tomography (PET between PCA and AD subjects. Methods: We performed 18F-AV45 PET, cerebrospinal fluid (CSF biomarker analysis and a neuropsychological assessment in 11 PCA patients and 12 AD patients. Results: The global and regional 18F-AV45 uptake was similar in the PCA and AD groups. No significant correlation was observed between global 18F-AV45 uptake and CSF biomarkers or between regional 18F-AV45 uptake and cognitive and affective symptoms. Conclusion: This 18F-AV45 PET amyloid imaging study showed no specific regional pattern of cortical 18F-AV45 binding in PCA patients. These results confirm that a distinct clinical phenotype in amnestic AD and PCA is not related to amyloid distribution.

  2. Efeitos da injeção subtenoniana posterior de corticóide em pacientes com uveíte

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    Finamor Luciana Peixoto

    2003-01-01

    Full Text Available OBJETIVO: Determinar os efeitos da injeção subtenoniana posterior de corticóide (ISPC sobre a pressão intra-ocular (Po e acuidade visual em uma série de pacientes com uveíte. MÉTODOS: Estudo prospectivo de 18 pacientes que foram submetidos à injeção subtenoniana posterior de acetato de triancinolona (Kenalog® 40 mg - 9 pacientes, 14 injeções ou acetato de metilprednisolona (Depomedrol® 40mg - 9 pacientes, 15 injeções para tratamento de inflamação intra-ocular crônica e/ou edema macular cistóide. RESULTADOS: A acuidade visual final melhorou em 92% dos pacientes após a primeira injeção periocular de corticóide. Cinqüenta por cento melhoraram 1 linha e 42% melhoraram pelo menos 3 linhas, sendo que o tempo médio para a melhora foi de 3 semanas. Aumento da pressão intra-ocular ocorreu em 44 % dos pacientes (8 pacientes com média de 31 mmHg, variando de 21 a 38 mmHg. O aumento da pressão intra-ocular foi mais freqüente nos pacientes jovens e nos que receberam Kenalog®, com início, em média, após 2,5 semanas. CONCLUSÃO: Ainjeção subtenoniana de corticóide é uma forma de tratamento eficaz para a baixa acuidade visual secundária a alguns tipos de uveíte, como uveíte intermediária, doença de Behçet, síndrome de Vogt-Koyanagi-Harada, vasculite retiniana e artrite reumatóide. Porém, pode induzir aumento da pressão intra-ocular em alguns pacientes, especialmente em crianças e jovens.

  3. Correlations between measures of executive attention and cortical thickness of left posterior middle frontal gyrus - a dichotic listening study

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    Lundervold Arvid

    2009-10-01

    Full Text Available Abstract Background The frontal lobe has been associated to a wide range of cognitive control functions and is also vulnerable to degeneration in old age. A recent study by Thomsen and colleagues showed a difference between a young and old sample in grey matter density and activation in the left middle frontal cortex (MFC and performance on a dichotic listening task. The present study investigated this brain behaviour association within a sample of healthy older individuals, and predicted a positive correlation between performance in a condition requiring executive attention and measures of grey matter structure of the posterior left MFC. Methods A dichotic listening forced attention paradigm was used to measure attention control functions. Subjects were instructed to report only the left or the right ear syllable of a dichotically presented consonant-vowel syllable pair. A conflict situation appears when subjects are instructed to report the left ear stimulus, caused by the conflict with the bottom-up, stimulus-driven right ear advantage. Overcoming this processing conflict was used as a measure of executive attention. Thickness and volumes of frontal lobe regions were derived from automated segmentation of 3D magnetic resonance image acquisitions. Results The results revealed a statistically significant positive correlation between the thickness measure of the left posterior MFC and performance on the dichotic listening measures of executive attention. Follow-up analyses showed that this correlation was only statistically significant in the subgroup that showed the typical bottom-up, stimulus-driven right ear advantage. Conclusion The results suggest that the left MFC is a part of an executive attention network, and that the dichotic listening forced attention paradigm may be a feasible tool for assessing subtle attentional dysfunctions in older adults.

  4. Primary microcephaly with ASPM mutation shows simplified cortical gyration with antero-posterior gradient pre- and post-natally.

    Science.gov (United States)

    Desir, Julie; Cassart, Marie; David, Philippe; Van Bogaert, Patrick; Abramowicz, Marc

    2008-06-01

    Primary microcephaly is a disorder of brain development characterized by a congenitally small but normally formed brain, and non-progressive mild-to-moderate mental retardation. Most cases are inherited in an autosomal recessive pattern, with genetic heterogeneity, the ASPM locus being most common. Postnatal imaging data are scarce and prenatal imaging unreported. Microcephaly with simplified gyral pattern shares features with primary microcephaly, but it is not clear whether these disorders are part of a phenotypic continuum. We examined a consanguineous family with a daughter affected with primary microcephaly and an ongoing pregnancy. We performed prenatal and postnatal brain magnetic resonance imaging and genetic analyses in the course of genetic evaluation. The affected daughter and the fetus were homozygous for polymorphic markers linked to the ASPM locus, and we identified a novel, truncating ASPM mutation by direct sequencing of the gene. Imaging at 30 and 35 gestational weeks showed microcephaly with simplified gyration, more severe anteriorly. The antero-posterior gradient of gyration persisted 1 week after birth. Brain imaging in the affected sister also showed some degree of a predominantly anterior simplification of gyration. Our data suggest that one form of autosomal recessive microcephaly is allelic to at least a subset of microcephaly with simplified gyral pattern, and that the neuronal depletion associated with the ASPM defect predominantly affects the anterior cortex.

  5. Atrofia nutricional e nanismo nutricional em escolares de Tabatinga, Amazonas, Brasil

    OpenAIRE

    Luís Enrique Gainette-Prates; Fernanda Soare-da-Costa; Ana Lúcia Garcia-Torres

    2015-01-01

    Este artículo tuvo como propósito evaluar la prevalencia de atrofia nutricional y enanismo nutricional en estudiantes, de 6 a 11 años de edad, de escuelas públicas de Tabatinga, Amazonas, Brasil. Fue realizado un estudio transversal en que fueron evaluados 340 estudiantes a través de datos antropométricos (peso y altura). Se utilizó los índices altura/edad y peso/edad basados en el score-z. Los estudiantes con altura/edad inferior a -2 desviación estándar fueron clasificados con atrofia nutri...

  6. Evolución en el tratamiento de la atrofia alveolar

    OpenAIRE

    Oscar García-Roco Pérez; Miguel Arredondo López

    2002-01-01

    Con el objetivo de describir la evolución del tratamiento de la atrofia alveolar se realiza una revisión bibliográfica actualizada de 25 referencias, se destacan las vestibuloplastias, injertos óseos, biomateriales, implantes endóseos, regeneración ósea guiada y la distracción ósea, que corrigen o compensan la atrofia alveolar con sus indicaciones, ventajas y desventajas.An updated literature review of 25 references was made to describe the development in the treatment of dental alveolar atro...

  7. Effects of single-pulse transcranial magnetic stimulation over the prefrontal and posterior parietal cortices during memory-guided saccades in humans.

    Science.gov (United States)

    Müri, R M; Vermersch, A I; Rivaud, S; Gaymard, B; Pierrot-Deseilligny, C

    1996-09-01

    1. We used single-pulse transcranial magnetic stimulation (TMS) to explore the temporal organization of the cortical control of memory-guided saccades in eight humans. The posterior parietal cortex (PPC) or the dorsolateral prefrontal cortex (DPFC), which are both known to be involved in the control of such saccades, were stimulated on the right side at different time intervals after the presentation of a flashed lateral visual target. The memorization delay was 2,000 ms. Single pulses were applied at 160, 260, and 360 ms after the flashed target, during the period of 700 and 1,500 ms, and finally at 2,100 ms, i.e., 100 ms after the extinguishing of the central fixation point. The effects of TMS were evaluated by calculating the percentage of error in amplitude (PEA) and latency of memory-guided saccades. The PEA was determined for the primary saccade (motor aspect) and the final eye position, i.e., after the end saccade (mnemonic aspect). Stimulation over the occipital cortex at the same time intervals served as control experiments. 2. After PPC stimulation, a significant increase in the PEA of the primary saccade and final eye position existed for contralateral saccades, compared with the PEA without stimulation, when stimulation was applied 260 ms after target presentation, but not at other time intervals. There was no significant effect on ipsilateral saccades. Latency was significantly increased bilaterally when stimulation was performed 2,100 ms after target presentation. 3. After prefrontal stimulation, a significant increase in the PEA of the primary saccade and final eye position existed for contralateral saccades, when stimulation was applied between 700 and 1,500 ms after target presentation, but not at other time intervals. There was no significant effect on ipsilateral saccades. Latency was not affected by prefrontal TMS at any stimulation times. 4. Occipital stimulation resulted in no significant effect on the PEA and latency of ipsilateral or

  8. Atrofia girata de coróide e retina: relato de caso Girate atrophy of the retina and choroid: case report

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    Emerson Kenji Oyamaguchi

    2003-08-01

    Full Text Available OBJETIVO: Relatar um caso de atrofia girata de coróide e retina com confirmação por meio da bioquímica do plasma. MÉTODO: Aferiu-se a melhor acuidade visual corrigida de ambos olhos (AO em tabela de Snellen. Foram realizados biomicroscopia do segmento anterior, refração, mapeamento de retina, angiografia fluoresceínica, campo visual e dosagem da ornitina sérica (aminoacidograma. RESULTADOS: Paciente de 22 anos, sexo feminino, cor branca, apresentando alta miopia e acuidade visual (AV 20/100 em AO. À biomicroscopia do segmento anterior apresentava catarata subcapsular posterior em AO. À oftalmoscopia foram verificadas lesões atróficas da coróide e da retina bem delimitadas em meia periferia de AO. O aminoacidograma constatou elevação correspondente ao complexo da ornitina. CONCLUSÃO: Relata-se um caso típico de atrofia girata, distrofia retiniana rara associada a hiperornitinemia.PURPOSE: To report a case of gyrate atrophy confirmed by biochemical blood analysis. METHODS: Best corrected visual acuity was evaluated. Biomicroscopy of the anterior segment, indirect ophthalmoscopy, fluorescein angiography and computerized visual fields were performed. Color vision was assessed and plasma ornithine level was determined. RESULTS: 22-year-old white female with high myopia, visual acuity of 20/100 in both eyes. Biomicroscopy showed posterior subcapsular cataract in both eyes. Retinography showed well-delineated atrophic lesions of the choroid and retina in the mid-periphery and around the optic nerve in both eyes. Blood aminoacid determination showed high levels of ornithine. CONCLUSION: We describe here a typical case of girate atrophy of the retina and choroid, a rare disease associated with high levels of plasma ornithine.

  9. Evolución en el tratamiento de la atrofia alveolar

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    Oscar García-Roco Pérez

    2002-08-01

    Full Text Available Con el objetivo de describir la evolución del tratamiento de la atrofia alveolar se realiza una revisión bibliográfica actualizada de 25 referencias, se destacan las vestibuloplastias, injertos óseos, biomateriales, implantes endóseos, regeneración ósea guiada y la distracción ósea, que corrigen o compensan la atrofia alveolar con sus indicaciones, ventajas y desventajas.An updated literature review of 25 references was made to describe the development in the treatment of dental alveolar atrophy. Some procedures that correct or compensate alveolar atrophies such as vestibuloplasty, bone grafting, biomaterials, endo-bone implants, guided bone regeneration and bone distraction. Their indications, advantages and disadvantages are set forth.

  10. ATROFIA MUSCULAR ESPINAL: MANEJO RESPIRATORIO EN LA PERSPECTIVA DE LOS RECIENTES AVANCES TERAPÉUTICOS

    OpenAIRE

    Browning, George G; Rovers, Maroeska M.; Williamson, Ian; Lous, Jørgen; Burton, Martin J

    2017-01-01

    La atrofia muscular espinal (AME) es la primera causa genética de mortalidad en lactantes. La severidad de las manifestaciones clínicas es un continuo, con tres principales subtipos en pediatría: AME1 que se presenta en recién nacidos y no logran sentarse, AME2 en niños que no logran caminar pero sí sentarse y AME3 que logran caminar. La complicación más seria es la insuficiencia respiratoria. El enfoque del manejo respiratorio es preventivo, con toma de decisiones anticipadas por parte de lo...

  11. Menopausia, una endocrinopatía: Atrofia Urogenital y Trastornos de la Sexualidad

    OpenAIRE

    Roberto Vergara Tamara; Alfredo Ruiz

    1995-01-01

    La atrofia urogonital causada por el estímulo deficiente estrogenito se manifiesta principalmente en la vagina, donde la mucosa sufre un adelgazamiento gradual que permite el predominio de células parabasales e intermedias propias del hipoestrogenismo, volviéndolo altamente sensible al trauma y la infección.

    Clínicamente se traduce en disminución de la humedad vaginal, sensación de llenura en el intróito, ruptura fácil de capilares vaginales con aparición de petequi...

  12. Atrofia nutricional e nanismo nutricional em escolares de Tabatinga, Amazonas, Brasil

    Directory of Open Access Journals (Sweden)

    Luís Enrique Gainette-Prates

    2015-01-01

    Full Text Available Este artículo tuvo como propósito evaluar la prevalencia de atrofia nutricional y enanismo nutricional en estudiantes, de 6 a 11 años de edad, de escuelas públicas de Tabatinga, Amazonas, Brasil. Fue realizado un estudio transversal en que fueron evaluados 340 estudiantes a través de datos antropométricos (peso y altura. Se utilizó los índices altura/edad y peso/edad basados en el score-z. Los estudiantes con altura/edad inferior a -2 desviación estándar fueron clasificados con atrofia nutricional y aquellas con peso/edad inferior a -2 desviación estándar con nanismo nutricional. El Consumo Energético-Proteico fue evaluado por medio de Cuestionario de Frecuencia Alimentaria. El ingreso familiar clasificado en clases económicas se basó en criterios de la Associação Brasileira de Empresas de Pesquisa. Se verificó que 18 estudiantes (5,3% presentaron altura/edad abajo de -2 desviación estándar. Sin embargo, no hubo estudiantes con peso/edad abajo de desviación estándar. Se percibe que ni todos los estudiantes con déficit nutricional eran de clases económicamente vulnerables (C, D, E. El consumo alimentario evidenció carencia de proteínas y de calorías saludables en la dieta de los estudiantes, siendo el principal determinante de la desnutrición en esa población. No hubo correlación entre el nanismo nutricional y el rendimiento escolar de los estudiantes.

  13. Thymic atrophy in cattle poisoned with Solanum glaucophyllum Atrofia do timo em bovinos intoxicados por Solanum glaucophyllum

    Directory of Open Access Journals (Sweden)

    Paula A. Fontana

    2009-03-01

    metabolismo ósseo, o metabolismo de cálcio e também mostra efeitos na imunomodulação. Precursores de timócitos derivados da medula óssea se diferenciam em linfócitos T maduros. A diferenciação da maioria dos linfócitos T é caracterizada pela expressão variável de moléculas de receptores CD4/CD8 e densidade aumentada dos receptores antigênicos de superfície de células T. Alem disso, há mudanças no padrão de glicosilação de glicolipídeos na superfície celular ou de glicoproteínas. Timócitos mostram uma influência de retro alimentação em células tímicas não-linfóides. Foram analisadas modificações induzidas pelo Sg em linfócitos T e células tímicas não-linfóides de bovinos. Novilhas foram divididas em 5 grupos (controle, intoxicadas com Sg durante 15, 30 ou 60 dias, e grupo provavelmente recuperado. As diferentes populações celulares das novilhas experimentais foram caracterizadas com técnicas histoquímicas, imuno-histoquímicas, lectina-histoquímicas e morfométricas. As novilhas intoxicadas com Sg mostraram uma atrofia cortical progressiva que foi caracterizada usando a lectina aglutinina de amendoim (PNA que reconhece timócitos imaturos. Estes animais também aumentaram as células não-linfóides tímicas por unidade de área, detectadas com a técnica de Picrosirius, lectinas WGA e DBA e anticorpos antipancitoqueratina e anti-S-100. A atrofia de timo observada nos animais intoxicados foi semelhante àquela do processo de envelhecimento fisiológico. Após supressão da intoxicação, foi observado um efeito de reversão nestas mudanças. Estes resultados sugerem que a intoxicação por Sg induza a alteração observada no timo diretamente, pela ação de 1,25-dihidroxivitamina D3, ou indiretamente, pela ação da hipercalcemia.

  14. Cirugía preprotésica e implantológica en pacientes con atrofia maxilar severa

    OpenAIRE

    González García, R.; Naval Gias, Luis; Mario F. Muñoz Guerra; Sastre Pérez, Jesús; Rodríguez Campo, Francisco José

    2005-01-01

    Objetivos. Valoración del éxito en la osteointegración de los implantes dentales en pacientes con atrofia maxilar severa sometidos a cirugía de elevación de seno maxilar y técnica por aposición mediante el uso de injertos de hueso autólogo. Diseño del estudio. Se realiza estudio descriptivo y analítico de 27 pacientes con atrofia maxilar severa y edentulismo parcial o total, durante 4 años de seguimiento. Todos los casos fueron tratados mediante cirugía con utilización de injertos óseos autól...

  15. Menopausia, una endocrinopatía: Atrofia Urogenital y Trastornos de la Sexualidad

    Directory of Open Access Journals (Sweden)

    Roberto Vergara Tamara

    1995-08-01

    Full Text Available

    La atrofia urogonital causada por el estímulo deficiente estrogenito se manifiesta principalmente en la vagina, donde la mucosa sufre un adelgazamiento gradual que permite el predominio de células parabasales e intermedias propias del hipoestrogenismo, volviéndolo altamente sensible al trauma y la infección.

    Clínicamente se traduce en disminución de la humedad vaginal, sensación de llenura en el intróito, ruptura fácil de capilares vaginales con aparición de petequias, irritación, prurito y dispareunia.

    A nivel del endometrio se pueden presentar uno de los siguientes cambios: proliferación débil, atrofia senil, hiperplasia quística, hiperplasia adenomatosa, neoplasia omás raramente trastorno secretor; cambios que corresponden clínicamente a intervalos oligomenorreicos interpuestos por episodios hemorrágicos que finalmente terminan en amenorrea definitiva. En casos de sangrados postoriores ameritaría estudios anatomopatológicos de control obtenidos por biopsia o legrado uterino. Otros cambios que se presentan en el útero incluyen la pérdida de tono en sus ligamentos y elementos de sostén así comola disminución del cuello y su secreción.

    A nivel urinario la pérdida del tono uretral cursará con prolapso de la mucosa a través del meato, uretritis ahacteriana recurrente manifestada por poliaquiuria, disuria de ardor e incluso incontinencia urinaria de esfuerzo.

    Los cambios descritos anteriormente, hacen que la sexualidad femenina sea perturbada al presentarse dispareunia, disminuyendo de ritmo sexual y libido de la mujer haciendo su vida de pareja difícil y caótica. Se ha descrito también que la disminución de estrógenos produce ansiedad, depresión, tensión e irritabilidad al no permitir la disociación del triptófano de la albúmina para así formar sustancias tales como la hidroxitriptamina que participa en el mejoramiento del estado de ánimo. Esta etapa será de adaptación difícil y

  16. Dificuldades diagnósticas na atrofia muscular espinhal Spinal muscular atrophy diagnostic difficulties

    Directory of Open Access Journals (Sweden)

    Alexandra Prufer de Q-C. Araújo

    2005-03-01

    Full Text Available OBJETIVO: Descrever o perfil clínico e laboratorial de pacientes com atrofia muscular espinhal (AME com deleção no gene da proteína sobrevivência do neurônio motor (SMN. MÉTODO: Estudo descritivo de uma série de casos confirmados pela presença da deleção no gene SMN. Determinação da freqüência da positividade dos critérios clínicos e laboratoriais revisados. RESULTADOS: Foram incluídos no estudo 22 casos. Em todos havia paresia simétrica, sendo a localização difusa predominante nos casos de início antes de 6 meses (75 %, enquanto nos demais havia predominância de localização proximal e/ou em membros inferiores (67 %. Fasciculações e atrofia foram freqüentes (82 %. Os exames complementares tiveram resultados variáveis, sendo a positividade da eletroneuromiografia (ENMG de 57 % e da biopsia muscular de 58 %. CONCLUSÃO: A presença de deleção no gene SMN pode ajudar a confirmar o diagnóstico de casos indefinidos .OBJECTIVE: To describe the clinical findings of patients with spinal muscular atrophy (SMA with survival motor neuron (SMN gene deletion. METHOD: Descriptive study of SMA cases confirmed with the deletion of the SMN gene. Frequency determination of positive clinical and laboratory revised diagnostic criteria. RESULTS: All of the 22 included patients had symmetrical muscle weakness, which was diffuse in those with onset of symptoms up to 6 months of age (75 %, and either proximal or predominant in lower limbs in the remaining group (67 %. Fasciculations and atrophy were both frequent findings (82 %. Laboratory tests findings were variable, with a positivity of 57 % for electrophysiology and of 58 % for muscle biopsy. CONCLUSION: The presence of a deletion in the SMN gene can help to confirm this diagnosis in unclear presentations.

  17. ATROFIA MUSCULAR ESPINAL: MANEJO RESPIRATORIO EN LA PERSPECTIVA DE LOS RECIENTES AVANCES TERAPÉUTICOS

    Directory of Open Access Journals (Sweden)

    Dra. María Angélica Palomino

    2017-01-01

    Full Text Available La atrofia muscular espinal (AME es la primera causa genética de mortalidad en lactantes. La severidad de las manifestaciones clínicas es un continuo, con tres principales subtipos en pediatría: AME1 que se presenta en recién nacidos y no logran sentarse, AME2 en niños que no logran caminar pero sí sentarse y AME3 que logran caminar. La complicación más seria es la insuficiencia respiratoria. El enfoque del manejo respiratorio es preventivo, con toma de decisiones anticipadas por parte de los cuidadores, que incluye optimizar el manejo de la tos, evitar la deformación de la caja torácica y permitir un desarrollo pulmonar adecuado, tratar la hipoventilación, manejar oportunamente las infecciones respiratorias, el trastorno de deglución, el reflujo gastroesofágico y la malnutrición. A las puertas del desarrollo de tratamientos específicos modificadores de la enfermedad, mediante oligonucleótidos antisentido o vectores genéticos entre otros, los cuidados en AME con enfoque multidisciplinario nos imponen nuevos desafíos donde los cuidados respiratorios deberían estar de acuerdo a lo sugerido en consensos de estándar de manejo, optimizando sus condiciones globales a la espera de tratamientos más específicos.

  18. Desproporção congênita de fibras: atrofia de fibras tipo I- relato de 11 casos

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    José Antonio Levy

    1987-06-01

    Full Text Available Os autores relatam 11 casos de desproporção congênita de fibras, comprovados pelos exames clínicos e complementares, em que as retrações fibrotendinosas precoces foram freqüentes, o CPK mostrou-se elevado e, na biópsia muscular, a histoquímica revelou atrofia seletiva das fibras tipo I. Trata-se de distrofia congênita pouco freqüente, de progressão lenta e evolução benigna.

  19. Atrofia óptica hereditaria autosómica dominante: A propósito de una familia Dominant autosomal hereditary optical atrophy: Apropos of a family

    Directory of Open Access Journals (Sweden)

    Noel Taboada Lugo

    2004-12-01

    Full Text Available Entre las causas de pérdida insidiosa, bilateral y simétrica de la visión central se deben tener siempre presente las atrofias ópticas heredo degenerativas. La atrofia óptica hereditaria autosómica dominante es la forma más frecuente de atrofia óptica heredofamiliar simple o monosintomática. Se realizó la caracterización clínica de una familia con el diagnóstico de esta discapacidad visual.Among the causes of insidious, bilateral and symmetric loss of the central vision, the hereditary and degenerative optical atrophies should always be taken into account. The dominant autosomal hereditary optical atrophy is the most frequent form of simple or monosymptomatic hereditary family optical atrophy. The clinical characterization of a family with the diagnosis of this visual impairment was made.

  20. Relação dose-dependente do uso crônico de fenitoína e atrofia cerebelar em pacientes com epilepsia

    OpenAIRE

    DEL NEGRO,ANDRÉ; DANTAS,CLARISSA DE ROSALMEIDA; ZANARDI,VERÔNICA; MONTENEGRO,MARIA AUGUSTA; CENDES,FERNANDO

    2000-01-01

    O uso crônico da fenitoína ou intoxicação aguda por essa droga produzem lesão cerebelar permanente com atrofia do vermis e hemisférios cerebelares, que pode ser evidenciada através de exames de neuroimagem. O objetivo deste estudo foi avaliar a correlação entre a dosagem e o tempo de uso da fenitoína com a ocorrência de atrofia cerebelar. Foram realizados levantamento de prontuários para a obtenção de dados clínicos e análise de tomografias de crânio para avaliação de atrofia cerebelar. Dos 6...

  1. Reversible posterior leukoencephalopathy syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ja; Yu, Won Jong; Ahn, Kook Jin; Jung, So Lyung; Lee, Yeon Soo; Kim, Ji Chang; Kang, Si Won [The Catholic Univ. of Korea, Taejon (Korea, Republic of); Song, Chang Joon [Chungnam National Univ. School of Medicine, Cheonju (Korea, Republic of); Song, Soon-Young; Koo, Ja Hong [Kwandong Univ. College of Medicine, Myungji Hospital, Seoul (Korea, Republic of); Kim, Man Deuk [College of Medicine Pochon CHA Univ., Seoul (Korea, Republic of)

    2001-10-01

    To review reversible posterior leukoencephalopathy syndrome. We reviewed 22 patients (M:F=3:19; age, 17-46 years) with the characteristic clinical and imaging features of reversible posterior leukoencephalopathy syndrome. All underwent brain MRI, and in three cases both CT and MRI were performed. In one, MRA was obtained, and in eleven, follow-up MR images were obtained. We evaluated the causes of this syndrome, its clinical manifestations, and MR findings including the locations of lesions, the presence or absence of contrast enhancement, and the changes seen at follow-up MRI. Of the 22 patients, 13 had eclampsia (six during pregnancy and seven during puerperium). Four were receiving immunosuppressive therapy (three, cyclosporine ; one, FK 506). Four suffered renal failure and one had complicated migraine. The clinical manifestations included headache (n=12), visual disturbance (n=13), seizure (n=15), focal neurologic sign (n=3), and altered mental status (n=2). Fifteen patients had hypertension and the others normotension. MRI revealed that lesions were bilateral (n=20) or unilateral (n=2). In all patients the lesion was found in the cortical and subcortical areas of the parieto-occipital lobes ; other locations were the basal ganglia (n=9), posterior temporal lobe (n=8), frontal lobe (n=5), cerebellum (n=5), pons (n=2), and thalamus (n=1). All lesions were of high signal intensity on T2-weighted images, and of iso to low intensity on T1-weighted images. One was combined with acute hematoma in the left basal ganglia. In eight of 11 patients who underwent postcontrast T1-weighted MRI, there was no definite enhancement ; in one, enhancement was mild, and in tow, patchy. CT studies showed low attenuation, and MRA revealed mild vasospasm. The symptoms of all patients improved. Follow-up MRI in nine of 11 patients depicted complete resolution of the lesions ; in two, small infarctions remained but the extent of the lesions had decreased. Reversible posterior

  2. [Cortical blindness].

    Science.gov (United States)

    Chokron, S

    2014-02-01

    Cortical blindness refers to a visual loss induced by a bilateral occipital lesion. The very strong cooperation between psychophysics, cognitive psychology, neurophysiology and neuropsychology these latter twenty years as well as recent progress in cerebral imagery have led to a better understanding of neurovisual deficits, such as cortical blindness. It thus becomes possible now to propose an earlier diagnosis of cortical blindness as well as new perspectives for rehabilitation in children as well as in adults. On the other hand, studying complex neurovisual deficits, such as cortical blindness is a way to infer normal functioning of the visual system. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  3. Caso clínico sobre el tratamiento fisioterapéutico de un paciente con Atrofia Multisistémica.

    OpenAIRE

    Viejo Espada, Marta

    2010-01-01

    Introducción: La Atrofia Multisistémica es una enfermedad degenerativa, que cursa con una disfunción del sistema nervioso autónomo y del sistema motor. El objetivo de este estudio es proponer un programa de tratamiento fisioterapéutico para un paciente diagnosticado de Atrofia Multisistémica. Presentación del caso: se describe la valoración de la capacidad funcional y las necesidades del paciente, los objetivos y un programa de tratamiento adaptado. Resultados: El presente e...

  4. Atrofia progressiva generalizada da retina em cães da raça Cocker Spaniel

    Directory of Open Access Journals (Sweden)

    Débora Gomes

    2013-08-01

    Full Text Available Atrofia progressiva generalizada da retina (APGR é uma doença frequente nos cães da raça Cocker Spaniel, caracterizada pela perda progressiva da função retiniana externa e desaparecimento dos fotorreceptores. A doença é bilateral, hereditária, autossômica recessiva, sem predisposição sexual e está frequentemente associada à catarata. Segundo estudos moleculares, a degeneração ocorre por mutação de diversos genes. Nos cães da raça Cocker Spaniel Americano, a doença é observada entre três e cinco anos de idade e, no Cocker Spaniel Inglês, entre quatro e oito anos de idade. Os sinais clínicos mais encontrados são: nictalopia, hiperreflexia tapetal e catarata. O diagnóstico baseia-se no histórico clínico, exame oftalmológico e em exames complementares, como eletrorretinograma, testes genéticos e ultrassom ocular. Este artigo teve como objetivo realizar uma revisão de literatura a respeito da atrofia progressiva generalizada da retina (APGR em cães da raça Cocker Spaniel portadores de catarata.

  5. Posterior plagiocephaly.

    Science.gov (United States)

    Kalra, Ricky; Walker, Marion L

    2012-09-01

    Asymmetrical cranial vaults resulting from external forces on an infant's head can be caused by abnormal sutural development (synostotic plagiocephaly) or abnormal external forces acting on an intrinsically normal, developing cranium (deformational plagiocephaly). The incidence of posterior plagiocephaly has increased dramatically since the initiation of the "Back to Sleep" campaign against sudden infant death syndrome. The majority of cases are due to deformational plagiocephaly, but rigorous diagnostic evaluation including physical examination and radiological imaging must be undertaken to rule out lambdoid synostosis in extreme or refractory cases. Unique clinical features and radiological examination using computed tomography technology are helpful in confirming the correct cause of posterior plagiocephaly. Plagiocephaly is considered a benign condition, but with the recent increase in cases, new studies have revealed developmental problems associated with cranial vault asymmetries. Treatment of positional/deformational plagiocephaly includes conservative measures, primarily behavior modification, and, in some cases, helmet therapy, whereas lambdoid synostotic plagiocephaly requires surgical intervention, making differentiation of the cause of the asymmetry critical.

  6. Atrofia progressiva generalizada da retina em cães da raça Cocker Spaniel

    OpenAIRE

    Débora Gomes; Denise Aya Otsuki; Ricardo Lisak; Angélica de Mendonça Vaz Safatle

    2013-01-01

    Atrofia progressiva generalizada da retina (APGR) é uma doença frequente nos cães da raça Cocker Spaniel, caracterizada pela perda progressiva da função retiniana externa e desaparecimento dos fotorreceptores. A doença é bilateral, hereditária, autossômica recessiva, sem predisposição sexual e está frequentemente associada à catarata. Segundo estudos moleculares, a degeneração ocorre por mutação de diversos genes. Nos cães da raça Cocker Spaniel Americano, a doença é observada entre três e ci...

  7. Posterior Tibial Tendon Dysfunction

    Science.gov (United States)

    .org Posterior Tibial Tendon Dysfunction Page ( 1 ) Posterior tibial tendon dysfunction is one of the most common problems of the foot and ankle. It occurs when the posterior tibial tendon becomes inflamed or torn. As a result, the ...

  8. Posterior Cruciate Ligament Injury

    Science.gov (United States)

    Posterior cruciate ligament injury Overview Posterior cruciate ligament (PCL) injury happens far less often than does injury to the knee's more vulnerable counterpart, the anterior cruciate ligament (ACL). The posterior cruciate ...

  9. Relação dose-dependente do uso crônico de fenitoína e atrofia cerebelar em pacientes com epilepsia Dose-related cerebellar atrophy in patients with epilepsy using phenytoin

    Directory of Open Access Journals (Sweden)

    ANDRÉ DEL NEGRO

    2000-06-01

    Full Text Available O uso crônico da fenitoína ou intoxicação aguda por essa droga produzem lesão cerebelar permanente com atrofia do vermis e hemisférios cerebelares, que pode ser evidenciada através de exames de neuroimagem. O objetivo deste estudo foi avaliar a correlação entre a dosagem e o tempo de uso da fenitoína com a ocorrência de atrofia cerebelar. Foram realizados levantamento de prontuários para a obtenção de dados clínicos e análise de tomografias de crânio para avaliação de atrofia cerebelar. Dos 66 pacientes estudados, 18 apresentaram atrofia moderada a severa, 15 atrofia leve e 33 foram considerados normais. Os pacientes com atrofia cerebelar moderada a severa foram aqueles com maior exposição à fenitoína (uso prolongado e dose total, apresentando diferença estatisticamente significativa se comparados aos pacientes com atrofia leve ou sem atrofia (p=0.02. Além disso, no subgrupo de pacientes em uso de fenitoína, aqueles com atrofia moderada a severa possuíam níveis séricos de fenitoína significativamente mais elevados que os pacientes com atrofia leve ou sem atrofia (p=0.008. Não houve relação entre duração do tratamento e dose de outros anticonvulsivantes e presença e grau de atrofia cerebelar. Os pacientes mais velhos apresentaram maior grau de atrofia cerebelar, indicando que o fator idade ou tempo de epilepsia, ou ambos, pode ser importante na determinação de degeneração cerebelar. Concluímos que apesar da possibilidade de lesão cerebelar relacionada a crises epilépticas repetidas, a contribuição da fenitoína pode ser claramente estabelecida como um dos determinantes da atrofia cerebelar, sobretudo naqueles pacientes com altas doses por tempo prolongado e níveis séricos elevados.The chronic treatment with phenytoin or the acute intoxication by this drug may cause permanent cerebellar injury with atrophy of cerebellum vermis and hemispheres, which can be detected by neuroimaging studies. The aim of

  10. Estudio clínico, genético y molecular en un paciente con atrofia muscular espinal

    Directory of Open Access Journals (Sweden)

    Ibis Menéndez Alejo

    1998-03-01

    Full Text Available Las atrofias musculares espinales (AME infantiles son enfermedades neuromusculares hereditarias caracterizadas por la degeneración de las motoneuronas alfa del asta anterior de la médula espinal. La enfermedad de Werdnig-Hoffmann, AME tipo I, es la forma más grave, se transmite como un carácter autosómico recesivo y los afectados suelen fallecer durante el primer año de vida por fallo respiratorio. En este trabajo se presenta una familia cubana con 2 hijos con AME tipo I, en la cual el estudio molecular en uno de ellos permitió identificar los 2 cromosomas parentales asociados con ésta. Se encontró además en el paciente una deleción de ambas copias del gen SMN (exón 8 y del gen NAIP (exón 5. Los hallazgos ilustran la utilidad de estos estudios, con vistas a posibilitar el diagnóstico prenatal de la enfermedad.The infantile spinal muscular atrophies (SMA are hereditary neuromuscular diseases characterized by degenerated Alfa-motoneurons of the anterior spinal marrow horn. Werdning-Hoffman disease, Type 1 SMA, is the most serious affection being transmitted as an autosomal recessive character, so those affected may die from respiratory failures in the first year of life. This paper presents a Cuban family with two kids who suffer from Type-1 SMA; the molecular analysis carried out in one of them identified two parental chromosomes responsible for the disease. Also, a deletion of both copies of SMN gene (exon 8 and NAIP gene (exon 5 were discovered in this patient. These findings showed the usefulness of this kind of studies with a view to making a prenatal diagnosis of Werdning-Hoffman disease.

  11. Cortical Visual Impairment

    Science.gov (United States)

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Cortical Visual Impairment En Español Read in Chinese What is cortical visual impairment? Cortical visual impairment (CVI) is a decreased ...

  12. Una visión desde la biología molecular a una deficiencia comúnmente encontrada en la práctica del fisioterapeuta: la atrofia muscular

    Directory of Open Access Journals (Sweden)

    Carolina Ramírez Ramírez

    2012-12-01

    Full Text Available La atrofia muscular es una deficiencia comúnmente encontrada en los usuarios de los servicios de Fisioterapia; comprender los mecanismos moleculares que regulan dicha condición permite tener una visión más profunda de la condición del paciente. Tres vías principales regulan la atrofia muscular: la de las calpaínas, la lisosomal y la ubiquitina proteosoma. Esta última regula la mayor parte de la degradación proteica en la atrofia muscular, sin importar su etiología. Atrogina-1 y MuRF1, dos enzimas que hacen parte de la vía ubiquitina proteosoma, se elevan significativamente en presencia de atrofia muscular, en parte mediante el aumento en los niveles de factor de necrosis tumoral alfa. Comprender los mecanismos moleculares involucrados en la regulación de la atrofia muscular es importante para el fisioterapeuta porque le ayuda a entender mejor la condición clínica sobre la cual interviene y a plantear preguntas de investigación susceptibles de ser respondidas con el uso de la biología molecular. Salud UIS 2012; 44 (3: 31-39

  13. Central cortical cleanup and zonular deficiency

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    Mansour AM

    2016-10-01

    Full Text Available Ahmad M Mansour,1,2 Rafic S Antonios,1 Iqbal Ike K Ahmed3 1Department of Ophthalmology, American University of Beirut, Beirut, Lebanon; 2Department of Ophthalmology, Rafic Hariri University Hospital, Beirut, Lebanon; 3Department of Ophthalmology, University of Toronto, Toronto, ON, Canada Background: Complete removal of the cortex has been advocated to prevent posterior capsular opacification but carries the risk of zonular dehiscence, hence there is a need for a safe maximal cortical cleanup technique in eyes with severe diffuse zonulopathy in subjects above age 90. Methods: We used bimanual central cortical cleaning by elevating central fibers and aspirating them toward the periphery. Peripheral cortical fibers were removed passively only when they became loose due to copious irrigation. A one-piece foldable implant was inserted without a capsular tension ring. Postoperative corticosteroid drops were used. Results: This technique was safely performed in a dozen eyes with severe pseudo-exfoliation or brunescent cataract with weak zonules. Posterior capsular rupture, iritis, vitreous loss, and lens subluxation were not observed. Moderate capsular phimosis occurred but with maintained central vision. Conclusion: The dogma of “complete cortical cleanup” in severe zonulopathy needs to be revisited in favor of a clear visual axis with maximal preservation of the damaged zonules. This technique is ideal in patients above age 90 where posterior capsular opacification and late dislocation of intraocular lens–capsule bag complex are unlikely to occur until several years postoperatively. Keywords: brunescent cataract, cortex aspiration, phacoemulsification, pseudo-exfoliation, weak zonules

  14. Central cortical cleanup and zonular deficiency.

    Science.gov (United States)

    Mansour, Ahmad M; Antonios, Rafic S; Ahmed, Iqbal Ike K

    2016-01-01

    Complete removal of the cortex has been advocated to prevent posterior capsular opacification but carries the risk of zonular dehiscence, hence there is a need for a safe maximal cortical cleanup technique in eyes with severe diffuse zonulopathy in subjects above age 90. We used bimanual central cortical cleaning by elevating central fibers and aspirating them toward the periphery. Peripheral cortical fibers were removed passively only when they became loose due to copious irrigation. A one-piece foldable implant was inserted without a capsular tension ring. Postoperative corticosteroid drops were used. This technique was safely performed in a dozen eyes with severe pseudo-exfoliation or brunescent cataract with weak zonules. Posterior capsular rupture, iritis, vitreous loss, and lens subluxation were not observed. Moderate capsular phimosis occurred but with maintained central vision. The dogma of "complete cortical cleanup" in severe zonulopathy needs to be revisited in favor of a clear visual axis with maximal preservation of the damaged zonules. This technique is ideal in patients above age 90 where posterior capsular opacification and late dislocation of intraocular lens-capsule bag complex are unlikely to occur until several years postoperatively.

  15. Pertinencia del uso de implantes dentales cortos en pacientes con atrofia ósea severa: revisión de la literatura

    OpenAIRE

    R. Azañón Hernández; I. Martínez Lara; J. Ferrer Gallego; R. Marzo Alzota

    2013-01-01

    El propósito de este artículo es determinar la pertinencia del uso de implantes cortos, definiéndolos como "aquellos cuya longitud es ≤8 mm" a través de la bibliografía existente. Hemos centrado la búsqueda en la comparación del uso de implantes de esta longitud, frente a otros tratamientos alternativos (injertos óseos, elevación de seno, transposición del nervio dentario, etc.) en pacientes con atrofia maxilar severa. Se dan respuesta a las siguientes cuestiones: ¿El uso de implantes dentale...

  16. Avaliação da dor em doentes com atrofia de sistemas múltiplos : estudo comparativo com a doença de Parkinson

    OpenAIRE

    Pinheiro, Sara Figueira da Câmara Lomelino

    2016-01-01

    Trabalho final de mestrado integrado em Medicina área cientifica de Neurologia, apresentado á Faculdade de Medicina da Universidade de Coimbra Introdução: A dor é um sintoma comum nos distúrbios Parkinsónicos, típicos e atípicos, influenciando negativamente a qualidade de vida destes doentes. Objectivo: Analisar a prevalência e as características da dor em doentes com Atrofia de Sistemas Múltiplos, comparando os resultados obtidos com a Doença de Parkinson. Métodos: Inclusão de 20 do...

  17. Cortical visual impairment

    OpenAIRE

    Koželj, Urša

    2013-01-01

    In this thesis we discuss cortical visual impairment, diagnosis that is in the developed world in first place, since 20 percent of children with blindness or low vision are diagnosed with it. The objectives of the thesis are to define cortical visual impairment and the definition of characters suggestive of the cortical visual impairment as well as to search for causes that affect the growing diagnosis of cortical visual impairment. There are a lot of signs of cortical visual impairment. ...

  18. Posterior Shoulder Instability.

    Science.gov (United States)

    Antosh, Ivan J; Tokish, John M; Owens, Brett D

    Posterior shoulder instability has become more frequently recognized and treated as a unique subset of shoulder instability, especially in the military. Posterior shoulder pathology may be more difficult to accurately diagnose than its anterior counterpart, and commonly, patients present with complaints of pain rather than instability. "Posterior instability" may encompass both dislocation and subluxation, and the most common presentation is recurrent posterior subluxation. Arthroscopic and open treatment techniques have improved as understanding of posterior shoulder instability has evolved. Electronic databases including PubMed and MEDLINE were queried for articles relating to posterior shoulder instability. Clinical review. Level 4. In low-demand patients, nonoperative treatment of posterior shoulder instability should be considered a first line of treatment and is typically successful. Conservative treatment, however, is commonly unsuccessful in active patients, such as military members. Those patients with persistent shoulder pain, instability, or functional limitations after a trial of conservative treatment may be considered surgical candidates. Arthroscopic posterior shoulder stabilization has demonstrated excellent clinical outcomes, high patient satisfaction, and low complication rates. Advanced techniques may be required in select cases to address bone loss, glenoid dysplasia, or revision. Posterior instability represents about 10% of shoulder instability and has become increasingly recognized and treated in military members. Nonoperative treatment is commonly unsuccessful in active patients, and surgical stabilization can be considered in patients who do not respond. Isolated posterior labral repairs constitute up to 24% of operatively treated labral repairs in a military population. Arthroscopic posterior stabilization is typically considered as first-line surgical treatment, while open techniques may be required in complex or revision settings.

  19. Multisensory Perception of Action in Posterior Temporal and Parietal Cortices

    Science.gov (United States)

    James, Thomas W.; VanDerKlok, Ross M.; Stevenson, Ryan A.; James, Karin Harman

    2011-01-01

    Environmental events produce many sensory cues for identifying the action that evoked the event, the agent that performed the action, and the object targeted by the action. The cues for identifying environmental events are usually distributed across multiple sensory systems. Thus, to understand how environmental events are recognized requires an…

  20. Localization of cortical areas activated by thinking

    DEFF Research Database (Denmark)

    Roland, P E; Friberg, L

    1985-01-01

    These experiments were undertaken to demonstrate that pure mental activity, thinking, increases the cerebral blood flow and that different types of thinking increase the regional cerebral blood flow (rCBF) in different cortical areas. As a first approach, thinking was defined as brain work...... that they started at their front door and then walked alternatively to the left or the right each time they reached a corner. The rCBF increased only in homotypical cortical areas during thinking. The areas in the superior prefrontal cortex increased their rCBF equivalently during the three types of thinking...... midtemporal cortex exclusively during jingle thinking. The intermediate and remote visual association areas, the superior occipital, posterior inferior temporal, and posterior superior parietal cortex, increased their rCBF exclusively during route-finding thinking. We observed no decreases in rCBF. All r...

  1. Mnemonic Encoding and Cortical Organization in Parietal and Prefrontal Cortices.

    Science.gov (United States)

    Masse, Nicolas Y; Hodnefield, Jonathan M; Freedman, David J

    2017-06-21

    Persistent activity within the frontoparietal network is consistently observed during tasks that require working memory. However, the neural circuit mechanisms underlying persistent neuronal encoding within this network remain unresolved. Here, we ask how neural circuits support persistent activity by examining population recordings from posterior parietal (PPC) and prefrontal (PFC) cortices in two male monkeys that performed spatial and motion direction-based tasks that required working memory. While spatially selective persistent activity was observed in both areas, robust selective persistent activity for motion direction was only observed in PFC. Crucially, we find that this difference between mnemonic encoding in PPC and PFC is associated with the presence of functional clustering: PPC and PFC neurons up to ∼700 μm apart preferred similar spatial locations, and PFC neurons up to ∼700 μm apart preferred similar motion directions. In contrast, motion-direction tuning similarity between nearby PPC neurons was much weaker and decayed rapidly beyond ∼200 μm. We also observed a similar association between persistent activity and functional clustering in trained recurrent neural network models embedded with a columnar topology. These results suggest that functional clustering facilitates mnemonic encoding of sensory information. SIGNIFICANCE STATEMENT Working memory refers to our ability to temporarily store and manipulate information. Numerous studies have observed that, during working memory, neurons in higher cortical areas, such as the parietal and prefrontal cortices, mnemonically encode the remembered stimulus. However, several recent studies have failed to observe mnemonic encoding during working memory, raising the question as to why mnemonic encoding is observed during some, but not all, conditions. In this study, we show that mnemonic encoding occurs when a cortical area is organized such that nearby neurons preferentially respond to the same

  2. A and B mode ultrasonography in preoperative evaluation of lens and posterior segment of dogs eyes with cataract

    Directory of Open Access Journals (Sweden)

    Bianca C. Martins

    2010-02-01

    Full Text Available Ultrasonography of the lens and posterior segment is an indispensable step in the preoperative evaluation of dogs with cataracts, since ophthalmoscopy is not feasible when there is opacification of the lens. This study evaluated the echographic conditions of cataractous lens and fundus of the eye in dogs affected by cataracts. The study was conducted in 30 dogs (56 eyes, 10 males and 20 females, with different types of cataracts at different stages of development. Echography in A and B modes, simultaneously, was carried out for the examination of the lens and posterior segment. The examinations revealed anterior cortical, posterior cortical and nuclear cataract in 12 eyes (21.4%, anterior cortical, posterior cortical, nuclear and posterior capsular in 23 eyes (41%, anterior cortical, posterior cortical and posterior capsular cataract in one eye (1.7%, anterior cortical and nuclear cataract in one eye (1.7%, anterior cortical, nuclear and posterior capsular cataract in five eyes (8.9%, and anterior cortical cataract in seven eyes (12.5%. Abnormal ultrasonographic alterations were observed in the posterior segment in 26 eyes evaluated (46.4%. Vitreal degeneration was detected in 12 eyes (21.4%, images of vitreal exudate or hemorrhage in seven eyes (12.5%, persistence of hyaloid artery in four eyes (7.1% and lens subluxation in three eyes (5.3%. The results obtained reiterate the importance of ultrasonography in canine patients presented for cataract surgery given that alterations of the posterior segment are difficult to identify in a clinical examination when the lens is opacified.A ultrassonografia do segmento posterior do bulbo do olho é etapa indispensável na avaliação de cães com catarata que serão submetidos à facectomia, uma vez que a oftalmoscopia não é factível quando há opacificação da lente, notadamente nas cataratas maduras. Este estudo avaliou as condições ecográficas da lente cataratogênica e do fundo de olho de c

  3. Progressive transcortical sensory aphasia and progressive ideational apraxia owing to temporoparietal cortical atrophy

    OpenAIRE

    Funayama, Michitaka; NAKAJIMA, Asuka

    2015-01-01

    Background In contrast to frontotemporal lobar degeneration, atrophy of the focal posterior lateral cortex has not been thoroughly studied. Three clinical types of focal cortical atrophy have been described: 1) logopenic variant of primary progressive aphasia, which presents with impaired repetition despite normal articulation; 2) posterior cortical atrophy, which presents with prominent visuospatial deficits; and 3) primary progressive apraxia. All three clinical types are characterized by s...

  4. Correlação entre atrofia hipocampal e déficit de memória em pacientes com epilepsia de lobo temporal mesial

    OpenAIRE

    Denise Pacagnella

    2012-01-01

    Resumo: A Epilepsia de Lobo Temporal Mesial (ELTM) é a forma mais frequente de epilepsia focal em adultos e geralmente está associada à atrofia hipocampal (AH) identificável pela ressonância magnética (RM) de alta resolução. Consiste em uma síndrome frequentemente refratária ao tratamento clínico e os pacientes podem apresentar déficits de memória devido a danos no sistema hipocampal, porém pouco se sabe a respeito do impacto da frequência de crises sobre a memória. Portanto, os objetivos do ...

  5. Cholelithiasis with atrophy of the right lateral hepatic lobe in a horse Colelitíase com atrofia do lobo lateral direito em um cavalo

    Directory of Open Access Journals (Sweden)

    Renato de Lima Santos

    2007-04-01

    Full Text Available A 22 year-old horse developed cholelithiasis with marked atrophy of the right lateral hepatic lobe. The horse had a history of intermittent colic since three years of age, and one of the first episodes of colic was associated with icterus. The size of the right lateral hepatic lobe was extremely reduced. There was a large choledocholith in the common hepatic duct, and several hepatoliths and choleliths in the intra- and extra-hepatic billiary ducts. Microscopically, there was severe atrophy of the right lobe with diffuse proliferation of connective tissue and billiary ducts. The left lateral lobe had peri-portal fibrosis with proliferation of billiary ducts, and billiary stasis. Chemical analysis of the calculi detected amorphous and triple phosphate, bilirubin, calcium, and iron.Um cavalo de 22 anos de idade desenvolveu quadro de colelitíase severa com atrofia do lobo lateral direito. O animal tinha histórico de cólica recorrente, desde os três anos de idade, sendo que um dos primeiros episódios de cólica foi acompanhado de icterícia. O lobo hepático lateral direito estava extremamente diminuído de volume. Havia um grande coledocólito localizado no ducto hepático comum e inúmeros hepatólitos e colélitos nos ductos biliares intra e extra-hepáticos. Microscopicamente, foi observada atrofia acentuada do lobo direito, com proliferação difusa de tecido conjuntivo fibroso e de ductos biliares. O lobo lateral esquerdo apresentava fibrose periportal difusa associada à proliferação acentuada de ductos biliares e estase biliar. Análise química das concreções detectou fosfato triplo e amorfo, bilirrubina, cálcio e ferro.

  6. Incomplete cortical reorganization in macular degeneration.

    Science.gov (United States)

    Liu, Tingting; Cheung, Sing-Hang; Schuchard, Ronald A; Glielmi, Christopher B; Hu, Xiaoping; He, Sheng; Legge, Gordon E

    2010-12-01

    Activity in regions of the visual cortex corresponding to central scotomas in subjects with macular degeneration (MD) is considered evidence for functional reorganization in the brain. Three unresolved issues related to cortical activity in subjects with MD were addressed: Is the cortical response to stimuli presented to the preferred retinal locus (PRL) different from other retinal loci at the same eccentricity? What effect does the role of age of onset and etiology of MD have on cortical responses? How do functional responses in an MD subject's visual cortex vary for task and stimulus conditions? Eight MD subjects-four with age-related onset (AMD) and four with juvenile onset (JMD)-and two age-matched normal vision controls, participated in three testing conditions while undergoing functional magnetic resonance imaging (fMRI). First, subjects viewed a small stimulus presented at the PRL compared with a non-PRL control location to investigate the role of the PRL. Second, they viewed a full-field flickering checkerboard compared with a small stimulus in the original fovea to investigate brain activation with passive viewing. Third, they performed a one-back task with scene images to investigate brain activation with active viewing. A small stimulus at the PRL generated more extensive cortical activation than at a non-PRL location, but neither yielded activation in the foveal cortical projection. Both passive and active viewing of full-field stimuli left a silent zone at the posterior pole of the occipital cortex, implying a lack of complete cortical reorganization. The silent zone was smaller in the task requiring active viewing compared with the task requiring passive viewing, especially in JMD subjects. The PRL for MD subjects has more extensive cortical representation than a retinal region with matched eccentricity. There is evidence for incomplete functional reorganization of early visual cortex in both JMD and AMD. Functional reorganization is more prominent

  7. Spondylolisthesis and Posterior Instability

    Energy Technology Data Exchange (ETDEWEB)

    Niggemann, P.; Beyer, H.K.; Frey, H.; Grosskurth, D. (Privatpraxis fuer Upright MRT, Koeln (Germany)); Simons, P.; Kuchta, J. (Media Park Klinik, Koeln (Germany))

    2009-04-15

    We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI.

  8. Posterior Elbow Dislocation

    Directory of Open Access Journals (Sweden)

    Victoria Oppenheim

    2016-09-01

    Full Text Available History of present illness: A 15-year old female presented with left elbow pain. While competing in a high school wrestling match, she extended her left arm to brace a fall and had immediate onset of sharp pain. She denied weakness or numbness of her left arm. She had no past medical history. Significant findings: Elbow dislocations are classified by the position of the radio-ulnar joint relative to the humerus.1 Images 1, 2, and 3 show a left posterior elbow dislocation; the radius and ulna are displaced posteriorly with respect to the distal humerus. The lateral view of the elbow most clearly shows this: trochlear notch of the ulna is empty and displaced posteriorly relative to the trochlea. There is no associated fracture. Images 4 and 5 show the elbow status-post reduction, demonstrating proper alignment of the distal humerus with the radius and ulna. Discussion: Traumatic dislocations of the elbow are relatively uncommon in pediatric patients, with a peak incidence at 13 to 14 years.1 Dislocations are usually posterior and occur after forced abduction and extension of the elbow.1 It is important to evaluate for an associated fracture or avulsion, which occurs in over 50% of pediatric elbow dislocations. Fractures most commonly involve the medial epicondyle, radial head and neck, or coronoid process.1 One should also consider a neurovascular injury to the ulnar or median nerve or to the brachial artery or its branches.1 Posterior elbow dislocations should be reduced as soon as possible.1 Patients should receive adequate sedation and/or analgesia. One method of reduction is the “puller” technique, during which a practitioner stabilizes the humerus, while a second practitioner applies force against the anterior forearm, with gentle traction distally.1 Post-reduction neurovascular reassessment is important. After successful reduction, patients can be immobilized in a posterior long arm splint.

  9. Posterior tracheal diverticulosis.

    Science.gov (United States)

    Madan, Karan; Das, Chandan J; Guleria, Randeep

    2014-10-01

    Multiple tracheal diverticulosis is a rare clinical entity. Tracheal diverticula are usually recognized radiologically as solitary right paratracheal air collections on thoracic computed tomography examination. They are usually asymptomatic but can occasionally present with persistent symptoms. We herein report the case of a 50-year-old male patient who underwent extensive evaluation for persistent cough. Multiple posterior right paratracheal air collections were recognized on thoracic multidetector computed tomography examination, which was confirmed as multiple-acquired posterior upper tracheal diverticula on flexible bronchoscopy. The patient improved with conservative medical management.

  10. Heterogeneidade genética em atrofia óptica autossômica dominante Genetic heterogeneity in autosomal dominant optic atrophy

    Directory of Open Access Journals (Sweden)

    Juliana Maria Ferraz Sallum

    2002-08-01

    Full Text Available Objetivos: A atrofia óptica autossômica dominante, tipo Kjer ou juvenil, é neuropatia óptica hereditária que causa perda de acuidade visual, anormalidades da visão de cores e defeitos do campo visual, caracterizada por palidez do disco óptico. O gene desta doença foi mapeado por análise de ligação genética em um intervalo de 1,4 cM no cromossomo 3q28-29 entre os marcadores microssatélites D3S3669 e D3S3562. Embora a maioria das famílias estudadas tenha mostrado ligação para a região cromossômica 3q28-29, uma família foi mapeada no cromossomo 18q12.2-12.3. Este trabalho analisa a ligação da atrofia óptica em três famílias com marcadores polimórficos para os cromossomos 3q28-29 e 18q12.2-12.3. Métodos: Cinqüenta e sete indivíduos de três famílias foram submetidos a exame oftalmológico e coleta de sangue. O DNA foi extraído e amplificado em reações de polimerase em cadeia (PCR com marcadores polimórficos para os cromossomos 3q28-29 e 18q12.2-12.3. Os fragmentos de PCR foram mensurados em seqüenciador automático (373 DNA sequencer. Estes números foram utilizados como alelos para análise de haplótipos. Os "lod scores" foram calculados pelo programa MLINK. Resultados: Na primeira família houve suspeita da atrofia óptica mapear para o cromossomo 3q28-29, mas sem significância estatística no valor do "lod score". Na segunda família a atrofia óptica apresentou ligação para este locus. Os eventos de recombinação nesta família localizaram o gene num intervalo de 2 cM entre os marcadores D3S3669 e D3S2305. O "lod score" máximo obtido foi de 3,56 no theta de 0,00 com o marcador D3S3669. A terceira família não apresentou ligação nos cromossomos 3q28-29 e 18q12.2-12.3. Conclusão: O fato da terceira família não mapear para nenhum dos dois loci já descritos é indicativo de que existe heterogeneidade genética na atrofia óptica autossômica dominante e levanta a possibilidade de existir um terceiro

  11. Alteraciones del polo posterior en la miopía degenerativa Alterations of the posterior pole in degenerative myopia patients

    Directory of Open Access Journals (Sweden)

    Suzel Ivón Lapido Polanco

    2012-12-01

    Full Text Available La miopía degenerativa constituye una de las causas fundamentales de pérdida de la visión. Esto está relacionado con las alteraciones del polo posterior, que afectan la retina neurosensorial, el epitelio pigmentario de la retina y las capas más internas de la coroides. Su curso lento y progresivo demanda una exploración integral, con seguimiento en el tiempo y constituye un reto para el oftalmólogo. Se realizó una revisión de artículos publicados e indexados en la base de datos de PubMed que se refirieran a las características clínicas del fondo de ojo en pacientes con miopía degenerativa, para describir las principales alteraciones del polo posterior del globo ocular en esta entidad. Se encontró entre las lesiones típicas de la alta miopía, al estafiloma posterior como un signo patognomónico de la enfermedad, asociado a la atrofia coriorretiniana en parches o difusa, así como las estrías de laca y las hemorragias maculares secundarias a ellas o provenientes de membranas neovasculares coroideas. La tomografía de coherencia óptica ha permitido un diagnóstico más preciso de otras lesiones maculares como la foveosquisis, el agujero macular y, más recientemente, la mácula en domo. Los cambios degenerativos del polo posterior parecen guardar relación unos con otros pero la patogenia no ha sido bien esclarecida a pesar de los avances tecnológicos.Degenerative myopia is one of the main causes of visual impairment. This is related to disorders in the posterior pole, affecting the neurosensorial retina, the retinal pigmented epithelium and the inner choroidal layers. The slow and progressive course of this condition demands comprehensive assessment and long follow-up, which is a challenging task for ophthalmologists. A review of the articles indexed in PubMed regarding the clinical characteristics of the fundus in patients with degenerative myopia was made to describe the main disorders of the posterior pole of the eyeball

  12. A huge glandular odontogenic cyst occurring at posterior mandible

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2004-12-15

    The glandular odontogenic cyst is a rare lesion described in 1987. It generally occurs at anterior region of mandible in adults over the age of 40 and has a slight tendency to recur. Histopathologically, a cystic cavity lined by a nonkeratinized, stratified squamous, or cuboidal epithelium varying in thickness is found including a superficial layer with glandular or pseudoglandular structures. A 21-year-old male visited Dankook University Dental Hospital with a chief complaint of swelling of the left posterior mandible. Radiographically, a huge multilocular radiolucent lesion involving impacted 3rd molar at the posterior mandible was observed. Buccolingual cortical expansion with partial perforation of buccal cortical bone was also shown. Histopathologically, this lesion was lined by stratified squamous epithelium with glandular structures in areas of plaque-like thickening. The final diagnosis was made as a glandular odontogenic cyst.

  13. Análise da freqüência de trombofilia em pacientes com atrofia branca de Milian Frequency analysis of thrombophilia in patients with atrophie blanche

    Directory of Open Access Journals (Sweden)

    Aline Donati Jorge

    2007-02-01

    Full Text Available FUNDAMENTOS - Atrofia branca de Milian ou vasculopatia livedóide é entidade clinicopatológica rara, cuja patogênese não é completamente compreendida. OBJETIVOS - Avaliar casos de atrofia branca de Milian para verificar a prevalência de diversas trombofilias. MATERIAL E MÉTODOS - Quatorze pacientes foram submetidos a exames laboratoriais incluindo pesquisa de fator V (Leiden, protrombina mutante, dosagem de antitrombina, proteína S e C, pesquisa de anticorpos anticardiolipina e anticoagulante lúpico, dosagem de homocisteína e pesquisa da mutação da metilenotetraidrofolatoredutase. RESULTADOS - Dos nove doentes cujos critérios de inclusão foram preenchidos para análise da freqüência de trombofilia, foram encontrados quatro com fatores relacionados à trombofilia: deficiência da antitrombina (um caso, deficiência da proteína S (um caso, mutação da metilenotetraidrofolatoredutase com hiperhomocisteinemia (um caso e presença de anticorpo anticardiolipina (um caso. CONCLUSÃO - Apesar de este estudo não apresentar casuística que possibilite a comparação com a população geral, os dados sugerem a presença de eventos geradores de trombofilia nesses doentes, contribuindo para adoção sistemática de um protocolo de investigação de trombofilia nos doentes portadores de vasculopatia livedóide no Brasil.INTRODUCTION: Atrophie blanche, or livedoid vasculopathy, is a rare clinicopathological entity of unknown etiology. A "thrombo-occlusive process" theory has recently been accepted. OBJECTIVES: To search the presence of several thrombophilic abnormalities in patients with livedoid vasculopathy. METHODS: Fourteen patients were evaluated and tested for factor V Leiden, prothrombin 20210G/A variant, antithrombin, C and S proteins, anticardiolipin and lupus anticoagulant antibodies, homocysteine and methylenetetrahydrofolate reductase mutation. RESULTS: Nine patients met all criteria to be included in the analysis and four of

  14. Permanent Cortical Blindness After Bronchial Artery Embolization

    Energy Technology Data Exchange (ETDEWEB)

    Doorn, Colette S. van, E-mail: cvandoorn@gmail.com; De Boo, Diederick W., E-mail: d.w.deboo@amc.uva.nl [Academic Medical Centre, Department of Radiology (Netherlands); Weersink, Els J. M., E-mail: e.j.m.weersink@amc.uva.nl [Academic Medical Centre, Department of Pulmonology (Netherlands); Delden, Otto M. van, E-mail: o.m.vandelden@amc.uva.nl; Reekers, Jim A., E-mail: j.a.reekers@amc.uva.nl; Lienden, Krijn P. van, E-mail: k.p.vanlienden@amc.uva.nl [Academic Medical Centre, Department of Radiology (Netherlands)

    2013-12-15

    A 35-year-old female with a known medical history of cystic fibrosis was admitted to our institution for massive hemoptysis. CTA depicted a hypertrophied bronchial artery to the right upper lobe and showed signs of recent bleeding at that location. Bronchial artery embolization (BAE) was performed with gelfoam slurry, because pronounced shunting to the pulmonary artery was present. Immediately after BAE, the patient developed bilateral cortical blindness. Control angiography showed an initially not opacified anastomosis between the embolized bronchial artery and the right subclavian artery, near to the origin of the right vertebral artery. Cessation of outflow in the bronchial circulation reversed the flow through the anastomosis and allowed for spill of embolization material into the posterior circulation. Unfortunately the cortical blindness presented was permanent.

  15. Síndrome de Charles Bonnet en cuatro casos con atrofia óptica Charles Bonnet syndrome in four cases with optical atrophy

    Directory of Open Access Journals (Sweden)

    Lester Pola Alvarado

    2012-12-01

    Full Text Available El síndrome de Charles Bonnet constituye un trastorno muy poco reportado. En Cuba, que se conozca, no hay referencia de casos publicados hasta este momento. Se caracteriza por la presencia de alucinaciones visuales complejas en individuos con pérdida visual, mentalmente sanos y con conciencia crítica de la naturaleza irreal de sus alucinaciones. Se presentan cuatro casos con este síndrome relacionados con déficit visual secundario a atrofia óptica. Solo el reconocimiento médico temprano de los síntomas del síndrome de Charles Bonnet y la posibilidad de brindar información, estrategias terapéuticas y asesoramiento adecuado, pueden beneficiar a estos pacientes en su nueva condición.Charles Bonnet syndrome is an underreported disorder. As far as we know, there are no publicized references in Cuba up to the present time. This syndrome involves complex visual hallucinations in visually impaired individuals, who are mentally healthy and have intact cognition of the unreal nature of their hallucinations. Four cases with this syndrome related to loss of vision due to optic atrophy were presented. The early recognition by clinicians of the symptoms of Charles Bonnet syndrome and the possibility of sharing proper information, therapeutic strategies and pieces of advice can help these patients suffering this disease.

  16. Posterior reversible encephalopathy syndrome in a hypertensive patient with renal failure

    OpenAIRE

    T Aatif; M R El Farouki; M. BENYAHIA

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and neuroimaging entity characterized by headache, visual field deficits, changes in mentation and seizures, and by typical neuro-imaging features such as areas of sub-cortical edema, occasionally cortical, involving predominantly the occipital and parietal lobes of both hemispheres. Hypertension, uremia, immunosuppressive drugs neurotoxicity, preeclampsia or eclampsia, renal disease, and sepsis are the most common etiologies o...

  17. Cortical Lewy Body Dementia

    Directory of Open Access Journals (Sweden)

    W. R. G. Gibb

    1990-01-01

    Full Text Available In cortical Lewy body dementia the distribution of Lewy bodies in the nervous system follows that of Parkinson's disease, except for their greater profusion in the cerebral cortex. The cortical tangles and plaques of Alzheimer pathology are often present, the likely explanation being that Alzheimer pathology provokes dementia in many patients. Pure cortical Lewy body dementia without Alzheimer pathology is uncommon. The age of onset reflects that of Parkinson's disease, and clinical features, though not diagnostic, include aphasias, apraxias, agnosias, paranoid delusions and visual hallucinations. Parkinsonism may present before or after the dementia, and survival duration is approximately half that seen in Parkinson's disease without dementia.

  18. [Posterior cruciate ligament injuries].

    Science.gov (United States)

    Schüttler, K F; Ziring, E; Ruchholtz, S; Efe, T

    2017-01-01

    Posterior cruciate ligament (PCL) injuries are still often overlooked and treatment of a ruptured PCL is inherently different in comparison to anterior cruciate ligaments (ACL). Conservative treatment is the first-line therapy for acute isolated PCL injuries leading to good clinical and biomechanical results. Injuries to the PCL combined with rupture of other stabilizing ligaments, such as the collateral ligaments or the posterolateral corner of the knee joint are treated surgically. The same is true for high grade chronic PCL insufficiency. Meticulous classification of PCL injuries taking all stabilizing factors of the knee joint as well as the time from injury into account are essential for successful treatment of PCL injuries.

  19. Proximity of maxillary posterior teeth roots to maxillary sinus and adjacent structures using Denta scan?

    OpenAIRE

    Fry, Ramesh Ram; Patidar, Dinesh Chand; Goyal, Samta; Malhotra, Aayush

    2016-01-01

    Aim: The study aimed to investigate the proximity of maxillary posterior teeth roots to maxillary sinus and measure the distance of maxillary posterior teeth roots and the sinus floor as well as the thickness of bone between the roots and alveolar cortical bone using Denta scan?. Materials and Methods: The study samples include Denta scan? images of fifty patients with normally erupted bilateral maxillary first premolar to maxillary second molar. The vertical relationship of each tooth root w...

  20. Sex, age, and cognitive correlates of asymmetries in thickness of the cortical mantle across the life span

    DEFF Research Database (Denmark)

    Plessen, Kerstin J; Hugdahl, Kenneth; Bansal, Ravi

    2014-01-01

    lateral, dorsal, and mesial surfaces of the frontal lobe, extending into primary sensory, superior parietal, and anterior superior temporal cortices. A right > left asymmetry was present in the lateral, mesial, and dorsal surfaces of the posterior temporal, parietal, and occipital cortices, as well...... scattered along the mesial surface of the brain. Age significantly moderated asymmetry measures in the inferior sensorimotor, inferior parietal, posterior temporal, and inferior occipital cortices. The age × asymmetry interaction derived from a steeper decline in cortical thickness with age in the right......We assessed the correlations of age, sex, and cognitive performance with measures of asymmetry in cortical thickness on high-resolution MRIs in 215 healthy human children and adults, 7-59 years of age. A left > right asymmetry in thickness of the cortical mantle was present throughout the entire...

  1. Posterior chamber pseudophakia.

    Science.gov (United States)

    Simcoe, C W

    1982-01-01

    Anatomically, the most physiological type of implant is that of the posterior chamber of the eye. After a brief historical review of these implants, two models differing by their loops are compared, these being either in the form of a J with narrow extremities or in the form of a C. The latter model possesses definite advantages. Firstly, the point of pressure on the lens capsule is less concentrated, reducing the pressure exerted by the loops and thus avoiding rupture of the zonular ciliaris, Secondly, contact in the form of an are prevents movement of the implant around its axis, a factor favorizing capsule slipping. Thirdly, the improved pressure distribution of the loops resulting from their greater flexibility also prevents the "windscreen wiper syndrome", providing improved stability of the implant. The technique employed avoids all contact taking place with the endothelium. The upper loop is placed in position after closure of the incision. Results in 1532 cases were very positive, and studies are currently being conducted with an implant with four loops in which the optic is within the posterior chamber, and which could be positioned after intracapsular extraction. A system of irrigation-aspiration is described which employs a fine curved canula that is easier to manage and permits improved cleaning of the capsule. Emphasis is placed on the need for narrow, deep, corneal sutures to reduce postoperative astigmatism.

  2. Progressive transcortical sensory aphasia and progressive ideational apraxia owing to temporoparietal cortical atrophy.

    Science.gov (United States)

    Funayama, Michitaka; Nakajima, Asuka

    2015-11-11

    In contrast to frontotemporal lobar degeneration, atrophy of the focal posterior lateral cortex has not been thoroughly studied. Three clinical types of focal cortical atrophy have been described: 1) logopenic variant of primary progressive aphasia, which presents with impaired repetition despite normal articulation; 2) posterior cortical atrophy, which presents with prominent visuospatial deficits; and 3) primary progressive apraxia. All three clinical types are characterized by specific patterns of hypometabolism/hypoperfusion: the left posterior perisylvian area in the logopenic variant of primary progressive aphasia, bilateral parietooccipital areas in posterior cortical atrophy, and the parietal cortex in primary progressive apraxia. However, not every patient clearly fits into one of these categories. Here we describe two patients with atypical focal cortical presentations. They presented with a history of a few years of progressive transcortical sensory aphasia characterized by fluent output with normal grammar and syntax, normal repetition, sentence comprehension deficits, and anomia without loss of word meaning. They also presented with progressive apraxia that began at the initial stages. Some forms of posterior symptoms including acalculia, agraphia, and visuospatial deficits were also observed. Hypoperfusion was noted mainly in the left temporoparietal region, which is slightly posterior to the perisylvian area. Although our cases lack in CSF findings and PIB scan, these two cases and previous reports might suggest the existence of a subgroup of patients presenting with transcortical sensory aphasia, apraxia, and posterior symptoms (acalculia, agraphia, and visuospatial deficits) in the setting of Alzheimer's disease. This subgroup may reflect the spectrum of clinical manifestations between logopenic variant of primary progressive aphasia and posterior cortical atrophy.

  3. Irreducible Traumatic Posterior Shoulder Dislocation

    Directory of Open Access Journals (Sweden)

    Blake Collier

    2017-01-01

    Full Text Available History of present illness: A 22-year-old male presented to the Emergency Department complaining of right shoulder pain after a motocross accident. He was traveling at approximately 10 mph around a turn when he lost control and was thrown over the handlebars, landing directly on his right shoulder. On arrival, he was holding his arm in adduction and internal rotation. An area of swelling was noted over his anterior shoulder. He was unable to abduct his shoulder. No humeral gapping was noted. He had normal neuro-vascular status distal to the injury. Significant findings: Radiographs demonstrated posterior displacement of the humeral head on the “Y” view (see white arrow and widening of the glenohumeral joint space on anterior-posterior view (see red arrow. The findings were consistent with posterior dislocation and a Hill-Sachs type deformity. Sedation was performed and reduction was attempted using external rotation, traction counter-traction. An immediate “pop” was felt during the procedure. Post-procedure radiographs revealed a persistent posterior subluxation with interlocking at posterior glenoid. CT revealed posterior dislocation with acute depressed impaction deformity medial to the biceps groove with the humeral head perched on the posterior glenoid, interlocked at reverse Hill-Sachs deformity (see blue arrow. Discussion: Posterior shoulder dislocations are rare and represent only 2% of all shoulder dislocations. Posterior shoulder dislocations are missed on initial diagnosis in more than 60% of cases.1 Posterior shoulder dislocations result from axial loading of the adducted and internally rotated shoulder, violent muscle contractions (resulting from seizures or electrocution, a direct posterior force applied to the anterior shoulder.1 Physical findings include decreased anterior prominence of the humeral head, increased palpable posterior prominence of the humeral head below the acromion, increased palpable prominence of the

  4. Atrofia muscular bulbo espinhal recessiva ligada ao cromossomo X (doença de Kennedy: estudo de uma família

    Directory of Open Access Journals (Sweden)

    KAIMEN-MACIEL DAMACIO RAMÓN

    1998-01-01

    Full Text Available A doença de Kennedy (DK é forma rara de doença do neurônio motor caracterizada por mutação na região codificadora do gene do receptor androgênico localizado no braço longo do cromossoma X (Xq 11-12. Há expansão das sequências de trinucleotídeos CAG que nos pacientes deve atingir número maior do que 347 repetições de pares de bases. Apresentamos quatro gerações de uma família com dez indivíduos acometidos. Avaliamos três pacientes do sexo masculino com idade variando entre 50 e 60 anos que desenvolveram sintomatologia por volta de 30 anos de idade caracterizada por fraqueza muscular progressiva associada a disfagia e disartria. O exame demonstrou ginecomastia, atrofia testicular, amiotrofia, fasciculações, paresia, abolição de reflexos e tremor postural. A análise do DNA pela técnica do PCR demonstrou número de repetições CAG aumentado no locus Xq 11-12 nos três pacientes e em uma mulher assintomática da família. Demonstramos a primeira família brasileira com diagnóstico de DK através de genética molecular. A DK deve fazer parte do diagnóstico diferencial das doenças do neurônio motor e a identificação destes pacientes é importante para o prognóstico e para o aconselhamento genético.

  5. Novel posterior fixation keratoprosthesis

    Science.gov (United States)

    Lacombe, Emmanuel

    1992-08-01

    The keratoprosthesis is the last solution for corneally blind patients that cannot benefit from corneal transplants. Keratoprostheses that have been designed to be affixed anteriorly usually necessitate multi-step surgical procedures and are continuously subjected to the extrusion forces generated by the positive intraocular pressure; therefore, clinical results in patients prove inconsistent. We proposed a novel keratoprosthesis concept that utilizes posterior corneal fixation which `a priori' minimizes the risk of aqueous leakage and expulsion. This prosthesis is implanted in a single procedure thereby reducing the number of surgical complications normally associated with anterior fixation devices. In addition, its novel design makes this keratoprosthesis implantable in phakic eyes. With an average follow-up of 13 months (range 3 to 25 months), our results on 21 cases are encouraging. Half of the keratoprostheses were implanted in severe burn cases, with the remainder in cases of pseudo- pemphigus. Good visual results and cosmetic appearance were obtained in 14 of 21 eyes.

  6. Posterior reversible encephalopathy syndrome.

    Science.gov (United States)

    Fischer, Marlene; Schmutzhard, Erich

    2017-08-01

    The posterior reversible encephalopathy syndrome (PRES) is a neurological disorder of (sub)acute onset characterized by varied neurological symptoms, which may include headache, impaired visual acuity or visual field deficits, disorders of consciousness, confusion, seizures, and focal neurological deficits. In a majority of patients the clinical presentation includes elevated arterial blood pressure up to hypertensive emergencies. Neuroimaging, in particular magnetic resonance imaging, frequently shows a distinctive parieto-occipital pattern with a symmetric distribution of changes reflecting vasogenic edema. PRES frequently develops in the context of cytotoxic medication, (pre)eclampsia, sepsis, renal disease or autoimmune disorders. The treatment is symptomatic and is determined by the underlying condition. The overall prognosis is favorable, since clinical symptoms as well as imaging lesions are reversible in most patients. However, neurological sequelae including long-term epilepsy may persist in individual cases.

  7. Posterior Vitreous Detachment and the Posterior Hyaloid Membrane.

    Science.gov (United States)

    Fincham, Gregory S; James, Sean; Spickett, Carl; Hollingshead, Michael; Thrasivoulou, Christopher; Poulson, Arabella V; McNinch, Annie; Richards, Allan; Snead, David; Limb, Gloria A; Snead, Martin P

    2017-08-31

    Despite posterior vitreous detachment being a common ocular event affecting most individuals in an aging population, there is little consensus regarding its precise anatomic definition. We investigated the morphologic appearance and molecular composition of the posterior hyaloid membrane to determine whether the structure clinically observed enveloping the posterior vitreous surface after posterior vitreous detachment is a true basement membrane and to postulate its origin. Understanding the relationship between the vitreous (in both its attached and detached state) and the internal limiting membrane of the retina is essential to understanding the cause of rhegmatogenous retinal detachment and vitreoretinal interface disorders, as well as potential future prophylactic and treatment strategies. Clinicohistologic correlation study. Thirty-six human donor globes. Vitreous bodies identified to have posterior vitreous detachment were examined with phase-contrast microscopy and confocal microscopy after immunohistochemically staining for collagen IV basement membrane markers, in addition to extracellular proteins that characterize the vitreoretinal junction (fibronectin, laminin) and vitreous gel (opticin) markers. The posterior retina similarly was stained to evaluate the internal limiting membrane. Findings were correlated to the clinical appearance of the posterior hyaloid membrane observed during slit-lamp biomicroscopy after posterior vitreous detachment and compared with previously published studies. Morphologic appearance and molecular composition of the posterior hyaloid membrane. Phase-contrast microscopy consistently identified a creased and distinct glassy membranous sheet enveloping the posterior vitreous surface, correlating closely with the posterior hyaloid membrane observed during slit-lamp biomicroscopy in patients with posterior vitreous detachment. Immunofluorescent confocal micrographs demonstrated the enveloping membranous structure identified on

  8. Patterns of cortical thinning in nondemented Parkinson's disease patients.

    Science.gov (United States)

    Uribe, Carme; Segura, Barbara; Baggio, Hugo Cesar; Abos, Alexandra; Marti, Maria Jose; Valldeoriola, Francesc; Compta, Yaroslau; Bargallo, Nuria; Junque, Carme

    2016-05-01

    Clinical variability in the Parkinson's disease phenotype suggests the existence of disease subtypes. We investigated whether distinct anatomical patterns of atrophy can be identified in Parkinson's disease using a hypothesis-free, data-driven approach based on cortical thickness data. T1-weighted 3-tesla MRI and a comprehensive neuropsychological assessment were performed in a sample of 88 nondemented Parkinson's disease patients and 31 healthy controls. We performed a hierarchical cluster analysis of imaging data using Ward's linkage method. A general linear model with cortical thickness data was used to compare clustering groups. We observed 3 patterns of cortical thinning in patients when compared with healthy controls. Pattern 1 (n = 30, 34.09%) consisted of cortical atrophy in bilateral precentral gyrus, inferior and superior parietal lobules, cuneus, posterior cingulate, and parahippocampal gyrus. These patients showed worse cognitive performance when compared with controls and the other 2 patterns. Pattern 2 (n = 29, 32.95%) consisted of cortical atrophy involving occipital and frontal as well as superior parietal areas and included patients with younger age at onset. Finally, in pattern 3 (n = 29, 32.95%), there was no detectable cortical thinning. Patients in the 3 patterns did not differ in disease duration, motor severity, dopaminergic medication doses, or presence of mild cognitive impairment. Three cortical atrophy subtypes were identified in nondemented Parkinson's disease patients: (1) parieto-temporal pattern of atrophy with worse cognitive performance, (2) occipital and frontal cortical atrophy and younger disease onset, and (3) patients without detectable cortical atrophy. These findings may help identify prognosis markers in Parkinson's disease. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. © 2016 The Authors. Movement Disorders

  9. Selective and superselective angiography of pediatric moyamoya disease angioarchitecture in the posterior circulation.

    Science.gov (United States)

    Baltsavias, Gerasimos; Khan, Nadia; Filipce, Venko; Valavanis, Anton

    2014-01-01

    The anastomotic network of the posterior circulation in children with moyamoya disease has not been analyzed. We aimed to investigate the angiographic anatomy of this unique vascular network in patients with childhood moyamoya disease. Selective and superselective injections of the posterior circulation were performed in six children with newly diagnosed moyamoya disease. The arterial branches feeding the moyamoya anastomotic network, their connections and the recipient vessels were demonstrated. Depending on the level of the steno-occlusive lesion, the feeding vessels were the thalamoperforators, the posterior choroidals, the splenic artery, parietoccipital artery, other cortical posterior cerebral artery (PCA) branches, the dural branch of the PCA, the premamillary artery and other posterior communicating artery perforators. Through connections, which are described, the recipient vessels were the striate and medullary arteries, other thalamic arteries with or without medullary extensions, the pericallosal artery, medial parietoccipital cortical branches of the PCA and the anterior choroidal artery. High quality selective and superselective angiography helped in demonstrating the angiographic anatomy of the moyamoya posterior anastomotic network previously either vaguely or incompletely described, as well as connections within the posterior circulation but also its relevance as a collateral to the anterior circulation.

  10. Decrease of Prefrontal-Posterior EEG Coherence: Loose Control during Social-Emotional Stimulation

    Science.gov (United States)

    Reiser, Eva M.; Schulter, Gunter; Weiss, Elisabeth M.; Fink, Andreas; Rominger, Christian; Papousek, Ilona

    2012-01-01

    In two experiments we aimed to investigate if individual differences in state-dependent decreases or increases of EEG coherence between prefrontal and posterior cortical regions may be indicative of a mechanism modulating the impact social-emotional information has on an individual. Two independent samples were exposed to an emotional stimulation…

  11. Spontaneous resorption of sub-retinal cortical lens material

    Directory of Open Access Journals (Sweden)

    Salil S Gadkari

    2014-01-01

    Full Text Available We report a rare case of retained sub-retinal cortical material, which underwent spontaneous resorption. Patient presented with a left eye traumatic retinal detachment with a large retinal tear and posteriorly dislocated cataractous lens. Vitrectomy, lensectomy, silicone oil injection, and endolaser were performed. A good visual result was achieved. The report draws attention to this condition and highlights possible technique for minimizing risk of this complication in similar cases.

  12. [Cortical control in locomotion].

    Science.gov (United States)

    Mori, Futoshi; Nakajima, Katsumi

    2010-11-01

    Although simple in appearance, bipedal (Bp) and even quadrupedal (Qp) locomotion are highly tuned motor behaviors that require coordinated control in the spatial and temporal domains of head, neck, trunk, and limbs. Seamless integration of limb movements and accompanying posture is a crucial determinant for the execution of desired locomotor movements. Recent functional brain imaging studies have shown that multiple cerebral sensorimotor cortices and the cerebellum are highly activated during human BP locomotion, suggesting that humans depend on the cerebrum and cerebellum for the elaboration of Bp locomotion. We have found that a young Japanese monkey, Macaca fuscata, acquires novel Bp walking capability with a long-term locomotor task and physical maturation. This model animal has kinematic features that are common with those of humans. Our imaging study showed that multiple cortical motor related areas are activated during monkey Bp walking, similar to that observed in humans. Furthermore, cortical inactivation studies revealed that each cortical region has an assigned functional role for the elaboration and refinements of its locomotor task. All these results show that selective yet multiple involvement of cortical motor regions are necessary for the elaboration of Bp locomotion in both humans and non-human primate models. Presumably, such multi-faceted recruitment of motor cortices is required to accommodate the limb movement and postural demands for Bp upright standing and walking. To cure locomotor dysfunctions due to CNS impairments, it is necessary to understand the CNS mechanisms involved in fine-tuning of limb movements and accompanying posture. Multi-comparative interdisciplinary studies should be initiated to reveal the CNS mechanisms involved in the control of Bp upright standing and locomotion in humans and non-human primate models.

  13. CONDICIONES QUE INDUCEN ATROFIA MUSCULAR ESQUELETICA AUMENTAN LA ACTIVIDAD FUNCIONAL DE LOS HEMICANALES PROMOVIDA POR RECEPTORES P2X7, LO QUE EXPLICA EL AUMENTO DE LA PERMEABILIDAD DE LA MEMBRANA CELULAR

    OpenAIRE

    CEA PISANI, LUIS ANDRES

    2010-01-01

    La mantención funcional de los músculos esqueléticos adultos normales de mamíferos depende en gran parte de su actividad e inervación. Así, diferentes estados patológicos, como la denervación, desuso y estados inflamatorios, conducen a la atrofia muscular, que es precedida por alteraciones de la permeabilidad de la membrana celular, cuya causa aún se desconoce. Por otro lado, los músculos normales expresan hemicanales formados por Panexinal (HCs-Panxl) pero se desconoce si expresan hemican...

  14. Enfermedad celíaca vs. atrofia villositaria serológicamente negativa: similitudes y diferencias histológicas y en el perfil inmunohistoquímico de linfocitos CD3, CD4, CD8 y CD56

    OpenAIRE

    Arévalo Suárez, Fernando; Portugal, Sabino; Barreda, Carlos; Montes, Pedro; Perez-Narrea, María Teresa; Rodríguez, Omar; Vergara, Greys; Monge, Eduardo

    2016-01-01

    Existe un grupo de enteropatía conocidas como AVSN que pueden simular enfermedad celíaca. Objetivo: El objetivo de este estudio es describir los hallazgos histológicos y de inmunohistoquímica en pacientes con enfermedad celíaca y AVSN. Material y métodos: 15 biopsias de pacientes con enfermedad celíaca y 19 biopsias con AVSN fueron reexaminados. Se estudió características histológicas tales como atrofia severa, hiperplasia de criptas, número de células plasmáticas, número de eosinófilos y pre...

  15. Hidroma subdural na fossa posterior

    Directory of Open Access Journals (Sweden)

    José Carlos Vasques

    1970-03-01

    Full Text Available Os autores relatam um caso de hidroma subdural na fossa craniana posterior conseqüente a traumatismo na região occipital. O paciente foi operado com pleno sucesso. A raridade da localização de hidroma na fossa posterior é salientada, sendo discutidos os possíveis mecanismos etio-patogênicos.

  16. [Posterior reversible encephalopathy syndrome].

    Science.gov (United States)

    Fischer, M; Schmutzhard, E

    2016-06-01

    Posterior reversible encephalopathy syndrome refers to a neurological disorder characterized by headache, disorders of consciousness, visual disturbances, epileptic seizures, and subcortical vasogenic edema. About two thirds of patients develop neurological symptoms, which are associated with blood pressure fluctuations. One hypothesis is that hypertensive episodes cause autoregulatory failure, and values above the upper limit of cerebral autoregulation result in a breakthrough followed by hyperperfusion and blood-brain barrier dysfunction. In another hypothesis, endothelial dysfunction triggered by numerous factors including preeclampsia, immunosuppressive agents, chemotherapeutics, sepsis, or autoimmune disorders is thought to be the key pathomechanism. Endo- or exogenic toxic agents including pharmacological substances, cytokines, or bacterial toxins are supposed to trigger endothelial activation and dysfunction resulting in the release of vasoconstrictors, pro-inflammatory mediators, and vascular leakage. Diagnosis is usually based on clinical and neuroimaging findings that frequently show a bilateral, symmetric, and parietooccipital pattern. However, the diagnosis can often only be confirmed during the course of disease after excluding important differential diagnoses. Currently, there is no specific treatment available. Lowering of arterial blood pressure and eliminating the underlying cause usually leads to an improvement of clinical and neuroradiological findings. Admission to a critical care unit is required in about 40 % of patients due to complicating conditions including status epilepticus, cerebral vasoconstriction, ischemia, or intracerebral hemorrhage. Prognosis is favorable; in the majority of patients neurological deficits and imaging findings resolve completely.

  17. Effect of intrinsic and extrinsic factors on global and regional cortical thickness.

    Directory of Open Access Journals (Sweden)

    Koushik A Govindarajan

    Full Text Available Global and regional cortical thicknesses based on T1-weighted magnetic resonance images acquired at 1.5 T and 3 T were measured on a relatively large cohort of 295 subjects using FreeSurfer software. Multivariate regression analysis was performed using Pillai's trace test to determine significant differences in cortical thicknesses measured at these two field strengths. Our results indicate that global cortical thickness is not affected by the field strength or gender. In contrast, the regional cortical thickness was observed to be field dependent. Specifically, the cortical thickness in regions such as parahippocampal, superior temporal, precentral and posterior cingulate is thicker at 3 T than at 1.5 T. In contrast regions such as cuneus and pericalcarine showed higher cortical thickness at 1.5 T than at 3 T. These differences appear to be age-dependent. The differences in regional cortical thickness between field strengths were similar in both genders. Further, male vs. female differences in regional cortical thickness were observed only at 1.5 T and not at 3 T. Our results indicate that magnetic field strength has a significant effect on the estimation of regional, but not global, cortical thickness. In addition, the pulse sequence, scanner type, and spatial resolution do not appear to have significant effect on the measured cortical thickness.

  18. Effect of intrinsic and extrinsic factors on global and regional cortical thickness.

    Science.gov (United States)

    Govindarajan, Koushik A; Freeman, Leorah; Cai, Chunyan; Rahbar, Mohammad H; Narayana, Ponnada A

    2014-01-01

    Global and regional cortical thicknesses based on T1-weighted magnetic resonance images acquired at 1.5 T and 3 T were measured on a relatively large cohort of 295 subjects using FreeSurfer software. Multivariate regression analysis was performed using Pillai's trace test to determine significant differences in cortical thicknesses measured at these two field strengths. Our results indicate that global cortical thickness is not affected by the field strength or gender. In contrast, the regional cortical thickness was observed to be field dependent. Specifically, the cortical thickness in regions such as parahippocampal, superior temporal, precentral and posterior cingulate is thicker at 3 T than at 1.5 T. In contrast regions such as cuneus and pericalcarine showed higher cortical thickness at 1.5 T than at 3 T. These differences appear to be age-dependent. The differences in regional cortical thickness between field strengths were similar in both genders. Further, male vs. female differences in regional cortical thickness were observed only at 1.5 T and not at 3 T. Our results indicate that magnetic field strength has a significant effect on the estimation of regional, but not global, cortical thickness. In addition, the pulse sequence, scanner type, and spatial resolution do not appear to have significant effect on the measured cortical thickness.

  19. A computerized tomographic study on the location of the mandibular canal and the cortical thickness of the mandible

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Ssang Yong; Song, Nam Kyu; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    1997-02-15

    The location of the mandibular canal and the cortical thickness of the mandible is important in the practice of dentistry. This study was preformed on twenty chosen dry mandibles, which were of adults and included fully erupted premolars and molars. The purpose of this study was to evaluate the location of the mandibular canal and the cortical thickness of the mandible on computed tomograms and to aid in the surgical treatment plans. The obtained results were as follows : 1. The horizontal distance between the mandibular canal and the buccal external border was 6.6 {+-} 0.9 mm on So (mesial root of the first molar), and it was increased posteriorly. The horizontal distance between the mandibular canal and the lingual external border was 4.1 {+-} 1.1 mm on So, and it was decreased posteriorly. 2. The vertical distance between the alveolar crest and the mandibular canal was 16.9 {+-} 1.6 mm on So, and it w as decreased posteriorly. The vertical distance between the inferior border of mandible and mandibular canal was 8.8 {+-} 1. 3 mm on So. and it was increased anteriorly and posteriorly. 3. The thickness of the buccal cortical plate was 2.2 {+-} 0.4 mm on So. and it was increased posteriorly. But, t hat of the lingual cortical plate was 2.0 {+-} 0.6 mm on So. and it was decreased posteriorly. 4. The area of the buccal cortical plate was 66.5 {+-} 1.0 mm{sup 2} on So. and it was increased posteriorly . But, that of the lingual cortical plate was 65.8 {+-} 0.9 mm{sup 2} on So and it was decreased posteriorly.

  20. Intracranial cortical localization of the human K-complex.

    Science.gov (United States)

    Wennberg, Richard

    2010-08-01

    The K-complex was first identified in human sleep EEG more than 70years ago, but the localization of its intracranial generators is an unresolved issue. In this study, K-complexes recorded using simultaneous scalp and intracranial EEG were analyzed to discover the intracranial distribution of the human K-complex. Stereoelectroencephalographic recordings were performed in six patients with medically-refractory epilepsy. Full 10-20 scalp montages were used and intracranial macroelectrodes sampled medial, lateral and basal frontal and temporal cortices, medial and lateral parietal and occipital cortices, as well as the hippocampus and thalamus. Spontaneous K-complexes were visually identified in stage II sleep and averaged off-line. The intracranial K-complex field was maximal over the anterior and superior aspects of the medial and lateral frontal lobe cortices, consistent with the frontal midline scalp EEG maximum. The frontal maximum surface-negative field was volume conducted as an inverted, positive field posteriorly and inferiorly, the polarity reversing laterally above the inferior temporal region and medially above the cingulate cortex. As suggested by the scalp EEG topography, the intracranial distribution of the human K-complex is maximal over the anterior and superior frontal cortices. K-complex generation appears limited to cortical regions above the inferior temporal sulcus laterally, the cingulate sulcus medially and the parietooccipital junction posteriorly. The human K-complex is produced by synchronous cortical activity that appears maximal intracranially over the superior medial and lateral aspects of the frontal lobes. The cingulate cortex and functionally related mesial temporal structures appear uninvolved in human K-complex generation. Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Fatal atypical reversible posterior leukoencephalopathy syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Golombeck Stefanie Kristin

    2013-01-01

    Full Text Available Abstract Introduction Reversible posterior leukoencephalopathy syndrome – a reversible subacute global encephalopathy clinically presenting with headache, altered mental status, visual symptoms such as hemianopsia or cortical blindness, motor symptoms, and focal or generalized seizures – is characterized by a subcortical vasogenic edema symmetrically affecting posterior brain regions. Complete reversibility of both clinical signs and magnetic resonance imaging lesions is regarded as a defining feature of reversible posterior leukoencephalopathy syndrome. Reversible posterior leukoencephalopathy syndrome is almost exclusively seen in the setting of a predisposing clinical condition, such as pre-eclampsia, systemic infections, sepsis and shock, certain autoimmune diseases, various malignancies and cytotoxic chemotherapy, transplantation and concomitant immunosuppression (especially with calcineurin inhibitors as well as episodes of abrupt hypertension. We describe for the first time clinical, radiological and histological findings in a case of reversible posterior leukoencephalopathy syndrome with an irreversible and fatal outcome occurring in the absence of any of the known predisposing clinical conditions except for a hypertensive episode. Case presentation A 58-year-old Caucasian woman presented with a two-week history of subacute and progressive occipital headache, blurred vision and imbalance of gait and with no evidence for raised arterial blood pressure during the two weeks previous to admission. Her past medical history was unremarkable except for controlled arterial hypertension. Cerebral magnetic resonance imaging demonstrated cortical and subcortical lesions with combined vasogenic and cytotoxic edema atypical for both venous congestion and arterial infarction. Routine laboratory and cerebrospinal fluid parameters were normal. The diagnosis of reversible posterior leukoencephalopathy syndrome was established. Within hours after

  2. Atrofia cervicouterina vs. Lesión intraepitelial escamosa de alto grado en paciente con colposcopia insatisfactoria y citología anormal: utilidad de la detección inmunohistoquímica de p16ink4a para el diagnóstico histológico, conducta clínica y pronóstico.

    OpenAIRE

    Benedetti-Padrón Inés; Barrios-García Lía; Borré-Arrieta Orlando; Contreras -Borrego Eusebio

    2011-01-01

    CASO CLÍNICO: paciente post-menopaúsica, con LIE-AG en citología, colposcopia insatisfactoria, estudio histológico de biopsia conhematoxilina – eosina (H-E) no concluyente, pero sugestivos de LIE-AG. Detección inmunohistoquímica de p16ink4a negativa. Se lerealiza conización cuyo estudio histológico descarta presencia de lesión oculta y confirma diagnóstico de atrofia cervical.COMENTARIOS: la atrofia cérvico-uterina en post-menopaúsicas dificulta el diagnóstico diferencial entre cambios histol...

  3. Manejo de las atrofias del maxilar superior clase V de Cawood y Howell mediante la adopción de la cirugía piezoeléctrica The management of atrophies classified as V class according to Cawood & Howell by piezo-electric surgery

    OpenAIRE

    Carini, F.; Porcaro, G; Ciaravino, M; Monai, D; Francesconi, M.; Baldoni, M.

    2009-01-01

    Introducción: Los casos analizados presentaban atrofias severas (V clase según Cawood y Howell) (1), que se caracterizan por presentar una densidad de la cresta transversal inferior a 4 mm y vertical inferior a 6 mm; ello hace pensar en la posibilidad de una rehabilitación implanto-soportada. Objetivo: Evaluación de la rehabilitación de pacientes afectados por severa atrofia del maxilar superior clase V según Cawood y Howell) (1) rehabilitados con elevación del seno maxilar e injerto de hueso...

  4. Word and face recognition deficits following posterior cerebral artery stroke

    DEFF Research Database (Denmark)

    Kuhn, Christina D.; Asperud Thomsen, Johanne; Delfi, Tzvetelina

    2016-01-01

    Abstract Recent findings have challenged the existence of category specific brain areas for perceptual processing of words and faces, suggesting the existence of a common network supporting the recognition of both. We examined the performance of patients with focal lesions in posterior cortical...... areas to investigate whether deficits in recognition of words and faces systematically co-occur as would be expected if both functions rely on a common cerebral network. Seven right-handed patients with unilateral brain damage following stroke in areas supplied by the posterior cerebral artery were...... included (four with right hemisphere damage, three with left, tested at least 1 year post stroke). We examined word and face recognition using a delayed match-to-sample paradigm using four different categories of stimuli: cropped faces, full faces, words, and cars. Reading speed and word length effects...

  5. Posterior capsular rupture causing posterior shoulder instability: a case report.

    Science.gov (United States)

    Shah, Anup A; Butler, R Bryan; Fowler, Rachel; Higgins, Laurence D

    2011-09-01

    We report the case of a 20-year-old male competitive football player who was treated for a midsubstance posterior capsule rupture after a posterior dislocation from falling onto his shoulder. Conservative management for 5 months after the injury failed to improve his subjective symptoms, with the primary symptom being activity-related posterior shoulder pain. Advanced imaging findings and physical examination were consistent with posterior instability, thought to be due to a posterior labral tear. At the time of a diagnostic arthroscopy, the patient was found to have an oval-shaped rupture of the capsule that was neither a reverse humeral avulsion of the glenohumeral ligament lesion nor a posterior labral tear. The capsular tear was repaired through an all-arthroscopic technique with nonabsorbable sutures. The patient returned to his previous competitive function, had no pain, and had full motion at final follow-up without recurrence of instability or pain symptoms. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  6. Posterior reversible encephalopathy syndrome and association with systemic lupus erythematosus.

    Science.gov (United States)

    Ferreira, T S; Reis, F; Appenzeller, S

    2016-10-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological complex disorder with many clinical associations and causative factors. It is important to recognize this condition because early diagnosis and treatment usually result in its complete resolution, radiological imaging becoming the key for the correct diagnosis. We retrospectively reviewed charts and magnetic resonance imaging findings in the University of Campinas from January 2005 to July 2015, selecting three cases of patients with systemic lupus erythematosus syndrome who developed PRES, for whom risk factors, characteristics, magnetic resonance imaging findings and neurological resolution were analyzed. We also conducted a review of the English-language literature. The three cases had neurological symptoms like acute onset of headache, altered mental status, cortical blindness and seizures. Brain magnetic resonance imaging demonstrated posterior cortical and white matter alterations involving posterior brain territories, which were more conspicuous on T2-weighted and fluid-attenuated inversion recovery. Spectroscopy, diffusion-weighted imaging and susceptibility-weighted imaging were also important for neuroradiological evaluation. Immunosuppressive drugs were taken in all cases. Partial clinical and radiological recovery was observed in two cases, and complete resolution was observed in the third patient. We found 52 cases of PRES in systemic lupus erythematosus patients. Almost all patients were women 94%, ranging from 8 to 62 years old. Posterior brain territory involvements were found in 98% of patients. Hemorrhagic complications involved 26% of patients, becoming a risk factor for clinical sequels. The total percentage of patients with no complete resolution of radiological findings on follow-up images was 27.5%. In patients with autoimmune disorders, endothelial dysfunction may occur secondary to autoimmunity and the use of cytotoxic drugs, supposedly facilitating the occurrence of more

  7. Atrofia muscular espinhal – Apoio ventilatório não invasivo em pediatria

    Directory of Open Access Journals (Sweden)

    Mónica Vasconcelos

    2005-09-01

    Full Text Available Resumo: A deterioração da função respiratória em crianças com doença neuromuscular degenerativa é a principal responsável pela elevada mortalidade associada a estas doenças. A ventilação não invasiva (VNI veio diminuir a morbilidade e a mortalidade por insuficiência respiratória nestas crianças. No entanto, o uso de suporte ventilatório nalguns casos de atrofia espinhal anterior (AEA é ainda controverso.Apresenta-se um estudo retrospectivo de 22 doentes com AEA seguidos no Hospital Pediátrico de Coimbra: 7 do tipo I, 11 do tipo II e 4 do tipo III. Em 17 casos foi iniciado apoio ventilatório por máscara e, em 3 destes, a VNI foi aplicada com intuitos profilácticos.As 7 crianças com AEA tipo I iniciaram VNI com uma idade média de 13 meses (3 meses – 3 anos e 5 faleceram, entre 1 a 15 meses após o início da ventilação. Das 11 crianças com AEA tipo II, em 8 foi instituída VNI, e uma faleceu 22 meses depois. Três crianças deste grupo iniciaram a VNI de forma profiláctica e em todas se verificou uma diminuição da deformidade torácica. Dos 4 doentes do tipo III, em 2 foi iniciado o suporte ventilatório. Na totalidade dos casos sintomáticos verificouse uma diminuição da frequência e gravidade de infecções respiratórias após o início do apoio ventilatório.O apoio respiratório com VNI pode melhorar a qualidade de vida de crianças com AEA e prolongar a sua sobrevida. Na AEA tipo I, cujas manifestações clínicas são muito precoces e o prognóstico muito grave, a aplicação deste apoio tem sido discutida.Rev Port Pneumol 2005; XI (5: 443-455 Abstract: The deterioration of the respiratory function in children suffering from degenerative neuromuscular disease is the main cause of the high mortality rate associated with these diseases. Noninvasive ventilation (NIV has reduced the morbidity and

  8. Cortical and spinal assessment

    DEFF Research Database (Denmark)

    Fischer, I W; Gram, Mikkel; Hansen, T M

    2017-01-01

    BACKGROUND: Standardized objective methods to assess the analgesic effects of opioids, enable identification of underlying mechanisms of drug actions in the central nervous system. Opioids may exert their effect on both cortical and spinal levels. In this study actions of morphine at both levels...... were investigated, followed by analysis of a possible correlation between the cortical processing and spinal transmission. METHODS: The study was conducted after a double-blinded, two-way crossover design in thirty-nine healthy participants. Each participant received 30mg morphine or placebo as oral...... morphine administration (P>0.05). CONCLUSIONS: Cold pressor EEG and the nociceptive reflex were more sensitive to morphine analgesia than resting EEG and can be used as standardized objective methods to assess opioid effects. However, no correlation between the analgesic effect of morphine on the spinal...

  9. Specialization of Binaural Responses in Ventral Auditory Cortices

    Science.gov (United States)

    Higgins, Nathan C.; Storace, Douglas A.; Escabí, Monty A.

    2010-01-01

    Accurate orientation to sound under challenging conditions requires auditory cortex, but it is unclear how spatial attributes of the auditory scene are represented at this level. Current organization schemes follow a functional division whereby dorsal and ventral auditory cortices specialize to encode spatial and object features of sound source, respectively. However, few studies have examined spatial cue sensitivities in ventral cortices to support or reject such schemes. Here Fourier optical imaging was used to quantify best frequency responses and corresponding gradient organization in primary (A1), anterior, posterior, ventral (VAF), and suprarhinal (SRAF) auditory fields of the rat. Spike rate sensitivities to binaural interaural level difference (ILD) and average binaural level cues were probed in A1 and two ventral cortices, VAF and SRAF. Continuous distributions of best ILDs and ILD tuning metrics were observed in all cortices, suggesting this horizontal position cue is well covered. VAF and caudal SRAF in the right cerebral hemisphere responded maximally to midline horizontal position cues, whereas A1 and rostral SRAF responded maximally to ILD cues favoring more eccentric positions in the contralateral sound hemifield. SRAF had the highest incidence of binaural facilitation for ILD cues corresponding to midline positions, supporting current theories that auditory cortices have specialized and hierarchical functional organization. PMID:20980610

  10. Cognitive Control Signals in Posterior Cingulate Cortex

    Directory of Open Access Journals (Sweden)

    Benjamin eHayden

    2010-12-01

    Full Text Available Efficiently shifting between tasks is a central function of cognitive control. The role of the default network—a constellation of areas with high baseline activity that declines during task performance—in cognitive control remains poorly understood. We hypothesized that task switching demands cognitive control to shift the balance of processing towards the external world, and therefore predicted that switching between the two tasks would require suppression of activity of neurons within the CGp. To test this idea, we recorded the activity of single neurons in posterior cingulate cortex (CGp, a central node in the default network, in monkeys performing two interleaved tasks. As predicted, we found that basal levels of neuronal activity were reduced following a switch from one task to another and gradually returned to pre-switch baseline on subsequent trials. We failed to observe these effects in lateral intraparietal cortex (LIP, part of the dorsal fronto-parietal cortical attention network directly connected to CGp. These findings indicate that suppression of neuronal activity in CGp facilitates cognitive control, and suggest that activity in the default network reflects processes that directly compete with control processes elsewhere in the brain..

  11. Posterior Reversible Leukoencephalopathy Syndrome Associated with Pazopanib

    Directory of Open Access Journals (Sweden)

    Robert Foerster

    2013-04-01

    Full Text Available A 62-year-old female patient with metastatic renal cell carcinoma under third-line treatment with pazopanib for 8 weeks suddenly developed severe headaches, grand mal seizures and paresis of the left arm in combination with gait instability as well as nausea and vomiting during her vacation abroad. The emergency physician measured systolic blood pressure values over 300 mm Hg and suspected a stroke. The CT imaging without contrast agent in a local hospital did not show any pathologic findings despite bone metastases. The colleagues suspected cerebral metastases or meningeosis carcinomatosa and referred the patient to our department for further diagnostics and treatment planning. An MRI scan ruled out the suspected cerebral metastases or meningeosis carcinomatosa, but showed signs of reversible posterior leukoencephalopathy syndrome (RPLS in the form of band-like hyperintensities as a sign of cytotoxic edema in the gray and white matter of the left parietal lobe. The patient then reported that similar blood pressure values had been measured shortly after the start of a first-line therapy with sunitinib, so that we discontinued the current treatment with pazopanib. Within 6 days the neurologic symptoms vanished and the patient was discharged. An intermittent hypertension persisted. A follow-up MRI 3 weeks later showed an RPLS-typical cortical infarction in the affected area. RPLS should be considered as the actual reason for neurologic findings in hypertensive patients with known metastatic cancers under tyrosine kinase inhibitor therapy.

  12. Phacoemulsification in posterior polar cataract

    Directory of Open Access Journals (Sweden)

    Servet Cetinkaya

    Full Text Available ABSTRACT Purpose: To evaluate the results and complications of phacoemulsification surgery in eyes with posterior polar cataracts and compare the techniques of viscodissection and hydrodissection. Methods: The medical records of 29 consecutive patients (16 males, 13 females with posterior polar cataracts (44 eyes who had undergone cataract surgery were retrospectively reviewed. Patients were divided into two groups according to the technique used; viscodissection was applied to the experimental group (group 1 and hydrodissection to the control group (group 2. Results: The postoperative best corrected visual acuity (BCVA was 0.19 ± 0.22 logMAR (mean ± standard deviation (range 0.00-0.70 in group 1 and 0.25 ± 0.18 logMAR (range 0.00-0.70 in group 2. Although the mean postoperative BCVA in group 1 was greater than that in group 2, the difference was not statistically significant (p=0.165. The mean postoperative BCVA was significantly greater than the mean preoperative BCVA in both groups (p=0.00. Intraoperatively, posterior capsular rupture occurred during the removal of the cortex in three eyes (13% of group 1 patients, with vitreous loss and anterior vitrectomy in one eye only. In group 2, six eyes (28.5% presented posterior capsular rupture, and anterior vitrectomy was performed because of vitreous loss in three eyes. Although the percentage of posterior capsular rupture was greater in group 2, the difference was not statistically significant (p=0.207. Conclusions: Complications in posterior polar cataract surgeries can be overcome by being careful throughout the surgery and using proper techniques. Viscodissection may be better for avoiding posterior capsular rupture than hydrodissection.

  13. Atrofia muscular progressiva: estudo clínico e laboratorial em onze pacientes Progressive muscular atrophy: clinical and laboratory study in eleven patients

    Directory of Open Access Journals (Sweden)

    Maria Elisabeth Matta de Rezende Ferraz

    2004-03-01

    Full Text Available A atrofia muscular progressiva (AMP é um tipo raro de doença do neurônio motor (DNM com acometimento exclusivo do neurônio motor inferior (NMI e com características clínicas bem definidas. A eletroneuromiografia é o principal exame subsidiário para a realização do diagnóstico, com demonstração de alterações neurogênicas generalizadas, agudas e crônicas. Outras doenças que mimetizam comprometimento do NMI devem ser excluídas através de investigação laboratorial ampla. Neste estudo são apresentados 11 casos de AMP (5,9% de todos os nossos casos de DNM, sendo 9 homens e 2 mulheres. O início dos sintomas ocorreu preferencialmente abaixo dos 50 anos, com média de idade de 45,5 anos. A cãibra foi o sintoma que mais comumente precedeu a fraqueza muscular. Outras queixas preliminares foram dor, fadiga muscular e fasciculações. O padrão mais freqüente de inauguração dos sintomas foi fraqueza muscular assimétrica, preferencialmente nos membros superiores. Com a evolução da doença, todos os pacientes apresentaram comprometimento bulbar. Não foi identificado nenhum fator predisponente para a doença, nem tampouco as evoluções foram distintas entre os casos. Oftalmoparesia e acometimento dos esfíncteres, sinais pouco comuns nas DNMs, foram observados em dois pacientes que se mantiveram por longo tempo em respiração artificial. As terapêuticas imunossupressoras / imunomodulatórias utilizadas (ciclofosfamida, gamaglobulina hiperimune, plasmaferese não tiveram resultado favorável. A doença teve caráter progressivo em todos os casos. Todos os pacientes faleceram, com tempo médio de sobrevida de 44 meses.Progressive muscular atrophy (PMA, an infrequent type of motor neuron disease (MND, is a predominantly lower motor neuron degeneration, causing muscle wasting and weakness with loss of weight and fasciculations. The diagnosis is based on rigid criteria, considering clinical aspects and eletroneuromyography findings

  14. Estimulação elétrica neuromuscular em cães com atrofia muscular induzida Neuromuscular electric stimulation in dogs with induced muscle atrophy

    Directory of Open Access Journals (Sweden)

    C. Pelizzari

    2008-02-01

    Full Text Available Empregou-se a estimulação elétrica neuromuscular (EENM de baixa freqüência no músculo quadríceps femoral de cães com atrofia induzida e avaliou-se a ocorrência de ganho de massa nessa musculatura. Foram utilizados oito cães com pesos entre 15 e 30kg, distribuídos aleatoriamente em dois grupos denominados de I ou controle e II ou tratado. A articulação femorotibiopatelar esquerda foi imobilizada por 30 dias pelo método de transfixação percutânea tipo II, com retirada de aparelho de imobilização após esse período. Decorridas 48 horas da remoção, foi realizada a EENM nos cães do grupo II, cinco vezes por semana, com intervalo de 24 horas cada sessão, pelo período de 60 dias. Foram avaliadas a circunferência da coxa, a goniometria do joelho, a análise clínica da marcha, as enzimas creatina-quinase (CK e aspartato-amino-transferase (AST e a morfometria das fibras musculares em cortes transversais do músculo vasto lateral colhido mediante biópsia muscular. A EENM foi empregada no músculo quadríceps femoral na freqüência de 50Hz, duração de pulso de 300 milisegundos e relação de tempo on/off de 1:2. Quanto à morfometria das fibras do músculo vasto lateral, no grupo tratado houve aumento significativo (PLow frequency neuromuscular electrical stimulation (NMES was used on the femoral quadriceps of dogs with induced muscular atrophy and the occurrence of gain in mass in these muscles was evaluated. Eight dogs from 15 to 30kg were randomly distributed in two groups named I, or control; and II, or treated. For the induction of muscular atrophy, the left femoral-tibial-patellar joint was immobilized for 30 days by percutaneous transfixation type II. After 30 days, the immobilization device was removed. The NMES treatment began 48 hours after the removal of the immobilization device of the dogs of group II, and it was carried out five times per week with an interval of 24 hours between each session, for 60 days. The

  15. Anterior and posterior MTL networks in aging and MCI.

    Science.gov (United States)

    Das, Sandhitsu R; Pluta, John; Mancuso, Lauren; Kliot, Daria; Yushkevich, Paul A; Wolk, David A

    2015-01-01

    Two neuroanatomically dissociable, large-scale cortical memory networks, referred to as the anterior and posterior medial temporal lobe (MTL) networks have recently been described in young adults using resting-state blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI)-based functional connectivity (fc-BOLD). They have been hypothesized to subserve distinct mnemonic and non-memory cognitive functions and are thought to be associated with differential vulnerability in neurological disorders. In this article, we demonstrate the existence of these functional networks in an older adult population and in a cohort of patients diagnosed with amnestic mild cognitive impairment (aMCI). Anatomic subregions of interest in the MTL were defined using high-resolution T2-weighted MRI and used as seeds for defining the putative networks using fc-BOLD. Although the literature has suggested that the posterior MTL network is particularly vulnerable to early Alzheimer's disease, we show that both the networks are affected in MCI, to varying degrees, compared with the control group. Furthermore, cortical thickness in the brain regions defined by these networks was reduced in MCI. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Disrupted Thalamus White Matter Anatomy and Posterior Default Mode Network Effective Connectivity in Amnestic Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Thomas Alderson

    2017-11-01

    Full Text Available Alzheimer’s disease (AD and its prodromal state amnestic mild cognitive impairment (aMCI are characterized by widespread abnormalities in inter-areal white matter fiber pathways and parallel disruption of default mode network (DMN resting state functional and effective connectivity. In healthy subjects, DMN and task positive network interaction are modulated by the thalamus suggesting that abnormal task-based DMN deactivation in aMCI may be a consequence of impaired thalamo-cortical white matter circuitry. Thus, this article uses a multimodal approach to assess white matter integrity between thalamus and DMN components and associated effective connectivity in healthy controls (HCs relative to aMCI patients. Twenty-six HC and 20 older adults with aMCI underwent structural, functional and diffusion MRI scanning using the high angular resolution diffusion-weighted acquisition protocol. The DMN of each subject was identified using independent component analysis (ICA and resting state effective connectivity was calculated between thalamus and DMN nodes. White matter integrity changes between thalamus and DMN were investigated with constrained spherical deconvolution (CSD tractography. Significant structural deficits in thalamic white matter projection fibers to posterior DMN components posterior cingulate cortex (PCC and lateral inferior parietal lobe (IPL were identified together with significantly reduced effective connectivity from left thalamus to left IPL. Crucially, impaired thalamo-cortical white matter circuitry correlated with memory performance. Disrupted thalamo-cortical structure was accompanied by significant reductions in IPL and PCC cortico-cortical effective connectivity. No structural deficits were found between DMN nodes. Abnormal posterior DMN activity may be driven by changes in thalamic white matter connectivity; a view supported by the close anatomical and functional association of thalamic nuclei effected by AD pathology and

  17. Broadband cortical desynchronization underlies the human psychedelic state.

    Science.gov (United States)

    Muthukumaraswamy, Suresh D; Carhart-Harris, Robin L; Moran, Rosalyn J; Brookes, Matthew J; Williams, Tim M; Errtizoe, David; Sessa, Ben; Papadopoulos, Andreas; Bolstridge, Mark; Singh, Krish D; Feilding, Amanda; Friston, Karl J; Nutt, David J

    2013-09-18

    Psychedelic drugs produce profound changes in consciousness, but the underlying neurobiological mechanisms for this remain unclear. Spontaneous and induced oscillatory activity was recorded in healthy human participants with magnetoencephalography after intravenous infusion of psilocybin--prodrug of the nonselective serotonin 2A receptor agonist and classic psychedelic psilocin. Psilocybin reduced spontaneous cortical oscillatory power from 1 to 50 Hz in posterior association cortices, and from 8 to 100 Hz in frontal association cortices. Large decreases in oscillatory power were seen in areas of the default-mode network. Independent component analysis was used to identify a number of resting-state networks, and activity in these was similarly decreased after psilocybin. Psilocybin had no effect on low-level visually induced and motor-induced gamma-band oscillations, suggesting that some basic elements of oscillatory brain activity are relatively preserved during the psychedelic experience. Dynamic causal modeling revealed that posterior cingulate cortex desynchronization can be explained by increased excitability of deep-layer pyramidal neurons, which are known to be rich in 5-HT2A receptors. These findings suggest that the subjective effects of psychedelics result from a desynchronization of ongoing oscillatory rhythms in the cortex, likely triggered by 5-HT2A receptor-mediated excitation of deep pyramidal cells.

  18. Posterior crossbite - treatment and stability

    Directory of Open Access Journals (Sweden)

    Renato Rodrigues de Almeida

    2012-04-01

    Full Text Available Posterior crossbite is defined as an inadequate transversal relationship of maxillary and mandibular teeth. Even when eliminating the etiologic factors, this malocclusion does not have a spontaneous correction, and should be treated with maxillary expansion as early as possible. This treatment aims at providing a better tooth/skeletal relationship, thereby improving masticatory function, and establishing a symmetrical condyle/fossa relationship. Should posterior crossbite not be treated early, it may result in skeletal changes, demanding a more complex approach. Additionally, an overcorrection expansion protocol should be applied in order to improve the treatment stability. Although the literature has reported a high rate of relapse after maxillary expansion, the goal of this study was to demonstrate excellent stability of the posterior crossbite correction 21 years post treatment.

  19. Rethinking "posterior" tongue-tie.

    Science.gov (United States)

    Douglas, Pamela Sylvia

    2013-12-01

    Currently, many clinicians who help with breastfeeding problems are diagnosing "posterior" tongue-tie in infants and performing or referring for frenotomy. In this "Speaking Out" article, I argue that the diagnosis of "posterior" tongue-tie has successfully raised awareness of the importance of impaired tongue function in breastfeeding difficulty. However, the diagnosis of "posterior" tongue-tie also applies a reductionist, medicalized theoretical frame to the complex problem of impaired tongue function, risking unintended outcomes. Impaired tongue function arises out of multiple interacting and co-evolving factors, including the interplay between social behaviors concerning breastfeeding and mother-infant biology. Consideration of theoretical frames is vital if we are to build an evidence base through efficient use of the scarce resources available for clinical breastfeeding research and minimize unintended outcomes.

  20. Elastic interactions between single microcrack and single osteon microstructure of human femur cortical bone

    Science.gov (United States)

    Mansor, N. N.; Daud, R.; Basaruddin, K. S.; Mat, F.; Bajuri, Y.; Ariffin, A. K.

    2017-09-01

    Inmultiscale Haversian system of cortical bone fracture, a homogenous bone modeling consideration is limited to only one Young modulus was significant for each cortex without having any constituents in that bone. A two dimension model of human femur cortical bone is presented by considering the anatomical positions of four cortices, e.g anterior, posterior, medial and lateral. The Haversian system is modeled under tensile loading by considering the interstitial matrix, osteon and cement line mechanical properties. The interaction between single microcrack and single osteon is evaluated using linear elastic fracture mechanics theory, and was determined using of stress intensity factor, strain energy release rate, and the critical stress intensity factor and critical strain energy release rate parameter. The results indicate that the medial cortex has the highest SIFs while the lowest was posterior cortex. The Young modulus of material was greatly influence the fracture parameters. More stiff the material, the SIF was reduced.

  1. Posterior reversible encephalopathy syndrome in a hypertensive patient with renal failure.

    Science.gov (United States)

    Aatif, T; El Farouki, M R; Benyahia, M

    2016-03-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and neuroimaging entity characterized by headache, visual field deficits, changes in mentation and seizures, and by typical neuro-imaging features such as areas of sub-cortical edema, occasionally cortical, involving predominantly the occipital and parietal lobes of both hemispheres. Hypertension, uremia, immunosuppressive drugs neurotoxicity, preeclampsia or eclampsia, renal disease, and sepsis are the most common etiologies of PRES. Less common, it has been described in the setting of autoimmune disease. We report a case of PRES which was associated with hypertensive crisis in a patient with renal failure. Antihypertensive therapy and hemodialysis resulted in complete recovery.

  2. Posterior reversible encephalopathy syndrome in a hypertensive patient with renal failure

    Directory of Open Access Journals (Sweden)

    T Aatif

    2016-01-01

    Full Text Available Posterior reversible encephalopathy syndrome (PRES is a clinical and neuroimaging entity characterized by headache, visual field deficits, changes in mentation and seizures, and by typical neuro-imaging features such as areas of sub-cortical edema, occasionally cortical, involving predominantly the occipital and parietal lobes of both hemispheres. Hypertension, uremia, immunosuppressive drugs neurotoxicity, preeclampsia or eclampsia, renal disease, and sepsis are the most common etiologies of PRES. Less common, it has been described in the setting of autoimmune disease. We report a case of PRES which was associated with hypertensive crisis in a patient with renal failure. Antihypertensive therapy and hemodialysis resulted in complete recovery.

  3. Cortical pathology in multiple sclerosis.

    Science.gov (United States)

    Stadelmann, Christine; Albert, Monika; Wegner, Christiane; Brück, Wolfgang

    2008-06-01

    Multiple sclerosis is the most common chronic, disabling central nervous system disease in young adults, characterized by inflammatory demyelinating white matter lesions with glial scar formation and axonal loss. Lately, evidence has accumulated that large areas of grey matter are affected in multiple sclerosis patients. Findings in post-mortem brain tissue support the notion that cortical demyelination is frequent and extensive, especially in patients with chronic multiple sclerosis. Cortical lesions differ from white matter lesions with respect to inflammatory cell infiltration, gliosis, and remyelination. Thus, differences in cortical and white matter lesion pathogenesis have been proposed. Experimental models suggest a decisive role for antimyelin antibodies in cortical demyelination. Topical studies focus on damage to neurons, dendrites, and synapses in cortical multiple sclerosis lesions. Improved imaging techniques for the detection of cortical lesions are currently developed and will provide the basis for future clinicopathological correlative studies. In summary, recent years have opened our eyes to the extensive grey matter involvement in multiple sclerosis. Studies on the pathogenesis of cortical demyelination, cortical damage, and repair will elucidate basic principles of multiple sclerosis lesion formation. However, more sensitive imaging tools are required to study the impact of cortical lesions on clinical symptoms, disability, and disease progression.

  4. Prefrontal, posterior parietal and sensorimotor network activity underlying speed control during walking

    Directory of Open Access Journals (Sweden)

    Thomas C Bulea

    2015-05-01

    Full Text Available Accumulating evidence suggests cortical circuits may contribute to control of human locomotion. Here, noninvasive electroencephalography (EEG recorded from able-bodied volunteers during a novel treadmill walking paradigm was used to assess neural correlates of walking. A systematic processing method, including a recently developed subspace reconstruction algorithm, reduced movement-related EEG artifact prior to independent component analysis and dipole source localization. We quantified cortical activity while participants tracked slow and fast target speeds across two treadmill conditions: an active mode that adjusted belt speed based on user movements and a passive mode reflecting a typical treadmill. Our results reveal frequency specific, multi-focal task related changes in cortical oscillations elicited by active walking. Low γ band power, localized to the prefrontal and posterior parietal cortices, was significantly increased during double support and early swing phases, critical points in the gait cycle since the active controller adjusted speed based on pelvis position and swing foot velocity. These phasic γ band synchronizations provide evidence that prefrontal and posterior parietal networks, previously implicated in visuo-spatial and somotosensory integration, are engaged to enhance lower limb control during gait. Sustained μ and β band desynchronization within sensorimotor cortex, a neural correlate for movement, was observed during walking thereby validating our methods for isolating cortical activity. Our results also demonstrate the utility of EEG recorded during locomotion for probing the multi-regional cortical networks which underpin its execution. For example, the cortical network engagement elicited by the active treadmill suggests that it may enhance neuroplasticity for more effective motor training.

  5. The ectopic posterior pituitary gland

    African Journals Online (AJOL)

    2013-11-04

    Nov 4, 2013 ... pituitary gland is absent, or attenuated and reduced in height, and the infundibular stalk may not be visible.[3] The infundibular stalk is best assessed after injection of gadolinium. Signal hyperintensity in the posterior aspect of the pituitary gland on T1-weighted images is related to the paramagnetic effect of ...

  6. Regional vulnerability of longitudinal cortical association connectivity

    Directory of Open Access Journals (Sweden)

    Rafael Ceschin

    2015-01-01

    Full Text Available Preterm born children with spastic diplegia type of cerebral palsy and white matter injury or periventricular leukomalacia (PVL, are known to have motor, visual and cognitive impairments. Most diffusion tensor imaging (DTI studies performed in this group have demonstrated widespread abnormalities using averaged deterministic tractography and voxel-based DTI measurements. Little is known about structural network correlates of white matter topography and reorganization in preterm cerebral palsy, despite the availability of new therapies and the need for brain imaging biomarkers. Here, we combined novel post-processing methodology of probabilistic tractography data in this preterm cohort to improve spatial and regional delineation of longitudinal cortical association tract abnormalities using an along-tract approach, and compared these data to structural DTI cortical network topology analysis. DTI images were acquired on 16 preterm children with cerebral palsy (mean age 5.6 ± 4 and 75 healthy controls (mean age 5.7 ± 3.4. Despite mean tract analysis, Tract-Based Spatial Statistics (TBSS and voxel-based morphometry (VBM demonstrating diffusely reduced fractional anisotropy (FA reduction in all white matter tracts, the along-tract analysis improved the detection of regional tract vulnerability. The along-tract map-structural network topology correlates revealed two associations: (1 reduced regional posterior–anterior gradient in FA of the longitudinal visual cortical association tracts (inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, optic radiation, posterior thalamic radiation correlated with reduced posterior–anterior gradient of intra-regional (nodal efficiency metrics with relative sparing of frontal and temporal regions; and (2 reduced regional FA within frontal–thalamic–striatal white matter pathways (anterior limb/anterior thalamic radiation, superior longitudinal fasciculus and cortical spinal tract

  7. Avaliação dos resultados do tratamento cirúrgico da escoliose na atrofia muscular espinhal tipo 2 Evaluación de los resultados del tratamiento quirúrgico de la escoliosis en la atrofia muscular espinal tipo 2 Results evaluation of surgical treatment of scoliosis in spinal muscular atrophy type 2

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Munhoz da Rocha

    2011-01-01

    Full Text Available OBJETIVO: Avaliar o resultado do tratamento cirúrgico da escoliose em pacientes com atrofia muscular espinhal (AME tipo 2. MÉTODO: Estudo retrospectivo com 12 pacientes portadores de AME tipo 2 submetidos à artrodese e instrumentação para correção da escoliose com mais de dois anos de seguimento. Foi avaliado o grau e percentual de correção da deformidade e da obliquidade pélvica no pós-operatório e a perda na última avaliação, além das complicações e o impacto do tratamento sobre a função respiratória. RESULTADOS: O seguimento médio foi de 77,5 meses (6,4 anos ± 58,9 meses (4,9 anos, o ângulo de Cobb pré-operatório médio foi de 76,1° ± 31,7° (35° a 144° e no pós-operatório de 29,5° ± 23,2° (5° a 90°, com a correção média de 46,6° (61,29%. A obliquidade pélvica média no pré-operatório foi de 15,1° ± 13,3° (variação de 0° a 37°, e no pós-operatório de 8,5° ± 9,9° (variação de 0° a 30°, com uma correção média de 6,5° (43,37%. Cinco pacientes tiveram complicações (41,6%. A Capacidade Ventilatória Forçada (CVF média pré-operatória foi de 62,9% ± 38,6% (variação de 23,3% a 89% e de 45,9% ± 25,0% (variação de 15% a 86,2%, na última avaliação. O declínio foi de 17% da capacidade vital, com redução de 2,4% por ano de seguimento. CONCLUSÕES: O tratamento cirúrgico da escoliose em pacientes com AME permite corrigir a obliquidade pélvica e restabelecer o balanço sagital e coronal liberando as mãos para as atividades da vida diária. A função pulmonar foi afetada positivamente pelo tratamento.OBJETIVO: Evaluar los resultados del tratamiento quirúrgico de la escoliosis en pacientes con atrofia muscular espinal (AME de tipo 2. MÉTODOS: Estudio retrospectivo de 12 pacientes con atrofia muscular espinal tipo 2 que fueron sometidos a artrodesis e instrumentación para la corrección de la escoliosis, con más de dos años de seguimiento. En la última evaluación, se

  8. Dynamics of Electrocorticographic (ECoG) Activity in Human Temporal and Frontal Cortical Areas During Music Listening

    Science.gov (United States)

    2012-04-14

    REPORT Dynamics of electrocorticographic (ECoG) activity in human temporal and frontal cortical areas during music listening 14. ABSTRACT 16. SECURITY...information about the sound intensity of music . ECoG activity in the high gamma band recorded from the posterior part of the superior temporal 1. REPORT...ECoG) activity in human temporal and frontal cortical areas during music listening Report Title ABSTRACT Previous studies demonstrated that brain

  9. Cortico-cortical communication dynamics

    Directory of Open Access Journals (Sweden)

    Per E Roland

    2014-05-01

    Full Text Available IIn principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG, and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

  10. Cortical complexity in bipolar disorder applying a spherical harmonics approach.

    Science.gov (United States)

    Nenadic, Igor; Yotter, Rachel A; Dietzek, Maren; Langbein, Kerstin; Sauer, Heinrich; Gaser, Christian

    2017-05-30

    Recent studies using surface-based morphometry of structural magnetic resonance imaging data have suggested that some changes in bipolar disorder (BP) might be neurodevelopmental in origin. We applied a novel analysis of cortical complexity based on fractal dimensions in high-resolution structural MRI scans of 18 bipolar disorder patients and 26 healthy controls. Our region-of-interest based analysis revealed increases in fractal dimensions (in patients relative to controls) in left lateral orbitofrontal cortex and right precuneus, and decreases in right caudal middle frontal, entorhinal cortex, and right pars orbitalis, and left fusiform and posterior cingulate cortices. While our analysis is preliminary, it suggests that early neurodevelopmental pathologies might contribute to bipolar disorder, possibly through genetic mechanisms. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  11. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  12. Cortical neural prosthetics.

    Science.gov (United States)

    Schwartz, Andrew B

    2004-01-01

    Control of prostheses using cortical signals is based on three elements: chronic microelectrode arrays, extraction algorithms, and prosthetic effectors. Arrays of microelectrodes are permanently implanted in cerebral cortex. These arrays must record populations of single- and multiunit activity indefinitely. Information containing position and velocity correlates of animate movement needs to be extracted continuously in real time from the recorded activity. Prosthetic arms, the current effectors used in this work, need to have the agility and configuration of natural arms. Demonstrations using closed-loop control show that subjects change their neural activity to improve performance with these devices. Adaptive-learning algorithms that capitalize on these improvements show that this technology has the capability of restoring much of the arm movement lost with immobilizing deficits.

  13. CT and MR Studies of Giant Dermoid Cyst Associated to Fat Dissemination at the Cortical and Cisternal Cerebral Spaces

    Directory of Open Access Journals (Sweden)

    Alessandro D'Amore

    2013-01-01

    Full Text Available This study focuses on CT and MR studies of adult patient with giant lesion of the posterior cranial fossa associated with micro- and macroaccumulations with density and signal like “fat” at the level of the cortical and cisternal cerebral spaces. This condition is compatible with previous asymptomatic ruptured dermoid cyst. Histological findings confirm the hypothesis formulated using the imaging. We also integrate elements of differential diagnosis by another giant lesion of the posterior cranial fossa.

  14. Subarachnoid hemorrhage due to ruptured intracranial aneurysm following posterior reversible encephalopathy syndrome

    OpenAIRE

    Takamasa Nanba; Hiroshi Kashimura; Hiroaki Saura; Masaru Takeda

    2016-01-01

    Although posterior reversible encephalopathy syndrome (PRES) is rarely associated with subarachnoid hemorrhage, to our knowledge, rupture of a concomitant cerebral aneurysm following PRES has not been reported. We describe a patient with atypical PRES involving the brainstem, thalamus, and periventricular white matter without cortical or subcortical edema of the parietooccipital lobe on magnetic resonance imaging, with rupture of a concomitant cerebral aneurysm. Preexisting extremely high blo...

  15. Visual attention in posterior stroke

    DEFF Research Database (Denmark)

    Fabricius, Charlotte; Petersen, Anders; Iversen, Helle K

    Objective: Impaired visual attention is common following strokes in the territory of the middle cerebral artery, particularly in the right hemisphere. However, attentional effects of more posterior lesions are less clear. The aim of this study was to characterize visual processing speed...... and apprehension span following posterior cerebral artery (PCA) stroke. We also relate these attentional parameters to visual word recognition, as previous studies have suggested that reduced visual speed and span may explain pure alexia. Methods: Nine patients with MR-verified focal lesions in the PCA......-territory (four left PCA; four right PCA; one bilateral, all >1 year post stroke) were compared to 25 controls using single case statistics. Visual attention was characterized by a whole report paradigm allowing for hemifield-specific speed and span measurements. We also characterized visual field defects...

  16. Posterior asymmetry and idiopathic scoliosis

    CERN Document Server

    Rousie, D L; Berthoz, A

    2009-01-01

    Study design Are there neuro-anatomical abnormalities associated with idiopathic scoliosis (IS)? Posterior Basicranium (PBA) reflects cerebellum growth and contains vestibular organs, two structures suspected to be involved in scoliosis. Objective The aim of this study was to compare posterior basicranium asymmetry (PBA) in Idiopathic scoliosis (IS) and normal subjects. Method: To measure the shape of PBA in 3D, we defined an intra-cranial frame of reference based on CNS and guided by embryology of the neural tube. Measurements concerned three directions of space referred to a specific intra cranial referential. Data acquisition was performed with T2 MRI (G.E. Excite 1.5T, mode Fiesta). We explored a scoliosis group of 76 women and 20 men with a mean age of 17, 2 and a control group of 26 women and 16 men, with a mean age of 27, 7. Results: IS revealed a significant asymmetry of PBA (Pr>|t|<.0001) in 3 directions of space compared to the control group. This asymmetry was more pronounced in antero-posterior...

  17. Nanotherapy for posterior eye diseases.

    Science.gov (United States)

    Kaur, Indu Pal; Kakkar, Shilpa

    2014-11-10

    It is assumed that more than 50% of the most enfeebling ocular diseases have their origin in the posterior segment. Furthermore, most of these diseases lead to partial or complete blindness, if left untreated. After cancer, blindness is the second most dreaded disease world over. However, treatment of posterior eye diseases is more challenging than the anterior segment ailments due to a series of anatomical barriers and physiological constraints confronted for delivery to this segment. In this regard, nanostructured drug delivery systems are proposed to defy ocular barriers, target retina, and act as permeation enhancers in addition to providing a controlled release. Since an important step towards developing effective treatment strategies is to understand the course or a route a drug molecule needs to follow to reach the target site, the first part of the present review discusses various pathways available for effective delivery to and clearance from the posterior eye. Promise held by nanocarrier systems, viz. liposomes, nanoparticles, and nanoemulsion, for effective delivery and selective targeting is also discussed with illustrative examples, tables, and flowcharts. However, the applicability of these nanocarrier systems as self-administration ocular drops is still an unrealized dream which is in itself a huge technological challenge. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Spinal hemianesthesia: Unilateral and posterior.

    Science.gov (United States)

    Imbelloni, Luiz Eduardo

    2014-01-01

    The injection of a non-isobaric local anesthetic should induce a unilateral spinal anesthesia in patients in a lateral decubitus position. The posterior spinal hemianesthesia only be obtained with hypobaric solutions injected in the jackknife position. The most important factors to be considered when performing a spinal hemianesthesia are: type and gauge of the needle, density of the local anesthetic relative to the CSF, position of the patient, speed of administration of the solution, time of stay in position, and dose/concentration/volume of the anesthetic solution. The distance between the spinal roots on the right-left sides and anterior-posterior is, approximately, 10-15 mm. This distance allows performing unilateral spinal anesthesia or posterior spinal anesthesia. The great advantage of obtaining spinal hemianesthesia is the reduction of cardiovascular changes. Likewise, both the dorsal and unilateral sensory block predominates in relation to the motor block. Because of the numerous advantages of producing spinal hemianesthesia, anesthesiologists should apply this technique more often. This review considers the factors which are relevant, plausible and proven to obtain spinal hemianesthesia.

  19. Age-dependent cortical thinning of peripheral visual field representations in primary visual cortex

    Directory of Open Access Journals (Sweden)

    Joseph Caleb Griffis

    2016-10-01

    Full Text Available The cerebral cortex changes throughout the lifespan, and the cortical grey matter in many brain regions becomes thinner with advancing age. Effects of aging on cortical thickness have been observed in many brain regions, including areas involved in basic perceptual functions such as processing visual inputs. An important property of early visual cortices is their topographic organization – the cortical structure of early visual areas forms a topographic map of retinal inputs. Primary visual cortex (V1 is considered to be the most basic cortical area in the visual processing hierarchy, and is topographically organized from posterior (central visual representation to anterior (peripheral visual representation along the calcarine sulcus. Some studies have reported strong age-dependent cortical thinning in portions of V1 that likely correspond to peripheral visual representations, while there is less evidence of substantial cortical thinning in central V1. However, the effect of aging on cortical thickness in V1 as a function of its topography has not been directly investigated. To address this gap in the literature, we estimated the cortical thickness of different eccentricity sectors in V1 using T1-weighted MRI scans acquired from groups of healthy younger and older adults, and then assessed whether between-group differences in V1 cortical thickness depended on cortical eccentricity. These analyses revealed age-dependent cortical thinning specific to peripheral visual field representations in anterior portions of V1, but did not provide evidence for age-dependent cortical thinning in other portions of V1. Additional analyses found similar effects when analyses were restricted to the gyral crown, sulcul depth, and sulcul wall, indicating that these effects are not likely due to differences in gyral/sulcul contributions to our regions of interest. Importantly, this finding indicates that age-dependent changes in cortical structure may differ among

  20. Cortical-Cortical Interactions And Sensory Information Processing in Autism

    Science.gov (United States)

    2008-04-30

    Additionally, these cortical areas have been implicated from significantly elevated TOJ thresholds (worse performance) in subjects with dyslexia [5...of the fact that above-average TOJ thresholds occur in subjects with known damage to these same cortical areas ( dyslexia [5], dystonia [6-8], and...volumes in autistic boys . Brain 2003, 126:1182-1192. 32. Hollander E, Anagnostou E, Chaplin W, Esposito K, Haznedar MM, Licalzi E, Wasserman S, Soorya L

  1. Variations in crestal cortical bone thickness at dental implant sites in different regions of the jawbone.

    Science.gov (United States)

    Ko, Yi-Chun; Huang, Heng-Li; Shen, Yen-Wen; Cai, Jyun-Yi; Fuh, Lih-Jyh; Hsu, Jui-Ting

    2017-06-01

    Dental implants have become reliable and predictable tools for treating missing teeth. The survival rate of dental implants is markedly influenced by the host bone quality and quantity of the jawbone. A better host bone provides higher initial stability of the dental implant, resulting in better osseointegration and a higher success rate. Host bone quality and quantity are determined by the crestal cortical bone thickness and inner cancellous bone density. The purpose of this study was to determine the crestal cortical bone thickness at dental implant sites in different regions of the jawbone through the use of dental cone-beam computed tomographic (CBCT) images. A total of 661 dental implant sites (81 in the anterior mandible, 122 in the anterior maxilla, 224 in the posterior mandible, and 234 in the posterior maxilla) were obtained from the jawbones of 173 humans. The data were subjected to statistical analysis to determine any correlation between crestal cortical bone thicknesses and jawbone regions using one-way analysis of variance with Tukey's post-test. The crestal cortical bone thicknesses at dental implant sites in the four regions decreased in the following order: posterior mandible (1.07 ± 0.47 mm, mean ± SD) >anterior mandible (0.99 ± 0.36 mm) >anterior maxilla (0.82 ± 0.30 mm) >posterior maxilla (0.75 ± 0.35 mm). The dental CBCT data demonstrate that crestal cortical bone thickness varies markedly between dental implant sites in the four regions of the jawbone. © 2017 Wiley Periodicals, Inc.

  2. Initial cognitive decline is associated with cortical thinning in early Parkinson disease.

    Science.gov (United States)

    Pereira, Joana B; Svenningsson, Per; Weintraub, Daniel; Brønnick, Kolbjørn; Lebedev, Alexander; Westman, Eric; Aarsland, Dag

    2014-06-03

    Our aim was to assess cortical thickness in a large multicenter cohort of drug-naive patients with early Parkinson disease (PD), with and without mild cognitive impairment (MCI), and explore the cognitive correlates of regional cortical thinning. One hundred twenty-three newly diagnosed patients with PD and 56 healthy controls with 3-tesla structural MRI scans and complete neuropsychological assessment from the Parkinson's Progression Markers Initiative were included. Modified Movement Disorders Society Task Force level II criteria were applied to diagnose MCI in PD. FreeSurfer image processing and analysis software was used to measure cortical thickness across groups and the association with cognitive domains and tests. In patients with MCI, atrophy was found in temporal, parietal, frontal, and occipital areas compared with controls. Specific regional thinning in the right inferior temporal cortex was also found in cognitively normal patients. Memory, executive, and visuospatial performance was associated with temporoparietal and superior frontal thinning, suggesting a relationship between cognitive impairment and both anterior and posterior cortical atrophy in the whole patient sample. These findings confirm that MCI is associated with widespread cortical atrophy. In addition, they suggest that regional cortical thinning is already present at the time of diagnosis in patients with early, untreated PD who do not meet the criteria for MCI. Together, the results indicate that cortical thinning can serve as a marker for initial cognitive decline in early PD. © 2014 American Academy of Neurology.

  3. Intermediate Latency-Evoked Potentials of Multimodal Cortical Vestibular Areas: Galvanic Stimulation.

    Science.gov (United States)

    Kammermeier, Stefan; Singh, Arun; Bötzel, Kai

    2017-01-01

    Human multimodal vestibular cortical regions are bilaterally anterior insulae and posterior opercula, where characteristic vestibular-related cortical potentials were previously reported under acoustic otolith stimulation. Galvanic vestibular stimulation likely influences semicircular canals preferentially. Galvanic stimulation was compared to previously established data under acoustic stimulation. 14 healthy right-handed subjects, who were also included in the previous acoustic potential study, showed normal acoustic and galvanic vestibular-evoked myogenic potentials. They received 2,000 galvanic binaural bipolar stimuli for each side during EEG recording. Vestibular cortical potentials were found in all 14 subjects and in the pooled data of all subjects ("grand average") bilaterally. Anterior insula and posterior operculum were activated exclusively under galvanic stimulation at 25, 35, 50, and 80 ms; frontal regions at 30 and 45 ms. Potentials at 70 ms in frontal regions and at 110 ms at all of the involved regions could also be recorded; these events were also found using acoustic stimulation in our previous study. Galvanic semicircular canal stimulation evokes specific potentials in addition to those also found with acoustic otolith stimulation in identically located regions of the vestibular cortex. Vestibular cortical regions activate differently by galvanic and acoustic input at the peripheral sensory level. Differential effects in vestibular cortical-evoked potentials may see clinical use in specific vertigo disorders.

  4. Intermediate Latency-Evoked Potentials of Multimodal Cortical Vestibular Areas: Galvanic Stimulation

    Directory of Open Access Journals (Sweden)

    Stefan Kammermeier

    2017-11-01

    Full Text Available IntroductionHuman multimodal vestibular cortical regions are bilaterally anterior insulae and posterior opercula, where characteristic vestibular-related cortical potentials were previously reported under acoustic otolith stimulation. Galvanic vestibular stimulation likely influences semicircular canals preferentially. Galvanic stimulation was compared to previously established data under acoustic stimulation.Methods14 healthy right-handed subjects, who were also included in the previous acoustic potential study, showed normal acoustic and galvanic vestibular-evoked myogenic potentials. They received 2,000 galvanic binaural bipolar stimuli for each side during EEG recording.ResultsVestibular cortical potentials were found in all 14 subjects and in the pooled data of all subjects (“grand average” bilaterally. Anterior insula and posterior operculum were activated exclusively under galvanic stimulation at 25, 35, 50, and 80 ms; frontal regions at 30 and 45 ms. Potentials at 70 ms in frontal regions and at 110 ms at all of the involved regions could also be recorded; these events were also found using acoustic stimulation in our previous study.ConclusionGalvanic semicircular canal stimulation evokes specific potentials in addition to those also found with acoustic otolith stimulation in identically located regions of the vestibular cortex. Vestibular cortical regions activate differently by galvanic and acoustic input at the peripheral sensory level.SignificanceDifferential effects in vestibular cortical-evoked potentials may see clinical use in specific vertigo disorders.

  5. Classification of Cortical Brain Malformations

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-03-01

    Full Text Available Clinical, radiological, and genetic classifications of 113 cases of malformations of cortical development (MCD were evaluated at the Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands.

  6. Posterior reversibile encephalopathic syndrom: case report and review of literature

    Directory of Open Access Journals (Sweden)

    Petrović Branko B.

    2003-01-01

    Full Text Available INTRODUCTION Reversible Posterior Leukoencephalopathy Syndrome was introduced into clinical practice in 1996 in order to describe unique syndrome, clinically expressed during hypertensive and uremic encephalopathy, eclampsia and during immunosuppressive therapy [1 ]. First clinical investigations showed that leucoencephalopathy is major characteristic of the syndrome, but further investigations showed no significant destruction in white cerebral tissue [2, 3,4]. In majority of cases changes are localize in posterior irrigation area of the brain and in the most severe cases anterior region is also involved. Taking into consideration all above mentioned facts, the suggested term was Posterior Reversible Encephalopathy Syndrome (PRES for the syndrome clinically expressed by neurological manifestations derived from cortical and subcortical changes localized in posterior regions of cerebral hemispheres cerebral trunk and cerebellum [5]. CASE REPORT Patient, aged 53 years, was re-hospitalized in Cardiovascular Institute "Dedinje" two months after succesfull aorto-coronary bypass performed in June 2001 due to the chest bone infection. During the treatment of the infection (according to the antibiogram in September 2001, patient in evening hours developed headache and blurred vision. The recorded blood pressure was 210/120 mmHg so antihypertensive treatment was applied (Nifedipin and Furosemid. After this therapy there was no improvement and intensive headache with fatigue and loss of vision developed. Neurological examination revealed cortical blindness and left hemiparesis. Manitol (20%, 60 ccm every 3 hours and iv. Nytroglicerin (high blood pressure. Brain CT revealed oedema of parieto-occipital regions of both hemispheres, more emphasized on the right. (Figure 1 a, b, c. There was no sign of focal ischemia even in deeper sections (Figure 1d, e, f. Following three days enormous high blood pressure values were registered. On the fourth day the

  7. Cortical activation during balancing on a balance board.

    Science.gov (United States)

    Herold, Fabian; Orlowski, Katja; Börmel, Sabrina; Müller, Notger G

    2017-01-01

    Keeping one's balance is a complex motor task which requires the integration and processing of different sensory information. For this, higher cortical processes are essential. However, in the past research dedicated to the brain's involvement in balance control has predominantly used virtual reality paradigms whilst little is known about cortical activation during the challenging balancing on unstable surfaces (e.g. balance board). Hence, the main goal of this study was the simultaneous evaluation of cortical activation patterns and sway parameters during balancing on a balance board. Ten healthy adults were instructed to balance on a balance board while brain activation in supplementary motor area (SMA), precentral gyrus (PrG) and postcentral gyrus (PoG) was measured with functional near-infrared spectroscopy (fNIRS). Additionally, sway parameters were simultaneously recorded with one inertial sensor. Enhanced activation of SMA, PrG and PoG was observed when balancing was compared with still standing. Furthermore, the sway of pelvis (indicated by root mean square) increased in medio-lateral (ML) and anterior-posterior (AP) direction during the balance condition. Notably, a strong negative correlation was found between SMA activation and sway in ML direction during balancing, which was not observed during standing. Our results underline the important role of sensorimotor cortical areas for balance control. Moreover, the observed correlations suggest a crucial involvement of SMA in online control of sway in ML direction. Further research is needed to understand the contribution of other cortical and subcortcial areas to online balance control. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Hiperostosis cortical infantil

    Directory of Open Access Journals (Sweden)

    Salvador Javier Santos Medina

    2015-04-01

    Full Text Available La enfermedad de Caffey, o hiperostosis cortical infantil, es una rara enfermedad ósea autolimitada, que aparece de preferencia en lactantes con signos inespecíficos sistémicos; el más relevante es la reacción subperióstica e hiperostosis en varios huesos del cuerpo, con predilección en el 75-80 % de los casos por la mandíbula. Su pronóstico es bueno, la mayoría no deja secuelas. El propósito del presente trabajo es describir las características clínicas, presentes en un lactante de cinco meses de edad, atendido en el Hospital Pediátrico Provincial “Mártires de Las Tunas” con este diagnóstico, quien ingresó en el servicio de miscelánea B por una celulitis facial. Presentaba aumento de volumen en la región geniana izquierda, febrícola e inapetencia. Se impuso tratamiento con cefazolina y se egresó a los siete días. Acudió nuevamente con tumefacción blanda y difusa de ambas hemicaras, irritabilidad y fiebre. Se interconsultó con cirugía maxilofacial, se indicaron estudios sanguíneos y radiológicos. Se diagnosticó como enfermedad de Caffey, basado en la edad del niño, tumefacción facial sin signos inflamatorios agudos e hiperostosis en ambas corticales mandibulares a la radiografía AP mandíbula; unido a anemia ligera, leucocitosis y eritrosedimentación acelerada. El paciente se trató sintomáticamente y con antinflamatorios no esteroideos. Esta rara entidad se debe tener presente en casos de niños y lactantes con irritabilidad y fiebre inespecífica

  9. Cross-regional cortical synchronization during affective image viewing.

    Science.gov (United States)

    Miskovic, Vladimir; Schmidt, Louis A

    2010-11-29

    Affective perception has been suggested to involve the coordinated activation of widely distributed cortical networks, including those involved in sensory storage/analysis and higher-order structures, such as the prefrontal cortex that regulate these processes. We measured regional electroencephalogram (EEG) activity while young adult participants viewed images varying in arousal and valence (pleasant, neutral, and unpleasant). Viewing highly arousing images led to a significant enhancement of EEG coherence between prefrontal and posterior electrodes in both cerebral hemispheres. Long distance interhemispheric coherence also increased during affective image viewing, but only among females. Increases in coherent brain electrical activity were specific to oscillations in the beta (14 to 30Hz) bandwidth, while right hemispheric networks oscillating in the theta (4 to 7Hz) range tended to de-synchronize during viewing of affective images. Although directionality could not be inferred, analyses of lead-lag relations showed the prefrontal electrodes leading the posterior clusters, consistent with top-down modulation. Our results suggest large-scale synchronization of cortical cells during affective viewing and emphasize the role of beta oscillations in mediating such binding. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Motor and functional evaluation of patients with spastic paraplegia, optic atrophy, and neuropathy (SPOAN Avaliação motora e funcional de pacientes com paraplegia espástica, atrofia óptica e neuropatia (SPOAN

    Directory of Open Access Journals (Sweden)

    Zodja Graciani

    2010-02-01

    Full Text Available Spastic paraplegia, optic atrophy, and neuropathy (SPOAN is an autosomal recessive complicated form of hereditary spastic paraplegia, which is clinically defined by congenital optic atrophy, infancy-onset progressive spastic paraplegia and peripheral neuropathy. In this study, which included 61 individuals (age 5-72 years, 42 females affected by SPOAN, a comprehensive motor and functional evaluation was performed, using modified Barthel index, modified Ashworth scale, hand grip strength measured with a hydraulic dynamometer and two hereditary spastic paraplegia scales. Modified Barthel index, which evaluate several functional aspects, was more sensitive to disclose disease progression than the spastic paraplegia scales. Spasticity showed a bimodal distribution, with both grades 1 (minimum and 4 (maximum. Hand grip strength showed a moderate inverse correlation with age. Combination of early onset spastic paraplegia and progressive polyneuropathy make SPOAN disability overwhelming.A paraplegia espástica, atrofia óptica e neuropatia (SPOAN é uma forma complicada de paraplegia espástica de herança autossômica recessiva, caracterizada por atrofia óptica congênita, paraplegia espástica progressiva de início na infância e neuropatia periférica. Este estudo avaliou o desempenho motor e funcional de 61 indivíduos com SPOAN (5 a 72 anos, por meio do índice de Barthel modificado, a escala modificada de Ashworth, da avaliação da força de preensão das mãos com dinamômetro hidráulico de Jamar e escalas de paraplegia espástica hereditária. O índice de Barthel modificado, que investiga aspectos funcionais, mostrou-se mais sensível para avaliar a progressão da doença do que as escalas de paraplegia espástica. A espasticidade apresentou distribuição bimodal, com o grau 1 (mínimo e 4 (máximo. A força de preensão mostrou correlação inversa moderada com a idade. A combinação de paraplegia espástica de início precoce com

  11. Ressonância magnética na mielopatia associada ao HTLV-I: Leucoencefalopatia e atrofia medular Magnetic resonance in HTLV-I associated myelopathy: leukoencephalopathy and spinal cord atrophy

    Directory of Open Access Journals (Sweden)

    Ana Claudia Ferraz

    1997-01-01

    Full Text Available Lesões na substância branca cerebral e atrofia medular têm sido descritas em pacientes com mielopatia associada ao HTLV-I (MAH. A freqüência e a importância clínica destes achados ainda não são totalmente conhecidas. Vinte e nove pacientes foram estudados por ressonância magnética (RM do crânio e da coluna. Imagens com hipersinal em T2 na substância branca, de diâmetro igual ou superior a 3 mm foram consideradas anormais. O tamanho da medula foi avaliado usando índice por nós denominado "índice medular". Os achados neurorradiológicos foram correlacionados às características clínicas da mielopatia. Lesões na substância branca cerebral ocorreram em 52% dos pacientes e atrofia medular ocorreu em 74%. Não houve correlação entre os achados neurorradiológicos e as características clínicas estudadas. Os resultados sugerem que a RM é um método útil na detecção de anormalidades cerebrais e medulares em pacientes com MAH. As lesões de substância branca não apresentaram correlação com idade ou com fatores de risco cardiovascular e podem estar associadas à infecção pelo vírus HTLV-I.Cerebral white matter lesions and spinal cord atrophy have been frequently reported in patients with HTLV-I associated myelopathy (HAM. The exact frequency and the clinical relevance of these findings still remain to be elucidated. Twenty-nine patients with HAM were studied by magnetic resonance imaging of the brain and spine. Cerebral white matter lesions equal or over 3 mm in diameter were considered abnormal. The spinal cord size was evaluated using an index we have called "spinal cord index". The radiological findings were correlated to the clinical features of the myelopathy. Cerebral white matter lesions occurred in 52% of the patients, and spinal cord atrophy in 74%. There was no significant correlation between these abnormalities and the clinical features studied. These findings suggest that the resonance imaging is a useful

  12. Lipoenxertia autóloga no tratamento da atrofia hemifacial progressiva (síndrome de Parry-Romberg: relato de caso e revisão da literatura Autologous fat transplantation for the treatment of progressive hemifacial atrophy (Parry-Romberg syndrome: case report and review of medical literatute

    Directory of Open Access Journals (Sweden)

    Júlio César Garcia de Alencar

    2011-08-01

    Full Text Available A Síndrome de Parry-Romberg, também conhecida como atrofia hemifacial progressiva, é uma doença rara caracterizada por lenta e progressiva atrofia de hemiface. O tratamento ofertado para a síndrome, geralmente, visa melhorar o aspecto estético. Os enxertos gordurosos, as injeções de silicone ou as próteses de acrílico são alternativas sugeridas para correção da atrofia facial. Atualmente, a técnica recomendada para correção da atrofia facial é cirurgia dermatológica cosmética com lipoenxertia autóloga. O objetivo deste estudo é relatar um caso de SPR e demonstrar que a cirurgia dermatológica pode aliviar danos sérios à anatomia do paciente, a partir da discussão dos aspectos terapêuticos da síndrome, com ênfase na lipoenxertia autólogaParry-Romberg syndrome, also known as progressive hemifacial atrophy, is a rare disorder characterized by slow and progressive hemifacial atrophy. The treatment offered for the syndrome generally aims at improving aesthetics. Fat grafts, silicone injections or acrylic prosthesis are alternatives suggested for correction of facial atrophy. Currently, the recommended technique for correction of facial atrophy is cosmetic dermatologic surgery with autologous fat grafting. This study reports a case of Parry-Romberg syndrome and demonstrates that dermatologic surgery can relieve serious damage to the patient's anatomy, starting from the discussion of the therapeutic aspects of the syndrome with emphasis on autologous fat grafting

  13. Paradigm Shift in the Management of the Atrophic Posterior Maxilla

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    Rabah Nedir

    2014-01-01

    Full Text Available When the posterior maxilla is atrophic, the reference standard of care would be to perform sinus augmentation with an autologous bone graft through the lateral approach and delayed implant placement. However, placement of short implants with the osteotome sinus floor elevation technique and without graft can be proposed for an efficient treatment of clinical cases with a maxillary residual bone height of 4 to 8 mm. The use of grafting material is recommended only when the residual bone height is ≤4 mm. Indications of the lateral sinus floor elevation are limited to cases with a residual bone height ≤ 2 mm and fused corticals, uncompleted healing of the edentulous site, and absence of flat cortical bone crest or when the patient wishes to wear a removable prosthesis during the healing period. The presented case report illustrates osteotome sinus floor elevation with and without grafting and simultaneous implant placement in extreme conditions: atrophic maxilla, short implant placement, reduced healing time, and single crown rehabilitation. After 6 years, all placed implants were functional with an endosinus bone gain.

  14. Bone strains around apically free versus grafted implants in the posterior maxilla of human cadavers.

    Science.gov (United States)

    Cehreli, Murat Cavit; Akkocaoglu, Murat; Comert, Ayhan; Tekdemir, Ibrahim; Akca, Kivanc

    2007-04-01

    The objective of this study was to compare the bone strains of apically free versus grafted implants in the posterior maxilla. The experiments were undertaken in four edentulous maxillary posterior regions of fresh human cadavers, having a minimum bone height of 8 mm. In each bone fragment, two Ø 4.1 mm x 12 mm Straumann implants were placed, and insertion torque values (ITV) and implant stability quotients (ISQ) of the implants were quantified to determine implant anchorage. Two splinted crowns were fabricated for each experimental model. Strain gauges were bonded on the buccal and sinus floor cortical bones around apically free and grafted implants. Microstrains were recorded by a data acquisition system and corresponding software at a sample rate of 10 KHz under central and buccally oriented lateral-axial static loads of 100 and 150 N in separate cases. The data were compared by independent T test at a significance level set at PBone tissue strains on the buccal cortical areas adjacent to apically free implants were higher than those of apically grafted implants (Pbone around apically free and grafted implants (PBone strains around anterior implants were higher than those of posterior implants. Microstrains in the sinus floor cortical bone in apically grafted models were slightly higher than apically free models. Bone tissue strains on the buccal cortical areas adjacent to apicallyfree implants are higher than those of apically grafted implants. Sinus lifting, resulting in an enhanced apical support, slightly increases strains at the sinus floor region, but leads to a decrease in bone strains around the collar of supporting implants.

  15. Stress fracture in posterior aspect of the tibia

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Tae Yong; Jung, Hyun Woo; Park, Chung Hun [Pusan National Univ. College of Medicine, Pusan (Korea, Republic of); Chun, Kyung Ah [Catholic Univ Hospital, Pusan (Korea, Republic of); Koo, Bong Sig [Donga Univ. Hospital, Pusan (Korea, Republic of); Lee, Sang Yong [Chunbuk Natinoal Univ. Hospital, Chunju (Korea, Republic of)

    1999-01-01

    To determine correlation between stress fracture of the posterior tibia and flexor digitorum longus muscle injury caused by athletic or sporting activity during adolescence. Eleven cases diagnosed as stress fracture after X-ray and MR imaging of the lower leg were reviewed. With regard to each fracture, the following features were noted : age, sex, and athletic or sporting activity of the patient, and site. Using MR imaging techniques, axial and sagittal T1 and T2 weighted imaged were obtained in all cases and T1-Gd DTPA images in seven. The activities undertaken were running (n=3), football (n=2), ballet (n=2), taekwando (n=1), badminton (n=1), field hockey (n=1), and basketball (n=1). MR images revealed localized cortical thickness (n=11), linear intramedullary callus showing a low signal on T1 and T2 weighted images (n=9), marrow hyperemia (n=7), and flexor digitorum longus muscle injury showing a high signal on T1-Gd DTPA and T2 weighted image (n=7). Stress fracture of the posterior tibia might be induced by flexor digitorum longus muscle activity induced by athletic or sporting activities during adolescence.

  16. Angulated Dental Implants in Posterior Maxilla FEA and Experimental Verification

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    Hamed A. Hamed

    2018-02-01

    Full Text Available AIM: This study aimed to evaluate the effect of different implant angulations in posterior maxilla on stress distribution by finite element analysis and verify its results experimentally. METHODS: Two simplified models were prepared for an implant placed vertically and tilted 25° piercing the maxillary sinus. Geometric models' components were prepared by Autodesk Inventor then assembled in ANSYS for finite element analysis. The results of finite element analysis were verified against experimental trials results which were statistically analysed using student t-test (level of significance p < 0.05. RESULTS: Implant - abutment complex absorbed the load energy in case of vertical implant better than the case of angulated one. That was reflected on cortical bone stress, while both cases showed stress levels within the physiological limits. Comparing results between FEA and experiment trials showed full agreement. CONCLUSION: It was found that the tilted implant by 25° can be utilised in the posterior region maxilla for replacing maxillary first molar avoiding sinus penetration. The implant-bone interface and peri-implant bones received the highest Von Mises stress. Implant - bone interface with angulated implant received about 66% more stresses than the straight one.

  17. Neural correlates of superior intelligence: stronger recruitment of posterior parietal cortex.

    Science.gov (United States)

    Lee, Kun Ho; Choi, Yu Yong; Gray, Jeremy R; Cho, Sun Hee; Chae, Jeong-Ho; Lee, Seungheun; Kim, Kyungjin

    2006-01-15

    General intelligence (g) is a common factor in diverse cognitive abilities and a major influence on life outcomes. Neuroimaging studies in adults suggest that the lateral prefrontal and parietal cortices play a crucial role in related cognitive activities including fluid reasoning, the control of attention, and working memory. Here, we investigated the neural bases for intellectual giftedness (superior-g) in adolescents, using fMRI. The participants consisted of a superior-g group (n = 18, mean RAPM = 33.9 +/- 0.8, >99%) from the national academy for gifted adolescents and the control group (n = 18, mean RAPM = 22.8 +/- 1.6, 60%) from local high schools in Korea (mean age = 16.5 +/- 0.8). fMRI data were acquired while they performed two reasoning tasks with high and low g-loadings. In both groups, the high g-loaded tasks specifically increased regional activity in the bilateral fronto-parietal network including the lateral prefrontal, anterior cingulate, and posterior parietal cortices. However, the regional activations of the superior-g group were significantly stronger than those of the control group, especially in the posterior parietal cortex. Moreover, regression analysis revealed that activity of the superior and intraparietal cortices (BA 7/40) strongly covaried with individual differences in g (r = 0.71 to 0.81). A correlated vectors analysis implicated bilateral posterior parietal areas in g. These results suggest that superior-g may not be due to the recruitment of additional brain regions but to the functional facilitation of the fronto-parietal network particularly driven by the posterior parietal activation.

  18. Migraine with brainstem aura: Why not a cortical origin?

    Science.gov (United States)

    Demarquay, Geneviève; Ducros, Anne; Montavont, Alexandra; Mauguiere, François

    2017-01-01

    Background Migraine with brainstem aura is defined as a migraine with aura including at least two of the following symptoms: dysarthria, vertigo, tinnitus, hypacusis, diplopia, ataxia and/or decreased level of consciousness. Aim The aim of this study is to review data coming from clinical observations and functional mapping that support the role of the cerebral cortex in the initiation of brainstem aura symptoms. Results Vertigo can result from a vestibular cortex dysfunction, while tinnitus and hypacusis can originate within the auditory cortex. Diplopia can reflect a parieto-occipital involvement. Dysarthria can be caused by dysfunctions located in precentral gyri. Ataxia can reflect abnormal processing of vestibular, sensory, or visual inputs by the parietal lobe. Alteration of consciousness can be caused by abnormal neural activation within specific consciousness networks that include prefrontal and posterior parietal cortices. Conclusion Any symptom of so-called brainstem aura can originate within the cortex. Based on these data, we suggest that brainstem aura could have a cortical origin. This hypothesis would explain the co-occurrence of typical and brainstem aura during attacks and would fit with the theory of cortical spreading depression. We propose that migraine with brainstem aura should be classified as a typical migraine aura.

  19. Cortical Correlates of Fitts’ Law

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    Peter eIfft

    2011-12-01

    Full Text Available Fitts' law describes the fundamental trade-off between movement accuracy and speed: It states that the duration of reaching movements is a function of target size and distance. While Fitts' law has been extensively studied in ergonomics and has guided the design of human-computer interfaces, there have been few studies on its neuronal correlates. To elucidate sensorimotor cortical activity underlying Fitts’ law, we implanted two monkeys with multielectrode arrays in the primary motor (M1 and primary somatosensory (S1 cortices. The monkeys performed reaches with a joystick-controlled cursor towards targets of different size. The reaction time, movement time and movement velocity changed with target size, and M1 and S1 activity reflected these changes. Moreover, modifications of cortical activity could not be explained by changes of movement parameters alone, but required target size as an additional parameter. Neuronal representation of target size was especially prominent during the early reaction time period where it influenced the slope of the firing rate rise preceding movement initiation. During the movement period, cortical activity was mostly correlated with movement velocity. Neural decoders were applied to simultaneously decode target size and motor parameters from cortical modulations. We suggest using such classifiers to improve neuroprosthetic control.

  20. Heterogeneous and nonlinear development of human posterior parietal cortex function.

    Science.gov (United States)

    Chang, Ting-Ting; Metcalfe, Arron W S; Padmanabhan, Aarthi; Chen, Tianwen; Menon, Vinod

    2016-02-01

    Human cognitive problem solving skills undergo complex experience-dependent changes from childhood to adulthood, yet most neurodevelopmental research has focused on linear changes with age. Here we challenge this limited view, and investigate spatially heterogeneous and nonlinear neurodevelopmental profiles between childhood, adolescence, and young adulthood, focusing on three cytoarchitectonically distinct posterior parietal cortex (PPC) regions implicated in numerical problem solving: intraparietal sulcus (IPS), angular gyrus (AG), and supramarginal gyrus (SMG). Adolescents demonstrated better behavioral performance relative to children, but their performance was equivalent to that of adults. However, all three groups differed significantly in their profile of activation and connectivity across the PPC subdivisions. Activation in bilateral ventral IPS subdivision IPS-hIP1, along with adjoining anterior AG subdivision, AG-PGa, and the posterior SMG subdivision, SMG-PFm, increased linearly with age, whereas the posterior AG subdivision, AG-PGp, was equally deactivated in all three groups. In contrast, the left anterior SMG subdivision, SMG-PF, showed an inverted U-shaped profile across age groups such that adolescents exhibited greater activation than both children and young adults. Critically, greater SMG-PF activation was correlated with task performance only in adolescents. Furthermore, adolescents showed greater task-related functional connectivity of the SMG-PF with ventro-temporal, anterior temporal and prefrontal cortices, relative to both children and adults. These results suggest that nonlinear up-regulation of SMG-PF and its interconnected functional circuits facilitate adult-level performance in adolescents. Our study provides novel insights into heterogeneous age-related maturation of the PPC underlying cognitive skill acquisition, and further demonstrates how anatomically precise analysis of both linear and nonlinear neurofunctional changes with age is

  1. Posterior ankle impingement in the dancer.

    Science.gov (United States)

    Moser, Brad R

    2011-01-01

    Dancers spend a lot of time in the relevé position in demi-pointe and en pointe in their training and their careers. Pain from both osseous and soft tissue causes may start to occur in the posterior aspect of their ankle. This article reviews the potential causes of posterior ankle impingement in dancers. It will discuss the clinical evaluation of a dancer and the appropriate workup and radiographic studies needed to further evaluate a dancer with suspected posterior ankle impingement.

  2. Imaging of the Posterior Skull Base.

    Science.gov (United States)

    Job, Joici; Branstetter, Barton F

    2017-01-01

    The posterior skull base can be involved by a variety of pathologic processes. They can be broadly classified as: traumatic, neoplastic, vascular, and inflammatory. Pathology in the posterior skull base usually involves the lower cranial nerves, either as a source of pathology or a secondary source of symptoms. This review will categorize pathology arising in the posterior skull base and describe how it affects the skull base itself and surrounding structures. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Cognitive function, P3a/P3b brain potentials, and cortical thickness in aging.

    Science.gov (United States)

    Fjell, Anders M; Walhovd, Kristine B; Fischl, Bruce; Reinvang, Ivar

    2007-11-01

    The purpose of the study was to assess the relationship between the P3a/P3b brain potentials, cortical thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy participants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire cortical mantle. In the young, thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to cortical thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that cortical thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional cortical thickness and P3 remained. It is concluded that thickness in specific cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function. Copyright 2007 Wiley-Liss, Inc.

  4. A Quantitative Electroencephalography Study on Cochlear Implant-Induced Cortical Changes in Single-Sided Deafness with Tinnitus

    Directory of Open Access Journals (Sweden)

    Jae-Jin Song

    2017-05-01

    Full Text Available The mechanism of tinnitus suppression after cochlear implantation (CI in single-sided deafness (SSD is not fully understood. In this regard, by comparing pre- and post-CI quantitative electroencephalography (qEEG, we explored cortical changes relevant to tinnitus improvement. In SSD patients who underwent CI, qEEG data were collected: (1 before CI, (2 6 months post-operatively with CI-on, and (3 30 min after CI-off and source-localized cortical activity/functional connectivity analyses were performed. Compared to the pre-operative baseline, the CI-on condition demonstrated significantly decreased activity in the right auditory- and orbitofrontal cortices (OFC for the delta frequency band as well as decreased connectivity between the auditory cortex/posterior cingulate cortex for the delta/beta2 bands. Meanwhile, compared to the CI-off condition, the CI-on condition displayed decreased activity in the right auditory cortices/OFC for the delta band, and in bilateral auditory cortices, left inferior frontal cortex/OFC for the gamma band. However, qEEG analyses showed no significant differences between the CI-off and baseline conditions. CI induced overall decreased cortical activity and functional connectivity. However, judging from no differences between the CI-off and baseline conditions, CI-induced cortical activity and functional connectivity changes are not by cortical plastic changes, but by dynamic peripheral reafferentation.

  5. Unexpected ruptured aneurysm during posterior fossa surgery.

    Science.gov (United States)

    Chenin, L; Capel, C; N'Da, H; Lefranc, M; Peltier, J

    2014-10-01

    Surgery is the recommended treatment for unique significant cerebellar metastasis, particularly in cases of hydrocephalus. Complications of posterior fossa surgery are associated with high risk of morbidity and mortality. We present a unique case of unexpected peroperative rupture of a cerebellar superior artery aneurysm during posterior fossa surgery. During posterior cranial fossa surgery, severe arterial bleeding occurred in front of the medulla oblongata. Immediate postoperative computed tomographic (CT) angiography revealed a fusiform aneurysm from a distal branch of the left superior cerebellar artery. To our knowledge, this is the first reported operative case of unexpected infratentorial ruptured aneurysm during posterior fossa surgery. Copyright © 2014. Published by Elsevier Masson SAS.

  6. Pterygoid implant for atrophic posterior maxilla

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    V R Balaji

    2017-01-01

    Full Text Available Replacement of missing teeth in the posterior maxilla is always a challenge for the treating implant surgeon as the posterior maxilla has several obstacles in the form of quality, quantity, the anatomy of the maxillary sinus, and inaccessibility. To overcome these deficiencies, several surgical procedures such as sinus lift, bone augmentation, tilted implants, short implants, and zygomatic implants were tried. Since these procedures have their own limitations, pterygomaxillary region provides us an excellent place for placement of implant and rehabilitation of posterior maxilla. This case report describes the usage of the pterygomaxillary region for placement of the implant to restore atrophic posterior maxilla, without any additional surgical procedures.

  7. Posterior reference guides do not always maintain the size of posterior femoral condyles in TKA.

    Science.gov (United States)

    Minoda, Yukihide; Mizokawa, Shigekazu; Ohta, Yoichi; Ikebuchi, Mitsuhiko; Itokazu, Maki; Yamamura, Kazumasa; Nakamura, Suguru; Nakamura, Hiroaki

    2016-08-01

    Posterior reference guides are provided by many manufacturers. However, the true posterior femoral condyle bone resection thicknesses using posterior reference guides are not stated by the manufacturers. The purpose of this study was to analyse the influence of the posterior reference guide designs on the posterior femoral condyle bone resection thickness. Thickness of posterior femoral condyle bone resection and thickness of prostheses were investigated in 8 types of total knee prostheses using the production drawings provided by the manufacturers. Posterior femoral condyle bone resection thickness differed between prostheses. Change in size of the medial posterior condyle ranged from -0.5 to 1.4 mm at 0° external rotation, from -2.9 to 1.4 mm at 3° external rotation, and from -5.3 to 1.4 mm at 6° external rotation. Change in size of lateral posterior condyle ranged from -0.5 to 1.4 mm at 0° external rotation, from -0.4 to 3.4 mm at 3° external rotation, and from -0.4 to 5.3 mm at 6° external rotation. This study showed that posterior femoral condyle bone resection thickness was different for each posterior reference guide. The rotation centre of posterior reference guides influenced the bone resection thickness in the posterior femoral condyle. The size of the posterior femoral condyles increased in some guides but decreased in other guides. The maximum differences in size changes of the posterior femoral condyles between the guides were 1.9 mm at 0° external rotation, 4.1 mm at 3° external rotation, and 6.3 mm at 6° external rotation. To control the size of posterior femoral condyles, the posterior reference guide design should be checked before use.

  8. Posterior acetabular arc angle of unstable posterior hip fracture-dislocation.

    Science.gov (United States)

    Harnroongroj, Thos; Riansuwan, Kongkhet; Sudjai, Narumol; Harnroongroj, Thossart

    2013-12-01

    Posterior hip fracture-dislocation needs stability evaluation. A previous study in the normal acetabulum has shown that the coronal posterior acetabular arc angle (PAAA) could be used to assess an unstable posterior hip fracture. Our study was designed to assess PAAA of unstable posterior hip fracture-dislocation and whether posterior acetabular wall fracture involves the superior acetabular dome. Using coronal computed tomography (CT) of the acetabulum and 3D reconstruction of the lateral pelvis, we measured coronal, vertical PAAA and posterior acetabular wall depth of 21 unstable posterior hip fracture-dislocations and of 50% normal contralateral acetabula. Posterior acetabular wall fracture was assessed to determine whether the fracture involved the superior acetabular dome and then defined as a high or low wall fracture using vertical PAAA in reference to the centroacetabulo-greater sciatic notch line. The coronal PAAA of unstable posterior hip fracture-dislocations and of 50% of the posterior acetabular wall of normal the contralateral acetabulum were 54.48° (9.09°) and 57.43° (5.88°) and corresponded to 15.06 (4.39) and 15.61 (2.01) mm of the posterior acetabular wall without significant difference (p > 0.05). The vertical PAAA of unstable posterior hip fracture-dislocation was 101.67° (20.44°). There were 16 high posterior acetabular wall fractures with 35.00 (16.18) vertical PAAA involving the acetabular dome and 5 low wall fractures. High posterior wall fractures resulted in four avascular necroses of the femoral head, three sciatic nerve injuries and one osteoarthritic hip. Coronal and vertical PAAA of unstable posterior hip fracture-dislocations were 54.48° and 101.67°. Vertical PAAA assesses high or low posterior acetabular wall fracture by referring to the centroacetabulo-greater sciatic notch line. High posterior wall fracture seems to be the most frequent and is involved with many complications.

  9. Lateralized occipital degeneration in posterior cortical atrophy predicts visual field deficits

    Directory of Open Access Journals (Sweden)

    Rebecca S Millington

    2017-01-01

    Conclusions: Detailed brain imaging shows that the asymmetric visual field deficits in patients with PCA reflect the pattern of degeneration of both white and gray matter in the occipital lobe. Understanding the nature of both visual field deficits and the neurodegenerative brain changes in PCA may improve diagnosis and understanding of this disease.

  10. Paroxysmal kinesigenic dyskinesia : Cortical or non-cortical origin

    NARCIS (Netherlands)

    van Strien, Teun W.; van Rootselaar, Anne-Fleur; Hilgevoord, Anthony A. J.; Linssen, Wim H. J. P.; Groffen, Alexander J. A.; Tijssen, Marina A. J.

    Paroxysmal kinesigenic dyskinesia (PKD) is characterized by involuntary dystonia and/or chorea triggered by a sudden movement. Cases are usually familial with an autosomal dominant inheritance. Hypotheses regarding the pathogenesis of PKD focus on the controversy whether PKD has a cortical or

  11. History of migraine with aura and cortical spreading depression from 1941 and onwards

    DEFF Research Database (Denmark)

    Tfelt-Hansen, P C

    2010-01-01

    Several personal descriptions of migraine with aura from 1870 onwards reported a slow, gradual progression of symptoms. Lashley in 1941 meticulously chartered his own auras and concluded that the symptomatology reflected a cortical process progressing with a speed of 3 mm/min across the primary...... visual cortex. Leão described cortical spreading depression (CSD) in rabbits in 1944 and noticed its similarity to the migraine aura. Despite these scattered pieces of evidence, the prevailing theory was that the migraine aura was caused by a vasospasm and cortical ischaemia. The advent of a technique...... for measurements of regional cerebral blood flow (rCBF) in 1974 made it possible to detect spreading oligaemia during migraine aura. Between 1981 and 1990 a series of studies of rCBF during migraine attacks showed reduced brain blood flow posteriorly spreading slowly and contiguously anteriorly and crossing...

  12. Personality functioning and the cortical midline structures--an exploratory FMRI study.

    Directory of Open Access Journals (Sweden)

    Stephan Doering

    Full Text Available OBJECTIVE: Recent neuroscience studies explored the neuronal mechanisms underlying our sense of self. Thereby the cortical midline structures and their anterior and posterior regions have been shown to be central. What remains unclear though is how both, self and cortical midline structures, are related to the identity of the self which is of central importance in especially personality disorders. METHODS: Conducting an exploratory study with a dimensional approach, we here compared subjects with high and low level of personality functioning and identity integration as measured in a standardized way in fMRI during both, emotion- and reward-related tasks. RESULTS: Low levels of personality functioning and identity integration were predicted by significantly decreased degrees of deactivation in the anterior and posterior cortical midline structures. CONCLUSIONS: Though exploratory our results show for the first time direct relationship between cortical midline structures and personality functioning in terms of identity integration. This does not only contribute to our understanding of the neuronal mechanism underlying self and identity but carries also major implications for the treatment of patients with personality disorders.

  13. Cerebellar Asymmetry and Cortical Connectivity in Monozygotic Twins with Discordant Handedness.

    Science.gov (United States)

    Rosch, R E; Cowell, P E; Gurd, J M

    2017-10-23

    Handedness differentiates patterns of neural asymmetry and interhemispheric connectivity in cortical systems that underpin manual and language functions. Contemporary models of cerebellar function incorporate complex motor behaviour and higher-order cognition, expanding upon earlier, traditional associations between the cerebellum and motor control. Structural MRI defined cerebellar volume asymmetries and correlations with corpus callosum (CC) size were compared in 19 pairs of adult female monozygotic twins strongly discordant for handedness (MZHd). Volume and asymmetry of cerebellar lobules were obtained using automated parcellation.CC area and regional widths were obtained from midsagittal planimetric measurements. Within the cerebellum and CC, neurofunctional distinctions were drawn between motor and higher-order cognitive systems. Relationships amongst regional cerebellar asymmetry and cortical connectivity (as indicated by CC widths) were investigated. Interactions between hemisphere and handedness in the anterior cerebellum were due to a larger right-greater-than-left hemispheric asymmetry in right-handed (RH) compared to left-handed (LH) twins. In LH twins only, anterior cerebellar lobule volumes (IV, V) for motor control were associated with CC size, particularly in callosal regions associated with motor cortex connectivity. Superior posterior cerebellar lobule volumes (VI, Crus I, Crus II, VIIb) showed no correlation with CC size in either handedness group. These novel results reflected distinct patterns of cerebellar-cortical relationships delineated by specific CC regions and an anterior-posterior cerebellar topographical mapping. Hence, anterior cerebellar asymmetry may contribute to the greater degree of bilateral cortical organisation of frontal motor function in LH individuals.

  14. Poor receptive joint attention skills are associated with atypical gray matter asymmetry in the posterior superior temporal gyrus of chimpanzees (Pan troglodytes)

    DEFF Research Database (Denmark)

    Hopkins, William D; Misiura, Maria; Reamer, Lisa A

    2014-01-01

    Clinical and experimental data have implicated the posterior superior temporal gyrus as an important cortical region in the processing of socially relevant stimuli such as gaze following, eye direction, and head orientation. Gaze following and responding to different socio-communicative signals i...

  15. Cortical deafness in multiple sclerosis

    OpenAIRE

    Tabira, T; Tsuji, S; Nagashima, T.; Nakajima, T.; Kuroiwa, Y

    1981-01-01

    Cortical deafness in a patient with multiple sclerosis is reported. Complete recovery from total deafness was seen following stages of auditory agnosia and pure word deafness. The otological and neurophysiological studies suggested lesions in subcortical white matter. This report stresses the rarity of the condition, its subcortical origin and good prognosis.

  16. Posterior Surgical Approach to Tuberculous Spondylitis | Shehu ...

    African Journals Online (AJOL)

    They both had power of 4/5 at the time they defaulted. Conclusion: Foraminotomy with or without discectomy is a simple posterior surgical approach to T B spine with good neurological outcome. It is adapted to our environment because no fusion or implant is required. Key words: Tuberculosis, Spondylitis, Posterior ...

  17. Dynamic tensile material properties of human pelvic cortical bone.

    Science.gov (United States)

    Kemper, Andrew R; McNally, Craig; Duma, Stefan M

    2008-01-01

    IIn order for finite element models of the human body to predict pelvic injuries accurately, the appropriate material properties must be applied. Therefore, the purpose of this study was to quantify the dynamic material properties of human pelvic cortical bone in tension. In order to accomplish this, a total of 20 tension coupon specimens were obtained from four regions of four human cadaver pelves: anterior ilium wing, posterior ilium wing, superior pubic ramus, and ischium body. For the anterior and posterior regions of the ilium wing, samples were taken in two orientations to investigate any direction dependence. A high-rate servo-hydraulic Material Testing System (MTS) with a custom slack adaptor was used to apply tension loads to failure at a constant loading rate of 0.5 strains/s. The horizontally oriented anterior ilium specimens were found to have a significantly larger ultimate stress (p=0.02), ultimate strain (p>0.01), and modulus (p=0.02) than the vertically oriented anterior ilium specimens. There were no significant differences in ultimate stress (p=0.27), ultimate strain (p=0.85), or modulus (p=0.87) found between horizontally oriented and vertically oriented posterior ilium specimens. However, additional testing should be conducted at specimen orientation 45 degree from the orientations used in the current study to further investigate the effect of specimen orientation on the posterior portion of the ilium wing. There were no significant differences in ultimate stress (p=0.79), ultimate strain (p=0.31), or modulus (p=0.15) found between the superior pubic ramus and ischium body specimens. However, the statistical comparison between superior pubic ramus and ischium body specimens was considered weak due to the limited samples and large variation between subjects.

  18. Automated cortical bone segmentation for multirow-detector CT imaging with validation and application to human studies.

    Science.gov (United States)

    Li, Cheng; Jin, Dakai; Chen, Cheng; Letuchy, Elena M; Janz, Kathleen F; Burns, Trudy L; Torner, James C; Levy, Steven M; Saha, Punam K

    2015-08-01

    thicker cortex (mean difference 0.33 mm and effect size 0.92 at the anterior region) with lower bone mineral density (mean difference -28.73 mg/cm(3) and effect size 1.35 at the posterior region) as compared to females. The algorithm presented is suitable for fully automated segmentation of cortical bone in MD-CT imaging of the distal tibia with high accuracy and reproducibility. Analysis of data from a pilot study demonstrated that the cortical bone indices allow quantification of gender differences in cortical bone from MD-CT imaging. Application to larger population groups, including those with compromised bone, is needed.

  19. Monte Carlo analysis of skew posterior distributions: an econometric example

    OpenAIRE

    Dijk, Herman; Kloek, Teun

    1983-01-01

    textabstractThe posterior distribution of a small-scale illustrative econometric model is used to compare symmetric simple importance sampling with asymmetric simple importance sampling. The numerical results include posterior first and second order moments, numerical error estimates of the first order moments, posterior modes, univariate marginal posterior densities and bivariate marginal posterior densities plotted in three-dimensional figures.

  20. Associations of the cortisol awakening response (CAR) with cortical activation asymmetry during the course of an exam stress period.

    Science.gov (United States)

    Hewig, Johannes; Schlotz, Wolff; Gerhards, Friedemann; Breitenstein, Caterina; Lürken, Alexander; Naumann, Ewald

    2008-01-01

    The cortisol awakening response (CAR) is a cortisol rise which is distinct from the circadian rise in hypothalamus-pituitary-adrenal (HPA) axis activity before awakening. The CAR has been shown to be related to experiences of stress and negative affect, and activation of neocortical networks has been suggested as a mechanism. Right-sided cortical activation has been shown to be correlated with negative affect, and an association of electroencephalogram (EEG) asymmetry measures with cortisol secretion has been demonstrated. Therefore, we investigated for associations of the CAR with lateralised trait-like cortical activation and with changes in EEG asymmetry during a putative stressful period. We examined 37 undergraduate students before, during, and after an academic exam period. CARs were measured five times and EEG was measured both about 6 weeks before the beginning of the exams and 1 day before an exam. Trait-like interindividual differences in posterior cortical asymmetry were differentially associated with CARs at different measurement occasions. Participants with greater right centroparietal cortical trait activation showed an increased CAR in anticipation of the exams, whereas all other participants showed an increased CAR in response to the exams. Furthermore, EEG measures taken directly before the exam revealed that greater right frontal cortical activation was related to higher cortisol levels after awakening. The results suggest that lateralised cortical activation moderates CAR changes during the course of a stressful period. Lateralised cortical activation may be an important link between the CAR and health-related variables like experiences of stress and negative affect.

  1. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. Copyright © 2016, American Association for the Advancement of Science.

  2. Central-Variant Posterior Reversible Encephalopathy due to Sulfasalazine: A Case Report.

    Science.gov (United States)

    Ocek, Levent; Sener, Ufuk; Demirtas, Burcu S; Ozcelik, Metin M; Oztekin, Ozgur; Zorlu, Yasar

    2015-01-01

    To report a rare case with central-variant posterior reversible encephalopathy syndrome due to sulfasalazine. A 55-year-old female patient presented with seizure and acute-onset hemiparesia. Thirty days earlier, treatment with sulfasalazine was commenced in response to a diagnosis of psoriatic arthritis. Laboratory examinations were normal. Brain magnetic resonance imaging showed symmetric edema within basal ganglia and thalami with sparing of the cerebral cortices. After stopping the treatment of sulfasalazine, clinical and radiological findings regressed dramatically. This was a case of central-variant posterior reversible encephalopathy syndrome due to sulfasalazine, and atypical imaging findings should be kept in mind for early diagnosis. © 2015 S. Karger AG, Basel.

  3. Managing the posterior polar cataract: An update

    Directory of Open Access Journals (Sweden)

    Abhay R Vasavada

    2017-01-01

    Full Text Available Posterior polar cataracts (PPC have always been a challenge for cataract surgeons due to their inherently higher propensity for posterior capsule rupture. Over the years, several technical modifications have been suggested to enhance safety and reduce posterior capsule rupture rates in these polar cataracts. This review article tries to present the various techniques and strategies to published in literature to manage PPCs. It also discusses pearls for making surgery more reproducible and consistent, as well as the role of newer diagnostic and surgical technology based on the published literature on the subject.

  4. Mapping of cortical activity in the first two decades of life: a high-density sleep electroencephalogram study.

    Science.gov (United States)

    Kurth, Salomé; Ringli, Maya; Geiger, Anja; LeBourgeois, Monique; Jenni, Oskar G; Huber, Reto

    2010-10-06

    Evidence that electroencephalography (EEG) slow-wave activity (SWA) (EEG spectral power in the 1-4.5 Hz band) during non-rapid eye movement sleep (NREM) reflects plastic changes is increasing (Tononi and Cirelli, 2006). Regional assessment of gray matter development from neuroimaging studies reveals a posteroanterior trajectory of cortical maturation in the first three decades of life (Shaw et al., 2008). Our aim was to test whether this regional cortical maturation is reflected in regional changes of sleep SWA. We evaluated all-night high-density EEG (128 channels) in 55 healthy human subjects (2.4-19.4 years) and assessed age-related changes in NREM sleep topography. As in adults, we observed frequency-specific topographical distributions of sleep EEG power in all subjects. However, from early childhood to late adolescence, the location on the scalp showing maximal SWA underwent a shift from posterior to anterior regions. This shift along the posteroanterior axis was only present in the SWA frequency range and remained stable across the night. Changes in the topography of SWA during sleep parallel neuroimaging study findings indicating cortical maturation starts early in posterior areas and spreads rostrally over the frontal cortex. Thus, SWA might reflect the underlying processes of cortical maturation. In the future, sleep SWA assessments may be used as a clinical tool to detect aberrations in cortical maturation.

  5. Autism as a neural systems disorder: A theory of frontal-posterior underconnectivity

    Science.gov (United States)

    Just, Marcel Adam; Keller, Timothy A.; Malave, Vicente L.; Kana, Rajesh K.; Varma, Sashank

    2012-01-01

    The underconnectivity theory of autism attributes the disorder to lower anatomical and functional systems connectivity between frontal and more posterior cortical processing. Here we review evidence for the theory and present a computational model of an executive functioning task (Tower of London) implementing the assumptions of underconnectivity. We make two modifications to a previous computational account of performance and brain activity in typical individuals in the Tower of London task (Newman et al., 2003): (1) the communication bandwidth between frontal and parietal areas was decreased and (2) the posterior centers were endowed with more executive capability (i.e., more autonomy, an adaptation is proposed to arise in response to the lowered frontal-posterior bandwidth). The autism model succeeds in matching the lower frontal-posterior functional connectivity (lower synchronization of activation) seen in fMRI data, as well as providing insight into behavioral response time results. The theory provides a unified account of how a neural dysfunction can produce a neural systems disorder and a psychological disorder with the widespread and diverse symptoms of autism. PMID:22353426

  6. Convergence of posteriors for discretized log Gaussian Cox processes

    DEFF Research Database (Denmark)

    Waagepetersen, Rasmus Plenge

    2004-01-01

    In Markov chain Monte Carlo posterior computation for log Gaussian Cox processes (LGCPs) a discretization of the continuously indexed Gaussian field is required. It is demonstrated that approximate posterior expectations computed from discretized LGCPs converge to the exact posterior expectations...

  7. Posterior alien hand syndrome: case report

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, S.; Weidauer, S.; Lanfermann, H.; Zanella, F. [Institute of Neuroradiology, Johann Wolfgang Goethe University, Schleusenweg 2-16, 60528 Frankfurt am Main (Germany)

    2002-11-01

    The alien hand syndrome (AHS) is involuntary uncontrolled movement of an arm with a sense of estrangement from the limb itself. AHS was initially used to describe interhemispheric disconnection phenomena in patients with lesions in the anterior corpus callosum, but it has been found in patients with posterior cerebral lesions without involvement of the corpus callosum, for example parietal infarcts or corticobasal degeneration. The posterior alien hand syndrome is less frequent and presents with nonpurposive behaviour like lifting the arm or writhing fingers. We report an 80-year-old woman with a posterior AHS of the dominant right hand. MRI showed atrophy of the pre- and postcentral gyri without involvement of the corpus callosum. We discuss the aetiology of the posterior AHS and the differences from the anterior varieties. (orig.)

  8. Posterior Urethral Valves with Severe Unilateral Vesicoureteral ...

    African Journals Online (AJOL)

    2004-08-10

    Aug 10, 2004 ... urinary catheter drainage, with no pedal oedema. There ... In patients with posterior urethral valves (PUV), severe unilateral vesicoureteral reflux (VUR) is one ... evaluation of urinary tract infection (UTI), voiding dysfunction, or ...

  9. Posterior reversible leukoencephalopathy syndrome after kratom ingestion.

    Science.gov (United States)

    Castillo, Austin; Payne, J Drew; Nugent, Kenneth

    2017-07-01

    Posterior reversible encephalopathy syndrome has been associated with hypertension, preeclampsia, cancer chemotherapy, and drugs of abuse, such as amphetamine and methamphetamine. We report a young man who suddenly developed severe headache, disorientation, and aphasia following ingestion of kratom and Adderall. Computed tomography and magnetic resonance imaging of his head revealed foci of vasogenic edema in the posterior occipital lobes, frontal lobes, and brainstem. In addition, he had a small area of hemorrhage in the left posterior occipital lobe. Lumbar puncture revealed an increased number of red blood cells but no other abnormalities. His initial blood pressure was elevated but returned to normal during hospitalization. This case suggests that kratom can cause posterior reversible encephalopathy syndrome and needs to be considered when patients present to emergency centers with headaches, confusion, and visual disturbances.

  10. Posterior reversible encephalopathy syndrome: Some novel ...

    African Journals Online (AJOL)

    transient and reversible neurological disorder clinically characterised by headache, seizures, blindness and altered consciousness associated with radiological ... presented with transient encephalopathy following blood transfusion but involving the anterior brain rather than the posterior part classically described in PRES.

  11. Posterior Fossa Tumors and Intellectual Impairment

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2005-01-01

    Full Text Available The effect of cerebellar damage on intellectual function in 76 children treated surgically for malignant posterior fossa tumor was investigated at the Gustave Roussy Institute, Villejuif, and the Department of Pediatric Neurosurgery, Necker Hospital, Paris, France.

  12. Concordancia entre los hallazgos citológicos de ASC-US en atrofia y metaplasia con la biopsia en el laboratorio de Patología de Clínica Colsanitas S.A. durante los años 2009 a 2012

    OpenAIRE

    Posada Restrepo, Alejandro

    2015-01-01

    Introducción: La categoría atipia de células escamosas de significado indeterminado (ASC-US) en la terminología Bethesda plantea un reto para el citólogo(a)/patólogo(a), necesitándose una estrecha correlación con otras herramientas diagnósticas para lograr un diagnóstico preciso y un tratamiento adecuado. Se puede observar ASC-US en extendidos con atrofia y metaplasia que dificultan la interpretación, haciéndose necesario otros métodos como la biopsia cervical para acercarnos al diagnóstico p...

  13. Evidence for cortical structural plasticity in humans after a day of waking and sleep deprivation.

    Science.gov (United States)

    Elvsåshagen, Torbjørn; Zak, Nathalia; Norbom, Linn B; Pedersen, Per Ø; Quraishi, Sophia H; Bjørnerud, Atle; Alnæs, Dag; Doan, Nhat Trung; Malt, Ulrik F; Groote, Inge R; Westlye, Lars T

    2017-08-01

    Sleep is an evolutionarily conserved process required for human health and functioning. Insufficient sleep causes impairments across cognitive domains, and sleep deprivation can have rapid antidepressive effects in mood disorders. However, the neurobiological effects of waking and sleep are not well understood. Recently, animal studies indicated that waking and sleep are associated with substantial cortical structural plasticity. Here, we hypothesized that structural plasticity can be observed after a day of waking and sleep deprivation in the human cerebral cortex. To test this hypothesis, 61 healthy adult males underwent structural magnetic resonance imaging (MRI) at three time points: in the morning after a regular night's sleep, the evening of the same day, and the next morning, either after total sleep deprivation (N=41) or a night of sleep (N=20). We found significantly increased right prefrontal cortical thickness from morning to evening across all participants. In addition, pairwise comparisons in the deprived group between the two morning scans showed significant thinning of mainly bilateral medial parietal cortices after 23h of sleep deprivation, including the precuneus and posterior cingulate cortex. However, there were no significant group (sleep vs. sleep deprived group) by time interactions and we can therefore not rule out that other mechanisms than sleep deprivation per se underlie the bilateral medial parietal cortical thinning observed in the deprived group. Nonetheless, these cortices are thought to subserve wakefulness, are among the brain regions with highest metabolic rate during wake, and are considered some of the most sensitive cortical regions to a variety of insults. Furthermore, greater thinning within the left medial parietal cluster was associated with increased sleepiness after sleep deprivation. Together, these findings add to a growing body of data showing rapid structural plasticity within the human cerebral cortex detectable with

  14. Posterior Decentering of the Humeral Head on Shoulder MR Arthrography: Significant Association With Posterior Synovial Proliferation.

    Science.gov (United States)

    Yun, Gabin; Kang, Yusuhn; Ahn, Joong Mo; Lee, Eugene; Lee, Joon Woo; Oh, Joo Han; Kang, Heung Sik

    2017-06-01

    The purpose of this study is to analyze MRI findings associated with posterior decentering of the humeral head on shoulder MR arthrogram. A total of 255 MR arthrograms were obtained during a 10-month period. MR arthrograms in patients with posterior decentering of the humeral head (n = 33) were reviewed and compared with those of randomly selected control group without posterior decentering (n = 66). MR arthrograms were retrospectively evaluated by two observers for posterior factors (posterior synovial proliferation, posterior capsular thickening, and posterior labral abnormality), rotator cuff factors related to fatty degeneration, glenoid version, and anterior factors (subcoracoid bursa effusion and rotator interval tear). The chi-square test, Fisher exact test, and linear-by-linear association were used for comparison of categoric data; the t test was used for comparison of the glenoid version; and multivariate stepwise logistic regression analysis was performed. At univariate analysis, posterior synovial proliferation (27.3% [9/33] in the posterior decentering group vs 6.1% [4/66] in the control group; p = 0.003); posterior capsule thickening (21.2% [7/33] vs 0.0% [0/66]; p < 0.001); fatty infiltration of the supraspinatus, infraspinatus, and teres minor (linear-by-linear association values, 7.944, 10.496, and 5.985, respectively; p = 0.005, 0.001, and 0.014, respectively); and rotator interval tear (51.5% [17/33] vs 30.3% [20/66]; p < 0.04) were more frequently found in the posterior decentering group, with a statistically significant difference. At multivariate analysis, only the posterior synovial proliferation was significantly associated with posterior decentering of the humeral head (odds ratio, 7.675; 95% CI, 2.159-27.288). Posterior decentering of the humeral head is most significantly associated with posterior synovial proliferation. In addition, rotator cuff interval abnormalities and rotator cuff atrophy are associated with posterior decentering of

  15. Posterior fossa syndrome—a narrative review

    OpenAIRE

    Wahab, Salima S.; Hettige, Samantha; Mankad, Kshtij; Aquilina, Kristian

    2016-01-01

    Posterior fossa syndrome (PFS), or cerebellar mutism syndrome (CMS), is a collection of neurological symptoms that occur following surgical resection of a posterior fossa tumour, and is characterised by either a reduction or an absence of speech. Some authors suggest that CM is only one symptom of the CMS complex that also includes ataxia, hypotonia and irritability as well as cranial nerve deficits, neurobehavioral changes and urinary retention or incontinence. It is seen almost exclusively ...

  16. Luxación posterior de hombro

    OpenAIRE

    Matson-Carballo Gustavo; Ramírez-Castro Jéssica Lorena

    2013-01-01

    Introduction: posterior shoulder dislocation is an infrequent pathology that is associated to electroshocks, convulsions and trauma in flexion and adduction of the superior extremities. Due to its clinical signs are slightly evident, it could be overlooked and become chronic. It might be accompanied of fractures of the proximal humerus. Clinical case: 39 years-of-age patient who consulted to the emergency service for presenting signs of posterior shoulder dislocation, without p...

  17. Posterior atlantoaxial dislocation without associated fracture

    Energy Technology Data Exchange (ETDEWEB)

    Sud, S.; Chaturvedi, S.; Buxi, T.B.S. [Department of CT and MRI, Sir Ganga Ram Hospital, Old Rajender Nagar, New Delhi - 110060 (India); Singh, S. [Department of Neurosurgery, Sir Ganga Ram Hospital, New Delhi (India)

    2002-09-01

    We report on a 38-year-old man with post-traumatic posterior displacement of the atlas with respect to the axis without any associated fracture or neurological deficit caused by the displacement. Radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) revealed posterior displacement of the atlas with the odontoid peg lying anterior and to the right of the anterior arch of the atlas. (orig.)

  18. Posterior atlantoaxial dislocation without odontoid fracture

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, Reema; Raut, Abhijit [King Edward VII Memorial Hospital, Department of Radiology, Parel, Mumbai (India); Chaudhary, Kshitij; Metkar, Umesh; Rathod, Ashok [King Edward VII Memorial Hospital, Department of Orthopaedics, Parel, Mumbai (India); Sanghvi, Darshana [King Edward VII Memorial Hospital, Department of Radiology, Parel, Mumbai (India); DMRD, DNB, Dadar, Mumbai (India)

    2008-04-15

    We report a case of posterior atlantoaxial dislocation without a fracture of the odontoid in a 35-year-old woman. There have been nine reported cases of similar injury in the English literature. The integrity of the transverse ligament following posterior atlantoaxial dislocations has not been well documented in these reports. In the present case, MRI revealed an intact transverse ligament, which probably contributed to the stability of the C1-C2 complex following closed reduction. (orig.)

  19. Evaluation and Management of Posterior Shoulder Instability

    Science.gov (United States)

    Tannenbaum, Eric; Sekiya, Jon K.

    2011-01-01

    Context: Posterior shoulder instability is a commonly misdiagnosed disorder in many competitive athletes. Type of Study: Clinical review. Evidence Acquisition: Relevant studies on posterior shoulder instability from 1950 to 2010 in PubMed and Cochrane databases were reviewed. Results: A total of 107 studies were reviewed. Conclusion: Patients who have undergone at least 6 months of physical therapy and still experience instability symptoms should be considered for surgical stabilization directed at their underlying pathology. PMID:23016015

  20. POSTERIOR INTEROSSEOUS FLAP IN PEDIATRIC HAND RECONSTRUCTIONS

    Directory of Open Access Journals (Sweden)

    I. O. Golubev

    2014-01-01

    Full Text Available Purpose: to assess early and long-term results of the pediatric hand reconstructions with posterior interosseous flap, including those in children younger than 3 years old. Materials and methods: results of the hand reconstructions with posterior interosseous artery reverse flap were studied in 10 children (4 males and 6 females aged from 1 year and 1 month to 13 years old. In 4 cases flap coverage were performed due to acquired posttraumatic hand deformity, in 6 cases reconstruction was assumed for congenital hand deformities. Combined procedures consisted of posterior interosseous artery flap coverage and other types of microsurgical reconstructions were suggested in 4 patients. Preoperative color doppler visualization of the posterior interosseous vessels were mandatory. All flaps were risen under 3.5x-4.5x magnification. Results: all flaps survived completely in 3 weeks postoperatively. There were no postoperative complications such as flap’s arterial or venous insufficiency, deep infection, or posterior interosseous nerve palsy. Nearly whole group (9 of 10 of patients and/or their parents were satisfied with the esthetic view of the reconstructed hand and donor site of the forearm 1 year postoperatively. Conclusion: posterior interosseous flap is a reliable and versatile option in pediatric hand reconstructions, providing excellent skin coverage with good color match and texture. Preservation of major vascular bundles of the forearm (radial and ulnar arteries during flap harvest gives a possibility to perform a simultaneous microsurgical reconstructions of the hand (e.g. free toe transfer.

  1. Traumatic lesions of the posterior urethra.

    Science.gov (United States)

    Velarde-Ramos, L; Gómez-Illanes, R; Campos-Juanatey, F; Portillo-Martín, J A

    2016-11-01

    The posterior urethral lesions are associated with pelvis fractures in 5-10% of cases. The posterior urethra is attached to the pelvis bone by puboprostatic ligaments and the perineal membrane, which explains why disruption of the pelvic ring can injure the urethra at this level. To identify suspected cases of posterior urethral trauma and to perform the diagnosis and its immediate or deferred management. Search in PubMed of articles related to traumatic posterior urethral lesions, written in English or Spanish. We reviewed the relevant publications including literature reviews and chapters from books related to the topic. With patients with pelvis fractures, we must always rule out posterior urethral lesions. The diagnostic examination of choice is retrograde urethrography, which, along with the severity of the condition, will determine the management in the acute phase and whether the treatment will be performed immediately or deferred. Early diagnosis and proper acute management decrease the associated complications, such as strictures, urinary incontinence and erectile dysfunction. Despite the classical association between posterior urethral lesions and pelvic fractures, the management of those lesions (whether immediate or deferred) remains controversial. Thanks to the growing interest in urethral disease, there are an increasing number of studies that help us achieve better management of these lesions. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Posterior Wnts Have Distinct Roles in Specification and Patterning of the Planarian Posterior Region.

    Science.gov (United States)

    Sureda-Gómez, Miquel; Pascual-Carreras, Eudald; Adell, Teresa

    2015-11-05

    The wnt signaling pathway is an intercellular communication mechanism essential in cell-fate specification, tissue patterning and regional-identity specification. A βcatenin-dependent signal specifies the AP (Anteroposterior) axis of planarians, both during regeneration of new tissues and during normal homeostasis. Accordingly, four wnts (posterior wnts) are expressed in a nested manner in central and posterior regions of planarians. We have analyzed the specific role of each posterior wnt and the possible cooperation between them in specifying and patterning planarian central and posterior regions. We show that each posterior wnt exerts a distinct role during re-specification and maintenance of the central and posterior planarian regions, and that the integration of the different wnt signals (βcatenin dependent and independent) underlies the patterning of the AP axis from the central region to the tip of the tail. Based on these findings and data from the literature, we propose a model for patterning the planarian AP axis.

  3. Cortical and subcortical mechanisms of brain-machine interfaces.

    Science.gov (United States)

    Marchesotti, Silvia; Martuzzi, Roberto; Schurger, Aaron; Blefari, Maria Laura; Del Millán, José R; Bleuler, Hannes; Blanke, Olaf

    2017-06-01

    Technical advances in the field of Brain-Machine Interfaces (BMIs) enable users to control a variety of external devices such as robotic arms, wheelchairs, virtual entities and communication systems through the decoding of brain signals in real time. Most BMI systems sample activity from restricted brain regions, typically the motor and premotor cortex, with limited spatial resolution. Despite the growing number of applications, the cortical and subcortical systems involved in BMI control are currently unknown at the whole-brain level. Here, we provide a comprehensive and detailed report of the areas active during on-line BMI control. We recorded functional magnetic resonance imaging (fMRI) data while participants controlled an EEG-based BMI inside the scanner. We identified the regions activated during BMI control and how they overlap with those involved in motor imagery (without any BMI control). In addition, we investigated which regions reflect the subjective sense of controlling a BMI, the sense of agency for BMI-actions. Our data revealed an extended cortical-subcortical network involved in operating a motor-imagery BMI. This includes not only sensorimotor regions but also the posterior parietal cortex, the insula and the lateral occipital cortex. Interestingly, the basal ganglia and the anterior cingulate cortex were involved in the subjective sense of controlling the BMI. These results inform basic neuroscience by showing that the mechanisms of BMI control extend beyond sensorimotor cortices. This knowledge may be useful for the development of BMIs that offer a more natural and embodied feeling of control for the user. Hum Brain Mapp 38:2971-2989, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. Echocardiographic Wall Motion Abnormality in Posterior Myocardial Infarction: The Diagnostic Value of Posterior Leads

    Directory of Open Access Journals (Sweden)

    A Darehzereshki

    2008-06-01

    Full Text Available Background: For the purpose of ascertaining myocardial infarction (MI and ischemia, the sensitivity of the initial 12-lead ECG is inadequate. It is risky to diagnose posterior MI using only precordial reciprocal changes, since the other leads may be more optimally positioned for the identification of electrocardiographic changes. In this study, we evaluated the relationship between electrocardiography changes and wall motion abnormalities in patients with posterior MI for earlier and better diagnosis of posterior MI.Methods: In this prospective cross-sectional study, we enrolled patients with posterior MI who had come to the Emergency Department of Shariati Hospital with their first episode of chest pain. A 12-lead surface electrocardiogram using posterior leads (V7-V9 was performed for all participants. Patients with ST elevation >0.05 mV or pathologic Q wave in the posterior leads, as well as those with specific changes indicating posterior MI in V1-V2, were evaluated by echocardiography in terms of wall motion abnormalities. All data were analyzed using SPSS and p<0.05 were considered statistically significant.Results: Of a total 79 patients enrolled, 48 (60.8% were men, and the mean age was 57.35±8.22 years. Smoking (54.4% and diabetes (48% were the most prevalent risk factors. In the echocardiographic evaluation, all patients had wall motion abnormalities in the left ventricle and 19 patients (24.1% had wall motion abnormalities in the right ventricle. The most frequent segment with motion abnormality among the all patients was the mid-posterior. The posterior leads showed better positive predictive value than the anterior leads for posterior wall motion abnormality.Conclusion: Electrocardiography of the posterior leads in patients with acute chest pain can help in earlier diagnosis and in time treatment of posterior MI.

  5. Stress Distribution on Short Implants at Maxillary Posterior Alveolar Bone Model With Different Bone-to-Implant Contact Ratio: Finite Element Analysis.

    Science.gov (United States)

    Yazicioglu, Duygu; Bayram, Burak; Oguz, Yener; Cinar, Duygu; Uckan, Sina

    2016-02-01

    The aim of this study was to evaluate the stress distribution of the short dental implants and bone-to-implant contact ratios in the posterior maxilla using 3-dimensional (3D) finite element models. Two different 3D maxillary posterior bone segments were modeled. Group 1 was composed of a bone segment consisting of cortical bone and type IV cancellous bone with 100% bone-to-implant contact. Group 2 was composed of a bone segment consisting of cortical bone and type IV cancellous bone including spherical bone design and homogenous tubular hollow spaced structures with 30% spherical porosities and 70% bone-to-implant contact ratio. Four-millimeter-diameter and 5-mm-height dental implants were assumed to be osseointegrated and placed at the center of the segments. Lateral occlusal bite force (300 N) was applied at a 25° inclination to the implants long axis. The maximum von Mises stresses in cortical and cancellous bones and implant-abutment complex were calculated. The von Mises stress values on the implants and the cancellous bone around the implants of the 70% bone-to-implant contact group were almost 3 times higher compared with the values of the 100% bone-to-implant contact group. For clinical reality, use of the 70% model for finite element analysis simulation of the posterior maxilla region better represents real alveolar bone and the increased stress and strain distributions evaluated on the cortical and cancellous bone around the dental implants.

  6. Posterior reversible leukoencephalopathy syndrome in children with hematologic disorders

    Directory of Open Access Journals (Sweden)

    Barış Malbora

    2010-09-01

    Full Text Available Objective: Posterior reversible leukoencephalopathy syndrome (PRES is characterized by headache, altered mental status, cortical blindness, and seizures associated with neuroradiological findings. It involves predominantly white matter of the parieto-occipital lobes. Several medications and disorders play a role in the etiology of PRES. In this study, we aimed to show how the prognosis of PRES in hematological diseases of childhood might be according to the etiological factors.Materials and Methods: Here, we report PRES in six patients, aged 4 to 14 years, with diagnoses of leukemia and aplastic anemia. Results: Suggested causes in our patients were chemotherapeutics, hypertension, infection and antimicrobial drug administration, tumor lysis syndrome, acute renal failure and hemodialysis, immunosuppressive drug administration, and hypomagnesemia. One of the patients died of sepsis, renal failure and pulmonary hemorrhage and another died of relapse after total recovery from PRES. The other four patients are under follow-up without problems. Conclusion: We suggest that PRES can recover fully with early diagnosis and treatment whereas it can show poor prognosis depending on the etiology.

  7. Posterior reversible encephalopathy syndrome in children with kidney disease

    Directory of Open Access Journals (Sweden)

    D N Gera

    2014-01-01

    Full Text Available Posterior reversible encephalopathy syndrome (PRES is a clinic-radiographic entity of heterogeneous etiologies that are grouped together because of similar findings on neuro-imaging and associated symptom complex of headache, vision loss, altered mentation, and seizures. Although usually considered benign and reversible, characteristics of this syndrome in pediatric patients remain obscure. This case series included 11 patients (8 males, 3 females, age 3-15 years of PRES during September 2010 to February 2012 out of a total 660 renal pediatric patients (1.66%. We studied their clinical profile, contributory factors, and outcome. Presenting symptoms were headache in 73%, dimness of vision or cortical blindness in 36%, seizures in 91%, and altered mentation in 55%. The associated renal diseases were acute renal failure (55%, chronic renal failure (9%, and 36% had normal renal function. The contributory factors were uncontrolled hypertension (100%, severe hypoproteinemia (9%, persistent hypocalcemia (9%, hemolytic uremic syndrome (36%, cyclosporine toxicity (9%, lupus nephritis (9%, high hematocrit (9%, and pulse methylprednisolone (9%. Brain imaging showed involvement of occipito-parietal area (100% and other brain areas (63%. All but one patient of hemolytic uremic syndrome had complete clinical neurological recovery in a week, and all had normal neurological imaging after 4-5 weeks. PRES is an underdiagnosed entity in pediatric renal disease patients. Associated hypertension, renal disease, and immunosuppressive treatment are important triggers. Early diagnosis and treatment of comorbid conditions is of prime importance for early reversal of syndrome.

  8. Slowly progressive anarthria with late anterior opercular syndrome: a variant form of frontal cortical atrophy syndromes.

    Science.gov (United States)

    Broussolle, E; Bakchine, S; Tommasi, M; Laurent, B; Bazin, B; Cinotti, L; Cohen, L; Chazot, G

    1996-12-01

    We describe eight patients with slowly progressive speech production deficit combining speech apraxia, dysarthria, dysprosody and orofacial apraxia, and initially no other deficit in other language and non-language neuropsychological domains. Long-term follow-up (6-10 years) in 4 cases showed an evolution to muteness, bilateral suprabulbar paresis with automatic-voluntary dissociation and frontal lobe cognitive slowing without generalised intellectual deterioration. Most disabled patients presented with an anterior opercular syndrome (Foix-Chavany-Marie syndrome), and pyramidal or extrapyramidal signs. CT and MRI findings disclosed asymmetric (left > right) progressive cortical atrophy of the frontal lobes predominating in the posterior inferior frontal region, notably the operculum. SPECT and PET revealed a decreased cerebral blood flow and metabolism, prominent in the left posterior-inferior frontal gyrus and premotor cortex, extending bilaterally in the most advanced cases. Pathological study of two cases showed non-specific neuronal loss, gliosis, and spongiosis of superficial cortical layers, mainly confined to the frontal lobes, with no significant abnormalities in the basal ganglia, thalamus, cerebellum, brain stem (except severe neuronal loss in the substantia nigra in one case), and spinal cord. We propose to call this peculiar syndrome Slowly Progressive Anarthria (SPA), based on its specific clinical presentation, and its metabolic and pathological correlates. SPA represents another clinical expression of focal cortical degeneration syndromes, that may overlap with other similar syndromes, specially primary progressive aphasia and the various frontal lobe dementias.

  9. Communication and wiring in the cortical connectome

    Science.gov (United States)

    Budd, Julian M. L.; Kisvárday, Zoltán F.

    2012-01-01

    In cerebral cortex, the huge mass of axonal wiring that carries information between near and distant neurons is thought to provide the neural substrate for cognitive and perceptual function. The goal of mapping the connectivity of cortical axons at different spatial scales, the cortical connectome, is to trace the paths of information flow in cerebral cortex. To appreciate the relationship between the connectome and cortical function, we need to discover the nature and purpose of the wiring principles underlying cortical connectivity. A popular explanation has been that axonal length is strictly minimized both within and between cortical regions. In contrast, we have hypothesized the existence of a multi-scale principle of cortical wiring where to optimize communication there is a trade-off between spatial (construction) and temporal (routing) costs. Here, using recent evidence concerning cortical spatial networks we critically evaluate this hypothesis at neuron, local circuit, and pathway scales. We report three main conclusions. First, the axonal and dendritic arbor morphology of single neocortical neurons may be governed by a similar wiring principle, one that balances the conservation of cellular material and conduction delay. Second, the same principle may be observed for fiber tracts connecting cortical regions. Third, the absence of sufficient local circuit data currently prohibits any meaningful assessment of the hypothesis at this scale of cortical organization. To avoid neglecting neuron and microcircuit levels of cortical organization, the connectome framework should incorporate more morphological description. In addition, structural analyses of temporal cost for cortical circuits should take account of both axonal conduction and neuronal integration delays, which appear mostly of the same order of magnitude. We conclude the hypothesized trade-off between spatial and temporal costs may potentially offer a powerful explanation for cortical wiring patterns

  10. Acute hepatic encephalopathy with diffuse cortical lesions

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, S.M.; Spreer, J.; Schumacher, M. [Section of Neuroradiology, Univ. of Freiburg (Germany); Els, T. [Dept. of Neurology, University of Freiburg (Germany)

    2001-07-01

    Acute hepatic encephalopathy is a poorly defined syndrome of heterogeneous aetiology. We report a 49-year-old woman with alcoholic cirrhosis and hereditary haemorrhagic telangiectasia who developed acute hepatic coma induced by severe gastrointestinal bleeding. Laboratory analysis revealed excessively elevated blood ammonia. MRI showed lesions compatible with chronic hepatic encephalopathy and widespread cortical signal change sparing the perirolandic and occipital cortex. The cortical lesions resembled those of hypoxic brain damage and were interpreted as acute toxic cortical laminar necrosis. (orig.)

  11. [BIOMECHANICS STUDY ON ACETABULAR POSTERIOR WALL FRACTURE].

    Science.gov (United States)

    Tang, Yang; Hu Xiaopeng; Lu, Xiongwei; Zhang, Yuntong; Zhang, Chuncai; Wang, Panfeng; Zhao, Xue

    2015-08-01

    To study the experimental biomechanics of acetabular posterior wall fractures so as to provide theoretical basis for its clinical treatment. Six formalin-preserved cadaveric pelvises were divided into groups A and B (n=3). The fracture models of superior-posterior wall and inferior-posterior wall of the acetabulum were created on both hips in group A; fractures were fixed with two interfragmentary screws and a locking reconstruction plate. The fracture models of superior-posterior wall of acetabulum were created on both hips in group B; fractures were fixed with two interfragmentary screws and a locking reconstruction plate at one side, and with acetabular tridimensional memory fixation system (ATMFS) at the other side. The biomechanical testing machine was used to load to 1 500 N at 10 mm/min speed for 30 seconds. The displacement of superior and inferior fracture sites was analyzed with the digital image correlation technology. No fracture or internal fixation breakage occurred during loading and measuring; the displacement valuess of the upper and lower fracture lines were below 2 mm (the clinically tolerable maximum value) in 2 groups. In group A, the displacement values of the upper and lower fracture lines at superior-posterior wall fracture site were significantly higher than those at inferior-posterior wall fracture site (P fracture line were significantly higher than those of lower fracture line (P fracture types. In group B, the displacement values of the upper and lower fracture lines at the side fixed with screws and a locking reconstruction plate were similar to the values at the side fixed with ATMFS, all being close to 2 mm; the displacement values of the upper fracture line were significantly higher than those of lower fracture line (P acetabulum is much greater than that of the inferior-posterior wall of acetabulum and they should be discriminated, which might be the reasons of reduction loss, femoral head subluxation, and traumatic arthritis

  12. Sindrome de encefalopatia posterior reversível: relato de caso Reversible posterior encephalopathy syndrome: case report

    Directory of Open Access Journals (Sweden)

    Francine Judith Freitas Fernandes

    2002-09-01

    Full Text Available A encefalopatia posterior reversível é uma síndrome aguda / subaguda geralmente causada pela encefalopatia hipertensiva, eclâmpsia, neurotoxicidade a ciclosporina-A, encefalopatia urêmica e púrpura trombocitopênica trombótica.. A maioria dos pacientes apresenta elevação acentuada dos níveis tensionais outros, níveis moderados ou normais. Os sintomas são progressivos e compreendem cefaléia, diminuição do nível de consciência, crises epilépticas e distúrbios visuais. A sintomatologia regride completamente se corrigidas em tempo as causas determinantes, caso contrário, podem instalar-se danos irreversíveis como a cegueira cortical e morte. A tomografia computadorizada (TC e, sobretudo, a ressonância magnética (RM contribuem para o diagnóstico. Tais métodos evidenciam edema da substância branca e cinzenta, principalmente das regiões parieto-occipitais. Os achados podem apresentar dificuldade no diagnóstico, hoje superado em parte, com a técnica de difusão pela RM, capaz de diferenciar edema citotóxico de vasogênico. Apresentamos um caso de encefalopatia posterior reversível decorrente de encefalopatia hipertensiva estudada com TC e RM.The posterior reversible leukoencephalopathy syndrome (PRES is a recently proposed cliniconeuroradiologic entity.The most common causes of PRES are hypertensive encephalopathy, eclampsia, cyclosporin A neurotoxicity and the uremic encephalopathies.Most patients are markedly hypertensive at presentation, although some have only middly elevated or even normal blood pressure. Symptoms may include headache, nausea , vomiting, altered mental status, seizures,stupor, and visual disturbances. On CT and MR studies, edema has been reported in a relatively symmetrical pattern, typically in the subcortical white matter and occasionally in the cortex of the occipital and parietal lobes. These often striking imaging findings usually are resolved on follow-up studies obtained after appropiate

  13. Decreased cortical inhibition and yet cerebellar pathology in 'familial cortical myoclonic tremor with epilepsy'

    NARCIS (Netherlands)

    van Rootselaar, Anne-Fleur; van der Salm, Sandra M. A.; Bour, Lo J.; Edwards, Mark J.; Brown, Peter; Aronica, Eleonora; Rozemuller-Kwakkel, Johanna M.; Koehler, Peter J.; Koelman, Johannes H. T. M.; Rothwell, John C.; Tijssen, Marina A. J.

    2007-01-01

    Cortical hyperexcitability is a feature of "familial cortical myoclonic tremor with epilepsy" (FCMTE). However, neuropathological investigations in a single FCMTE patient showed isolated cerebellar pathology. Pathological investigations in a second FCMTE patient, reported here, confirmed cerebellar

  14. Is posterior delamination in arthroscopic rotator cuff repair hidden to the posterior viewing portal?

    Science.gov (United States)

    Han, Yung; Shin, Jin-Hyup; Seok, Chang-Woo; Lee, Chang-Hyun; Kim, Seung-Ho

    2013-11-01

    The purposes of this study were (1) to examine whether posterior delamination is hidden to the most commonly used posterior viewing portal compared with differential rotator cuff portals and (2) to observe posterior delamination patterns so that a treatment-based classification system may be proposed. One-hundred thirty consecutive patients undergoing arthroscopic rotator cuff repair by 4 different surgeons were evaluated for the presence of posterior delamination viewable through the posterior, posterolateral, and lateral portals. Randomized arthroscopic pictures were viewed by 2 independent blinded observers, and the Fleiss κ was used to assess inter-reliability agreement. In addition, patterns of posterior delamination and surgical treatment were assessed. The incidence of posterior delamination was 88%. Only 11% of cases were visualized through the posterior portal, whereas 70% and 100% were visualized through the posterolateral and lateral portals, respectively. The Fleiss κ was 0.78 (95% confidence interval, 0.73 to 0.83), indicating substantial agreement. Three general patterns of posterior delamination with specific surgical repair strategies were identified and subclassified into 5 types: type A1, full-thickness tears with extensive posterior delamination separating the rotator cuff into 2 layers and sometimes with dissociation of the rotator cable; type A2, bursal-sided partial-thickness tears with posterior delamination; type B1, delamination with an L-shaped bursal layer tear and crescent-shaped articular layer tear; type B2, a partial-thickness articular-sided tear with extensive posterior delamination; and type C, extensive degeneration with multiple longitudinal bursal-sided tears. The incidence of posterior delamination is extremely high, and most of these lesions are missed if one is viewing from just the posterior portal. Differential rotator cuff portals are needed to appreciate and treat posterior delamination. Patterns of delamination can be

  15. Role of posterior parietal cortex in reaching movements in humans. Clinical implication for ‘optic ataxia’

    Science.gov (United States)

    Inouchi, Morito; Matsumoto, Riki; Taki, Junya; Kikuchi, Takayuki; Mitsueda-Ono, Takahiro; Mikuni, Nobuhiro; Wheaton, Lewis; Hallett, Mark; Fukuyama, Hidenao; Shibasaki, Hiroshi; Takahashi, Ryosuke; Ikeda, Akio

    2014-01-01

    Objective To clarify the spatio-temporal profile of cortical activity related to reaching movement in the posterior parietal cortex (PPC) in humans. Methods Four patients with intractable partial epilepsy who underwent subdural electrode implantation were studied as a part of pre-surgical evaluation. We investigated the Bereitschaftspotential (BP) associated with reaching and correlated the findings with the effect of electrical stimulation of the same cortical area. Results BPs specific for reaching, as compared with BPs for simple movements by the hand or arm contralateral to the implanted hemisphere, were recognized in all patients, mainly around the intraparietal sulcus (IPS), the superior parietal lobule (SPL) and the precuneus. BPs near the IPS had the earlier onset than BPs in the SPL. Electrical stimulation of a part of the PPC, where the reach-specific BPs were recorded, selectively impaired reaching. Conclusions Intracranial BP recording and cortical electrical stimulation delineated human reach-related areas in the PPC. Significance The present study for the first time by direct cortical recording in humans demonstrates that parts of the cortices around the IPS and SPL play a crucial role in visually-guided reaching. PMID:23831168

  16. Atypical frontal-posterior synchronization of Theory of Mind regions in autism during mental state attribution.

    Science.gov (United States)

    Kana, Rajesh K; Keller, Timothy A; Cherkassky, Vladimir L; Minshew, Nancy J; Just, Marcel Adam

    2009-01-01

    This study used fMRI to investigate the functioning of the Theory of Mind (ToM) cortical network in autism during the viewing of animations that in some conditions entailed the attribution of a mental state to animated geometric figures. At the cortical level, mentalizing (attribution of metal states) is underpinned by the coordination and integration of the components of the ToM network, which include the medial frontal gyrus, the anterior paracingulate, and the right temporoparietal junction. The pivotal new finding was a functional underconnectivity (a lower degree of synchronization) in autism, especially in the connections between frontal and posterior areas during the attribution of mental states. In addition, the frontal ToM regions activated less in participants with autism relative to control participants. In the autism group, an independent psychometric assessment of ToM ability and the activation in the right temporoparietal junction were reliably correlated. The results together provide new evidence for the biological basis of atypical processing of ToM in autism, implicating the underconnectivity between frontal regions and more posterior areas.

  17. Posterior Predictive Bayesian Phylogenetic Model Selection

    Science.gov (United States)

    Lewis, Paul O.; Xie, Wangang; Chen, Ming-Hui; Fan, Yu; Kuo, Lynn

    2014-01-01

    We present two distinctly different posterior predictive approaches to Bayesian phylogenetic model selection and illustrate these methods using examples from green algal protein-coding cpDNA sequences and flowering plant rDNA sequences. The Gelfand–Ghosh (GG) approach allows dissection of an overall measure of model fit into components due to posterior predictive variance (GGp) and goodness-of-fit (GGg), which distinguishes this method from the posterior predictive P-value approach. The conditional predictive ordinate (CPO) method provides a site-specific measure of model fit useful for exploratory analyses and can be combined over sites yielding the log pseudomarginal likelihood (LPML) which is useful as an overall measure of model fit. CPO provides a useful cross-validation approach that is computationally efficient, requiring only a sample from the posterior distribution (no additional simulation is required). Both GG and CPO add new perspectives to Bayesian phylogenetic model selection based on the predictive abilities of models and complement the perspective provided by the marginal likelihood (including Bayes Factor comparisons) based solely on the fit of competing models to observed data. [Bayesian; conditional predictive ordinate; CPO; L-measure; LPML; model selection; phylogenetics; posterior predictive.] PMID:24193892

  18. Posterior root tears of the lateral meniscus.

    Science.gov (United States)

    Feucht, Matthias J; Salzmann, Gian M; Bode, Gerrit; Pestka, Jan M; Kühle, Jan; Südkamp, Norbert P; Niemeyer, Philipp

    2015-01-01

    To summarize and discuss the current knowledge on posterior lateral meniscus root tears. A comprehensive review of the MEDLINE database was carried out to identify relevant articles using different keywords (e.g. "meniscus root", "root tear", "meniscus avulsion", "radial tear" and "lateral meniscus"). The reference lists of the reviewed articles were searched for additional relevant articles. Posterior lateral meniscus root tears are found in 7-12% of patients with a tear of the anterior cruciate ligament (ACL). Biomechanical studies have found an increase in lateral compartment contact pressure of approximately 50% after creation of a posterior lateral meniscus root tear. There is some evidence that the biomechanical consequences of these injuries are significantly influenced by the presence and integrity of the meniscofemoral ligaments. Clinical studies have found encouraging results after repair of posterior lateral meniscus root tears. Whether root repair can prevent the development of osteoarthritis is currently unknown. A posterior lateral meniscus root tear is a clinical relevant but most likely underrecognized concomitant injury in patients with a tear of the ACL. This article may support clinicians in diagnosing and treating this unique type of meniscus tear. V.

  19. Cushing, Penfield, and cortical stimulation.

    Science.gov (United States)

    Leblanc, Richard

    2018-01-26

    Harvey Cushing and Wilder Penfield enjoyed a unique professional and personal relationship. Shortly before his retirement from Harvard University in 1933, Cushing sent Penfield 8 sketches that he drew in 1902 and 1903 while he was at Johns Hopkins Hospital. The first series of 3 sketches illustrate the relationship between a cortical hemorrhagic lesion and the motor strip in a patient with focal motor seizures. The second series also comprises 3 sketches. These depict the operative findings in a patient in whom Cushing had electrically stimulated the precentral gyrus, before resecting the cortex subserving motility of the upper extremity to control painful dyskinetic movements. The third series consists of 2 sketches that illustrate the results of stimulation of the motor strip as an aid in the safe resection of an epileptogenic focus in a patient with Jacksonian seizures. These sketches are the subjects of this paper. They add to the relatively sparse record of Cushing's activities in cortical stimulation and in the treatment of functional disorders.

  20. SLEEP AND OLFACTORY CORTICAL PLASTICITY

    Directory of Open Access Journals (Sweden)

    Dylan eBarnes

    2014-04-01

    Full Text Available In many systems, sleep plays a vital role in memory consolidation and synaptic homeostasis. These processes together help store information of biological significance and reset synaptic circuits to facilitate acquisition of information in the future. In this review, we describe recent evidence of sleep-dependent changes in olfactory system structure and function which contribute to odor memory and perception. During slow-wave sleep, the piriform cortex becomes hypo-responsive to odor stimulation and instead displays sharp-wave activity similar to that observed within the hippocampal formation. Furthermore, the functional connectivity between the piriform cortex and other cortical and limbic regions is enhanced during slow-wave sleep compared to waking. This combination of conditions may allow odor memory consolidation to occur during a state of reduced external interference and facilitate association of odor memories with stored hedonic and contextual cues. Evidence consistent with sleep-dependent odor replay within olfactory cortical circuits is presented. These data suggest that both the strength and precision of odor memories is sleep-dependent. The work further emphasizes the critical role of synaptic plasticity and memory in not only odor memory but also basic odor perception. The work also suggests a possible link between sleep disturbances that are frequently co-morbid with a wide range of pathologies including Alzheimer’s disease, schizophrenia and depression and the known olfactory impairments associated with those disorders.

  1. Cortical control of facial expression.

    Science.gov (United States)

    Müri, René M

    2016-06-01

    The present Review deals with the motor control of facial expressions in humans. Facial expressions are a central part of human communication. Emotional face expressions have a crucial role in human nonverbal behavior, allowing a rapid transfer of information between individuals. Facial expressions can be either voluntarily or emotionally controlled. Recent studies in nonhuman primates and humans have revealed that the motor control of facial expressions has a distributed neural representation. At least five cortical regions on the medial and lateral aspects of each hemisphere are involved: the primary motor cortex, the ventral lateral premotor cortex, the supplementary motor area on the medial wall, and the rostral and caudal cingulate cortex. The results of studies in humans and nonhuman primates suggest that the innervation of the face is bilaterally controlled for the upper part and mainly contralaterally controlled for the lower part. Furthermore, the primary motor cortex, the ventral lateral premotor cortex, and the supplementary motor area are essential for the voluntary control of facial expressions. In contrast, the cingulate cortical areas are important for emotional expression, because they receive input from different structures of the limbic system. © 2015 Wiley Periodicals, Inc.

  2. Pars plana vitrectomy with posterior iris claw implantation for posteriorly dislocated nucleus and intraocular lens

    Directory of Open Access Journals (Sweden)

    Kishor B Patil

    2011-01-01

    Full Text Available We evaluated the safety and efficacy of pars plana vitrectomy (PPV with primary posterior iris claw intraocular lens (IOL implantation in cases of posterior dislocation of nucleus and IOL without capsular support. This was a retrospective interventional case series. Fifteen eyes underwent PPV with primary posterior iris claw IOL implantation performed by a single vitreoretinal surgeon. The main outcome measures were changes in best corrected visual acuity and anterior and posterior segment complications. A total of 15 eyes were included in this study. Eight had nucleus drop, three had IOL drop during cataract surgery and four had traumatic posterior dislocation of lens. The final postoperative best corrected visual acuity was 20/60 or better in 11 patients. This procedure is a viable option in achieving good functional visual acuity in eyes without capsular support.

  3. Ipsilateral testicular necrosis and atrophy after 1,080-degree torsion of the spermatic cord in rats Necrose e atrofia do testículo ipsilateral após torção de 1080 graus do cordão espermático em ratos

    Directory of Open Access Journals (Sweden)

    Frederico Ramalho Romero

    2009-04-01

    Full Text Available PURPOSE: To assess the incidence of testicular necrosis/atrophy immediately after 1 to 4 hours of 1,080-degree torsion of the spermatic cord, and 60 days after detorsion of the spermatic cord. METHODS: 42 rats were divided in 7 groups. Except for the control group, surgical torsion of the right spermatic cord was performed in all groups (T0. After 1, 2, or 4 hours of torsion, each group underwent either ipsilateral orchiectomy (groups OT1, OT2, and OT4, or detorsion of the spermatic cord and observation for 60 days (groups DT1, DT2, and DT4, before they were evaluated for the presence of testicular necrosis/atrophy. RESULTS: Only one rat (5.5% in groups OT1, OT2, and OT4 had testicular necrosis, in comparison with six rats (33.3% in groups DT1, DT2, and DT4 (p=0.04. The incidence of testicular necrosis/atrophy was not different between subgroups T1, T2, and T4, and the control group (p>0.05. There was, however, a tendency toward greater incidence of necrosis/atrophy in the rats in group DT4. CONCLUSION: The incidence of testicular necrosis/atrophy immediately after 1 to 4 hours of 1,080-degree torsion of the spermatic cord is 5.5%, in comparison with 33.3% sixty days after detorsion of the spermatic cord.OBJETIVO: Avaliar a incidência de necrose/atrofia testicular imediatamente após 1 a 4 horas de torção de 1080 graus do cordão espermático e 60 dias após a destorção do cordão espermático. MÉTODOS: 42 ratos foram separados em 7 grupos. Exceto para o grupo controle, todos os animais foram submetidos à torção operatória do cordão espermático direito (T0. Após 1, 2 ou 4 horas de torção, cada grupo foi submetido a orquiectomia ipsilateral (grupos OT1, OT2 e OT4, ou destorção do cordão espermático e observação por 60 dias (grupos DT1, DT2 e DT4, antes de serem avaliados para a presença de necrose/atrofia testicular. RESULTADOS: Somente um rato (5,5% nos grupos OT1, OT2 e OT4 apresentou necrose testicular em comparação com

  4. A technique of anterior screw removal through a posterior costotransversectomy approach for posterior-based osteotomies.

    Science.gov (United States)

    Lewis, Stephen J; David, Kenny; Singer, Syndie; Bacon, Sarah A; Kopka, Michaela; Gray, Randolph; Magana, Sofia

    2010-05-15

    Case report. To describe a novel technique to remove anterior instrumentation from a posterior approach while performing posterior-based osteotomies for spinal deformities. Posterior-based osteotomies such as pedicle subtraction osteotomies (PSOs) and vertebral column resections are performed to restore sagittal alignment. The removal of previously placed anterior implants at the desired osteotomy level can often be challenging. We propose a technique for the removal of anterior instrumentation through a posterior approach to facilitate osteotomy closure and deformity correction, while avoiding the need for an anterior incision. A 34-year-old woman presented with a residual deformity after several anterior and posterior procedures. The residual coronal Cobb angle measured 60 degrees between T7 and L2, with a 46 degrees thoracolumbar kyphosis between T10 and L2. The screw head at the desired osteotomy level was in close proximity to the liver after the previous right-sided thoracoabdominal approach. Therefore, the T11 anterior screw was accessed through a posterior costotransversectomy approach and disconnected from the rod proximally and distally with a high-speed side-cutting burr. A portion of the right lateral vertebral body of T11 was removed to expose the neck of the screw, which was separated from the shaft with the same burr. A PSO was performed at T11 and the remaining screw shank was removed with the posterior-based osteotomy. No major complications were encountered during the procedure. The anterior screw at T11 was removed from posteriorly, and the PSO was completed successfully. Postoperative recovery was without incident, and the patient was very satisfied with her results. This technique describes a novel, safe, and effective method to deal with anterior instrumentation from the posterior approach while performing posterior-based osteotomies for rigid spinal deformities.

  5. Radiographic diagnosis of posterior facet talocalcaneal coalition

    Energy Technology Data Exchange (ETDEWEB)

    Staser, Jonathan [Indiana University School of Medicine, Indiana University Hospital, Department of Radiology, Indianapolis, IN (United States); Karmazyn, Boaz [Indiana University/Purdue University at Indianapolis, Riley Hospital for Children, Department of Radiology, Indianapolis, IN (United States); Riley Hospital for Children, Department of Radiology, Indianapolis, IN (United States); Lubicky, John [Indiana University School of Medicine, Riley Hospital for Children, Department of Orthopedics, Indianapolis, IN (United States)

    2007-01-15

    Tarsal coalition is a relatively common segmentation abnormality of the hindfoot that can result in foot and ankle pain in both adolescents and adults. The most common types are calcaneonavicular and talocalcaneal. Posterior subtalar facet coalition is less common. We present a 10-year-old boy with a history of chronic left ankle and foot pain. Radiographs demonstrated calcaneal ''humpback'' sign, representing the posterior subtalar bony coalition, and CT demonstrated in more detail the extent of bony and fibrous coalition. These findings led to surgical intervention. (orig.)

  6. [Hydatid cyst of the posterior fossa].

    Science.gov (United States)

    Saqui, Abderrazzak El; Aggouri, Mohamed; Benzagmout, Mohamed; Chakour, Khaled; Faizchaoui, Mohamed El

    2017-01-01

    Hydatidosis is an endemic affection in Morocco. Cerebral echinococcosis is a relatively rare entity accounting for only 1-2% of all hydatid cysts in humans. hydatid cyst of the posterior fossa is a very uncommon site for the disease. We report the case of a 12 year-old child admitted for high intracranial pressure. Brain CT scan showed a posterior fossa cyst without enhancement after contrast medium injection. Operative finding revealed a hydatid cyst. The histological examination of the tissue sample confirmed the diagnosis. The patient was given albendazole post operatively. He feels well six months later.

  7. Preformed posterior stainless steel crowns: an update.

    Science.gov (United States)

    Croll, T P

    1999-02-01

    For almost 50 years, dentists have used stainless steel crowns for primary and permanent posterior teeth. No other type of restoration offers the convenience, low cost, durability, and reliability of such crowns when interim full-coronal coverage is required. Preformed stainless steel crowns have improved over the years. Better luting cements have been developed and different methods of crown manipulation have evolved. This article reviews stainless steel crown procedures for primary and permanent posterior teeth. Step-by-step placement of a primary molar stainless steel crown is documented and permanent molar stainless steel crown restoration is described. A method for repairing a worn-through crown also is reviewed.

  8. Cortical atrophy patterns in multiple sclerosis are non-random and clinically relevant.

    Science.gov (United States)

    Steenwijk, Martijn D; Geurts, Jeroen J G; Daams, Marita; Tijms, Betty M; Wink, Alle Meije; Balk, Lisanne J; Tewarie, Prejaas K; Uitdehaag, Bernard M J; Barkhof, Frederik; Vrenken, Hugo; Pouwels, Petra J W

    2016-01-01

    Grey matter atrophy is common in multiple sclerosis. However, in contrast with other neurodegenerative diseases, it is unclear whether grey matter atrophy in multiple sclerosis is a diffuse 'global' process or develops, instead, according to distinct anatomical patterns. Using source-based morphometry we searched for anatomical patterns of co-varying cortical thickness and assessed their relationships with white matter pathology, physical disability and cognitive functioning. Magnetic resonance imaging was performed at 3 T in 208 patients with long-standing multiple sclerosis (141 females; age = 53.7 ± 9.6 years; disease duration = 20.2 ± 7.1 years) and 60 age- and sex-matched healthy controls. Spatial independent component analysis was performed on cortical thickness maps derived from 3D T1-weighted images across all subjects to identify co-varying patterns. The loadings, which reflect the presence of each cortical thickness pattern in a subject, were compared between patients with multiple sclerosis and healthy controls with generalized linear models. Stepwise linear regression analyses were used to assess whether white matter pathology was associated with these loadings and to identify the cortical thickness patterns that predict measures of physical and cognitive dysfunction. Ten cortical thickness patterns were identified, of which six had significantly lower loadings in patients with multiple sclerosis than in controls: the largest loading differences corresponded to the pattern predominantly involving the bilateral temporal pole and entorhinal cortex, and the pattern involving the bilateral posterior cingulate cortex. In patients with multiple sclerosis, overall white matter lesion load was negatively associated with the loadings of these two patterns. The final model for physical dysfunction as measured with Expanded Disability Status Scale score (adjusted R(2) = 0.297; P regression models, they explained limited incremental variance (to a maximum of 4

  9. Quantitative investigation of palatal bone depth and cortical bone thickness for mini-implant placement in adults.

    Science.gov (United States)

    Baumgaertel, Sebastian

    2009-07-01

    Cortical bone thickness and overall bone depth are important factors to consider when placing an orthodontic mini-implant. The purpose of this study was to investigate both variables in the palate quantitatively to aid clinicians in planning successful mini-implant placements. Thirty dry skulls were imaged with cone-beam computed tomography technology. Coronal slices were generated on which overall bone depth and cortical bone thickness were measured at 4 levels and 34 palatal placement sites. One-way analysis of variance (ANOVA) was used for data analysis. Overall bone depth decreased with increasing distance from the midsagittal plane and from the anterior to the posterior palatal regions. Cortical bone thickness decreased from anterior to posterior, but no differences were detectable within measurement levels. Bone depth and cortical bone thickness of the palate were most favorable for temporary anchorage device placement at the level of the first and second premolars. This information could aid clinicians in choosing suitable palatal placement sites for orthodontic mini-implants.

  10. Transient cortical blindness following vertebral angiography in a young adult with cerebellar haemangioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Till, Viktor; Stojanovic, Sanja; Avramov, Predrag [Clinical Centre of Vojvodina, Centre of Radiology, Novi Sad (RS); Koprivsek, Katarina [Institute of Oncology, Diagnostic Imaging Department, Sremska Kamenica (RS); Vulekovic, Petar [Clinical Centre of Vojvodina, Neurosurgery Clinic, Novi Sad (RS)

    2009-11-15

    Transient cortical blindness is reported to occur in 0.3% to 1% of cerebral angiography procedures. It develops within minutes of contrast medium injection and lasts for up to several days. We report a long episode of transient cortical blindness in a 17-year-old boy with cerebellar haemangioblastoma, which started during the preoperative vertebral angiography and lasted for 5 days. CT performed 2 days after the sudden onset of bilateral visual loss showed multiple asymmetrical lesions within the brain parenchyma in the distribution of the posterior cerebral circulation. Even though the patient's vision was completely restored 5 days after angiography, repeat MRI performed 2 months after angiography showed improvement but with residual lesions in the thalami, cerebellum and occipital lobe. (orig.)

  11. Histologic changes in selenite cortical cataract.

    Science.gov (United States)

    Anderson, R S; Trune, D R; Shearer, T R

    1988-09-01

    Massive cortical cataract was produced 15-30 days after a single injection of an overdose of sodium selenite into 14-day-old rats. Most of the cortical cataract appeared to be due to extensive liquefaction of cortical fibers. Water influx, following initial damage to the epithelium by selenium, and action of lens proteases were probable mechanisms for the extensive liquefaction. Remarkably, selenite cortical cataract spontaneously cleared after several months, restoring essentially normal cells to the epithelium and outer and mid-cortex. Major mechanisms for clearing probably involved: (1) removal of damaged proteins from the lens by extensive proteolysis; and (2) replacement of fibers by resumption of normal fibergenesis. The data emphasized the remarkable reparative potential of the lens, and indicated the usefulness of the selenite cortical cataract as a model to study such processes.

  12. Cortical Odor Processing in Health and Disease

    Science.gov (United States)

    Wilson, Donald A.; Xu, Wenjin; Sadrian, Benjamin; Courtiol, Emmanuelle; Cohen, Yaniv; Barnes, Dylan C.

    2014-01-01

    The olfactory system has a rich cortical representation, including a large archicortical component present in most vertebrates, and in mammals neocortical components including the entorhinal and orbitofrontal cortices. Together, these cortical components contribute to normal odor perception and memory. They help transform the physicochemical features of volatile molecules inhaled or exhaled through the nose into the perception of odor objects with rich associative and hedonic aspects. This chapter focuses on how olfactory cortical areas contribute to odor perception and begins to explore why odor perception is so sensitive to disease and pathology. Odor perception is disrupted by a wide range of disorders including Alzheimer’s disease, Parkinson’s disease, schizophrenia, depression, autism, and early life exposure to toxins. This olfactory deficit often occurs despite maintained functioning in other sensory systems. Does the unusual network of olfactory cortical structures contribute to this sensitivity? PMID:24767487

  13. Syllabic discrimination in premature human infants prior to complete formation of cortical layers.

    Science.gov (United States)

    Mahmoudzadeh, Mahdi; Dehaene-Lambertz, Ghislaine; Fournier, Marc; Kongolo, Guy; Goudjil, Sabrina; Dubois, Jessica; Grebe, Reinhard; Wallois, Fabrice

    2013-03-19

    The ontogeny of linguistic functions in the human brain remains elusive. Although some auditory capacities are described before term, whether and how such immature cortical circuits might process speech are unknown. Here we used functional optical imaging to evaluate the cerebral responses to syllables at the earliest age at which cortical responses to external stimuli can be recorded in humans (28- to 32-wk gestational age). At this age, the cortical organization in layers is not completed. Many neurons are still located in the subplate and in the process of migrating to their final location. Nevertheless, we observed several points of similarity with the adult linguistic network. First, whereas syllables elicited larger right than left responses, the posterior temporal region escaped this general pattern, showing faster and more sustained responses over the left than over the right hemisphere. Second, discrimination responses to a change of phoneme (ba vs. ga) and a change of human voice (male vs. female) were already present and involved inferior frontal areas, even in the youngest infants (29-wk gestational age). Third, whereas both types of changes elicited responses in the right frontal region, the left frontal region only reacted to a change of phoneme. These results demonstrate a sophisticated organization of perisylvian areas at the very onset of cortical circuitry, 3 mo before term. They emphasize the influence of innate factors on regions involved in linguistic processing and social communication in humans.

  14. Cortical cartography and Caret software.

    Science.gov (United States)

    Van Essen, David C

    2012-08-15

    Caret software is widely used for analyzing and visualizing many types of fMRI data, often in conjunction with experimental data from other modalities. This article places Caret's development in a historical context that spans three decades of brain mapping--from the early days of manually generated flat maps to the nascent field of human connectomics. It also highlights some of Caret's distinctive capabilities. This includes the ease of visualizing data on surfaces and/or volumes and on atlases as well as individual subjects. Caret can display many types of experimental data using various combinations of overlays (e.g., fMRI activation maps, cortical parcellations, areal boundaries), and it has other features that facilitate the analysis and visualization of complex neuroimaging datasets. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Bilateral Visual Loss as Presenting Symptom of Posterior Reversible Encephalopathy Syndrome in a Patient with HIV/Tuberculosis Coinfection: A Case Report

    Directory of Open Access Journals (Sweden)

    S. Guerriero

    2012-01-01

    Full Text Available Posterior reversible encephalopathy syndrome (PRES is a neurotoxic state accompanied by a unique brain imaging pattern. This cliniconeuroradiological entity usually presents with visual disturbances (cortical blindness, homonymous hemianopia, visual neglect, and blurred vision along with neurotoxic manifestations. Only a few cases of PRES have previously been reported in patients with advanced HIV disease. The authors describe a case of posterior reversible encephalopathy syndrome (PRES in a patient with advanced HIV/TBC infection who developed a neurotoxic state following TB and ART therapy initiation. They present a comprehensive review of the literature and discuss the pathogenetic hypotheses.

  16. Unsupervised fetal cortical surface parcellation

    Science.gov (United States)

    Dahdouh, Sonia; Limperopoulos, Catherine

    2016-03-01

    At the core of many neuro-imaging studies, atlas-based brain parcellations are used for example to study normal brain evolution across the lifespan. These atlases rely on the assumption that the same anatomical features are present on all subjects to be studied and that these features are stable enough to allow meaningful comparisons between different brain surfaces and structures These methods, however, often fail when applied to fetal MRI data, due to the lack of consistent anatomical features present across gestation. This paper presents a novel surface-based fetal cortical parcellation framework which attempts to circumvent the lack of consistent anatomical features by proposing a brain parcellation scheme that is based solely on learned geometrical features. A mesh signature incorporating both extrinsic and intrinsic geometrical features is proposed and used in a clustering scheme to define a parcellation of the fetal brain. This parcellation is then learned using a Random Forest (RF) based learning approach and then further refined in an alpha-expansion graph-cut scheme. Based on the votes obtained by the RF inference procedure, a probability map is computed and used as a data term in the graph-cut procedure. The smoothness term is defined by learning a transition matrix based on the dihedral angles of the faces. Qualitative and quantitative results on a cohort of both healthy and high-risk fetuses are presented. Both visual and quantitative assessments show good results demonstrating a reliable method for fetal brain data and the possibility of obtaining a parcellation of the fetal cortical surfaces using only geometrical features.

  17. Arthroscopic treatment for posterior tibial tendon lesions with a posterior approach.

    Science.gov (United States)

    Hua, Yinghui; Chen, Shiyi; Li, Yunxia; Wu, Zhiying

    2015-03-01

    To evaluate clinical results of arthroscopic treatment for posterior tibial tendon (PTT) lesions using a posterior approach. Sixteen patients with PTT lesions underwent arthroscopic treatment using a posterior approach. After routine posterior arthroscopy to expose the posterior tibiotalar compartment, the posterior subtalar compartment, and the flexor hallucis longus tendon, the shaver was then moved through the flexor hallucis longus tendon to detect and treat the PTT lesion, including synovectomy, debridement, and repair of the PTT. American Orthopaedic Foot and Ankle Society Ankle-Hindfoot (AOFAS) scale and visual analog scale (VAS) for subjective satisfaction were used to evaluate pre- and post-operative clinical results. Fifteen patients (94 %) (15 ankles) were followed for a mean of 26 ± 10 months. No patients experienced vascular or nerve complications during or after the operation. Mean AOFAS score improved from 49 ± 12 points preoperatively to 84 ± 8.5 points post-operatively (p = 0.000). Mean VAS improved from 6.2 ± 1.7 preoperatively to 2.4 ± 1.3 post-operatively (p = 0.000). There were three patients (20 %) with excellent outcomes, eight patients (53 %) with good outcomes, three patients (20 %) with fair outcomes, and one patient (7 %) with a poor outcome at follow-up. A posterior arthroscopic approach can provide a safe, reliable technique for detecting and treating PTT lesions and a satisfactory surgical outcome. The technique is an alternative to PTT tendoscopy.

  18. Plication of the posterior capsule for intraoperative posterior instability during anatomic total shoulder arthroplasty.

    Science.gov (United States)

    Alentorn-Geli, Eduard; Assenmacher, Andrew T; Sperling, John W; Cofield, Robert H; Sánchez-Sotelo, Joaquín

    2017-06-01

    Restoration of soft tissue balance for intraoperative posterior instability during anatomic total shoulder arthroplasty (TSA) is particularly difficult. The effectiveness of posterior capsular plication (PCP) in restoring soft tissue balance is largely unknown. The purpose of this study was to report the outcomes, complications, and reoperations of primary TSA in which a PCP was performed to correct excessive intraoperative posterior subluxation. Thirty-eight shoulders (37 patients) underwent PCP for intraoperative posterior instability during anatomic TSA. The mean (standard deviation) age was 68 (10) years, and the median (range) clinical and radiographic follow-up periods were 60 (10-154) and 48 (1.5-154) months, respectively. A retrospective chart review was conducted to obtain clinical and radiographic data. TSA resulted in significant improvements in pain and range of motion. The mean (standard deviation) Simple Shoulder Test and American Shoulder and Elbow Surgeons scores were 9.4 (2.7) and 81.1 (19.8), respectively. PCP resulted in restoration of soft tissue balance in 27 shoulders (71%). The remaining 11 shoulders had evidence of posterior subluxation, including posterior dislocation in 2 shoulders. Revision surgery was performed in only 3 shoulders (7.9%), all for instability. However, there was a high rate of radiographic glenoid component loosening (12 shoulders, 32%). Overall results were excellent in 24 (63.2%), satisfactory in 10 (26.3%), and unsatisfactory in 4 (10.5%) shoulders. Recurrence of posterior subluxation was associated with worse motion and strength as well as with a higher rate of glenoid loosening. PCP seems to correct excessive intraoperative posterior subluxation in approximately two-thirds of the shoulders undergoing anatomic TSA. However, posterior subluxation does recur in the remaining third, and the overall rate of radiographic glenoid loosening is of concern. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of

  19. Cortical responses to consciousness of schematic emotional facial expressions: a high-resolution EEG study.

    Science.gov (United States)

    Babiloni, Claudio; Vecchio, Fabrizio; Buffo, Paola; Buttiglione, Maura; Cibelli, Giuseppe; Rossini, Paolo Maria

    2010-10-01

    Is conscious perception of emotional face expression related to enhanced cortical responses? Electroencephalographic data (112 channels) were recorded in 15 normal adults during the presentation of cue stimuli with neutral, happy or sad schematic faces (duration: "threshold time" inducing about 50% of correct recognitions), masking stimuli (2 s), and go stimuli with happy or sad schematic faces (0.5 s). The subjects clicked left (right) mouse button in response to go stimuli with happy (sad) faces. After the response, they said "seen" or "not seen" with reference to previous cue stimulus. Electroencephalographic data formed visual event-related potentials (ERPs). Cortical sources of ERPs were estimated by LORETA software. Reaction time to go stimuli was generally shorter during "seen" than "not seen" trials, possibly due to covert attention and awareness. The cue stimuli evoked four ERP components (posterior N100, N170, P200, and P300), which had similar peak latency in the "not seen" and "seen" ERPs. Only N170 amplitude showed differences in amplitude in the "seen" versus "not seen" ERPs. Compared to the "not seen" ERPs, the "seen" ones showed prefrontal, premotor, and posterior parietal sources of N170 higher in amplitude with the sad cue stimuli and lower in amplitude with the neutral and happy cue stimuli. These results suggest that nonconscious and conscious processing of schematic emotional facial expressions shares a similar temporal evolution of cortical activity, and conscious processing induces an early enhancement of bilateral cortical activity for the schematic sad facial expressions (N170). © 2010 Wiley-Liss, Inc.

  20. Extensive Supratentorial Hemorrhages Following Posterior Fossa ...

    African Journals Online (AJOL)

    Agarwal, et al.: Supratentorial hemorrhages following posterior fossa surgery. Author Institution Mapping (AIM). Please note that not all the institutions may get mapped due to non-availability of the requisite information in the Google Map. For AIM of other issues, please check the Archives/Back Issues page on the journal's ...

  1. Posterior Predictive Model Checking in Bayesian Networks

    Science.gov (United States)

    Crawford, Aaron

    2014-01-01

    This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…

  2. Selective posterior lumbosacral rhizotomy for the management ...

    African Journals Online (AJOL)

    Selective posterior lumbosacral rhizotomy for the management ofcerebral palsy spasticity. A 10-year ... were attending cerebral palsy schools and receiving spe- cialised neurodevelopmental physiotherapy at least ..... The natural history of spondylolysis and spondylolisthesis. J Bone. Joint Surg (Am) 1984; 66: 699-707. 20.

  3. [Anatomy in relation to posterior maxillary osteotomy].

    Science.gov (United States)

    Hua, Z; Chen, Z; Hu, X

    2000-09-01

    The most common site of haemorrhage in maxillary osteotomies is the posterior maxilla. Better understanding of the anatomy of this region would minimize possible vascular complications. The aim of this study is to investigate the anatomy of posterior maxilla and establish safety guidelines for Le Fort I osteotomy. Thirty dry human skulls were selected for direct measurement and computerized image analysis. Synosteosis of the pterygomaxillary junction was noted in 10% of the samples. The height of the pterygomaxillary junction was 13.15 mm. The height from the inferior point of the pterygomaxillary junction to the inferior point of the maxillary tuberosity was 5.25 mm. The height from the superior point of the pterygomaxillary junction to the inferior point of the maxillary tuberrosity was 18.05 mm. The average distance from the piriform rim to the descending palatine canal was 35.25 mm. The width of the pterygoid process was 12.34 mm. The average length from the zygo-alveolar ridge to the pterygomaxillary junction was 25.47 mm. The average length from anterior nasal spine to the posterior nasal spine was 46.27 mm, and the angle between the descending palatine canal and the palate plane was 58 degrees 47'. The study is to provide further understanding of the posterior maxillary anatomy in relation to the bone-cut design of Le fort I osteotomy and to create clinical safety guidelines in order to avoid damaging the descending palatine vessels.

  4. Isolated posterior fossa involvement of progressive multifocal ...

    African Journals Online (AJOL)

    2017-11-14

    Nov 14, 2017 ... Open Access frontal lobe. Supratentorial lesions typically involve the subcortical white matter with a scalloping appearance.2. White matter of the posterior fossa is the next common area of involvement; however, isolated cerebellar white matter or isolated medullary involvement is less common.2. One study ...

  5. Posterior reversibel encefalopati efterbehandling af malignt lymfom

    DEFF Research Database (Denmark)

    Thomsen, Rasmus Heje; Zakarian, Kristine; Hansen, Per Boye

    2015-01-01

    We present a 56-year-old woman who received chemotherapy for relapsed diffuse large B-cell lymphoma and developed posterior reversible encephalopathy syndrome (PRES) with generalized seizures 27 days after treatment with rituximab, ifosfamide, carboplatin and etoposide (R-ICE). The patient had...

  6. Posterior capsular rent: Prevention and management

    Science.gov (United States)

    Chakrabarti, Arup; Nazm, Nazneen

    2017-01-01

    This review article deals with a potentially sight threatening complication – rupture of the posterior capsule – during cataract surgery. Cataract surgery is the most commonly performed surgical procedure in ophthalmology and despite tremendous technical and technological advancements, posterior capsular rent (PCR) still occurs. PCR occurs both in the hands of experienced senior surgeons and the neophyte surgeons, although with a higher frequency in the latter group. Additionally, certain types of cataracts are prone to this development. If managed properly in a timely manner the eventual outcome may be no different from that of an uncomplicated case. However, improper management may lead to serious complications with a higher incidence of permanent visual disability. The article covers the management of posterior capsular rent from two perspectives: 1. Identifying patients at higher risk and measures to manage such patients by surgical discipline, and 2. Intraoperative management of posterior capsular rent and various case scenarios to minimize long-term complications. This review is written for experienced and not-so-experienced eye surgeons alike to understand and manage PCR. PMID:29208816

  7. A posterior tibial tendon skipping rope

    NARCIS (Netherlands)

    van Sterkenburg, M. N.; Haverkamp, D.; van Dijk, C. N.; Kerkhoffs, G. M. M. J.

    2010-01-01

    This report presents an athletic patient with swelling and progressive pain on the posteromedial side of his right ankle on weight bearing. MRI demonstrated tenosynovitis and suspicion of a length rupture. On posterior tibial tendoscopy, there was no rupture, but medial from the tendon a tissue cord

  8. Hydro-dissection and posterior capsule opacity

    African Journals Online (AJOL)

    Windows2G

    whose refracted vision was less then optimal. Conclusion: Hydrodissection is associated with a marginal reduction in post-operative posterior capsule opacity formation following ECCE-IOL surgery. It may however be associated with early post operative complications such as cornea striae, epithelial oedema and iritis due ...

  9. Hindfoot endoscopy for posterior ankle pain

    NARCIS (Netherlands)

    van Dijk, C. Niek

    2006-01-01

    Hindfoot pain can be caused by a variety of pathologies, most of which can be diagnosed and treated with endoscopy. The main indications are posterior tibial tenosynovectomy, diagnosis of a longitudinal peroneus brevis rupture, peroneal tendon adhesiolysis, flexor hallucis longus release, os

  10. Posterior spinal decompression, stabilization and arthrodesis in ...

    African Journals Online (AJOL)

    The outcome was significantly associated with the etiology (0.030) of the indication for surgery and preoperative power grade (0.000). Conclusion: Spinal trauma and degenerative spine disease are the two most common indications for posterior spinal decompression, stabilization and fusion in our center. It is associated ...

  11. Restoration of the endodontically treated posterior tooth

    Directory of Open Access Journals (Sweden)

    Andrea Polesel

    2014-06-01

    Results and conclusions: Direct adhesive restorations, indirect bonded restorations and traditional full crown are three therapeutic options for the single posterior endodontically treated teeth. The amount of remaining sound tooth structure is the most significant factor influencing the therapeutic approach. The clinician's operative skill is a determining aspect for long-term success of adhesive inlays.

  12. Posterior skulderluksation--en diagnostisk udfordring

    DEFF Research Database (Denmark)

    Trollegaard, Anton Mitchell

    2009-01-01

    A case of posterior shoulder dislocation is described. The dislocation was misinterpreted twice clinically and radiographically in two different casualty departments before it was diagnosed and treated with closed reposition in a third facility. Treatment was conservative and the arm was placed...... in an abduction sling for four weeks with subsequent active physiotherapy. Udgivelsesdato: 2009-Aug...

  13. stabilisation of posterior sternoclavicular joint dislocation using

    African Journals Online (AJOL)

    JOINT DISLOCATION USING PALMARIS LONGUS TENDON. AUTOGRAFT: A CASE REPORT. V. M. Mutiso* .... Post operative follow up was uneventful. The skin healed well and she was commenced on physiotherapy with good ... The treatment of posterior sternoclavicular joint dislocation is varied owing to the rarity of the.

  14. POSTERIOR CRANIAL FOSSA TUMOURS IN CHILDREN AT ...

    African Journals Online (AJOL)

    hi-tech

    2004-05-05

    May 5, 2004 ... symptoms were the most common mode of presentation (30%) followed by headaches and vomiting. Twenty percent of our patients ... paediatric posterior fossa tumours are medulloblastoma. (20%) astrocytoma (15%) ... cranial nerve palsies, headaches, vomiting and blindness due to raised intracranial ...

  15. Stabilisation of Posterior Sternoclavicular Joint Dislocation using ...

    African Journals Online (AJOL)

    Posterior sternoclavicular joint dislocation is a rare injury. It is usually sustained acutely in activities such as contact sports eg. rugby and motorcycle accidents. Plain radiography of the chest will often miss the diagnosis and confirmation is by CT scans. However CT scans are often reported to miss epiphyseal injuries.

  16. Hydro-dissection and posterior capsule opacity

    African Journals Online (AJOL)

    Windows2G

    the proliferation of human lens epithelial cells3. The incidence of PCO reduces with greater attention to meticulous ... effect to prevent the proliferation of lens epithelial cells on to the posterior capsule4,5. Hydrodissection is ... counter pressure from a lens extractor and squint hook. Majority of the intraocular lenses were from.

  17. Selective posterior lumbosacral rhizotomy for the management ...

    African Journals Online (AJOL)

    S, eds. Neurosurgery Update. New York: McGraw-Hill, 1990: 403-. 407. 7. Reigel DH. Editorial note. Pediacr Neurosurg 1991; 16: 1-2. 8. Arens LJ, Peacock WJ, Peter Je. Selective posterior rhizotomy: a long-tenn follow-up. Childs Nerv Syst 1989; 5: 148-152. 9. Molteno CD, Arens LJ. Cerebral palsy. In: Kibel M, WagstaffLA,.

  18. Surgical site infection in posterior spine surgery

    African Journals Online (AJOL)

    2016-03-20

    Mar 20, 2016 ... Comorbidities such as diabetes mellitus, obesity, and anemia were significant risk factors. The organisms cultured were Pseudomonas and Staphylococcus species. Conclusions: Wound infection is a significant complication of posterior spine surgery. This causes distress for both patient and surgeons alike ...

  19. Posterior capsular rent: Prevention and management.

    Science.gov (United States)

    Chakrabarti, Arup; Nazm, Nazneen

    2017-12-01

    This review article deals with a potentially sight threatening complication - rupture of the posterior capsule - during cataract surgery. Cataract surgery is the most commonly performed surgical procedure in ophthalmology and despite tremendous technical and technological advancements, posterior capsular rent (PCR) still occurs. PCR occurs both in the hands of experienced senior surgeons and the neophyte surgeons, although with a higher frequency in the latter group. Additionally, certain types of cataracts are prone to this development. If managed properly in a timely manner the eventual outcome may be no different from that of an uncomplicated case. However, improper management may lead to serious complications with a higher incidence of permanent visual disability. The article covers the management of posterior capsular rent from two perspectives: 1. Identifying patients at higher risk and measures to manage such patients by surgical discipline, and 2. Intraoperative management of posterior capsular rent and various case scenarios to minimize long-term complications.This review is written for experienced and not-so-experienced eye surgeons alike to understand and manage PCR.

  20. Frozen shoulder or missed posterior dislocation?

    African Journals Online (AJOL)

    posterior shoulder dislocation or adhesive capsulitis. Discussion. PSD is a rare entity. Incidence is approximately 2 - 5% of all shoulder dislocations.[1] Most often PSD is the result of an epileptic seizure. Less frequent causes are seizures due to alcoholic withdrawal or other metabolic disorders, electrocution or during a ...

  1. Selective posterior lumbosacral rhizotomy for the management ...

    African Journals Online (AJOL)

    One hundred and sixty-eight patients had selective lumbosacral posterior rhizotomies for the treatment of cerebral palsy spasticity at Red Cross War Memorial Children's Hospital and Groote Schuur Hospital during the 10-year period 1981 - 1991. There was no mortality and insignificant early postoperative morbidity.

  2. Endovascular treatment of ruptured distal posterior inferior ...

    African Journals Online (AJOL)

    Objective: To investigate the clinical characteristics and endovascular treatment of ruptured distal posterior inferior cerebellar artery (PICA) aneurysms. Methods: 11 consecutive patients (7 women, 4 men, mean age of 49.2 years) with ruptured distal PICA aneurysms were studied retrospectively. All had onset of acute ...

  3. Midterm results of posterior arthroscopic ankle fusion

    NARCIS (Netherlands)

    de Leeuw, Peter A. J.; Hendrickx, Roel P. M.; van Dijk, C. Niek; Stufkens, Sjoerd S.; Kerkhoffs, Gino M. M. J.

    2016-01-01

    The presented study was performed to evaluate the midterm clinical and radiological results and complication rates of the first 40 patients with an ankle fusion through a posterior arthroscopic approach. Forty consecutive patients with end-stage post-traumatic ankle osteoarthritis were treated with

  4. Posterior capsular rent: Prevention and management

    Directory of Open Access Journals (Sweden)

    Arup Chakrabarti

    2017-01-01

    Full Text Available This review article deals with a potentially sight threatening complication – rupture of the posterior capsule – during cataract surgery. Cataract surgery is the most commonly performed surgical procedure in ophthalmology and despite tremendous technical and technological advancements, posterior capsular rent (PCR still occurs. PCR occurs both in the hands of experienced senior surgeons and the neophyte surgeons, although with a higher frequency in the latter group. Additionally, certain types of cataracts are prone to this development. If managed properly in a timely manner the eventual outcome may be no different from that of an uncomplicated case. However, improper management may lead to serious complications with a higher incidence of permanent visual disability. The article covers the management of posterior capsular rent from two perspectives: 1. Identifying patients at higher risk and measures to manage such patients by surgical discipline, and 2. Intraoperative management of posterior capsular rent and various case scenarios to minimize long-term complications.This review is written for experienced and not-so-experienced eye surgeons alike to understand and manage PCR.

  5. The relationship between cerebral infarction on MR and angiographic findings in moyamoya disease: significance of the posterior circulation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ja; Song, Soon Young [College of Medicine, Kwangdong Univ., Koyang (Korea, Republic of); Yu, Won Jong; Jung, So Lyung; Chung, Bong Gak; Kag, Si Won [College of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of); Kim, Man Deuk [College of Medicine, Pochon CHA Univ., Pochon (Korea, Republic of)

    2002-06-01

    To investigate the relationship between changes in the posterior and anterior circulation, as seen at angiography, and the frequency and extent of cerebral infarction revealed by MR imaging in moyamoya disease. This study involved 34 patients (22 females and 12 males, aged 2-52 years) in whom cerebral angiography revealed the presence of moyamoya disease (bilateral; unilateral= 24:10; total hemispheres=58) and who also underwent brain MR imaging. To evaluate the angiographic findings, we applied each angiographic staging system to the anterior and posterior circulation. Leptomeningeal collateral circulation from the cortical branches of the posterior cerebral artery (PCA) was also assigned one of four grades. At MR imaging, areas of cerebral cortical or subcortical infarction in the hemisphere were divided into six zones. White matter and basal ganglionic infarction, ventricular dilatation, cortical atrophy, and hemorrhagic lesions were also evaluated. To demonstrate the statistical significance of the relationship between the angiographic and the MR findings, both the Mantel-Haenszel chi-square test for trend and the chi-square test were used. The degree of steno-occlusive PCA change correlated significantly with the internal carotid artery (ICA) stage (p<0.0001). As PCA stages advanced, the degree of leptomeningeal collaterals from the PCA decreased significantly (P<0.0001), but ICA stages were not significant (p>0.05). The prevalence of infarction showed significant correlation with the degree of steno-occlusive change in both the ICA and PCA. The degree of cerebral ischemia in moyamoya patients increased proportionally with the severity of PCA stenosis rather than with that of steno-occlusive lesins of the anterior circulation. Infarctions tended to be distributed in the anterior part of the hemisphere at PCA state I or II, while in more advanced PCA lesions, they were also found posteriorly, especially in the territories of the posterior middle cerebral artery

  6. Avaliação fonoaudiológica na atrofia de múltiplos sistemas: estudo com cinco pacientes Multiple system atrophy speech assessment: study of five cases

    Directory of Open Access Journals (Sweden)

    Denise Botelho Knopp

    2002-09-01

    Full Text Available A atrofia de múltiplos sistemas (AMS é caracterizada pela presença de sinais parkinsonianos, cerebelares, autonômicos e piramidais, em várias combinações. O aparecimento de disartria e disfagia no primeiro ano de manifestação de parkinsonismo, sugere o diagnóstico de AMS. O objetivo deste estudo foi o de caracterizar do ponto de vista fonoaudiológico os distúrbios da fala e da voz dos pacientes com AMS. Foram selecionados cinco pacientes, com idade média de 51,2 anos e com diagnóstico provável de AMS. Cada paciente foi submetido a avaliação neurológica e fonoaudiológica. Esta última foi composta dos seguintes itens: anamnese; avaliação miofuncional e avaliação perceptivo-auditiva da fala. Os sintomas de fala e voz apareceram 1,1 ano após o início dos sintomas motores e a disartrofonia apresentada por todos os pacientes foi a do tipo mista, mesclando os componentes hipocinético, atáxico e espástico, com predomínio do primeiro. Nossos achados são diferentes daqueles comumente vistos em pacientes com a doença de Parkinson, onde o componente hipocinético é o único achado. Os dados levantados indicam que a avaliação fonoaudiológica é importante no diagnóstico diferencial e no planejamento terapêutico da AMS.Multiple system atrophy (MSA is characterized by parkinsonian, cerebellar and pyramidal features along with autonomic dysfunction in different combinations. Onset of dysarthria during the first year of the manifestation of a parkinsonian syndrome suggests the diagnosis of MSA. The aim of this study was to characterize the voice and the speech of patients with MSA. We studied five MSA patients with a mean age of 51.2 years. Each patient was submitted to a neurological and a specific speech and voice assessment. The latter consisted of the following: clinical interview, myofunctional examination, and perceptual speech evaluation. Speech and voice complaints occurred at an average time of 1.1 year after the

  7. Encoding Cortical Dynamics in Sparse Features

    Directory of Open Access Journals (Sweden)

    Sheraz eKhan

    2014-05-01

    Full Text Available Distributed cortical solutions of magnetoencephalography (MEG and electroencephalography (EEG exhibit complex spatial and temporal dynamics. The extraction of patterns of interest and dynamic features from these cortical signals has so far relied on the expertise of investigators. There is a definite need in both clinical and neuroscience research for a method that will extract critical features from high-dimensional neuroimaging data in an automatic fashion. We have previously demonstrated the use of optical flow techniques for evaluating the kinematic properties of motion field projected on non-flat manifolds like in a cortical surface. We have further extended this framework to automatically detect features in the optical flow vector field by using the modified and extended 2-Riemannian Helmholtz Hodge Decomposition (HHD. Here, we applied these mathematical models on simulation and MEG data recorded from a healthy individual during a somatosensory experiment and an epilepsy pediatric patient during sleep. We tested whether our technique can automatically extract salient dynamical features of cortical activity. Simulation results indicated that we can precisely reproduce the simulated cortical dynamics with HHD; encode them in sparse features and represent the propagation of brain activity between distinct cortical areas. Using HHD, we decoded the somatosensory N20 component into two HHD features and represented the dynamics of brain activity as a traveling source between two primary somatosensory regions. In the epilepsy patient, we displayed the propagation of the epileptiform activity around the margins of a brain lesion. Our findings indicate that HHD measures computed from cortical dynamics can: (i quantitatively access the cortical dynamics in both healthy and disease brain in terms of sparse features and dynamic brain activity propagation between distinct cortical areas, and (ii facilitate a reproducible, automated analysis of MEG

  8. Tibial cortical lesions: A multimodality pictorial review

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, P.A., E-mail: philippa.tyler@rnoh.nhs.uk [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Mohaghegh, P., E-mail: pegah1000@gmail.com [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Foley, J., E-mail: jfoley1@nhs.net [Department of Radiology, Glasgow Royal Infirmary, 16 Alexandra Parade, Glasgow G31 2ES (United Kingdom); Isaac, A., E-mail: amandaisaac@doctors.org.uk [Department of Radiology, King' s College Hospital, Denmark Hill, London SE5 9RS (United Kingdom); Zavareh, A., E-mail: ali.zavareh@gmail.com [Department of Radiology, North Bristol NHS Trust, Frenchay, Bristol BS16 1LE (United Kingdom); Thorning, C., E-mail: cthorning@doctors.org.uk [Department of Radiology, East Surrey Hospital, Canada Avenue, Redhill, Surrey RH1 5RH (United Kingdom); Kirwadi, A., E-mail: anandkirwadi@gmail.com [Department of Radiology, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL (United Kingdom); Pressney, I., E-mail: ipressney@hotmail.com [Department of Radiology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Amary, F., E-mail: fernanda.amary@rnoh.nhs.uk [Department of Histopathology, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore HA7 4LP (United Kingdom); Rajeswaran, G., E-mail: grajeswaran@gmail.com [Department of Radiology, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH (United Kingdom)

    2015-01-15

    Highlights: • Multimodality imaging plays an important role in the investigation and diagnosis of shin pain. • We review the multimodality imaging findings of common cortically based tibial lesions. • We also describe the rarer pathologies of tibial cortical lesions. - Abstract: Shin pain is a common complaint, particularly in young and active patients, with a wide range of potential diagnoses and resulting implications. We review the natural history and multimodality imaging findings of the more common causes of cortically-based tibial lesions, as well as the rarer pathologies less frequently encountered in a general radiology department.

  9. Posterior Wnts Have Distinct Roles in Specification and Patterning of the Planarian Posterior Region

    Directory of Open Access Journals (Sweden)

    Miquel Sureda-Gómez

    2015-11-01

    Full Text Available The wnt signaling pathway is an intercellular communication mechanism essential in cell-fate specification, tissue patterning and regional-identity specification. A βcatenin-dependent signal specifies the AP (Anteroposterior axis of planarians, both during regeneration of new tissues and during normal homeostasis. Accordingly, four wnts (posterior wnts are expressed in a nested manner in central and posterior regions of planarians. We have analyzed the specific role of each posterior wnt and the possible cooperation between them in specifying and patterning planarian central and posterior regions. We show that each posterior wnt exerts a distinct role during re-specification and maintenance of the central and posterior planarian regions, and that the integration of the different wnt signals (βcatenin dependent and independent underlies the patterning of the AP axis from the central region to the tip of the tail. Based on these findings and data from the literature, we propose a model for patterning the planarian AP axis.

  10. Posterior Pole Sparing Laser Photocoagulation Combined with Intravitreal Bevacizumab Injection in Posterior Retinopathy of Prematurity

    Directory of Open Access Journals (Sweden)

    Rebecca Kim

    2014-01-01

    Full Text Available Purpose. To report the results of the posterior pole sparing laser photocoagulation combined with intravitreal bevacizumab injection (IVB in retinopathy of prematurity (ROP. Methods. A retrospective chart review of premature babies with ROP, all of whom received laser photocoagulation with IVB. Eleven eyes of 6 infants with advanced zone I ROP underwent laser ablation sparing posterior pole with concurrent IVB. The results were compared with those of full-laser treatment combined with IVB to 8 eyes of 5 infants with advanced ROP without involvement of the posterior pole. Results. The posterior pole sparing laser with IVB was performed with zone I, stage 3+ ROP at the mean postmenstrual age of 36 weeks and 5 days. The plus sign decreased significantly at postoperative day 1, the neovascular proliferation regressed by postoperative week 1, and the normal vascularization started at postoperative day 32 on the average. Two months after treatment, vascularization of the spared avascular area was completed. There was no macular dragging, tractional retinal detachment, foveal destruction by laser scars, or any other adverse event. No significant anatomical differences were identified from those of full-laser ablation combined with IVB. Conclusions. Posterior pole sparing laser with IVB can give favorable results without destruction of posterior pole retina.

  11. Hand Shape Representations in the Human Posterior Parietal Cortex.

    Science.gov (United States)

    Klaes, Christian; Kellis, Spencer; Aflalo, Tyson; Lee, Brian; Pejsa, Kelsie; Shanfield, Kathleen; Hayes-Jackson, Stephanie; Aisen, Mindy; Heck, Christi; Liu, Charles; Andersen, Richard A

    2015-11-18

    Humans shape their hands to grasp, manipulate objects, and to communicate. From nonhuman primate studies, we know that visual and motor properties for grasps can be derived from cells in the posterior parietal cortex (PPC). Are non-grasp-related hand shapes in humans represented similarly? Here we show for the first time how single neurons in the PPC of humans are selective for particular imagined hand shapes independent of graspable objects. We find that motor imagery to shape the hand can be successfully decoded from the PPC by implementing a version of the popular Rock-Paper-Scissors game and its extension Rock-Paper-Scissors-Lizard-Spock. By simultaneous presentation of visual and auditory cues, we can discriminate motor imagery from visual information and show differences in auditory and visual information processing in the PPC. These results also demonstrate that neural signals from human PPC can be used to drive a dexterous cortical neuroprosthesis. This study shows for the first time hand-shape decoding from human PPC. Unlike nonhuman primate studies in which the visual stimuli are the objects to be grasped, the visually cued hand shapes that we use are independent of the stimuli. Furthermore, we can show that distinct neuronal populations are activated for the visual cue and the imagined hand shape. Additionally we found that auditory and visual stimuli that cue the same hand shape are processed differently in PPC. Early on in a trial, only the visual stimuli and not the auditory stimuli can be decoded. During the later stages of a trial, the motor imagery for a particular hand shape can be decoded for both modalities. Copyright © 2015 the authors 0270-6474/15/3515466-11$15.00/0.

  12. The posterior parietal cortex (PPC) mediates anticipatory motor control.

    Science.gov (United States)

    Krause, Vanessa; Weber, Juliane; Pollok, Bettina

    2014-01-01

    Flexible and precisely timed motor control is based on functional interaction within a cortico-subcortical network. The left posterior parietal cortex (PPC) is supposed to be crucial for anticipatory motor control by sensorimotor feedback matching. Intention of the present study was to disentangle the specific relevance of the left PPC for anticipatory motor control using transcranial direct current stimulation (tDCS) since a causal link remains to be established. Anodal vs. cathodal tDCS was applied for 10 min over the left PPC in 16 right-handed subjects in separate sessions. Left primary motor cortex (M1) tDCS served as control condition and was applied in additional 15 subjects. Prior to and immediately after tDCS, subjects performed three tasks demanding temporal motor precision with respect to an auditory stimulus: sensorimotor synchronization as measure of anticipatory motor control, interval reproduction and simple reaction. Left PPC tDCS affected right hand synchronization but not simple reaction times. Motor anticipation was deteriorated by anodal tDCS, while cathodal tDCS yielded the reverse effect. The variability of interval reproduction was increased by anodal left M1 tDCS, whereas it was reduced by cathodal tDCS. No significant effects on simple reaction times were found. The present data support the hypothesis that left PPC is causally involved in right hand anticipatory motor control exceeding pure motor implementation as processed by M1 and possibly indicating subjective timing. Since M1 tDCS particularly affects motor implementation, the observed PPC effects are not likely to be explained by alterations of motor-cortical excitability. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

    DEFF Research Database (Denmark)

    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe

    2013-01-01

    magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified...... reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann...... of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first...

  14. Tensile mechanical properties of swine cortical mandibular bone.

    Science.gov (United States)

    Brosh, Tamar; Rozitsky, Doron; Geron, Silvia; Pilo, Raphael

    2014-01-01

    Temporary orthodontic mini implants serve as anchorage devices in orthodontic treatments. Often, they are inserted in the jaw bones, between the roots of the teeth. The stability of the mini implants within the bone is one of the major factors affecting their success and, consequently, that of the orthodontic treatment. Bone mechanical properties are important for implant stability. The aim of this study was to determine the tensile properties of the alveolar and basal mandible bones in a swine model. The diametral compression test was employed to study the properties in two orthogonal directions: mesio-distal and occluso-gingival. Small cylindrical cortical bone specimens (2.6 mm diameter, 1.5 mm thickness) were obtained from 7 mandibles using a trephine drill. The sites included different locations (anterior and posterior) and aspects (buccal and lingual) for a total of 16 specimens from each mandible. The load-displacement curves were continuously monitored while loading half of the specimens in the oclluso-gingival direction and half in the mesio-distal direction. The stiffness was calculated from the linear portion of the curve. The mesio-distal direction was 31% stiffer than the occluso-gingival direction. The basal bone was 40% stiffer than the alveolar bone. The posterior zone was 46% stiffer than the anterior zone. The lingual aspect was stiffer than the buccal aspect. Although bone specimens do not behave as brittle materials, the diametral compression test can be adequately used for determining tensile behavior when only small bone specimens can be obtained. In conclusion, to obtain maximal orthodontic mini implant stability, the force components on the implants should be oriented mostly in the mesio-distal direction.

  15. Decreased cortical response to verbal working memory following sleep deprivation.

    Science.gov (United States)

    Mu, Qiwen; Nahas, Ziad; Johnson, Kevin A; Yamanaka, Kaori; Mishory, Alexander; Koola, Jejo; Hill, Sarah; Horner, Michael D; Bohning, Daryl E; George, Mark S

    2005-01-01

    To investigate the cerebral hemodynamic response to verbal working memory following sleep deprivation. Subjects were scheduled for 3 functional magnetic resonance imaging scanning visits: an initial screening day (screening state), after a normal night of sleep (rested state), and after 30 hours of sleep deprivation (sleep-deprivation state). Subjects performed the Sternberg working memory task alternated with a control task during an approximate 13-minute functional magnetic resonance imaging scan. Inpatient General Clinical Research Center and outpatient functional magnetic resonance imaging center. Results from 33 men (mean age, 28.6 +/- 6.6 years) were included in the final analyses. None. Subjects performed the same Sternberg working memory task at the 3 states within the magnetic resonance imaging scanner. Neuroimaging data revealed that, in the screening and rested states, the brain regions activated by the Sternberg working memory task were found in the left dorsolateral prefrontal cortex, Broca's area, supplementary motor area, right ventrolateral prefrontal cortex, and the bilateral posterior parietal cortexes. After 30 hours of sleep deprivation, the activations in these brain regions significantly decreased, especially in the bilateral posterior parietal cortices. Task performance also decreased. A repeated-measures analysis of variance revealed that subjects at the screening and rested states had similar activation patterns, with each having significantly more activation than during the sleep-deprivation state. These results suggest that human sleep-deprivation deficits are not caused solely or even predominantly by prefrontal cortex dysfunction and that the paretal cortex, in particular, and other brain regions involved in verbal working memory exhibit significant sleep-deprivation vulnerability.

  16. Long range frontal/posterior phase synchronization during remembered pursuit task is impaired in schizophrenia.

    Science.gov (United States)

    Krishna, Nithin; O'Neill, Hugh; Sánchez-Morla, Eva María; Thaker, Gunvant K

    2014-08-01

    Although smooth pursuit eye movement (SPEM) is a reliable endophenotype of schizophrenia, exact underlying cognitive and neural substrates remain unknown. A simple mechanistic model of SPEM assumes an efficient interaction in integrating sensory input from the medial temporal (MT)/medial superior temporal (MST) brain regions and subsequent motor response through the frontal eye field (FEF). Poor functional connectivity between these two regions could explain impaired motion perception and SPEM maintenance in schizophrenia. In the present study, we combined an eye tracking paradigm with electroencephalography (EEG) recordings to investigate the putative functional connectivity among frontal/posterior brain regions in mediating the modulation of SPEM. Twenty four schizophrenic (SZ) and 22 healthy control (HC) participants performed remembered pursuit tasks with EEG recordings. Behaviorally, HC subjects showed significant improvement in SPEM response on repeated presentations of target compared to SZ subjects. Neurophysiologically HC subjects showed higher frontal/posterior phase synchronization in the beta to low gamma range frequency bands during all target presentations. In addition there was a significant increase in phase synchronization in the beta-2 frequency band in HC subjects during late compared to early target presentation. In contrast, higher frontal/posterior phase synchronization in the beta-2 frequency predicted better performance during late target presentation and lower enduring psychosis in SZ subjects. These data suggest a pathologically perturbed connectivity between frontal and posterior cortical regions during SPEM in SZ. The integrative eye tracking-EEG approach used in this study to dissect the endophenotype may reveal novel targets for studying schizophrenia psychopathology. Published by Elsevier B.V.

  17. Dermoid cyst of the posterior fossa.

    Science.gov (United States)

    Benzagmout, Mohammed; Agharbi, Sanae; Chakour, Khalid; Chaoui, Mohammed E

    2011-04-01

    Intracranial dermoid tumors represent a rare clinical entity accounting for 0.1-0.7% of all intracranial tumors. Their location in the posterior fossa is uncommon. We report a 16-year-old male patient who presented with clinical signs of increased intracranial pressure and cerebellar symptoms. The CT scan revealed a median cystic lesion of the fourth ventricle causing an active triventicular hydrocephalus. The MRI showed a median well shaped cystic lesion, of low signal intensity compared to the CSF, with capsular contrast enhancement. He underwent endoscopic third ventriculostomy before subtotal removal of the lesion. The postoperative course was uneventful, and the histological diagnosis was a dermoid cyst. Through this observation, we aim to discuss the clinical, and radiological aspects of the posterior fossa dermoid cyst, and to review the therapeutic strategies.

  18. Posterior reversible encephalopathy syndrome: A case report

    Directory of Open Access Journals (Sweden)

    Kostić Dejan

    2015-01-01

    Full Text Available Posterior reversible encephalopathy syndrome (PRES is characterized by the following symptoms: seizures, impaired consciousness and/or vision, vomiting, nausea, and focal neurological signs. Diagnostic imaging includes examination by magnetic resonance (MR and computed tomography (CT, where brain edema is visualized bi-laterally and symmetrically, predominantly posteriorly, parietally, and occipitally. Case report. We presented a 73-year-old patient with the years-long medical history of hipertension and renal insufficiency, who developed PRES with the symptomatology of the rear cranium. CT and MR verified changes in the white matter involving all lobes on both sides of the brain. After a two-week treatment (antihypertensive, hypolipemic and rehydration therapy clinical improvement with no complications occurred, with complete resolution of changes in the white matter observed on CT and MR. Conclusion. PRES is a reversible syndrome in which the symptoms withdraw after several days to several weeks if early diagnosis is made and appropriate treatment started without delay.

  19. Superresolution improves MRI cortical segmentation with FACE

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Manjón, José V.; Coupé, Pierrick

    Brain cortical surface extraction from MRI has applications for measurement of gray matter (GM) atrophy, functional mapping, source localization and preoperative neurosurgical planning. Accurate cortex segmentation requires high resolution morphological images and several methods for extracting...

  20. The Diversity of Cortical Inhibitory Synapses

    Directory of Open Access Journals (Sweden)

    Yoshiyuki eKubota

    2016-04-01

    Full Text Available The most typical and well known inhibitory action in the cortical microcircuit is a strong inhibition on the target neuron by axo-somatic synapses. However, it has become clear that synaptic inhibition in the cortex is much more diverse and complicated. Firstly, at least ten or more inhibitory non-pyramidal cell subtypes engage in diverse inhibitory functions to produce the elaborate activity characteristic of the different cortical states. Each distinct non-pyramidal cell subtype has its own independent inhibitory function. Secondly, the inhibitory synapses innervate different neuronal domains, such as axons, spines, dendrites and soma, and their IPSP size is not uniform. Thus cortical inhibition is highly complex, with a wide variety of anatomical and physiological modes. Moreover, the functional significance of the various inhibitory synapse innervation styles and their unique structural dynamic behaviors differ from those of excitatory synapses. In this review, we summarize our current understanding of the inhibitory mechanisms of the cortical microcircuit.

  1. Posterior sternoclavicular dislocation: an American football injury

    DEFF Research Database (Denmark)

    Marker, L B; Klareskov, B

    1996-01-01

    Posterior dislocation of the sternoclavicular joint is uncommon, accounting for less than 0.1% of all dislocations. Since 1824 a little more than 100 cases have been reported, and the majority in the past 20 years. A review of published reports suggests that this injury is seen particularly in co...... in connection with American football. A typical case is described. The importance of this injury is that there is often a delay in diagnosis with potentially serious complications....

  2. Restoration of the endodontically treated posterior tooth

    OpenAIRE

    Andrea Polesel

    2014-01-01

    Objectives: To analyse the key factors of the restoration in the posterior endodontically treated teeth, through a literature review and clinical cases presentation. To focus on the clinical advantages of the adhesive indirect restorations, describing the basic principles for long-term success. Materials and methods: The biomechanical changes due to the root canal therapy and the degree of healthy dental tissue lost because of pathology and iatrogenic factors are the critical points leadin...

  3. Posterior sternoclavicular dislocation: an American football injury

    DEFF Research Database (Denmark)

    Marker, L B; Klareskov, B

    1996-01-01

    Posterior dislocation of the sternoclavicular joint is uncommon, accounting for less than 0.1% of all dislocations. Since 1824 a little more than 100 cases have been reported, and the majority in the past 20 years. A review of published reports suggests that this injury is seen particularly...... in connection with American football. A typical case is described. The importance of this injury is that there is often a delay in diagnosis with potentially serious complications....

  4. Primary posterior perineal herniation of urinary bladder

    Directory of Open Access Journals (Sweden)

    Kurumboor Prakash

    2013-01-01

    Full Text Available Primary perineal hernia is a rare clinical condition wherein herniation of viscera occurs through pelvic diaphragm. They are usually mistaken for sciatic hernia, rectal prolapse or other diseases in the perineum. Correct identification of the type of hernia by imaging is crucial for planning treatment. We present a case of primary posterior herniation of urinary bladder and rectal wall through levator ani repaired laparoscopically using a mesh repair.

  5. Posterior midline cervical fetal cystic hygroma.

    Directory of Open Access Journals (Sweden)

    Oak S

    1992-04-01

    Full Text Available Posterior midline cervical cystic hygromas (PMC are frequently found associated with chromosomal aberrations and usually do not survive. The present report illustrates diagnosis of this condition by sonography in an 18 weeks old fetus and an amniocentesis revealed 45 x0 karyotype and increased concentration of alpha-fetoproteins. Pregnancy was terminated in view of Turner′s syndrome. The etiology and natural history of the condition is reviewed.

  6. Delayed primary realignment of posterior urethral rupture

    African Journals Online (AJOL)

    are still mobile. As these are rare injuries and because most patients who sustain these injuries rarely present to the urolo— gist acutely, it is difficult for any single urology unit to accumu- late enough cases for randomization. Aim of the study. The aim of the study is to find out the outcome of pa- tients who sustained posterior ...

  7. Cervical disc hernia operations through posterior laminoforaminotomy

    Science.gov (United States)

    Yolas, Coskun; Ozdemir, Nuriye Guzin; Okay, Hilmi Onder; Kanat, Ayhan; Senol, Mehmet; Atci, Ibrahim Burak; Yilmaz, Hakan; Coban, Mustafa Kemal; Yuksel, Mehmet Onur; Kahraman, Umit

    2016-01-01

    Objective: The most common used technique for posterolateral cervical disc herniations is anterior approach. However, posterior cervical laminotoforaminomy can provide excellent results in appropriately selected patients with foraminal stenosis in either soft disc prolapse or cervical spondylosis. The purpose of this study was to present the clinical outcomes following posterior laminoforaminotomy in patients with radiculopathy. Materials and Methods: We retrospectively evaluated 35 patients diagnosed with posterolateral cervical disc herniation and cervical spondylosis with foraminal stenosis causing radiculopathy operated by the posterior cervical keyhole laminoforaminotomy between the years 2010 and 2015. Results: The file records and the radiographic images of the 35 patients were assessed retrospectively. The mean age was 46.4 years (range: 34-66 years). Of the patients, 19 were males and 16 were females. In all of the patients, the neurologic deficit observed was radiculopathy. The posterolaterally localized disc herniations and the osteophytic structures were on the left side in 18 cases and on the right in 17 cases. In 10 of the patients, the disc level was at C5-6, in 18 at C6-7, in 2 at C3-4, in 2 at C4-5, in 1 at C7-T1, in 1 patient at both C5-6 and C6-7, and in 1 at both C4-5 and C5-6. In 14 of these 35 patients, both osteophytic structures and protruded disc herniation were present. Intervertebral foramen stenosis was present in all of the patients with osteophytes. Postoperatively, in 31 patients the complaints were relieved completely and four patients had complaints of neck pain and paresthesia radiating to the arm (the success of operation was 88.5%). On control examinations, there was no finding of instability or cervical kyphosis. Conclusion: Posterior cervical laminoforaminotomy is an alternative appropriate choice in both cervical soft disc herniations and cervical stenosis. PMID:27217655

  8. Duloxetine-related posterior reversible encephalopathy syndrome

    OpenAIRE

    Zappella, Nathalie; Perier, Fran?ois; Pico, Fernando; Palette, Catherine; Muret, Alexandre; Merceron, Sybille; Girbovan, Andrei; Marquion, Fabien; Legriel,Stephane

    2016-01-01

    Abstract Background: Posterior reversible encephalopathy syndrome (PRES) has well-established links with several drugs. Whether a link also exists with serotonin?norepinephrine reuptake inhibitor such as duloxetine is unclear. Methods: We report on a patient who developed PRES with a coma and myoclonus related to hypertensive encephalopathy a few days after starting duloxetine treatment. Magnetic resonance imaging was performed and catecholamine metabolites assayed. Results: The patient achie...

  9. Reversible Posterior Leukoencephalopathy Syndrome Induced by Pazopanib

    Directory of Open Access Journals (Sweden)

    Chelis Leonidas

    2012-10-01

    Full Text Available Abstract Background The reversible posterior leukoencephalopathy syndrome is a clinical/radiological syndrome characterized by headache, seizures, impaired vision, acute hypertension, and typical magnetic resonance imaging findings. There are several reports in the literature that depict its occurrence in cancer patients. The list of common anticancer and supportive care drugs that predispose to reversible posterior leukoencephalopathy syndrome is expanding and includes not only a large number of chemotherapeutic agents but also an increased number of new targeted drugs, particularly angiogenesis inhibitors such as bevacizumab,sorefenib and sunitinib. Pazopanib is an oral tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit which after a positive phase III randomized clinical trial in patients with advanced renal cell cancer received FDA approval for the treatment of advanced renal cell carcinoma. Until now no cases of reversible posterior leukoencephalopathy syndrome induced by pazopanib have been reported. Case report We present the case of a 40 years old female patient with heavily pre-treated metastatic renal cell carcinoma who received pazopanib as salvage treatment. After 21 days of pazopanib therapy the patient referred to the emergency department with epileptic seizure, impaired vision at both eyes and headache. MRI of the brain revealed subcortical oedema at the occipital and parietal lobes bilaterally. She was treated with anticonvulsants, i.v. administration of mannitol and antihypertensives and she recovered completely from her symptoms and was discharged on the tenth hospital day. A brain MRI performed 3 weeks after showed that the subcortical oedema had been subsided. Conclusion In conclusion this is the first case of pazopanib induced reversible posterior leukoencephalopathy syndrome. Although usually reversible, this syndrome is a serious and

  10. CT in thrombosed dilated posterior epidural vein

    Energy Technology Data Exchange (ETDEWEB)

    Bammatter, S.; Schnyder, P.; Preux, J. de

    1987-05-01

    The authors report a case of thrombosis of the distal end of an enlarged right posterior epidural vein. The patient had a markedly narrow lumbar canal due to L5 spondylolisthesis. The dilated vein and the thrombosis were displayed by computed tomography but remained unrecognized until surgery. Pathogenesis of this condition is discussed. A review of the English, French and German literature revealed no prior radiological reports of a similar condition.

  11. Posterior reversible encephalopathy syndrome: An atypical postpartum complication

    National Research Council Canada - National Science Library

    Paul, Debashish; Kulkarni, SachinNarayan; Choudhury, MiliDas; Maity, GD

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is presented by headache, altered mental status, blurring of vision, vomiting and seizure in conjunction with radiological finding of posterior cerebral white matter edema...

  12. [Posterior release in congenital talipes equinovarus adductus].

    Science.gov (United States)

    Fuentes-Nucamendi, M A; Camarena-Hernández, H P; Bonfil-Ojeda, J R; Martínez-Bonilla, E

    2012-01-01

    To show the utility of posterior release to correct adduct congenital talipes equinovarus (CTE) and describe the surgical technique. This clinical trial was conducted from February 2002 to November 2008. Patients ages 0-24 months old with a diagnosis of adduct CTE were enrolled. Surgical treatment consisted of a posterior approach to the foot with Z-plasty of the tibialis posterior, flexor digitorum longus and flexor hallucis longus, capsulotomy, adductor hallucis release, and cast immobilization for 8 weeks. The sampling was non-randomized, non-probabilistic; patients were enrolled based on the diagnosis. The statistical analysis included the central trend and scatter measures, the Student "t" test, RR, and homogeneity chi square test. Twenty-five patients were enrolled, 13 females and 12 males, with a total of 30 feet, 10 left and 6 right, and 7 bilateral patients. Median age was 15 years (range 11-24 years). Correction was achieved and maintained in 27 feet. Three cases had adduct relapse and were managed conservatively. The statistical analysis showed the effectiveness of treatment. The result of the Student "t" test and the chi square test was p 18 months was a risk factor for residual adduct with a RR = 3.7.

  13. Posterior fossa syndrome-a narrative review.

    Science.gov (United States)

    Wahab, Salima S; Hettige, Samantha; Mankad, Kshtij; Aquilina, Kristian

    2016-10-01

    Posterior fossa syndrome (PFS), or cerebellar mutism syndrome (CMS), is a collection of neurological symptoms that occur following surgical resection of a posterior fossa tumour, and is characterised by either a reduction or an absence of speech. Some authors suggest that CM is only one symptom of the CMS complex that also includes ataxia, hypotonia and irritability as well as cranial nerve deficits, neurobehavioral changes and urinary retention or incontinence. It is seen almost exclusively in children. In 1985 Rekate et al. published the first work describing CM as a clinical entity, occurring as a consequence of bilateral cerebellar injury. Other associated symptoms include visual impairment, altered mood, impaired swallowing and significant gross and fine motor deficits. The effects of this can have a devastating impact on both the patient and their carers, posing a significant clinical challenge to neurorehabilitation services. The reported incidence was between 8% and 31% of children undergoing surgery for posterior fossa tumour. The underlying pathologies include vasospasm, oedema, and axonal/neuronal injury. Neuroimaging has contributed to a better understanding of the anatomical location of postoperative injury. There have been a number of suggestions for treatment interventions for PFS. However, apart from some individual reports, there have been no clinical trials indicating possible benefit. Occupational therapy, speech and language therapy, as well as neurocognitive support, contribute to the recovery of these patients.

  14. The tumor suppressor gene Trp53 protects the mouse lens against posterior subcapsular cataracts and the BMP receptor Acvr1 acts as a tumor suppressor in the lens

    Directory of Open Access Journals (Sweden)

    Luke A. Wiley

    2011-07-01

    We previously found that lenses lacking the Acvr1 gene, which encodes a bone morphogenetic protein (BMP receptor, had abnormal proliferation and cell death in epithelial and cortical fiber cells. We tested whether the tumor suppressor protein p53 (encoded by Trp53 affected this phenotype. Acvr1 conditional knockout (Acvr1CKO mouse fiber cells had increased numbers of nuclei that stained for p53 phosphorylated on serine 15, an indicator of p53 stabilization and activation. Deletion of Trp53 rescued the Acvr1CKO cell death phenotype in embryos and reduced Acvr1-dependent apoptosis in postnatal lenses. However, deletion of Trp53 alone increased the number of fiber cells that failed to withdraw from the cell cycle. Trp53CKO and Acvr1;Trp53DCKO (double conditional knockout, but not Acvr1CKO, lenses developed abnormal collections of cells at the posterior of the lens that resembled posterior subcapsular cataracts. Cells from human posterior subcapsular cataracts had morphological and molecular characteristics similar to the cells at the posterior of mouse lenses lacking Trp53. In Trp53CKO lenses, cells in the posterior plaques did not proliferate but, in Acvr1;Trp53DCKO lenses, many cells in the posterior plaques continued to proliferate, eventually forming vascularized tumor-like masses at the posterior of the lens. We conclude that p53 protects the lens against posterior subcapsular cataract formation by suppressing the proliferation of fiber cells and promoting the death of any fiber cells that enter the cell cycle. Acvr1 acts as a tumor suppressor in the lens. Enhancing p53 function in the lens could contribute to the prevention of steroid- and radiation-induced posterior subcapsular cataracts.

  15. Cortical Neural Computation by Discrete Results Hypothesis.

    Science.gov (United States)

    Castejon, Carlos; Nuñez, Angel

    2016-01-01

    One of the most challenging problems we face in neuroscience is to understand how the cortex performs computations. There is increasing evidence that the power of the cortical processing is produced by populations of neurons forming dynamic neuronal ensembles. Theoretical proposals and multineuronal experimental studies have revealed that ensembles of neurons can form emergent functional units. However, how these ensembles are implicated in cortical computations is still a mystery. Although cell ensembles have been associated with brain rhythms, the functional interaction remains largely unclear. It is still unknown how spatially distributed neuronal activity can be temporally integrated to contribute to cortical computations. A theoretical explanation integrating spatial and temporal aspects of cortical processing is still lacking. In this Hypothesis and Theory article, we propose a new functional theoretical framework to explain the computational roles of these ensembles in cortical processing. We suggest that complex neural computations underlying cortical processing could be temporally discrete and that sensory information would need to be quantized to be computed by the cerebral cortex. Accordingly, we propose that cortical processing is produced by the computation of discrete spatio-temporal functional units that we have called "Discrete Results" (Discrete Results Hypothesis). This hypothesis represents a novel functional mechanism by which information processing is computed in the cortex. Furthermore, we propose that precise dynamic sequences of "Discrete Results" is the mechanism used by the cortex to extract, code, memorize and transmit neural information. The novel "Discrete Results" concept has the ability to match the spatial and temporal aspects of cortical processing. We discuss the possible neural underpinnings of these functional computational units and describe the empirical evidence supporting our hypothesis. We propose that fast-spiking (FS

  16. VAGUS NERVE STIMULATION INHIBITS CORTICAL SPREADING DEPRESSION

    OpenAIRE

    Chen, Shih-Pin; Ay, Ilknur; de Morais, Andreia Lopes; Qin, Tao; Zheng,Yi; Sadhegian, Homa; Oka, Fumiaki; Simon, Bruce; Eikermann-Haerter, Katharina; Ayata, Cenk

    2016-01-01

    Vagus nerve stimulation has recently been reported to improve symptoms of migraine. Cortical spreading depression is the electrophysiological event underlying migraine aura, and a trigger for headache. We tested whether vagus nerve stimulation inhibits cortical spreading depression to explain its anti-migraine effect. Vagus nerve stimulation was delivered either non-invasively through the skin or directly by electrodes placed around the vagus nerve unilaterally. Systemic physiology was monito...

  17. Regional specialization in pyramidal cell structure in the limbic cortex of the vervet monkey (Cercopithecus pygerythrus): an intracellular injection study of the anterior and posterior cingulate gyrus.

    Science.gov (United States)

    Elston, Guy N; Benavides-Piccione, Ruth; Elston, Alejandra; Manger, Paul; Defelipe, Javier

    2005-12-01

    The pyramidal cell phenotype varies quite dramatically in structure among different cortical areas in the primate brain. Comparative studies in visual cortex, in particular, but also in sensorimotor and prefrontal cortex, reveal systematic trends for pyramidal cell specialization in functionally related cortical areas. Moreover, there are systematic differences in the extent of these trends between different primate species. Recently we demonstrated differences in pyramidal cell structure in the cingulate cortex of the macaque monkey; however, in the absence of other comparative data it remains unknown as to whether the neuronal phenotype differs in cingulate cortex between species. Here we extend the basis for comparison by studying the structure of the basal dendritic trees of layer III pyramidal cells in the posterior and anterior cingulate gyrus of the vervet monkey (Brodmann's areas 23 and 24, respectively). Cells were injected with Lucifer Yellow in flat-mounted cortical slices, and processed for a light-stable DAB reaction product. Size, branching pattern, and spine density of basal dendritic arbors were determined, and somal areas measured. As in the macaque monkey, we found that pyramidal cells in anterior cingulate gyrus (area 24) were more branched and more spinous than those in posterior cingulate gyrus (area 23). In addition, the extent of the difference in pyramidal cell structure between these two cortical regions was less in the vervet monkey than in the macaque monkey.

  18. Elastic Properties of Chimpanzee Craniofacial Cortical Bone.

    Science.gov (United States)

    Gharpure, Poorva; Kontogiorgos, Elias D; Opperman, Lynne A; Ross, Callum F; Strait, David S; Smith, Amanda; Pryor, Leslie C; Wang, Qian; Dechow, Paul C

    2016-12-01

    Relatively few assessments of cranial biomechanics formally take into account variation in the material properties of cranial cortical bone. Our aim was to characterize the elastic properties of chimpanzee craniofacial cortical bone and compare these to the elastic properties of dentate human craniofacial cortical bone. From seven cranial regions, 27 cylindrical samples were harvested from each of five chimpanzee crania. Assuming orthotropy, axes of maximum stiffness in the plane of the cortical plate were derived using modified equations of Hooke's law in a Mathcad program. Consistent orientations among individuals were observed in the zygomatic arch and alveolus. The density of cortical bone showed significant regional variation (P  E2  > E1 . Shear moduli were significantly different among regions (P < 0.001). The pattern by which chimpanzee cranial cortical bone varies in elastic properties resembled that seen in humans, perhaps suggesting that the elastic properties of craniofacial bone in fossil hominins can be estimated with at least some degree of confidence. Anat Rec, 299:1718-1733, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Sacroiliac joint injection using the posterior superior iliac spines as ...

    African Journals Online (AJOL)

    For each cadaver, the gluteal region was dissected to expose the bony posterior superior iliac spines (PSIS) and the posterior long sacroiliac ligaments. The proximal third of both posterior long sacroiliac ligaments were removed to expose the clefts between the two bones on both sides for the introduction of an IV cannula ...

  20. Structural alteration of the dorsal visual network in DLB patients with visual hallucinations: a cortical thickness MRI study.

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    Stefano Delli Pizzi

    Full Text Available Visual hallucinations (VH represent one of the core features in discriminating dementia with Lewy bodies (DLB from Alzheimer's Disease (AD. Previous studies reported that in DLB patients functional alterations of the parieto-occipital regions were correlated with the presence of VH. The aim of our study was to assess whether morphological changes in specific cortical regions of DLB could be related to the presence and severity of VH. We performed a cortical thickness analysis on magnetic resonance imaging data in a cohort including 18 DLB patients, 15 AD patients and 14 healthy control subjects. Relatively to DLB group, correlation analysis between the cortical thickness and the Neuropsychiatric Inventory (NPI hallucination item scores was also performed. Cortical thickness was reduced bilaterally in DLB compared to controls in the pericalcarine and lingual gyri, cuneus, precuneus, superior parietal gyrus. Cortical thinning was found bilaterally in AD compared to controls in temporal cortex including the superior and middle temporal gyrus, part of inferior temporal cortex, temporal pole and insula. Inferior parietal and supramarginal gyri were also affected bilaterally in AD as compared to controls. The comparison between DLB and AD evidenced cortical thinning in DLB group in the right posterior regions including superior parietal gyrus, precuneus, cuneus, pericalcarine and lingual gyri. Furthermore, the correlation analysis between cortical thickness and NPI hallucination item scores showed that the structural alteration in the dorsal visual regions including superior parietal gyrus and precuneus closely correlated with the occurrence and severity of VH. We suggest that structural changes in key regions of the dorsal visual network may play a crucial role in the physiopathology of VH in DLB patients.

  1. A Double Dissociation between Anterior and Posterior Superior Temporal Gyrus for Processing Audiovisual Speech Demonstrated by Electrocorticography.

    Science.gov (United States)

    Ozker, Muge; Schepers, Inga M; Magnotti, John F; Yoshor, Daniel; Beauchamp, Michael S

    2017-06-01

    Human speech can be comprehended using only auditory information from the talker's voice. However, comprehension is improved if the talker's face is visible, especially if the auditory information is degraded as occurs in noisy environments or with hearing loss. We explored the neural substrates of audiovisual speech perception using electrocorticography, direct recording of neural activity using electrodes implanted on the cortical surface. We observed a double dissociation in the responses to audiovisual speech with clear and noisy auditory component within the superior temporal gyrus (STG), a region long known to be important for speech perception. Anterior STG showed greater neural activity to audiovisual speech with clear auditory component, whereas posterior STG showed similar or greater neural activity to audiovisual speech in which the speech was replaced with speech-like noise. A distinct border between the two response patterns was observed, demarcated by a landmark corresponding to the posterior margin of Heschl's gyrus. To further investigate the computational roles of both regions, we considered Bayesian models of multisensory integration, which predict that combining the independent sources of information available from different modalities should reduce variability in the neural responses. We tested this prediction by measuring the variability of the neural responses to single audiovisual words. Posterior STG showed smaller variability than anterior STG during presentation of audiovisual speech with noisy auditory component. Taken together, these results suggest that posterior STG but not anterior STG is important for multisensory integration of noisy auditory and visual speech.

  2. Cortical Auditory-Evoked Responses in Preterm Neonates: Revisited by Spectral and Temporal Analyses.

    Science.gov (United States)

    Kaminska, A; Delattre, V; Laschet, J; Dubois, J; Labidurie, M; Duval, A; Manresa, A; Magny, J-F; Hovhannisyan, S; Mokhtari, M; Ouss, L; Boissel, A; Hertz-Pannier, L; Sintsov, M; Minlebaev, M; Khazipov, R; Chiron, C

    2017-08-11

    Characteristic preterm EEG patterns of "Delta-brushes" (DBs) have been reported in the temporal cortex following auditory stimuli, but their spatio-temporal dynamics remains elusive. Using 32-electrode EEG recordings and co-registration of electrodes' position to 3D-MRI of age-matched neonates, we explored the cortical auditory-evoked responses (AERs) after 'click' stimuli in 30 healthy neonates aged 30-38 post-menstrual weeks (PMW). (1) We visually identified auditory-evoked DBs within AERs in all the babies between 30 and 33 PMW and a decreasing response rate afterwards. (2) The AERs showed an increase in EEG power from delta to gamma frequency bands over the middle and posterior temporal regions with higher values in quiet sleep and on the right. (3) Time-frequency and averaging analyses showed that the delta component of DBs, which negatively peaked around 550 and 750 ms over the middle and posterior temporal regions, respectively, was superimposed with fast (alpha-gamma) oscillations and corresponded to the late part of the cortical auditory-evoked potential (CAEP), a feature missed when using classical CAEP processing. As evoked DBs rate and AERs delta to alpha frequency power decreased until full term, auditory-evoked DBs are thus associated with the prenatal development of auditory processing and may suggest an early emerging hemispheric specialization. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Combining diffusion magnetic resonance tractography with stereology highlights increased cross-cortical integration in primates.

    Science.gov (United States)

    Charvet, Christine J; Hof, Patrick R; Raghanti, Mary Ann; Van Der Kouwe, Andre J; Sherwood, Chet C; Takahashi, Emi

    2017-04-01

    The isocortex of primates is disproportionately expanded relative to many other mammals, yet little is known about what the expansion of the isocortex entails for differences in cellular composition and connectivity patterns in primates. Across the depth of the isocortex, neurons exhibit stereotypical patterns of projections. Upper-layer neurons (i.e., layers II-IV) project within and across cortical areas, whereas many lower-layer pyramidal neurons (i.e., layers V-VI) favor connections to subcortical regions. To identify evolutionary changes in connectivity patterns, we quantified upper (i.e., layers II-IV)- and lower (i.e., layers V-VI)-layer neuron numbers in primates and other mammals such as rodents and carnivores. We also used MR tractography based on high-angular resolution diffusion imaging and diffusion spectrum imaging to compare anterior-to-posterior corticocortical tracts between primates and other mammals. We found that primates possess disproportionately more upper-layer neurons as well as an expansion of anterior-to-posterior corticocortical tracts compared with other mammals. Taken together, these findings demonstrate that primates deviate from other mammals in exhibiting increased cross-cortical connectivity. J. Comp. Neurol. 525:1075-1093, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Subarachnoid hemorrhage due to ruptured intracranial aneurysm following posterior reversible encephalopathy syndrome

    Directory of Open Access Journals (Sweden)

    Takamasa Nanba

    2016-01-01

    Full Text Available Although posterior reversible encephalopathy syndrome (PRES is rarely associated with subarachnoid hemorrhage, to our knowledge, rupture of a concomitant cerebral aneurysm following PRES has not been reported. We describe a patient with atypical PRES involving the brainstem, thalamus, and periventricular white matter without cortical or subcortical edema of the parietooccipital lobe on magnetic resonance imaging, with rupture of a concomitant cerebral aneurysm. Preexisting extremely high blood pressure may trigger atypical PRES, and failure to lower blood pressure may lead to a concomitant aneurysm rupture. In the future treatment of hypertensive urgency with a recurrence of symptoms and mean arterial blood pressure >150 mmHg, it is advisable to immediately hospitalize the patient for aggressive blood pressure management, especially if PRES is suspected based on clinical and radiological features.

  5. Subarachnoid hemorrhage due to ruptured intracranial aneurysm following posterior reversible encephalopathy syndrome.

    Science.gov (United States)

    Nanba, Takamasa; Kashimura, Hiroshi; Saura, Hiroaki; Takeda, Masaru

    2016-01-01

    Although posterior reversible encephalopathy syndrome (PRES) is rarely associated with subarachnoid hemorrhage, to our knowledge, rupture of a concomitant cerebral aneurysm following PRES has not been reported. We describe a patient with atypical PRES involving the brainstem, thalamus, and periventricular white matter without cortical or subcortical edema of the parietooccipital lobe on magnetic resonance imaging, with rupture of a concomitant cerebral aneurysm. Preexisting extremely high blood pressure may trigger atypical PRES, and failure to lower blood pressure may lead to a concomitant aneurysm rupture. In the future treatment of hypertensive urgency with a recurrence of symptoms and mean arterial blood pressure >150 mmHg, it is advisable to immediately hospitalize the patient for aggressive blood pressure management, especially if PRES is suspected based on clinical and radiological features.

  6. Posterior reversible encephalopathy syndrome in malignant hypertension secondary to focal segmental glomerulosclerosis.

    Science.gov (United States)

    Abdullah, Hafez Mohammad Ammar; Ullah, Waqas; Ahmad, Ejaz; Anwer, Faiz

    2016-08-17

    Posterior reversible encephalopathy syndrome (PRES) is a neurological condition that occurs secondary to a variety of causes like autoimmune diseases, uncontrolled hypertension and immunosuppressive agents. We report an unusual association of PRES and malignant hypertension secondary to focal segmental glomerulosclerosis in a young woman, presenting with sudden loss of vision and seizures. She had uncontrolled hypertension and a Glasgow Coma Scale of 6/15. Brain MRI revealed high signals in cortical and subcortical white matter and some involvement of the periventricular areas. She improved dramatically with antihypertensive and antiepileptic medications and was discharged home in a stable condition. It is important to have a high clinical suspicion for this uncommon condition in an appropriate clinical setting, because a timely intervention can prevent long-term complications. 2016 BMJ Publishing Group Ltd.

  7. Cortical stimulation mapping of phantom limb rolandic cortex. Case report.

    Science.gov (United States)

    Ojemann, J G; Silbergeld, D L

    1995-04-01

    Findings of intraoperative rolandic cortex mapping during awake craniotomy for a tumor in a patient with a contralateral upper-extremity amputation are presented. This patient sustained a traumatic amputation at the mid-humerus 24 years previously. Initially he had experienced rare painless phantom limb sensations but none in the past 10 years. Functional mapping during an awake craniotomy was performed to maximize safe tumor resection. Typical temporal and frontal speech areas were identified; motor representation of face and jaw extended more superiorly than sensory representation. Shoulder movements were evoked more laterally than usual at the superior aspect of the craniotomy. A small region of precentral gyrus, between the jaw and shoulder representations, elicited no detectable effect when stimulated. Somatosensory mapping showed a similar topographical distribution of face and mouth cortex; however, posterior and inferior to the shoulder motor cortex, right arm and hand (phantom) sensations were evoked. Evidence suggests that significant motor reorganization occurs following an amputation, with expansion of neighboring homuncular representations without loss of somatosensory representation, despite a long period of time without any sensation referable to the amputated limb. Contrary to models of sensory cortex plasticity, the plasticity of the adult cortex may be system specific, with reorganization present in motor, but not in sensory, cortical systems.

  8. Occlusal load distribution through the cortical and trabecular bone of the human mid-facial skeleton in natural dentition: a three-dimensional finite element study.

    Science.gov (United States)

    Janovic, Aleksa; Saveljic, Igor; Vukicevic, Arso; Nikolic, Dalibor; Rakocevic, Zoran; Jovicic, Gordana; Filipovic, Nenad; Djuric, Marija

    2015-01-01

    Understanding of the occlusal load distribution through the mid-facial skeleton in natural dentition is essential because alterations in magnitude and/or direction of occlusal forces may cause remarkable changes in cortical and trabecular bone structure. Previous analyses by strain gauge technique, photoelastic and, more recently, finite element (FE) methods provided no direct evidence for occlusal load distribution through the cortical and trabecular bone compartments individually. Therefore, we developed an improved three-dimensional FE model of the human skull in order to clarify the distribution of occlusal forces through the cortical and trabecular bone during habitual masticatory activities. Particular focus was placed on the load transfer through the anterior and posterior maxilla. The results were presented in von Mises stress (VMS) and the maximum principal stress, and compared to the reported FE and strain gauge data. Our qualitative stress analysis indicates that occlusal forces distribute through the mid-facial skeleton along five vertical and two horizontal buttresses. We demonstrated that cortical bone has a priority in the transfer of occlusal load in the anterior maxilla, whereas both cortical and trabecular bone in the posterior maxilla are equally involved in performing this task. Observed site dependence of the occlusal load distribution may help clinicians in creating strategies for implantology and orthodontic treatments. Additionally, the magnitude of VMS in our model was significantly lower in comparison to previous FE models composed only of cortical bone. This finding suggests that both cortical and trabecular bone should be modeled whenever stress will be quantitatively analyzed. Copyright © 2014 Elsevier GmbH. All rights reserved.

  9. Anterior and posterior fixation for delayed treatment of posterior atlantoaxial dislocation without fracture.

    Science.gov (United States)

    Yu, Hai Ming; Malhotra, Karan; Butler, Joseph S; Wu, Shi Qiang

    2015-10-29

    Posterior atlantoaxial dislocation (PAAD) without fracture of the odontoid process is a rare injury. Authors have variously reported closed or open reduction, followed by either anterior or posterior fixation, but there is no consensus on best treatment. We present a particularly unstable case of PAAD. Open reduction through a retropharyngeal approach with odontoidectomy was required for reduction. Anterior fixation with transarticular lag screws was required prior to posterior fixation with pedicle screws. Despite non-compliance with postoperative immobilisation, imaging at 20-month follow-up confirmed solid fusion. The patient is pain-free with a good range of movement of the neck and has returned to a manual job. Our case had a greater degree of instability than was previously reported, which necessitated 360° fixation. This is the first reported case of this treatment strategy, which provided a very stable fixation allowing fusion despite early movement and without causing undue stiffness. 2015 BMJ Publishing Group Ltd.

  10. Disrupted cortical connectivity theory as an explanatory model for autism spectrum disorders

    Science.gov (United States)

    Kana, Rajesh K.; Libero, Lauren E.; Moore, Marie S.

    2011-12-01

    Recent findings of neurological functioning in autism spectrum disorder (ASD) point to altered brain connectivity as a key feature of its pathophysiology. The cortical underconnectivity theory of ASD (Just et al., 2004) provides an integrated framework for addressing these new findings. This theory suggests that weaker functional connections among brain areas in those with ASD hamper their ability to accomplish complex cognitive and social tasks successfully. We will discuss this theory, but will modify the term underconnectivity to ‘disrupted cortical connectivity’ to capture patterns of both under- and over-connectivity in the brain. In this paper, we will review the existing literature on ASD to marshal supporting evidence for hypotheses formulated on the disrupted cortical connectivity theory. These hypotheses are: 1) underconnectivity in ASD is manifested mainly in long-distance cortical as well as subcortical connections rather than in short-distance cortical connections; 2) underconnectivity in ASD is manifested only in complex cognitive and social functions and not in low-level sensory and perceptual tasks; 3) functional underconnectivity in ASD may be the result of underlying anatomical abnormalities, such as problems in the integrity of white matter; 4) the ASD brain adapts to underconnectivity through compensatory strategies such as overconnectivity mainly in frontal and in posterior brain areas. This may be manifested as deficits in tasks that require frontal-parietal integration. While overconnectivity can be tested by examining the cortical minicolumn organization, long-distance underconnectivity can be tested by cognitively demanding tasks; and 5) functional underconnectivity in brain areas in ASD will be seen not only during complex tasks but also during task-free resting states. We will also discuss some empirical predictions that can be tested in future studies, such as: 1) how disrupted connectivity relates to cognitive impairments in skills

  11. Osmosis in Cortical Collecting Tubules

    Science.gov (United States)

    Schafer, James A.; Troutman, Susan L.; Andreoli, Thomas E.

    1974-01-01

    The present experiments were designed to evaluate the effects of varying the osmolality of luminal solutions on the antidiuretic hormone (ADH)-independent water and solute permeability properties of isolated rabbit cortical collecting tubules. In the absence of ADH, the osmotic water permeability coefficient (cm s–1) Pfl→b, computed from volume flows from hypotonic lumen to isotonic bath, was 20 ± 4 x 10–4 (SEM); the value of Pfb→l in the absence of ADH, computed from volume flows from isotonic bath to hypertonic lumen, was 88 ± 15 x 10–4 cm s–1. We also measured apparent urea permeability coefficients (cm s–1) from 14C-urea fluxes from lumen to bath (PDDureal→b) and from bath to lumen (PDDureab→l). For hypotonic luminal solutions and isotonic bathing solutions, PDDureal→b was 0.045 ± 0.004 x 10–4 and was unaffected by ADH. The ADH-independent values of PDDureal→b and Pureab→l were, respectively, 0.216 ± 0.022 x 10–4 cm s–1 and 0.033 ± 0.002 x 10–4 cm s–1 for isotonic bathing solutions and luminal solutions made hypertonic with urea, i.e., there was an absolute increase in urea permeability and asymmetry of urea fluxes. Significantly, PDDureal→b did not rise when luminal hypertonicity was produced by sucrose; and, bathing fluid hypertonicity did not alter tubular permeability to water or to urea. We interpret these data to indicate that luminal hypertonicity increased the leakiness of tight junctions to water and urea but not sucrose. Since the value of Pfb→l in the absence of ADH, when tight junctions were open to urea, was approximately half of the value of Pfl→b in the presence of ADH, when tight junctions were closed to urea, we conclude that tight junctions are negligible paracellular shunts for lumen to bath osmosis with ADH. These findings, together with those in the preceding paper, are discussed in terms of a solubility-diffusion model for water permeation in which ADH increases water solubility in luminal

  12. Ephaptic coupling in cortical neurons

    Directory of Open Access Journals (Sweden)

    Costas Anastassiou

    2014-03-01

    Full Text Available The electrochemical processes that underlie neural function manifest themselves in ceaseless spatial and temporal fluctuations in the extracellular electric field. The local field potential (LFP, used to study neural interactions during various brain states, is regarded as an epiphenomenon of coordinated neural activity. Yet the extracellular field activity feeds back onto the electrical potential across the neuronal membrane via ephaptic coupling (Jefferys et al, Physiol Rev, 1995. The extent to which such ephaptic coupling alters the functioning of individual neurons and neural assemblies under physiological conditions has remained largely speculative despite recent advances (Ozen et al, JNeurosci, 2010; Fröhlich & McCormick, Neuron, 2010, Anastassiou et al, JNeurosci, 2010. To address this question we use a 12-pipette setup that allows independent positioning of each pipette under visual control with μm accuracy, with the flexibility of using an arbitrary number of these as patching, extracellularly stimulating or extracellular recording pipettes only a few μm away from the cell body of patched neurons (Anastassiou et al, Nat Neurosci, 2011. We stimulated in rat somatosensory cortical slices a variety of layer 5 neural types and recorded inside and outside their cell bodies while pharmacologically silencing synaptic transmission. Pyramidal cells couple to the extracellular field distinctly different from interneurons. Ephaptic coupling strength depends both on the field strength (as measured at the neuron soma as well as the spike-history of neurons. In particular, we find that ephaptic coupling strength depends both on the field strength (as measured at the cell body as well as the spike-history of neurons. How do such effects manifest themselves in vivo? We address this question through detailed large-scale simulations from thousands of biophysically realistic and interconnected neurons (Reimann, Anastassiou et al, Neuron, 2013 emulating

  13. Posterior surgery in high-grade spondylolisthesis.

    Science.gov (United States)

    Lengert, R; Charles, Y P; Walter, A; Schuller, S; Godet, J; Steib, J-P

    2014-09-01

    High-grade L5-S1 spondylolisthesis alters sagittal spinopelvic balance, which can cause low back pain and progressive neurologic disorder. The present study assessed spondylolisthesis reduction and maintenance over time with L4-S1 versus L5-S1 fusion using a lever-arm system and posterior fusion combined with lumbosacral graft. Forty patients were operated on for symptomatic high-grade spondylolisthesis, 34 of whom had full pre- and post-operative radiological analysis, with a mean follow-up of 5.4years. There were 9 L5-S1 and 25 L4-S1 instrumentations. Analysis of spinopelvic and slipping parameters and the evolution of segmental lordosis compared results between L5-S1 and L4-S1 instrumentation. Mean Taillard spondylolisthesis index decreased from 64% to 37% (P=0.0001). Overall sagittal spinopelvic balance was not significantly changed. Overall L1-S1 and segmental L4-L5 lordosis were not affected by instrumentation. Mean L5-S1 segmental lordosis increased from 11° to 18°. There was loss of reduction from 19° to 14° with L5-S1 instrumentation, in contrast to maintained reduction with L4-S1 instrumentation (P=0.006). The lever-arm system provided anterior-posterior reduction of spondylolisthesis and corrected slippage. Postoperative change in overall sagittal spinopelvic balance was slight and constant. Posterior L4-S1 fusion provided better long-term control of L5-S1 lordosis reduction than the shorter L5-S1 fusion. Retrospective study of level IV. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  14. SINDROME DE COLAPSO DE MORDIDA POSTERIOR

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    Paula Alejandra Baldión

    2012-12-01

    Full Text Available El Síndrome de Colapso de Mordida posterior es una patología oclusal que se presenta como consecuencia de problemas dentales, periodontales y oclusales, que exige la correcta evaluación de los signos y síntomas que lo caracterizan.  El objetivo del artículo es describir la manera como evoluciona la enfermedad, la evaluación multidisciplinaria para obtener un diagnóstico preciso y la secuencia de tratamiento integral, revisando los conceptos para un mejor entendimiento del tratamiento periodontal y restaurativo que requieren los pacientes con síndrome de colapso de mordida posterior; caracterizado por procesos patológicos como enfermedad periodontal, caries dental con subsecuente alteración de la integridad del arco dentario que genera perdida de soporte posterior conllevando a un trauma oclusal secundario y disminución de la dimensión vertical oclusal. El control del proceso inflamatorio y la estabilización periodontal son puntos de partida indispensables en el tratamiento integral del paciente. La migración patológica de los dientes y las alteraciones del plano oclusal pueden exigir la corrección ortodóntica de los arcos y en algunos casos el concurso de cirugía oral para la nivelación del plano oclusal. La secuencia organizada del tratamiento por fases permite la restauración predecible de los pacientes con este síndrome, tomando en cuenta las diferentes alternativas protésicas tanto removibles como fijas con o sin implantes de oseointegración, para el éxito integral a largo plazo.

  15. MRI of the fetal posterior fossa

    Energy Technology Data Exchange (ETDEWEB)

    Adamsbaum, Catherine; Andre, Christine; Merzoug, Valerie; Ferey, Solene [St Vincent de Paul Hospital, Department of Radiology, Paris Cedex 14 (France); Moutard, Marie Laure [St Vincent de Paul Hospital, Department of Neuropaediatrics, Paris (France); Quere, Marie Pierre [CHU, Department of Radiology, Nantes (France); Lewin, Fanny [St Vincent de Paul Hospital, Maternity Department, Paris (France); Fallet-Bianco, Catherine [Ste Anne Hospital, Department of Neuropathology, Paris (France)

    2005-02-01

    MRI is a useful tool to complement US for imaging of the fetal posterior fossa (PF). In France, the discovery of a PF malformation in the fetus frequently leads to termination of pregnancy (80% in a personal series). However, despite improved accuracy in the diagnosis of PF abnormalities, prognosis remains uncertain. The first objective of this review is to document the normal MRI landmarks of the developing fetal PF. Because of their thinness, the visibility of the cerebellar fissures is dramatically delayed on MRI compared to macroscopic data. An important landmark is identification of the primary fissure of the vermis, normally seen at around 25-26 weeks' gestation (WG) on the sagittal slice, separating the larger posterior lobe from the anterior lobe (volume ratio around 2:1). The prepyramidal and secondary fissures are usually only identifiable after 32 WG and the hemispheric fissures are difficult to see until the end of pregnancy. Considering the signal changes, high signal on T2-weighted (T2-W) sequences is seen from 25 WG in the posterior part of the brain stem (tegmentum and ascending sensory tracts) related to myelination. The low signal intensities seen within the cerebellum on T2-W images correspond to high cellularity of grey matter (deep nuclei), as there is no myelination within the white matter before 38 WG. The second objective is to highlight the signs highly predictive of a poor neurological prognosis. Lack of pontine curvature or vermian agenesis without a PF cyst (small volume of PF) is greatly associated with poor neurological status. The third objective is to propose a diagnostic strategy in difficult cases where prognosis is important, e.g. the Dandy Walker continuum. (orig.)

  16. Nonlinear coupling between cortical oscillations and muscle activity during isotonic wrist flexion

    Directory of Open Access Journals (Sweden)

    Yuan Yang

    2016-12-01

    Full Text Available Coupling between cortical oscillations and muscle activity facilitates neuronal communication during motor control. The linear part of this coupling, known as corticomuscular coherence, has received substantial attention, even though neuronal communication underlying motor control has been demonstrated to be highly nonlinear. A full assessment of corticomuscular coupling, including the nonlinear part, is essential to understand the neuronal communication within the sensorimotor system. In this study, we applied the recently developed n:m coherence method to assess nonlinear corticomuscular coupling during isotonic wrist flexion. The n:m coherence is a generalized metric for quantifying nonlinear cross-frequency coupling as well as linear iso-frequency coupling. By using independent component analysis and equivalent current dipole source localization, we identify four sensorimotor related brain areas based on the locations of the dipoles, i.e. the contralateral primary sensorimotor areas, supplementary motor area, prefrontal area and posterior parietal cortex. For all these areas, linear coupling between EEG and EMG is present with peaks in the beta band (15-35 Hz, while nonlinear coupling is detected with both integer (1:2, 1:3, 1:4 and non-integer (2:3 harmonics. Significant differences between brain areas is shown in linear coupling with stronger coherence for the primary sensorimotor areas and motor association cortices (supplementary motor area, prefrontal area compared to the sensory association area (posterior parietal cortex; but not for the nonlinear coupling. Moreover, the detected nonlinear coupling is similar to previously reported nonlinear coupling of cortical activity to somatosensory stimuli. We suggest that the descending motor pathways mainly contribute to linear corticomuscular coupling, while nonlinear coupling likely originates from sensory feedback.

  17. Cervical ossification of the posterior longitudinal ligament: Anterior versus posterior approach

    Directory of Open Access Journals (Sweden)

    Dasheng Lin

    2012-01-01

    Full Text Available Background: The optimal approach to provide satisfactory decompression and minimize complications for ossification of the posterior longitudinal ligament (OPLL involving multiple levels (3 levels or more remains controversial. The purpose of this study was to compare the results of two surgical approaches for cervical OPLL involving multiple levels; anterior direct decompression and fixation, and posterior indirect decompression and fixation. We present a retrospective review of 56 cases followed at a single Institution. Materials and Methods: We compared patients of multiple levels cervical OPLL that were treated at a single institution either with anterior direct decompression and fixation or with posterior indirect decompression and fixation. The clinical records of the patients with a minimum duration of follow-up of 2 years were reviewed. The associated complications were recorded. Results: Fifty-six patients constitute the clinical material. 26 cases were treated by anterior corpectomy and fixation and 30 cases received posterior laminectomy and fixation. The two populations were similar. It was found that both anterior and posterior decompression and fixation can achieve satisfactory outcomes, and posterior surgery was accomplished in a shorter period of time with lesser blood loss. Although patients had comparable preoperative Japanese Orthopaedics Association (JOA scores, those with a canal occupancy by OPLL more than 50% and managed anteriorly had better outcomes. However, for those with more severe stenosis, anterior approach was more difficult and associated with higher risks and complications. Despite its limitations in patients with high occupancy OPLLs, through the multiple level laminectomy, posterior fixation can achieve effective decompression, maintaining or restoring stability of the cervical spine, and thereby improving neural outcome and preventing the progression of OPLL. Conclusions: The posterior indirect decompression

  18. Post-partum posterior reversible encephalopathy syndrome

    DEFF Research Database (Denmark)

    Aaen, Anne Albers; Jeppesen, Jørgen; Obaid, Hayder

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a complex clinical condition with vasogenic subcortical oedema caused by hypertension. Oedema is often seen on magnetic resonance imaging. The wide clinical spectrum ranges from headaches to vision loss and even death. Early diagnosis...... and treatment is important for the reversibility of the condition. In this case report we emphasize the importance of blood pressure control in a post-partum woman, who had a rather complicated pregnancy. The symptoms of PRES were not recognized immediately because of failure to use and acknowledge a blood...

  19. Superior labrum anterior-to-posterior tear.

    Science.gov (United States)

    Sum, Jonathan C; Omid, Reza

    2012-12-01

    The patient was a 25-year-old male college student with a chief complaint of right shoulder pain. The patient was initially diagnosed with bicipital tendinitis by his physician and had been treated for 4 weeks by a physical therapist. However, his symptoms did not improve and he was unable to return to his preinjury activity levels, so he sought the services of another physical therapist for a second opinion. Due to concern for a labrum tear, the physical therapist referred the patient to an orthopaedic surgeon. Magnetic resonance arthrography revealed findings consistent with a superior labrum anterior-to-posterior tear.

  20. Posterior chamber intraocular lens dislocations and malpositions.

    Science.gov (United States)

    Obstbaum, S A; To, K

    1989-08-01

    Decentration and malposition of posterior chamber intraocular lenses (PC IOL) accounts for one of the remaining and unresolved conditions associated with the implantation of these lenses. This condition assumes importance since in approximately 50% of cases where a PC IOL is removed there is an aspect of improper positioning. The common types of malpositions are: pupil capture; sunset syndrome; sunrise syndrome; horizontal decentration; and the windshield wiper syndrome. This paper will explore the causes and management of these conditions and discuss the virtues of capsular bag implantation.

  1. Rotura ocular posterior traumática

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    Laine García Ferrer

    Full Text Available El trauma ocular es una causa importante de morbilidad oftalmológica en el mundo con implicaciones socioeconómicas importantes para el paciente y sus familiares. Ocurre generalmente en adultos jóvenes, con una buena agudeza visual al inicio del evento traumático, la cual se verá comprometida según la severidad del trauma, las estructuras oculares que afecte y las complicaciones que puedan aparecer. Presentamos dos pacientes con rotura escleral posterior secundario a trauma ocular a globo abierto contuso. Se describe el manejo personalizado el seguimiento en cada caso y sus resultados visuales.

  2. A Short History of Posterior Dynamic Stabilization

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    Cengiz Gomleksiz

    2012-01-01

    Full Text Available Interspinous spacers were developed to treat local deformities such as degenerative spondylolisthesis. To treat patients with chronic instability, posterior pedicle fixation and rod-based dynamic stabilization systems were developed as alternatives to fusion surgeries. Dynamic stabilization is the future of spinal surgery, and in the near future, we will be able to see the development of new devices and surgical techniques to stabilize the spine. It is important to follow the development of these technologies and to gain experience using them. In this paper, we review the literature and discuss the dynamic systems, both past and present, used in the market to treat lumbar degeneration.

  3. Posterior breast cancer: Mammographic and ultrasonographic features

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    Janković Ana

    2013-01-01

    Full Text Available Background/Aim. Posterior breast cancers are located in the prepectoral region of the breast. Owing to this distinctive anatomical localization, physical examination and mammographic or ultrasonographic evaluation can be difficult. The purpose of the study was to assess possibilities of diagnostic mammography and breast ultrasonography in detection and differentiation of posterior breast cancers. Methods. The study included 40 women with palpable, histopathological confirmed posterior breast cancer. Mammographic and ultrasonographic features were defined according to Breast Imaging Reporting and Data System (BI-RADS lexicon. Results. Based on standard two-view mammography 87.5%, of the cases were classified as BI-RADS 4 and 5 categories, while after additional mammographic views all the cases were defined as BIRADS 4 and 5 categories. Among 96 mammographic descriptors, the most frequent were: spiculated mass (24.0%, architectural distortion (16.7%, clustered microcalcifications (12.6% and focal asymmetric density (12.6%. The differentiation of the spiculated mass was significantly associated with the possibility to visualize the lesion at two-view mammography (p = 0.009, without the association with lesion diameter (p = 0.083 or histopathological type (p = 0.055. Mammographic signs of invasive lobular carcinoma were significantly different from other histopathological types (architectural distortion, p = 0.003; focal asymmetric density, p = 0.019; association of four or five subtle signs of malignancy, p = 0.006. All cancers were detectable by ultrasonography. Mass lesions were found in 82.0% of the cases. Among 153 ultrasonographic descriptors, the most frequent were: irregular mass (15.7%, lobulated mass (7.2%, abnormal color Doppler signals (20.3%, posterior acoustic attenuation (18.3%. Ultrasonographic BI-RADS 4 and 5 categories were defined in 72.5% of the cases, without a significant difference among various histopathological types (p = 0

  4. Sindrome de colapso de mordida posterior

    OpenAIRE

    Paula Alejandra Baldión; Diego Enrique Betancourt Castro

    2012-01-01

    El Síndrome de Colapso de Mordida posterior es una patología oclusal que se presenta como consecuencia de problemas dentales, periodontales y oclusales, que exige la correcta evaluación de los signos y síntomas que lo caracterizan.  El objetivo del artículo es describir la manera como evoluciona la enfermedad, la evaluación multidisciplinaria para obtener un diagnóstico preciso y la secuencia de tratamiento integral, revisando los conceptos para un mejor entendimiento del tratamiento periodon...

  5. Cortical microtubule nucleation can organise the cytoskeleton of Drosophila oocytes to define the anteroposterior axis

    Science.gov (United States)

    Khuc Trong, Philipp; Doerflinger, Hélène; Dunkel, Jörn; St Johnston, Daniel; Goldstein, Raymond E

    2015-01-01

    Many cells contain non-centrosomal arrays of microtubules (MTs), but the assembly, organisation and function of these arrays are poorly understood. We present the first theoretical model for the non-centrosomal MT cytoskeleton in Drosophila oocytes, in which bicoid and oskar mRNAs become localised to establish the anterior-posterior body axis. Constrained by experimental measurements, the model shows that a simple gradient of cortical MT nucleation is sufficient to reproduce the observed MT distribution, cytoplasmic flow patterns and localisation of oskar and naive bicoid mRNAs. Our simulations exclude a major role for cytoplasmic flows in localisation and reveal an organisation of the MT cytoskeleton that is more ordered than previously thought. Furthermore, modulating cortical MT nucleation induces a bifurcation in cytoskeletal organisation that accounts for the phenotypes of polarity mutants. Thus, our three-dimensional model explains many features of the MT network and highlights the importance of differential cortical MT nucleation for axis formation. DOI: http://dx.doi.org/10.7554/eLife.06088.001 PMID:26406117

  6. Higher cortical modulation of pain perception in the human brain: Psychological determinant.

    Science.gov (United States)

    Chen, Andrew Cn

    2009-10-01

    Pain perception and its genesis in the human brain have been reviewed recently. In the current article, the reports on pain modulation in the human brain were reviewed from higher cortical regulation, i.e. top-down effect, particularly studied in psychological determinants. Pain modulation can be examined by gene therapy, physical modulation, pharmacological modulation, psychological modulation, and pathophysiological modulation. In psychological modulation, this article examined (a) willed determination, (b) distraction, (c) placebo, (d) hypnosis, (e) meditation, (f) qi-gong, (g) belief, and (h) emotions, respectively, in the brain function for pain modulation. In each, the operational definition, cortical processing, neuroimaging, and pain modulation were systematically deliberated. However, not all studies had featured the brain modulation processing but rather demonstrated potential effects on human pain. In our own studies on the emotional modulation on human pain, we observed that emotions could be induced from music melodies or pictures perception for reduction of tonic human pain, mainly in potentiation of the posterior alpha EEG fields, likely resulted from underneath activities of precuneous in regulation of consciousness, including pain perception. To sum, higher brain functions become the leading edge research in all sciences. How to solve the information bit of thinking and feeling in the brain can be the greatest challenge of human intelligence. Application of higher cortical modulation of human pain and suffering can lead to the progress of social humanity and civilization.

  7. Role of altered cerebello-thalamo-cortical network in the neurobiology of essential tremor

    Energy Technology Data Exchange (ETDEWEB)

    Lenka, Abhishek; Bhalsing, Ketaki Swapnil; Jhunjhunwala, Ketan [National Institute of Mental Health and Neurosciences, Department of Neurology, Bangalore, Karnataka (India); National Institute of Mental Health and Neurosciences, Department of Clinical Neurosciences, Bangalore, Karnataka (India); Panda, Rajanikant; Saini, Jitender; Bharath, Rose Dawn [National Institute of Mental Health and Neurosciences, Department of Neuroimaging and Interventional Radiology, Bangalore, Karnataka (India); Naduthota, Rajini M.; Yadav, Ravi; Pal, Pramod Kumar [National Institute of Mental Health and Neurosciences, Department of Neurology, Bangalore, Karnataka (India)

    2017-02-15

    Essential tremor (ET) is the most common movement disorder among adults. Although ET has been recognized as a mono-symptomatic benign illness, reports of non-motor symptoms and non-tremor motor symptoms have increased its clinical heterogeneity. The neural correlates of ET are not clearly understood. The aim of this study was to understand the neurobiology of ET using resting state fMRI. Resting state functional MR images of 30 patients with ET and 30 age- and gender-matched healthy controls were obtained. The functional connectivity of the two groups was compared using whole-brain seed-to-voxel-based analysis. The ET group had decreased connectivity of several cortical regions especially of the primary motor cortex and the primary somatosensory cortex with several right cerebellar lobules compared to the controls. The thalamus on both hemispheres had increased connectivity with multiple posterior cerebellar lobules and vermis. Connectivity of several right cerebellar seeds with the cortical and thalamic seeds had significant correlation with an overall score of Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) as well as the subscores for head tremor and limb tremor. Seed-to-voxel resting state connectivity analysis revealed significant alterations in the cerebello-thalamo-cortical network in patients with ET. These alterations correlated with the overall FTM scores as well as the subscores for limb tremor and head tremor in patients with ET. These results further support the previous evidence of cerebellar pathology in ET. (orig.)

  8. Biomechanical evaluation of a novel dynamic posterior cruciate ligament brace.

    Science.gov (United States)

    Heinrichs, Christian H; Schmoelz, Werner; Mayr, Raul; Keiler, Alexander; Schöttle, Philip B; Attal, René

    2016-03-01

    Use of a rigid brace or cast immobilization is recommended in conservative treatment or postoperative rehabilitation after a posterior cruciate ligament injury. To prevent the loss of knee joint function and muscle activity often associated with this, a flexible knee brace has been developed that allows an adjustable anteriorly directed force to be applied to the calf in order to prevent posterior tibial translation. The purpose of this biomechanical study was to evaluate the impact of this novel dynamic brace on posterior tibial translation after posterior cruciate ligament injury and reconstruction. A Telos stress device was used to provoke posterior tibial translation in seven human lower limb specimens, and stress radiographs were taken at 90° of knee flexion. Posterior tibial translation was measured in the native knees with an intact posterior cruciate ligament; after arthroscopic posterior cruciate ligament dissection with and without a brace; and after posterior cruciate ligament reconstruction with and without a brace. The force applied with the brace was measured using a pressure sensor. Posterior tibial translation was significantly reduced (P=0.032) after application of the brace with an anteriorly directed force of 50N to the knees with the dissected posterior cruciate ligament. The brace also significantly reduced posterior tibial translation after posterior cruciate ligament reconstruction in comparison with reconstructed knees without a brace (P=0.005). Posterior tibial translation was reduced to physiological values using this dynamic brace system that allows an anteriorly directed force to be applied to the calf. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Cortical Gyrification Patterns Associated with Trait Anxiety.

    Directory of Open Access Journals (Sweden)

    Tara A Miskovich

    Full Text Available Dispositional anxiety is a stable personality trait that is a key risk factor for internalizing disorders, and understanding the neural correlates of trait anxiety may help us better understand the development of these disorders. Abnormal cortical folding is thought to reflect differences in cortical connectivity occurring during brain development. Therefore, assessing gyrification may advance understanding of cortical development and organization associated with trait anxiety. Previous literature has revealed structural abnormalities in trait anxiety and related disorders, but no study to our knowledge has examined gyrification in trait anxiety. We utilized a relatively novel measure, the local gyrification index (LGI, to explore differences in gyrification as a function of trait anxiety. We obtained structural MRI scans using a 3T magnetic resonance scanner on 113 young adults. Results indicated a negative correlation between trait anxiety and LGI in the left superior parietal cortex, specifically the precuneus, reflecting less cortical complexity among those high on trait anxiety. Our findings suggest that aberrations in cortical gyrification in a key region of the default mode network is a correlate of trait anxiety and may reflect disrupted local parietal connectivity.

  10. Decreased prefrontal cortical dopamine transmission in alcoholism.

    Science.gov (United States)

    Narendran, Rajesh; Mason, Neale Scott; Paris, Jennifer; Himes, Michael L; Douaihy, Antoine B; Frankle, W Gordon

    2014-08-01

    Basic studies have demonstrated that optimal levels of prefrontal cortical dopamine are critical to various executive functions such as working memory, attention, inhibitory control, and risk/reward decisions, all of which are impaired in addictive disorders such as alcoholism. Based on this and imaging studies of alcoholism that have demonstrated less dopamine in the striatum, the authors hypothesized decreased dopamine transmission in the prefrontal cortex in persons with alcohol dependence. To test this hypothesis, amphetamine and [11C]FLB 457 positron emission tomography were used to measure cortical dopamine transmission in 21 recently abstinent persons with alcohol dependence and 21 matched healthy comparison subjects. [11C]FLB 457 binding potential, specific compared to nondisplaceable uptake (BPND), was measured in subjects with kinetic analysis using the arterial input function both before and after 0.5 mg kg-1 of d-amphetamine. Amphetamine-induced displacement of [11C]FLB 457 binding potential (ΔBPND) was significantly smaller in the cortical regions in the alcohol-dependent group compared with the healthy comparison group. Cortical regions that demonstrated lower dopamine transmission in the alcohol-dependent group included the dorsolateral prefrontal cortex, medial prefrontal cortex, orbital frontal cortex, temporal cortex, and medial temporal lobe. The results of this study, for the first time, unambiguously demonstrate decreased dopamine transmission in the cortex in alcoholism. Further research is necessary to understand the clinical relevance of decreased cortical dopamine as to whether it is related to impaired executive function, relapse, and outcome in alcoholism.

  11. Intraoperative determination and display of cortical function

    Science.gov (United States)

    Bass, W. Andrew; Galloway, Robert L., Jr.; Dawant, Benoit M.; Maciunas, Robert J.

    1997-05-01

    One of the most important issues in neurosurgical lesion resection is margin definition. And while there is still some effort required to exactly determine lesion boundaries from tomographic images, the lesions are at least perceptible on the scans. What is not visible is the location of function. Functional imaging such as PET and fMRI hold some promise for cortical function localization; however, intraoperative cortical mapping can provide exact localization of function without ambiguity. Since tomographic images can provide lesion margin definition and cortical mapping can provide functional information we have developed a system for combining the two in our Interactive, Image-Guided system. For cortical surface mapping we need a surface description. Brain contours are extracted from a MRI volume using a deformable model approach and rendered from multiple angular positions. As the surgeon moves a probe, its position is displayed on the view closes to the angular position of the probe. During functional mapping, positive response to stimulation result in a color overlay 'dot' added to the cortical surface display. Different colored dots are used to distinguish between motor function and language function. And a third color is used to display overlapping functionality. This information is used to guide the resection around functionally eloquent areas of the cortex.

  12. Somatosensory evoked magnetic fields elicited by dorsal penile, posterior tibial and median nerve stimulation.

    Science.gov (United States)

    Nakagawa, H; Namima, T; Aizawa, M; Uchi, K; Kaiho, Y; Yoshikawa, K; Orikasa, S; Nakasato, N

    1998-01-01

    The aim of this study is to localize the primary sensory cortex of urogenital organs in the human brain. Using a newly developed MRI-linked magnetoencephalography system, we measured somatosensory evoked magnetic fields (SEFs) for unilateral stimuli on the dorsal penile nerve (DPN), posterior tibial nerve (PTN) and median nerve (MN). In five healthy male subjects, SEFs were clearly observed. Peak latency of the first cortical components were 63.8 +/- 9.2 ms for DPN, 39.8 +/- 3.0 ms for PTN and 20.7 +/- 0.7 ms for MN stimuli. Peak amplitude of the first cortical components were 63.1 +/- 10.8 fT for DPN, 160.2 +/- 50.1 fT for PTN and 335.2 +/- 70.3 fT for MN stimuli. Isofield map for the peak latencies indicated a single dipolar pattern for DPN as well as for PTN and MN stimuli. Using a single current dipole model, all SEF sources were localized on the contralateral central sulcus to the stimuli, indicating the primary sensory cortex. The DPN sources were localized on the interhemispheric surfaces, corresponding to previous speculations by direct cerebral stimulation. This non-invasive SEF technique promises further brain functional mapping for the urogenital organs.

  13. Posterior Interosseous Nerve Syndrome from Thermal Injury

    Directory of Open Access Journals (Sweden)

    Vijay A. Singh

    2014-01-01

    Full Text Available Background. Due to anatomical proximity to bone, the radial nerve is the most frequently injured major nerve of the upper extremity, frequently secondary to fractures (Li et al. (2013. We describe an incidence when a branch of the radial nerve is injured as a result of a thermal injury. Observation. Radial nerve injury can occur anywhere along the anatomical course with varied etiologies, but commonly related to trauma. The most frequent site is in the proximal forearm involving the posterior interosseous branch. However, problems can occur at the junction of the middle and proximal thirds of the humerus and wrist radially. When the radial nerve is injured by a burn, a new rehabilitation dynamic arises. Not only does one agonize about the return of nerve function but also fret about the skin grafts that replaced the devitalized tissue housing that compartment. Discussion. Although posterior interosseous nerve syndrome has been described in the context of many different etiologies, it has not previously been discussed in relation to burn injuries. In this case, not only did the patient’s rehabilitation involve aggressive therapy for return of sensation and function of the arm, but also prevention of contracture normally seen in replacement of full thickness burns.

  14. Translimbal fixation of posterior chamber lenses.

    Science.gov (United States)

    Yospaiboon, Yosanan; Wongwai, Pantipa; Ratanapakorn, Tanapat; Sinawat, Suthasinee

    2005-11-01

    To evaluate the result of a surgical technique to insert and secure a standard posterior chamber lens through a simple limbal incision in eyes that had no capsular support or whose capsule was inadvertently ruptured during extracapsular cataract extraction. Retrospective review of the medical records of patients who underwent translimbal fixation of posterior chamber lenses according to age, gender, preoperative visual acuity, postoperative visual acuity, follow-up period and any complications, especially those that may be related to the surgical technique. Twelve patients were recruited in the present study. The patents' age ranged from 31 to 77 years, with a mean of 62.58 years. There were 9 male and 3 female patients. The preoperative visual acuity ranged from hand motion to counting fingers, and the postoperative visual acuity ranged from 6/6 to 6/24 except one patient who had postoperative visual acuity of counting fingers due to a pre-existing macular hole. The length of follow-up period ranged from 3 to 12 months, with a mean of 6.17 months. There was no clinically significant lens-related complication. This simple surgical technique controls the location of the needle entry and exit to decrease the risk of bleeding and increase the chance of ciliary sulcus placement. An inferior groove was made to bury the suture knot and was sutured closed to prevent the knot erosion through the conjunctiva.

  15. Posterior Cruciate Ligament: Current Concepts Review

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    Santiago Pache

    2018-01-01

    Full Text Available The posterior cruciate ligament (PCL is the largest and strongest ligament in the human knee, and the primary posteriorstabilizer. Recent anatomy and biomechanical studies have provided an improved understanding of PCL function. PCLinjuries are typically combined with other ligamentous, meniscal and chondral injuries. Stress radiography has becomean important and validated objective measure in surgical decision making and post-operative assessment. Isolatedgrade I or II PCL injuries can usually be treated non-operatively. However, when acute grade III PCL ruptures occurtogether with other ligamentous injury and/or repairable meniscal body/root tears, surgery is indicated. Anatomic singlebundlePCL reconstruction (SB-PCLR typically restores the larger anterolateral bundle (ALB and represents the mostcommonly performed procedure. Unfortunately, residual posterior and rotational tibial instability after SB-PCLR hasled to the development of an anatomic double-bundle (DB PCLR to restore the native PCL footprint and co-dominantbehavior of the anterolateral and posteromedial bundles and re-establish normal knee kinematics. The purpose of thisarticle is to review the pertinent details regarding PCL anatomy, biomechanics, injury diagnosis and treatment options,with a focus on arthroscopically assisted DB-PCLR.

  16. Acute Spontaneous Posterior Fossa Subdural Hematoma

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    Osama Shukir Muhammed Amin

    2014-02-01

    Full Text Available Acute posterior fossa subdural hematomas are rare and most of them are trauma-related. Non-traumatic ones have been reported in patients who had idiopathic thrombocytopenic purpura or those who had been receiving anticoagulant therapy. We report on the case of 57-year-old Iranian man who developed sudden severe occipital headache, drowsiness, repeated vomiting, and instability of stance and gait. He was neither hypertensive nor diabetic. No history of head trauma was obtained and he denied illicit drug or alcohol ingestion. A preliminary diagnosis of acute intra-cerebellar hemorrhage was made. His CT brain scan revealed an acute right-sided, extra-axial, crescent-shaped hyperdense area at the posterior fossa. His routine blood tests, platelets count, bleeding time, and coagulation profile were unremarkable. The patient had spontaneous acute infratentorial subdural hematoma. He was treated conservatively and discharged home well after 5 days. Since then, we could not follow-up him, clinically and radiologically because he went back to Iran. Our patient’s presentation, clinical course, and imaging study have called for conservative management, as the overall presentation was relatively benign. Unless the diagnosis is entertained and the CT brain scan is well-interpreted, the diagnosis may easily escape detection.

  17. Reconstruction of Acetabular Posterior Wall Fractures

    Science.gov (United States)

    Ahn, Jae-Min; Hur, Jun-Oh; Lee, Jong-Seo; Cheon, Sang-Jin

    2011-01-01

    Background The results after acetabular fracture are primarily related to the quality of the articular reduction. We evaluated the results of internal fixation of posterior wall fractures with using three-step reconstruction. Methods Thirty-three patients (mean age at the time of injury, 47.9 years; 28 males and 5 females) were followed for a minimum of 2 years after surgery. The three-step reconstruction included 1) preservation of soft tissues and reduction of the marginally impacted osteochondral (articular) fragments using screws, 2) filling the impacted cancellous void with a bone graft, and 3) reinforcement with buttress-plating. Clinical evaluation was done according to the criteria of D'aubigne and Postel, while the radiological criteria were those of Matta. The associated injuries and complications were evaluated. Results The clinical results were excellent in 15 (45.5%) patients and they were good in 5 (15.2%), (i.e., satisfactory in 60.7%), while the radiologic results were excellent in 10 (30.3%) and good in 14 (42.4%) (satisfactory in 72.7%). Heterotopic ossification was common, but this did not require excision, even without prophylactic treatment with indomethacin. Deep infection was the worst complication and this was accompanied by a poor outcome. Conclusions This study confirms that three-step reconstruction facilitates accurate and firm reduction of displaced posterior wall fractures of the acetabulum. Therefore, we anticipate less long-term arthrosis in the patients treated this way. PMID:21629471

  18. Treatment of posterior wall fractures of acetabulum.

    Science.gov (United States)

    Qi, Xin; Liu, Jian-Guo; Gong, Yu-Bao; Yang, Chen; Li, Shu-Qiang; Feng, Wei

    2009-04-01

    To explore the treatment methods and outcome of posterior wall fractures of the acetabulum. The data of 31 patients (25 males and 6 females, aged 19-59 years, mean: 40.5 years) with posterior wall fractures of the acetabulum hospitalized in our department from 2002 to 2006 were analyzed retrospectively in this study. The types of fractures, number of fragments, combined dislocations, and sciatic nerve function were documented before admission. All the fractures were treated with open reduction and internal fixation. Based on the fracture type and site, either screws alone or reconstructive plates were used. The patients were immobilized for an average of 12 weeks before partial weight bearing was permitted. After follow-up for 12-70 months (43.6 months on average), modified Merle d'Aubigne score was adopted to evaluate the outcomes of the operations. The percentages of the excellent, good, fair and poor results were 48.4%, 41.9%, 6.5%, and 3.3%, respectively, with a good to excellent rate of 90.2%. Idiopathic sciatic nerve injury occurred in only one case. The sciatic nerve should be routinely exposed and protected during the surgery. The type of fixation should be based on the fracture type and site. Prolonged immobilization may be helpful in improving the final outcomes.

  19. Posterior repair with perforated porcine dermal graft

    Directory of Open Access Journals (Sweden)

    G. Bernard Taylor

    2008-02-01

    Full Text Available OBJECTIVE: To compare postoperative vaginal incision separation and healing in patients undergoing posterior repair with perforated porcine dermal grafts with those that received grafts without perforations. Secondarily, the tensile properties of the perforated and non-perforated grafts were measured and compared. MATERIALS AND METHODS: This was a non-randomized retrospective cohort analysis of women with stage II or greater rectoceles who underwent posterior repair with perforated and non-perforated porcine dermal grafts (PelvicolTM CR Bard Covington, GA USA. The incidence of postoperative vaginal incision separation (dehiscence was compared. A secondary analysis to assess graft tensile strength, suture pull out strength, and flexibility after perforation was performed using standard test method TM 0133 and ASTM bending and resistance protocols. RESULTS: Seventeen percent of patients (21/127 who received grafts without perforations developed vaginal incision dehiscence compared to 7% (5/71 of patients who received perforated grafts (p = 0.078. Four patients with vaginal incision dehiscence with non-perforated grafts required surgical revision to facilitate healing. Neither tensile strength or suture pull out strength were significantly different between perforated and non-perforated grafts (p = 0.81, p = 0.29, respectively. There was no difference in the flexibility of the two grafts (p = 0.20. CONCLUSION: Perforated porcine dermal grafts retain their tensile properties and are associated with fewer vaginal incision dehiscences.

  20. Neurodynamics of somatosensory cortices studied by magnetoencephelography.

    Science.gov (United States)

    Kishida, Kuniharu

    2013-09-01

    From the viewpoint of statistical inverse problems, identification of transfer functions in feedback models is applied for neurodynamics of somatosensory cortices, and brain communication among active regions can be expressed in terms of transfer functions. However, brain activities have been investigated mainly by averaged waveforms in the conventional magnetoencephalography analysis, and thus brain communication among active regions has not yet been identified. It is shown that brain communication among two more than three brain regions is determined, when fluctuations related to concatenate averaged waveforms can be obtained by using a suitable blind source separation method. In blind identification of feedback model, some transfer functions or their impulse responses between output variables of current dipoles corresponding to active regions are identified from reconstructed time series data of fluctuations by the method of inverse problem. Neurodynamics of somatosensory cortices in 5 Hz median nerve stimuli can be shown by cerebral communication among active regions of somatosensory cortices in terms of impulse responses of feedback model.

  1. The posterior impingement view: an alternative conventional projection to detect bony posterior ankle impingement

    NARCIS (Netherlands)

    Wiegerinck, Johannes I.; Vroemen, Joy C.; van Dongen, Tristen H.; Sierevelt, Inger N.; Maas, Mario; van Dijk, C. Niek

    2014-01-01

    The purpose of the current study was to clinically evaluate the diagnostic value of the new posterior impingement (PIM) view in the detection of an os trigonum, compared with the standard lateral view, using computed tomography (CT) as a reference standard. Three observers, 2 experienced

  2. Posterior Reversible Encephalopathy Syndrome in Two Omani Children with Underlying Renal Diseases

    Directory of Open Access Journals (Sweden)

    Mohamed A. El-Naggari

    2015-08-01

    Full Text Available Posterior reversible encephalopathy syndrome (PRES is a neurological condition with a combination of clinical and radiological features. Clinical symptoms include headaches, confusion, seizures, disturbed vision or an altered level of consciousness. Classic magnetic resonance imaging (MRI findings indicate subcortical and cortical oedema, affecting mainly the posterior cerebral region. We report two paediatric cases of PRES with underlying renal diseases presenting at the Sultan Qaboos University Hospital in Muscat, Oman, in April 2010 and August 2011. The first case was an 11-year-old girl diagnosed with systemic lupus erythematosus and the second was a six-and-a-half-year-old boy on peritoneal dialysis due to multi-drug-resistant nephrotic syndrome. Both patients were hypertensive and treated with blood pressure control medications. No residual neurological dysfunction was noted in the patients at a one-year follow-up and at discharge, respectively. The role of hypertension in paediatric PRES cases, among other important risk factors, is emphasised. Additionally, MRI is an important diagnostic and prognostic tool. Prompt diagnosis and aggressive management is fundamental to preventing permanent neurological damage.

  3. Quantitative and qualitative bone assessment of the posterior mandible in patients with diabetes mellitus: a cone beam computed tomography study.

    Science.gov (United States)

    Nemtoi, A; Ladunca, Oana; Dragan, Eliza; Budacu, C; Mihai, C; Haba, Danisia

    2013-01-01

    Evaluation of mandibular bone features is very important for the diagnosis, treatment planning and management of dental procedures such as osseointegrated implants. To evaluate the bone quantity and quality of the posterior region of the mandible using the CBCT technique for implant planning in patients with diabetes mellitus. Twenty-three patients with diabetes mellitus and 27 control subjects participated in the study. Mandibular bone measurements were performed on the cone beam computed tomography (CBCT) images. One previously calibrated oral radiologist with CBCT experience measured the distance from mandibular canal to alveolar ridge and the distance from bucal to lingual cortical wall. Also, it was assessed the bone quality of each region of interest, by measuring the bone mineral density. The study protocol was approved by the local Ethics Committee. The study revealed the presence of significant correlations between bone quality and values ofglycosylated hemoglobin and a significant association between patient gender and bone type. There is a significant inverse correlation between the values of cortical and trabecular bone density in the posterior region of the mandible and HbA1c. In conclusion the use of CBCT in preoperative bone measurements will help provide valuable information about the quantity and quality of bone before the placement of dental implants.

  4. Study of prognostic significance of antenatal ultrasonography and renin angiotensin system activation in predicting disease severity in posterior urethral valves

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    Divya Bhadoo

    2015-01-01

    Full Text Available Aims: Study on prognostic significance of antenatal ultrasonography and renin angiotensin system activation in predicting disease severity in posterior urethral valves. Materials and Methods: Antenatally diagnosed hydronephrosis patients were included. Postnatally, they were divided into two groups, posterior urethral valve (PUV and non-PUV. The studied parameters were: Gestational age at detection, surgical intervention, ultrasound findings, cord blood and follow up plasma renin activity (PRA values, vesico-ureteric reflux (VUR, renal scars, and glomerular filtration rate (GFR. Results: A total of 25 patients were included, 10 PUV and 15 non-PUV. All infants with PUV underwent primary valve incision. GFR was less than 60 ml/min/1.73 m 2 body surface area in 4 patients at last follow-up. Keyhole sign, oligoamnios, absent bladder cycling, and cortical cysts were not consistent findings on antenatal ultrasound in PUV. Cord blood PRA was significantly higher (P < 0.0001 in PUV compared to non-PUV patients. Gestational age at detection of hydronephrosis, cortical cysts, bladder wall thickness, and amniotic fluid index were not significantly correlated with GFR while PRA could differentiate between poor and better prognosis cases with PUV. Conclusions: Ultrasound was neither uniformly useful in diagnosing PUV antenatally, nor differentiating it from cases with non-PUV hydronephrosis. In congenital hydronephrosis, cord blood PRA was significantly higher in cases with PUV compared to non-PUV cases and fell significantly after valve ablation. Cord blood PRA could distinguish between poor and better prognosis cases with PUV.

  5. Three-Dimensional Eye Position Signals Shape Both Peripersonal Space and Arm Movement Activity in the Medial Posterior Parietal Cortex.

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    Kostas eHadjidimitrakis

    2012-06-01

    Full Text Available Research conducted over the last decades has established that the medial part of posterior parietal cortex is crucial for controlling visually guided actions in human and non-human primates. Within this cortical sector there is area V6A, a crucial node of the parietofrontal network involved in arm movement control in both monkeys and humans. However, the encoding of action-in-depth by V6A cells had been not studied till recently. Recent neurophysiological studies show the existence in V6A neurons of signals related to the distance of targets from the eyes. These signals are integrated, often at the level of single cells, with information about the direction of gaze, thus encoding spatial location in 3D space. Moreover, 3D eye position signals seem to be further exploited at two additional levels of neural processing: a in determining whether targets are located in the peripersonal space or not, and b in shaping the spatial tuning of arm movement related activity towards reachable targets. These findings are in line with studies in putative homolog regions in humans and together point to a role of medial posterior parietal cortex in encoding both the vergence angle of the eyes and peripersonal space. Besides this role in spatial encoding also in depth, several findings demonstrate the involvement of this cortical sector in non-spatial processes.

  6. Cortical Reorganisation during a 30-Week Tinnitus Treatment Program.

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    Catherine M McMahon

    Full Text Available Subjective tinnitus is characterised by the conscious perception of a phantom sound. Previous studies have shown that individuals with chronic tinnitus have disrupted sound-evoked cortical tonotopic maps, time-shifted evoked auditory responses, and altered oscillatory cortical activity. The main objectives of this study were to: (i compare sound-evoked brain responses and cortical tonotopic maps in individuals with bilateral tinnitus and those without tinnitus; and (ii investigate whether changes in these sound-evoked responses occur with amelioration of the tinnitus percept during a 30-week tinnitus treatment program. Magnetoencephalography (MEG recordings of 12 bilateral tinnitus participants and 10 control normal-hearing subjects reporting no tinnitus were recorded at baseline, using 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz tones presented monaurally at 70 dBSPL through insert tube phones. For the tinnitus participants, MEG recordings were obtained at 5-, 10-, 20- and 30- week time points during tinnitus treatment. Results for the 500 Hz and 1000 Hz sources (where hearing thresholds were within normal limits for all participants showed that the tinnitus participants had a significantly larger and more anteriorly located source strengths when compared to the non-tinnitus participants. During the 30-week tinnitus treatment, the participants' 500 Hz and 1000 Hz source strengths remained higher than the non-tinnitus participants; however, the source locations shifted towards the direction recorded from the non-tinnitus control group. Further, in the left hemisphere, there was a time-shifted association between the trajectory of change of the individual's objective (source strength and anterior-posterior source location and subjective measures (using tinnitus reaction questionnaire, TRQ. The differences in source strength between the two groups suggest that individuals with tinnitus have enhanced central gain which is not significantly influenced by

  7. Cortical Reorganisation during a 30-Week Tinnitus Treatment Program

    Science.gov (United States)

    McMahon, Catherine M.; Ibrahim, Ronny K.; Mathur, Ankit

    2016-01-01

    Subjective tinnitus is characterised by the conscious perception of a phantom sound. Previous studies have shown that individuals with chronic tinnitus have disrupted sound-evoked cortical tonotopic maps, time-shifted evoked auditory responses, and altered oscillatory cortical activity. The main objectives of this study were to: (i) compare sound-evoked brain responses and cortical tonotopic maps in individuals with bilateral tinnitus and those without tinnitus; and (ii) investigate whether changes in these sound-evoked responses occur with amelioration of the tinnitus percept during a 30-week tinnitus treatment program. Magnetoencephalography (MEG) recordings of 12 bilateral tinnitus participants and 10 control normal-hearing subjects reporting no tinnitus were recorded at baseline, using 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz tones presented monaurally at 70 dBSPL through insert tube phones. For the tinnitus participants, MEG recordings were obtained at 5-, 10-, 20- and 30- week time points during tinnitus treatment. Results for the 500 Hz and 1000 Hz sources (where hearing thresholds were within normal limits for all participants) showed that the tinnitus participants had a significantly larger and more anteriorly located source strengths when compared to the non-tinnitus participants. During the 30-week tinnitus treatment, the participants’ 500 Hz and 1000 Hz source strengths remained higher than the non-tinnitus participants; however, the source locations shifted towards the direction recorded from the non-tinnitus control group. Further, in the left hemisphere, there was a time-shifted association between the trajectory of change of the individual’s objective (source strength and anterior-posterior source location) and subjective measures (using tinnitus reaction questionnaire, TRQ). The differences in source strength between the two groups suggest that individuals with tinnitus have enhanced central gain which is not significantly influenced by the

  8. Alternativas a la elevación de seno maxilar: rehabilitación del sector posterior del maxilar atrófico mediante implantes pterigoideos Alternatives to maxillary sinus lift: posterior area of the atrophic maxilla rehabilitation by means pterigoideal implants

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    X. Rodríguez-Ciurana

    2008-12-01

    Full Text Available El primer y segundo molar son los dientes que se pierden más a menudo debido a la enfermedad periodontal y al exceso de fuerzas oclusales. A pesar de la frecuencia del edentulismo parcial del sector posterior raramente se ubican los implantes más allá de los premolares debido al aumento del índice de fallos. El escaso volumen óseo y la pobre mineralización del sector posterior del maxilar comprometen la viabilidad de las rehabilitaciones con implantes a largo plazo. Además, la cresta ósea a nivel del seno maxilar, en el maxilar atrófico, no suele permitir el anclaje de implantes de 10 mm. Se han propuesto varias técnicas para rehabilitar el sector posterior del maxilar atrófico: implantes cortos, extensiones protésicas, injerto sinusal, implante cigomático. El implante pterigoideo es otro de los posibles tratamientos para rehabilitar el sector posterior del maxilar atrófico. Anclado en el hueso cortical de la apófisis del esfenoides el implante pterigoideo evita la necesidad de injertar o utilizar extensiones protésicas. El objetivo de este artículo es analizar las indicaciones, la técnica, complicaciones y supervivencia del implante pterigoideo en el sector posterior del maxilar atrófico.The first and second molar are the teeth most commonly lost in the maxilla, mainly due to periodontal disease and excessive occlusal force. 1 Although partial edentulism of the posterior maxilla is common, implants are seldom placed distal to the premolars because failure rates in the posterior maxilla have historically been high. Poor volume and low density of bone are the worst conditions for long-term anchorage in the maxilla. 7 Moreover, bone under the maxillary sinus, in the atrophic maxilla, is usually insufficient to enable placement of 10 mm implants. Several techniques have been proposed to restore the atrophic posterior maxilla: short implants, prosthetic cantilevers, sinus bone graft, zigomatic fixtures. Pterygoid implants are

  9. Posterior cortex epilepsy surgery in childhood and adolescence: Predictors of long-term seizure outcome.

    Science.gov (United States)

    Ramantani, Georgia; Stathi, Angeliki; Brandt, Armin; Strobl, Karl; Schubert-Bast, Susanne; Wiegand, Gert; Korinthenberg, Rudolf; van Velthoven, Vera; Zentner, Josef; Schulze-Bonhage, Andreas; Bast, Thomas

    2017-03-01

    We aimed to investigate the long-term seizure outcome of children and adolescents who were undergoing epilepsy surgery in the parietooccipital cortex and determine their predictive factors. We retrospectively analyzed the data of 50 consecutive patients aged 11.1 (mean) ± 5.1 (standard deviation) years at surgery. All patients but one had a magnetic resonance imaging (MRI)-visible lesion. Resections were parietal in 40%, occipital in 32%, and parietooccipital in 28% cases; 24% patients additionally underwent a resection of the posterior border of the temporal lobe. Etiology included focal cortical dysplasia in 44%, benign tumors (dysembryoplastic neuroepithelial tumor, ganglioglioma, angiocentric glioma, and pilocystic astrocytoma) in 32%, peri- or postnatal ischemic lesions in 16%, and tuberous sclerosis in 8% cases. At last follow-up (mean 8 years, range 1.5-18 years), 60% patients remained seizure-free (Engel class I): 30% had discontinued and 20% had reduced antiepileptic drugs. Most seizure recurrences (71%) occurred within the first 6 months, and only three patients presented with seizures ≥2 years after surgery. Independent predictors of seizure recurrence included left-sided as well as parietal epileptogenic zones and resections. Longer epilepsy duration to surgery was identified as the only modifiable independent predictor of seizure recurrence. Our study demonstrates that posterior cortex epilepsy surgery is highly effective in terms of lasting seizure control and antiepileptic drug cessation in selected pediatric candidates. Most importantly, our data supports the early consideration of surgical intervention in children and adolescents with refractory posterior cortex epilepsy. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  10. Multimodal connectivity mapping of the human left anterior and posterior lateral prefrontal cortex.

    Science.gov (United States)

    Reid, Andrew T; Bzdok, Danilo; Langner, Robert; Fox, Peter T; Laird, Angela R; Amunts, Katrin; Eickhoff, Simon B; Eickhoff, Claudia R

    2016-06-01

    Working memory is essential for many of our distinctly human abilities, including reasoning, problem solving, and planning. Research spanning many decades has helped to refine our understanding of this high-level function as comprising several hierarchically organized components, some which maintain information in the conscious mind, and others which manipulate and reorganize this information in useful ways. In the neocortex, these processes are likely implemented by a distributed frontoparietal network, with more posterior regions serving to maintain volatile information, and more anterior regions subserving the manipulation of this information. Recent meta-analytic findings have identified the anterior lateral prefrontal cortex, in particular, as being generally engaged by working memory tasks, while the posterior lateral prefrontal cortex was more strongly associated with the cognitive load required by these tasks. These findings suggest specific roles for these regions in the cognitive control processes underlying working memory. To further characterize these regions, we applied three distinct seed-based methods for determining cortical connectivity. Specifically, we employed meta-analytic connectivity mapping across task-based fMRI experiments, resting-state BOLD correlations, and VBM-based structural covariance. We found a frontoparietal pattern of convergence which strongly resembled the working memory networks identified in previous research. A contrast between anterior and posterior parts of the lateral prefrontal cortex revealed distinct connectivity patterns consistent with the idea of a hierarchical organization of frontoparietal networks. Moreover, we found a distributed network that was anticorrelated with the anterior seed region, which included most of the default mode network and a subcomponent related to social and emotional processing. These findings fit well with the internal attention model of working memory, in which representation of

  11. Correlation between the thickness of the crestal and buccolingual cortical bone at varying depths and implant stability quotients.

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    Kanthanat Chatvaratthana

    Full Text Available Resonance frequency analysis (RFA is clinically used in dentistry to access the stiffness of dental implants in surrounding bone. However, the clear advantages and disadvantages of this method are still inconclusive. The aim of this study was to investigate and compare implant stability quotient (ISQ values obtained from RFA with parameters obtained from a cone beam computed tomography (CBCT scan of the same region.Nineteen implants (Conelog were inserted in the posterior maxillary and mandibular partially edentulous regions of 16 patients. At the time of implant placement, the ISQ values were obtained using RFA (Osstell. CBCT was used to measure the thickness of the crestal, cortical, buccolingual cortical, and cancellous bone at 3, 6, and 9 mm below the crestal bone level, as indicated by radiographic markers. The ratio of the thickness of the cortical to cancellous bone at varying depths was also calculated and classified into 4 groups (Group 1-4.There was a strong correlation between the crestal cortical bone thickness and ISQ values (P<0.001. The thickness of the buccolingual cortical bone and ratio of the cortical to cancellous bone thickness at 3 mm were significantly related to the ISQ (P = 0.018 and P = 0.034, respectively. Furthermore, the ISQs in Group 1 were the highest compared with those in Group 2 and Group 3, whereas the CBCT parameters at 6 and 9 mm did not have any specific correlation with the ISQ values.This study showed that the ISQ values obtained from RFA highly correlated with the quantity and quality of bone 3 mm below the crestal bone level. The correlation between the ISQ and bone surrounding the implant site was dependent on the depth of measurement. Therefore, RFA can help to predict the marginal bone level, as confirmed in this study.

  12. Dexmedetomidine sedation in painful posterior segment surgery

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    Mansour A

    2012-12-01

    Full Text Available Ahmad Mansour,1,2 Samar Taha31Department of Ophthalmology, American University of Beirut, Beirut, Lebanon; 2Rafik Hariri University Hospital, Beirut, Lebanon; 3Department of Anesthesiology, American University of Beirut, Beirut, LebanonPurpose: To present a case series on the use of dexmedetomidine (Precedex sedation in painful posterior segment surgery performed under topical anesthesia, similar to its use in cataract surgery.Methods: A prospective review of cases that had posterior segment surgery under topical anesthesia and that needed sedation. Dexmedetomidine-loading infusion was 1 mcg/kg over 10 minutes, followed by a maintenance infusion (0.5 mcg/kg/h.Results: Nine patients were operated on under topical anesthesia: two scleral buckle, five cryopexy, one scleral laceration, and one pars plana vitrectomy with very dense laser therapy in an albinotic fundus; six patients had retinal detachment. General or local anesthesia were not possible due to medical or ocular morbidities, use of anticoagulants, or the surgery plan changed intraoperatively when new pathologies were discovered. The surgeon achieved good surgical control in eight of nine cases, with one patient having ocular and bodily movements that were disturbing. Six patients had no pain, while three patients reported mild pain. No adverse effects were noted and all patients had successful surgical outcomes. Heart rate, blood pressure, and oxygen saturation were well controlled throughout the procedures. The most frequent adverse reactions of dexmedetomidine reported in the literature in less than 5% (hypotension, bradycardia, and dry mouth were not recorded in the present study.Conclusion: When a surgeon has planned to do a pars plana vitrectomy under topical anesthesia and the surgical situation dictates the addition of cryopexy, scleral buckle, or intense laser retinopexy, then sedation with dexmedetomidine can help in the control of ocular pain in the majority of cases, with good

  13. Shape change in the atlas with congenital midline non-union of its posterior arch: a morphometric geometric study.

    Science.gov (United States)

    Ríos, Luis; Palancar, Carlos; Pastor, Francisco; Llidó, Susana; Sanchís-Gimeno, Juan Alberto; Bastir, Markus

    2017-10-01

    The congenital midline non-union of the posterior arch of the atlas is a developmental variant present at a frequency ranging from 0.7% to 3.9%. Most of the reported cases correspond to incidental findings during routine medical examination. In cases of posterior non-union, hypertrophy of the anterior arch and cortical bone thickening of the posterior arches have been observed and interpreted as adaptive responses of the atlas to increased mechanical stress. We sought to determine if the congenital non-union of the posterior arch results in a change in the shape of the atlas. This study is an analysis of the first cervical vertebrae from osteological collections through morphometric geometric techniques. A total of 21 vertebrae were scanned with a high-resolution three-dimensional scanner (Artec Space Spider, Artec Group, Luxembourg). To capture vertebral shape, 19 landmarks and 100 semilandmarks were placed on the vertebrae. Procrustes superimposition was applied to obtain size and shape data (MorphoJ 1.02; Klingenberg, 2011), which were analyzed through principal component analysis (PCA) and mean shape comparisons. The PCA resulted in two components explaining 22.32% and 18.8% of the total shape variance. The graphic plotting of both components indicates a clear shape difference between the control atlas and the atlas with posterior non-union. This observation was supported by statistically significant differences in mean shape comparisons between both types of vertebra (patlas is associated with significant changes in the shape of the vertebra. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Preliminary Findings Show Maternal Hypothyroidism May Contribute to Abnormal Cortical Morphology in Offspring

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    Julieta E. Lischinsky

    2016-02-01

    Full Text Available In rodents, insufficient thyroid hormone (TH gestationally has adverse effects on cerebral cortex development. Comparable studies of humans examining how TH insufficiency affects cortical morphology are limited to children with congenital hypothyroidism or offspring of hypothyroxinemic women; effects on cortex of children born to women with clinically diagnosed hypothyroidism are not known. We studied archived MRI scans from 22 children aged 10 to 12 years born to women treated for preexisting or de novo hypothyroidism within pregnancy (HYPO and 24 similar age and sex controls from euthyroid women. FreeSurfer Image Analysis Suite software was used to measure cortical thickness (CT and a vertex-based approach served to compare HYPO versus control groups and Severe versus Mild HYPO subgroups as well as to perform regression analyses examining effects of trimester-specific maternal TSH on CT. Results showed that relative to controls, HYPO had multiple regions of both cortical thinning and thickening, which differed for left and right hemispheres. In HYPO, thinning was confined to medial and mid-lateral regions of each hemisphere and thickening to superior regions (primarily frontal of the left hemisphere and inferior regions (particularly occipital and temporal of the right. The Severe HYPO subgroup showed more thinning than Mild in frontal and temporal regions and more thickening in bilateral posterior and frontal regions. Maternal TSH values predicted degree of thinning and thickening within multiple brain regions, with the pattern and direction of correlations differing by trimester. Notably, some correlations remained when cases born to women with severe hypothyroidism were removed from the analyses suggesting mild variations of maternal TH may permanently affect offspring cortex. We conclude that maternal hypothyroidism during pregnancy has long-lasting manifestations on the cortical morphology of their offspring with specific effects

  15. Cortical spectral activity and connectivity during active and viewed arm and leg movement

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    Julia eKline

    2016-03-01

    Full Text Available Active and viewed limb movement activate many similar neural pathways, however, to date most comparison studies have focused on subjects making small, discrete movements of the hands and feet. The purpose of this study was to determine if high-density electroencephalography (EEG could detect differences in cortical activity and connectivity during active and viewed rhythmic arm and leg movements in humans. Our primary hypothesis was that we would detect similar but weaker electrocortical spectral fluctuations and effective connectivity fluctuations during viewed limb exercise compared to active limb exercise due to the similarities in neural recruitment. A secondary hypothesis was that we would record stronger cortical spectral fluctuations for arm exercise compared to leg exercise, because rhythmic arm exercise would be more dependent on supraspinal control than rhythmic leg exercise. We recorded EEG data while ten young healthy subjects exercised on a recumbent stepper with: 1 both arms and legs, 2 just legs, and 3 just arms. Subjects also viewed video playback of themselves or another individual performing the same exercises. We performed independent component analysis, dipole fitting, spectral analysis, and effective connectivity analysis on the data. Cortical areas comprising the premotor and supplementary motor cortex, the anterior cingulate, the posterior cingulate, and the parietal cortex exhibited significant spectral fluctuations during rhythmic limb exercise. These fluctuations tended to be greater for the arms exercise conditions than for the legs only exercise condition, which suggests that human rhythmic arm movements are under stronger cortical control than rhythmic leg movements. We did not find consistent spectral fluctuations in these areas during the viewed conditions, but effective connectivity fluctuated at harmonics of the exercise frequency during both active and viewed rhythmic limb exercise. The right premotor and

  16. Cortical Spectral Activity and Connectivity during Active and Viewed Arm and Leg Movement.

    Science.gov (United States)

    Kline, Julia E; Huang, Helen J; Snyder, Kristine L; Ferris, Daniel P

    2016-01-01

    Active and viewed limb movement activate many similar neural pathways, however, to date most comparison studies have focused on subjects making small, discrete movements of the hands and feet. The purpose of this study was to determine if high-density electroencephalography (EEG) could detect differences in cortical activity and connectivity during active and viewed rhythmic arm and leg movements in humans. Our primary hypothesis was that we would detect similar but weaker electrocortical spectral fluctuations and effective connectivity fluctuations during viewed limb exercise compared to active limb exercise due to the similarities in neural recruitment. A secondary hypothesis was that we would record stronger cortical spectral fluctuations for arm exercise compared to leg exercise, because rhythmic arm exercise would be more dependent on supraspinal control than rhythmic leg exercise. We recorded EEG data while ten young healthy subjects exercised on a recumbent stepper with: (1) both arms and legs, (2) just legs, and (3) just arms. Subjects also viewed video playback of themselves or another individual performing the same exercises. We performed independent component analysis, dipole fitting, spectral analysis, and effective connectivity analysis on the data. Cortical areas comprising the premotor and supplementary motor cortex, the anterior cingulate, the posterior cingulate, and the parietal cortex exhibited significant spectral fluctuations during rhythmic limb exercise. These fluctuations tended to be greater for the arms exercise conditions than for the legs only exercise condition, which suggests that human rhythmic arm movements are under stronger cortical control than rhythmic leg movements. We did not find consistent spectral fluctuations in these areas during the viewed conditions, but effective connectivity fluctuated at harmonics of the exercise frequency during both active and viewed rhythmic limb exercise. The right premotor and supplementary motor

  17. Posterior α EEG Dynamics Dissociate Current from Future Goals in Working Memory-Guided Visual Search.

    Science.gov (United States)

    de Vries, Ingmar E J; van Driel, Joram; Olivers, Christian N L

    2017-02-08

    Current models of visual search assume that search is guided by an active visual working memory representation of what we are currently looking for. This attentional template for currently relevant stimuli can be dissociated from accessory memory representations that are only needed prospectively, for a future task, and that should be prevented from guiding current attention. However, it remains unclear what electrophysiological mechanisms dissociate currently relevant (serving upcoming selection) from prospectively relevant memories (serving future selection). We measured EEG of 20 human subjects while they performed two consecutive visual search tasks. Before the search tasks, a cue instructed observers which item to look for first (current template) and which second (prospective template). During the delay leading up to the first search display, we found clear suppression of α band (8-14 Hz) activity in regions contralateral to remembered items, comprising both local power and interregional phase synchronization within a posterior parietal network. Importantly, these lateralization effects were stronger when the memory item was currently relevant (i.e., for the first search) compared with when it was prospectively relevant (i.e., for the second search), consistent with current templates being prioritized over future templates. In contrast, event-related potential analysis revealed that the contralateral delay activity was similar for all conditions, suggesting no difference in storage. Together, these findings support the idea that posterior α oscillations represent a state of increased processing or excitability in task-relevant cortical regions, and reflect enhanced cortical prioritization of memory representations that serve as a current selection filter.SIGNIFICANCE STATEMENT Our days are filled with looking for relevant objects while ignoring irrelevant visual information. Such visual search activity is thought to be driven by current goals activated in

  18. Combat Veterans with PTSD after Mild TBI Exhibit Greater ERPs from Posterior-medial Cortical Areas While Appraising Facial Features

    Science.gov (United States)

    2014-01-01

    E.W., Karl , A., 2013. Meta-analytic review of P3 components in posttraumatic stress disorder and their clinical utility. Clin. EEG Neurosci.. Jorge...Weiner, J., Marx , C.E., Cernak, I., McCarthy, G., Group, M.W., 2012. Effects of chronic mild traumatic brain injury on white matter integrity in Iraq and

  19. Transverse malocclusion, posterior crossbite and severe discrepancy

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    Roberto Carlos Bodart Brandão

    2012-02-01

    Full Text Available This article reports the orthodontic treatment of a 14 years and 2 months old female patient, presenting both anterior and posterior unilateral left crossbite, related to a transverse atrophy of the maxilla and a severe negative tooth-arch discrepancy in the upper arch. A maxillary expansion with a modified Haas appliance was the first therapeutic attempt. Then, fixed appliances were used in both arches, and the second left premolar was extracted. The space for the upper left lateral incisor was achieved with compressed springs and tooth movement was accomplished with double archwires. The final result showed a good intercuspation, considering that the left molar relation remained as a Class II, which demanded special occlusal adjustments. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics, representing category 5, as a partial requirement for the BBO certificate.

  20. Iodine-125 radiation of posterior uveal melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Packer, S.

    1987-12-01

    Twenty-eight cases of posterior choroidal melanoma were treated with iodine-125 in gold eye plaques. Eleven cases were located within 3.0 mm of the optic nerve (group A), nine were within 3.0 mm of the fovea (group B), and eight were within 3.0 mm of the optic nerve and fovea (group C). The mean follow-up of group A was 46.3 months; group B, 25.5 months; and group C, 42.7 months. Complications included macular edema, cataract and tumor growth. Visual acuity remained within two lines of that tested preoperatively for 4 of 11 patients in group A, 4 of 9 in group B, and 5 of 8 in group C. These results with iodine-125 suggest it as an appropriate treatment for patients with choroidal melanoma located near optic nerve and/or macula.

  1. MR imaging of posterior cruciate ligament injuries

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    Takahashi, Nobuyuki [Tsukuba Univ., Ibaraki (Japan). Hospital; Niitsu, Mamoru; Itai, Yuji; Sato, Motohiro; Kujiraoka, Yuka; Ikeda, Kotaro; Kanamori, Akihiro

    2001-07-01

    Posterior cruciate ligament (PCL) injuries are less frequent than anterior cruciate ligament (ACL) injuries, but are presumably more common than once thought. Thirty-nine patients with PCL injuries identified on MR images were studied. The criteria for PCL injury were complete tear, partial tear, and avulsion fracture. The approximate site of a partial tear was categorized as proximal, midsubstance, distal, or combination. Fourteen patients (35.9%) had complete tears of the PCL, 21 patients (53.8%) had partial tears, and four patients (10.3%) had avulsion fractures. A total of 12 patients (30.7%) had isolated PCL injuries, while the remaining 27 patients demonstrated evidence of other coexistent knee injuries, such as meniscal tears and ligamentous injuries. Of coexistent knee injuries, meniscal tears (18 patients, 46.2%) were most often seen. (author)

  2. Imaging of the posterior pelvic floor

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, Jaap [Department of Radiology, Academic Medical Center, University of Amsterdam (Netherlands); Bartram, Clive I.; Halligan, Steve [Intestinal Imaging Centre, St. Mark' s Hospital, London (United Kingdom)

    2002-04-01

    Disorders of the posterior pelvic floor are relatively common. The role of imaging in this field is increasing, especially in constipation, prolapse and anal incontinence, and currently imaging is an integral part of the investigation of these pelvic floor disorders. Evacuation proctography provides both structural and functional information for rectal voiding and prolapse. Dynamic MRI may be a valuable alternative as the pelvic floor muscles are visualised, and it is currently under evaluation. Endoluminal imaging is important in the management of anal incontinence. Both endosonography and endoanal MRI can be used for detection of anal sphincter defects. Endoanal MRI has the advantage of simultaneously evaluating external sphincter atrophy, which is an important predictive factor for the outcome of sphincter repair. Many aspects of constipation and prolapse remain incompletely understood and treatment is partly empirical; however, imaging has a central role in management to place patients into treatment-defined groups. (orig.)

  3. Elastic K-means using posterior probability.

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    Aihua Zheng

    Full Text Available The widely used K-means clustering is a hard clustering algorithm. Here we propose a Elastic K-means clustering model (EKM using posterior probability with soft capability where each data point can belong to multiple clusters fractionally and show the benefit of proposed Elastic K-means. Furthermore, in many applications, besides vector attributes information, pairwise relations (graph information are also available. Thus we integrate EKM with Normalized Cut graph clustering into a single clustering formulation. Finally, we provide several useful matrix inequalities which are useful for matrix formulations of learning models. Based on these results, we prove the correctness and the convergence of EKM algorithms. Experimental results on six benchmark datasets demonstrate the effectiveness of proposed EKM and its integrated model.

  4. αTubulin 67C and Ncd are essential for establishing a cortical microtubular network and formation of the Bicoid mRNA gradient in Drosophila.

    Science.gov (United States)

    Fahmy, Khalid; Akber, Mira; Cai, Xiaoli; Koul, Aabid; Hayder, Awais; Baumgartner, Stefan

    2014-01-01

    The Bicoid (Bcd) protein gradient in Drosophila serves as a paradigm for gradient formation in textbooks. To explain the generation of the gradient, the ARTS model, which is based on the observation of a bcd mRNA gradient, proposes that the bcd mRNA, localized at the anterior pole at fertilization, migrates along microtubules (MTs) at the cortex to the posterior to form a bcd mRNA gradient which is translated to form a protein gradient. To fulfil the criteria of the ARTS model, an early cortical MT network is thus a prerequisite. We report hitherto undiscovered MT activities in the early embryo important for bcd mRNA transport: (i) an early and omnidirectional MT network exclusively at the anterior cortex of early nuclear cycle embryos showing activity during metaphase and anaphase only, (ii) long MTs up to 50 µm extending into the yolk at blastoderm stage to enable basal-apical transport. The cortical MT network is not anchored to the actin cytoskeleton. The posterior transport of the mRNA via the cortical MT network critically depends on maternally-expressed αTubulin67C and the minus-end motor Ncd. In either mutant, cortical transport of the bcd mRNA does not take place and the mRNA migrates along another yet undisclosed interior MT network, instead. Our data strongly corroborate the ARTS model and explain the occurrence of the bcd mRNA gradient.

  5. Long-lasting enhancements of memory and hippocampal-cortical functional connectivity following multiple-day targeted noninvasive stimulation.

    Science.gov (United States)

    Wang, Jane X; Voss, Joel L

    2015-08-01

    Noninvasive stimulation can alter the function of brain networks, although the duration of neuroplastic changes are uncertain and likely vary for different networks and stimulation parameters. We have previously shown that multiple-day repetitive transcranial magnetic stimulation can influence targeted hippocampal-cortical networks, producing increased functional MRI connectivity of these networks and concomitant improvements in memory that outlast stimulation by ∼24 h. Here, we present new analyses showing that multiple-day targeted stimulation of hippocampal-cortical networks produces even longer-lasting enhancement. The ability to learn novel, arbitrary face-word pairings improved over five consecutive daily stimulation sessions, and this improvement remained robust at follow-up testing performed an average of 15 days later. Furthermore, stimulation increased functional MRI connectivity of the targeted portion of the hippocampus with distributed regions of the posterior hippocampal-cortical network, and these changes in connectivity remained robust at follow-up testing. Neuroplastic changes of hippocampal-cortical networks caused by multiple-day noninvasive stimulation therefore persist for extended periods. These findings have implications for the design of multiple-day stimulation experiments and for the development of stimulation-based interventions for memory disorders. © 2015 Wiley Periodicals, Inc.

  6. Changes in crystallin concentration in rat aqueous and vitreous humors after selenium-induced reversible cortical cataract.

    Science.gov (United States)

    Watanabe, H; Komoto, M; David, L L; Shearer, T R

    1990-01-01

    Five months after selenite injection, 58% of the rats that had developed cataract earlier underwent a reversal of the cortical opacity. The purpose of this study was to determine if lenses undergoing recovery from cortical opacity reestablish their ability to retain crystallins. By direct ELISA method, the aqueous humor (AH) of control rats was found to contain 18, 39 and 10 ng/ml alpha-, beta- and gamma-crystallin, respectively, while vitreous humor (VH) contained 43, 98 and 23 ng/ml of alpha-, beta- and gamma-crystallin, respectively. In rats with mature cataracts which did not recover by 5 months after selenite injection, there was an approximately 10-fold greater crystallin concentration in the AH and about 20 times greater crystallin concentration in the VH than in the controls. In contrast, rats undergoing recovery from cortical cataract showed almost normal concentration of crystallins in the AH. While crystallins were still elevated in the VH of the rats undergoing recovery from cortical cataract, the crystallin content was lower than in the rats which did not recover. Higher crystallin concentrations in the VH could be explained by either a greater loss through the posterior capsule, or a slower turnover of VH. Decreased crystallin loss from lenses undergoing recovery suggested that the recovered lens at least partly reestablishes its ability to retain crystallins. These data may demonstrate that the lens fiber permeability is lowered while lens repair is occurring.

  7. Playing and Listening to Tailor-Made Notched Music: Cortical Plasticity Induced by Unimodal and Multimodal Training in Tinnitus Patients

    Directory of Open Access Journals (Sweden)

    Janna Pape

    2014-01-01

    Full Text Available Background. The generation and maintenance of tinnitus are assumed to be based on maladaptive functional cortical reorganization. Listening to modified music, which contains no energy in the range of the individual tinnitus frequency, can inhibit the corresponding neuronal activity in the auditory cortex. Music making has been shown to be a powerful stimulator for brain plasticity, inducing changes in multiple sensory systems. Using magnetoencephalographic (MEG and behavioral measurements we evaluated the cortical plasticity effects of two months of (a active listening to (unisensory versus (b learning to play (multisensory tailor-made notched music in nonmusician tinnitus patients. Taking into account the fact that uni- and multisensory trainings induce different patterns of cortical plasticity we hypothesized that these two protocols will have different affects. Results. Only the active listening (unisensory group showed significant reduction of tinnitus related activity of the middle temporal cortex and an increase in the activity of a tinnitus-coping related posterior parietal area. Conclusions. These findings indicate that active listening to tailor-made notched music induces greater neuroplastic changes in the maladaptively reorganized cortical network of tinnitus patients while additional integration of other sensory modalities during training reduces these neuroplastic effects.

  8. Divergent Human Cortical Regions for Processing Distinct Acoustic-Semantic Categories of Natural Sounds: Animal Action Sounds vs. Vocalizations

    Science.gov (United States)

    Webster, Paula J.; Skipper-Kallal, Laura M.; Frum, Chris A.; Still, Hayley N.; Ward, B. Douglas; Lewis, James W.

    2017-01-01

    A major gap in our understanding of natural sound processing is knowledge of where or how in a cortical hierarchy differential processing leads to categorical perception at a semantic level. Here, using functional magnetic resonance imaging (fMRI) we sought to determine if and where cortical pathways in humans might diverge for processing action sounds vs. vocalizations as distinct acoustic-semantic categories of real-world sound when matched for duration and intensity. This was tested by using relatively less semantically complex natural sounds produced by non-conspecific animals rather than humans. Our results revealed a striking double-dissociation of activated networks bilaterally. This included a previously well described pathway preferential for processing vocalization signals directed laterally from functionally defined primary auditory cortices to the anterior superior temporal gyri, and a less well-described pathway preferential for processing animal action sounds directed medially to the posterior insulae. We additionally found that some of these regions and associated cortical networks showed parametric sensitivity to high-order quantifiable acoustic signal attributes and/or to perceptual features of the natural stimuli, such as the degree of perceived recognition or intentional understanding. Overall, these results supported a neurobiological theoretical framework for how the mammalian brain may be fundamentally organized to process acoustically and acoustic-semantically distinct categories of ethologically valid, real-world sounds. PMID:28111538

  9. Playing and listening to tailor-made notched music: cortical plasticity induced by unimodal and multimodal training in tinnitus patients.

    Science.gov (United States)

    Pape, Janna; Paraskevopoulos, Evangelos; Bruchmann, Maximilian; Wollbrink, Andreas; Rudack, Claudia; Pantev, Christo

    2014-01-01

    BACKGROUND. The generation and maintenance of tinnitus are assumed to be based on maladaptive functional cortical reorganization. Listening to modified music, which contains no energy in the range of the individual tinnitus frequency, can inhibit the corresponding neuronal activity in the auditory cortex. Music making has been shown to be a powerful stimulator for brain plasticity, inducing changes in multiple sensory systems. Using magnetoencephalographic (MEG) and behavioral measurements we evaluated the cortical plasticity effects of two months of (a) active listening to (unisensory) versus (b) learning to play (multisensory) tailor-made notched music in nonmusician tinnitus patients. Taking into account the fact that uni- and multisensory trainings induce different patterns of cortical plasticity we hypothesized that these two protocols will have different affects. RESULTS. Only the active listening (unisensory) group showed significant reduction of tinnitus related activity of the middle temporal cortex and an increase in the activity of a tinnitus-coping related posterior parietal area. CONCLUSIONS. These findings indicate that active listening to tailor-made notched music induces greater neuroplastic changes in the maladaptively reorganized cortical network of tinnitus patients while additional integration of other sensory modalities during training reduces these neuroplastic effects.

  10. Esclerite posterior: características clínicas, associação sistêmica, tratamento e evolução de 23 pacientes Posterior scleritis: clinical features, systemic association, treatment and evolution of 23 patients

    Directory of Open Access Journals (Sweden)

    Danuza de Oliveira Machado

    2009-06-01

    Full Text Available OBJETIVOS: Documentar características clínicas, associações sistêmicas, tratamento e evolução de 23 pacientes com esclerite posterior, examinados no serviço de uveítes da Universidade Federal de Minas Gerais. MÉTODOS: Revisão de todos os pacientes com esclerite atendidos neste serviço, de 1999 até 2006, para identificar aqueles com esclerite posterior. Identificados 23 pacientes, registrados e analisados os dados com relação aos sinais e sintomas oculares, visão, alterações na ecografia, manifestações sistêmicas, tratamento e evolução. RESULTADOS: Dezesseis pacientes do sexo feminino e 7 do sexo masculino com média de idade de 44,7 anos. Esclerite posterior ocorreu associada à esclerite anterior em 10 pacientes, envolvimento unilateral em 17 pacientes e, bilateral simultâneo, em 6 pacientes. Esclerite posterior associada à doença sistêmica ocorreu em 8 pacientes (síndrome de Cogan, tuberculose, granulomatose de Wegener, herpes simples e zoster, aspergilose, retocolite-ulcerativa e sarcoidose. A principal queixa foi dor ocular seguida de embaçamento visual e o sinal fundoscópico que predominou foi o descolamento seroso de retina. O achado mais comum na ecografia foi espessamento da parede escleral observado em 18 pacientes e a principal forma de tratamento, o uso de corticóide sistêmico. Somente 4 pacientes necessitaram de imunossupressor. CONCLUSÃO: Esclerite posterior é doença de difícil diagnóstico e pode ser potencialmente devastadora. Análises estatísticas são incapazes de revelar outras características específicas da esclerite posterior, características clínicas dos pacientes e evolução da doença que poderiam ajudar na identificação dos casos com maior risco de perda visual ou com maior probabilidade de doença sistêmica.PURPOSE: To document the clinical features, systemic association, treatment and evolution of 23 patients with posterior scleritis evaluated in the Uveitis service of the

  11. Stability of the Syndesmosis After Posterior Malleolar Fracture Fixation.

    Science.gov (United States)

    Miller, Matthew A; McDonald, Tyler C; Graves, Matthew L; Spitler, Clay A; Russell, George V; Jones, LaRita C; Replogle, William; Wise, Jeremy A; Hydrick, Josie; Bergin, Patrick F

    2018-01-01

    We sought to define the rate of syndesmotic instability after anatomic reduction of the posterior malleolus when posterior stabilization of a trimalleolar or trimalleolar equivalent ankle fracture was chosen vs when a supine position and initially conservative management of the posterior elements was chosen. The types of syndesmotic and posterior malleolar fixation used to treat adult patients with ankle fractures involving the posterior malleolus at our level I trauma center were retrospectively assessed (N = 198). Specifically, both bimalleolar and trimalleolar fractures were included. Exclusion criteria included pilon fractures, trimalleolar fractures with Chaput fragments, and neurologic injury. Demographics, fracture classification, initial operative position, medial clear space, and posterior malleolar fragment size were recorded for each fracture. In total, 151 patients (76.3%) were initially positioned supine, 27.2% of whom had syndesmotic instability requiring operative stabilization. Almost 25% of supine patients also underwent posterior malleolar stabilization for posterior instability. Overall, 73 (48.3%) patients who were initially treated in the supine position needed some form of additional stabilization. Forty-seven patients (23.7%) were initially positioned prone. Syndesmotic stability was restored in 97.9% of these patients. This 2.1% rate of instability vastly differs from the 13-fold higher syndesmotic instability rate observed in the supine group ( P < .001). Our data demonstrate that the rate of syndesmotic instability was reduced in trimalleolar and trimalleolar equivalent fractures when prone positioning and direct fixation of the posterior malleolus were first performed. Using traditional preoperative estimates of posterior stability to determine the need for posterior malleolar fixation may be inadequate since almost a quarter of patients treated supine received posterior stabilization. Level III, retrospective comparative series.

  12. Building the posterior lateral line system in zebrafish

    OpenAIRE

    Chitnis, Ajay B; Nogare, Damian Dalle; Matsuda, Miho

    2012-01-01

    The posterior lateral line in zebrafish has emerged as an excellent system to study how a sensory organ system develops. Here we review recent studies that illustrate how interactions between multiple signaling pathways coordinate cell fate, morphogenesis and collective migration of cells in the posterior lateral line primordium. These studies also illustrate how the posterior lateral line system is contributing much more broadly to our understanding of mechanisms operating during the growth,...

  13. Minimally invasive surgical approach to treat posterior urethral diverticulum

    Science.gov (United States)

    Alsowayan, Ossamah; Almodhen, Fayez; Alshammari, Ahmed

    2015-01-01

    Urethral diverticulum is a localized saccular or fusiform out-pouching of the urethra. It may occur at any point along the urethra in both male and females. Male urethral diverticulum is rare, and could be either congenital or acquired, anterior or posterior. The mainstay treatment of posterior urethral diverticulum (PUD) is the open surgical approach. Here we discuss our minimally invasive surgical approach (MIS) in managing posterior urethral diverticulum. PMID:25834967

  14. Minimally invasive surgical approach to treat posterior urethral diverticulum

    Directory of Open Access Journals (Sweden)

    Ossamah Alsowayan

    2015-01-01

    Full Text Available Urethral diverticulum is a localized saccular or fusiform out-pouching of the urethra. It may occur at any point along the urethra in both male and females. Male urethral diverticulum is rare, and could be either congenital or acquired, anterior or posterior. The mainstay treatment of posterior urethral diverticulum (PUD is the open surgical approach. Here we discuss our minimally invasive surgical approach (MIS in managing posterior urethral diverticulum.

  15. Minimally invasive surgical approach to treat posterior urethral diverticulum

    OpenAIRE

    Ossamah Alsowayan; Fayez Almodhen; Ahmed Alshammari

    2015-01-01

    Urethral diverticulum is a localized saccular or fusiform out-pouching of the urethra. It may occur at any point along the urethra in both male and females. Male urethral diverticulum is rare, and could be either congenital or acquired, anterior or posterior. The mainstay treatment of posterior urethral diverticulum (PUD) is the open surgical approach. Here we discuss our minimally invasive surgical approach (MIS) in managing posterior urethral diverticulum.

  16. Bilateral, posterior parietal polymicrogyria as part of speech therapy ...

    African Journals Online (AJOL)

    parietal polymicrogyria in a child with speech pathology. Introduction. Polymicrogyria is an abnormality in the cortical development where the normal development of the cortex is interrupted in the late stages of neuronal migration and cortical organisation.1 This interruption results in abnormal development of the deep ...

  17. Posterior reversible encephalopathy syndrome as a complication of Henoch-Schönlein purpura in a seven-year-old girl.

    Science.gov (United States)

    Dos Santos, Daiane; Langer, Felipe Welter; Dos Santos, Tatiane; Rafael Tronco Alves, Giordano; Feiten, Marisa; Teixeira de Paula Neto, Walter

    2017-02-01

    Introduction Henoch-Schönlein purpura is a multisystem small vessel vasculitis. Neurologic manifestations are uncommon. Posterior reversible encephalopathy syndrome is a rare complication of Henoch-Schönlein purpura with typical clinical and neuroimaging findings that occurs most commonly in the setting of severe hypertension and renal injury. Case presentation A seven-year-old girl was admitted to our institution presenting with clinical and laboratory findings suggestive of Henoch-Schönlein purpura. Glucocorticoid therapy was initiated, but five days following her admission, she developed altered consciousness, seizures, arterial hypertension, and cortical blindness. Brain MRI scan revealed areas of vasogenic oedema in parieto-occipital lobes, consistent with posterior reversible encephalopathy syndrome. She was immediately initiated on antihypertensives and antiepileptics, which successfully improved her neurologic symptoms. Further laboratory work-up disclosed a rapidly progressive glomerulonephritis secondary to Henoch-Schönlein purpura that was the likely cause of her sudden blood pressure elevation. Immunosuppressive therapy was undertaken, and at one-year follow-up, the patient exhibited complete renal and neurologic recovery. Conclusion Posterior reversible encephalopathy syndrome is a severe complication of Henoch-Schönlein purpura. If promptly diagnosed and treated, children with Henoch-Schönlein purpura presenting with posterior reversible encephalopathy syndrome usually have a good prognosis. Clinicians should be familiar with the characteristic presentation of posterior reversible encephalopathy syndrome and be aware that hypertension and renal injury may predispose Henoch-Schönlein purpura patients to developing this complication.

  18. Spontaneously emerging cortical representations of visual attributes

    Science.gov (United States)

    Kenet, Tal; Bibitchkov, Dmitri; Tsodyks, Misha; Grinvald, Amiram; Arieli, Amos

    2003-10-01

    Spontaneous cortical activity-ongoing activity in the absence of intentional sensory input-has been studied extensively, using methods ranging from EEG (electroencephalography), through voltage sensitive dye imaging, down to recordings from single neurons. Ongoing cortical activity has been shown to play a critical role in development, and must also be essential for processing sensory perception, because it modulates stimulus-evoked activity, and is correlated with behaviour. Yet its role in the processing of external information and its relationship to internal representations of sensory attributes remains unknown. Using voltage sensitive dye imaging, we previously established a close link between ongoing activity in the visual cortex of anaesthetized cats and the spontaneous firing of a single neuron. Here we report that such activity encompasses a set of dynamically switching cortical states, many of which correspond closely to orientation maps. When such an orientation state emerged spontaneously, it spanned several hypercolumns and was often followed by a state corresponding to a proximal orientation. We suggest that dynamically switching cortical states could represent the brain's internal context, and therefore reflect or influence memory, perception and behaviour.

  19. Prenatal Alcohol Exposure and Cortical Angiogenesis

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    J Gordon Millichap

    2013-02-01

    Full Text Available Researchers at Normandy University, and Rouen and Brest Universities, France studied the effects of prenatal alcohol exposure on the cortical microvascular and the action of alcohol, glutamate, and vascular endothelial growth factor A (VEGF on activity, plasticity, and survival of microvessels in mice.

  20. Simplified Classification of Focal Cortical Dysplasia

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    J Gordon Millichap

    2002-09-01

    Full Text Available Sections of cortex from 52 of 224 (23% patients with cortical dysplasia, operated on for drug-resistant partial epilepsy, were retrospectively re-examined histologically at Niguarda Hospital, and Istituto Nazionale Neurologico ‘C. Besta’, Milan, Italy.

  1. Cortical thickness abnormalities in late adolescence with online gaming addiction

    National Research Council Canada - National Science Library

    Yuan, Kai; Cheng, Ping; Dong, Tao; Bi, Yanzhi; Xing, Lihong; Yu, Dahua; Zhao, Limei; Dong, Minghao; von Deneen, Karen M; Liu, Yijun; Qin, Wei; Tian, Jie

    2013-01-01

    ...) and age-, education- and gender-matched controls (n = 18) were acquired. The cortical thickness measurement method was employed to investigate alterations of cortical thickness in individuals with online gaming addiction...

  2. Difficulty in Distinguishing Posterior Reversible Encephalopathy Syndrome, Hypoxic-Ischemic Insult, and Acute Toxic Leukoencephalopathy in Children.

    Science.gov (United States)

    Luckman, Judith; Zahavi, Alon; Efrati, Shai; Gilad, Gil; Snir, Moshe; Michowiz, Shalom; Goldenberg-Cohen, Nitza

    2016-01-01

    This study aims to describe our experience of unique pediatric neurological cases and associated difficulty in differentiating posterior reversible encephalopathy syndrome (PRES) from hypoxic-ischemic insult (HII), and acute toxic leukoencephalopathy (ATL). The study included three children with a clinical picture suggestive of PRES, HII, and ATL of different etiologies who were diagnosed and treated at a tertiary pediatric medical center in 2011 to 2014. All patients presented with blindness following seizures with asphyxia/aspiration in a syndromatic child, too-rapid lipid infusion in a child with acute lymphoblastic leukemia, and repeated vomiting in a child with cerebral palsy, hydrocephalus, and malfunction of ventriculoperitoneal shunt. All patients had cortical blindness and high-signal foci in the cortical and subcortical regions on magnetic resonance imaging. All children improved. Familiarity with the clinical and radiological characteristics of neurological conditions leading to reversible cortical blindness is essential for diagnosis and management. Distinguishing PRES from HII and ATL can be challenging. Our cases most likely combined these etiologies, with the first patient diagnosed with PRES with HII, the second with PRES with ATL, and the third with focal HII. Given the diversity of the findings and the unclear prognostic significance, studies of the pathophysiology of PRES are warranted. Georg Thieme Verlag KG Stuttgart · New York.

  3. Anatomical substrates of the alerting, orienting and executive control components of attention: focus on the posterior parietal lobe.

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    Xuntao Yin

    Full Text Available Both neuropsychological and functional neuroimaging studies have identified that the posterior parietal lobe (PPL is critical for the attention function. However, the unique role of distinct parietal cortical subregions and their underlying white matter (WM remains in question. In this study, we collected both magnetic resonance imaging and diffusion tensor imaging (DTI data in normal participants, and evaluated their attention performance using attention network test (ANT, which could isolate three different attention components: alerting, orienting and executive control. Cortical thickness, surface area and DTI parameters were extracted from predefined PPL subregions and correlated with behavioural performance. Tract-based spatial statistics (TBSS was used for the voxel-wise statistical analysis. Results indicated structure-behaviour relationships on multiple levels. First, a link between the cortical thickness and WM integrity of the right inferior parietal regions and orienting performance was observed. Specifically, probabilistic tractography demonstrated that the integrity of WM connectivity between the bilateral inferior parietal lobules mediated the orienting performance. Second, the scores of executive control were significantly associated with the WM diffusion metrics of the right supramarginal gyrus. Finally, TBSS analysis revealed that alerting performance was significant correlated with the fractional anisotropy of local WM connecting the right thalamus and supplementary motor area. We conclude that distinct areas and features within PPL are associated with different components of attention. These findings could yield a more complete understanding of the nature of the PPL contribution to visuospatial attention.

  4. Estimulação elétrica neuromuscular de média freqüência (russa em cães com atrofia muscular induzida Medium frequency neuromuscular electrical stimulation (russian in dogs with induced muscle atrophy

    Directory of Open Access Journals (Sweden)

    Charles Pelizzari

    2008-06-01

    Full Text Available A estimulação elétrica neuromuscular (EENM de média freqüência (Russa ou de Kotz pode ser empregada para a recuperação de massa muscular em animais apresentando atrofia muscular por desuso. Assim, o objetivo deste trabalho foi empregar a EENM de média freqüência no quadríceps femoral de cães com atrofia muscular induzida, avaliando-se a ocorrência de ganho de massa. Foram utilizados oito cães em dois grupos denominados de GI ou controle e de GII ou tratado. Para a indução da atrofia muscular, a articulação fêmoro-tíbio-patelar esquerda foi imobilizada por 30 dias. Após 48 horas da remoção, foi realizada a EENM nos cães do grupo II, três vezes por semana, com intervalo de 48 horas cada sessão, pelo período de 60 dias. Foram avaliadas a mensuração da perimetria da coxa, da goniometria do joelho, as enzimas creatina-quinase (CK e morfometria das fibras musculares em cortes transversais do músculo vasto lateral, colhido mediante a biópsia muscular. A EENM foi empregada no músculo quadríceps femoral numa freqüência de 2.500Hz, largura de pulso de 50% e relação de tempo on/off de 1:2. Não houve diferença significativa quanto aos valores de perimetria da coxa e a atividade da enzima CK entre os grupos I e II. Na goniometria, houve diminuição significativa (PThe medium frequency neuromuscular electrical stimulation (NMES (Russa or Kotz is designed for recuperation of muscle mass in dogs with muscular atrophy in disuse. This study aims to utilize medium frequency NMES on the femoral quadriceps of dogs with induced muscular atrophy and evaluate the occurrence of gain in mass. Eight dogs in two groups denominated GI, or control, and GII, or treated were used. For the induction of muscular atrophy, the left femoral-tibial-patellar joint was immobilized for 30 days. NMES treatment began 48 hours after the removal of the immobilization device on dogs from group II and was carried out three times per week, with an

  5. Mild cognitive impairment, poor episodic memory, and late-life depression are associated with cerebral cortical thinning and increased white matter hyperintensities

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    Motonobu eFujishima

    2014-11-01

    Full Text Available In various independent studies to date, cerebral cortical thickness and white matter hyperintensity (WMH volume have been associated with episodic memory, depression, and mild cognitive impairment (MCI. The aim of this study was to uncover variations in cortical thickness and WMH volume in association with episodic memory, depressive state, and the presence of MCI simultaneously in a single study population. The participants were 186 individuals with MCI (clinical dementia rating [CDR] of 0.5 and 136 healthy elderly controls (HCs; CDR of 0 drawn from two community-based cohort studies in northern Japan. We computed cerebral cortical thickness and WMH volume by using MR scans and statistically analyzed differences in these indices between HCs and MCI participants. We also assessed the associations of these indices with memory performance and depressive state in participants with MCI. Compared with HCs, MCI participants exhibited thinner cortices in the temporal and inferior parietal lobes and greater WMH volumes in the corona radiata and semioval center. In MCI participants, poor episodic memory was associated with thinner cortices in the left entorhinal region and increased WMH volume in the posterior periventricular regions. Compared with non-depressed MCI participants, depressed MCI participants showed reduced cortical thickness in the anterior medial temporal lobe and ambient gyrus adjacent to the amygdala bilaterally, as well as greater WMH volume as a percentage of the total intracranial volume (WMHr. A higher WMHr was associated with cortical thinning in the frontal, temporal, and parietal regions in MCI participants. These results demonstrate that episodic memory and depression are associated with both cortical thickness and WMH volume in MCI participants. Additional longitudinal studies are needed to clarify the dynamic associations and interactions among these indices.

  6. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

    Directory of Open Access Journals (Sweden)

    Andreas A Ioannides

    2013-08-01

    Full Text Available Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1 and motor (M1 cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45 to 70 Hz activity at latencies of 20 to 50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occured in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

  7. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

    Science.gov (United States)

    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

    2013-01-01

    Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

  8. Regional vulnerability of longitudinal cortical association connectivity: Associated with structural network topology alterations in preterm children with cerebral palsy.

    Science.gov (United States)

    Ceschin, Rafael; Lee, Vince K; Schmithorst, Vince; Panigrahy, Ashok

    2015-01-01

    Preterm born children with spastic diplegia type of cerebral palsy and white matter injury or periventricular leukomalacia (PVL), are known to have motor, visual and cognitive impairments. Most diffusion tensor imaging (DTI) studies performed in this group have demonstrated widespread abnormalities using averaged deterministic tractography and voxel-based DTI measurements. Little is known about structural network correlates of white matter topography and reorganization in preterm cerebral palsy, despite the availability of new therapies and the need for brain imaging biomarkers. Here, we combined novel post-processing methodology of probabilistic tractography data in this preterm cohort to improve spatial and regional delineation of longitudinal cortical association tract abnormalities using an along-tract approach, and compared these data to structural DTI cortical network topology analysis. DTI images were acquired on 16 preterm children with cerebral palsy (mean age 5.6 ± 4) and 75 healthy controls (mean age 5.7 ± 3.4). Despite mean tract analysis, Tract-Based Spatial Statistics (TBSS) and voxel-based morphometry (VBM) demonstrating diffusely reduced fractional anisotropy (FA) reduction in all white matter tracts, the along-tract analysis improved the detection of regional tract vulnerability. The along-tract map-structural network topology correlates revealed two associations: (1) reduced regional posterior-anterior gradient in FA of the longitudinal visual cortical association tracts (inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, optic radiation, posterior thalamic radiation) correlated with reduced posterior-anterior gradient of intra-regional (nodal efficiency) metrics with relative sparing of frontal and temporal regions; and (2) reduced regional FA within frontal-thalamic-striatal white matter pathways (anterior limb/anterior thalamic radiation, superior longitudinal fasciculus and cortical spinal tract) correlated with

  9. Life-threatening posterior reversible encephalopathy syndrome in the cerebellum treated by posterior fossa decompression.

    Science.gov (United States)

    Abusabha, Yousef; Petridis, Athanasios K; Kraus, Bastian; Kamp, Marcel A; Steiger, Hans-Jakob; Beseoglu, Kerim

    2017-07-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-neuroradiological syndrome associated with various clinical conditions, such as headache, encephalopathy, and seizures. It is reversible if a prompt diagnosis is made and treatment undertaken. We report a 52-year-old male with hypertensive crisis. Progressing somnolence and an unresponsive left pupil occurred. MRI revealed an intra-axial hyperintensity of the cerebellum and brainstem and occlusive hydrocephalus suggestive of encephalitis or a tumor. Because of the life-threatening clinical picture, posterior fossa decompression was performed. Histopathology failed to identify any pathology. After decompression, the edema improved immediately. Under life-threatening conditions, a decompressive craniectomy in PRES seems to achieve the same results as supportive treatment.

  10. Glaucoma persistente secundário à injeção subtenoniana posterior de acetato de triancinolona (Kenalog®: relato de casos

    Directory of Open Access Journals (Sweden)

    Finamor Luciana Peixoto

    2003-01-01

    Full Text Available OBJETIVO: Descrever 3 casos de crianças submetidas à injeção subtenoniana posterior de acetato de triancinolona (Kenalog® 40mg para tratamento de uveíte intermediária, com desenvolvimento de glaucoma secundário refratário. MÉTODOS: Relato de caso. RESULTADOS: Três crianças com diagnóstico de uveíte intermediária, submetidas à injeção subtenoniana posterior de acetato de triancinolona para tratamento de inflamação vítrea crônica e/ou edema macular cistóide, desenvolveram glaucoma refratário e foram submetidos à excisão cirúrgica do corticóide de depósito e/ou cirurgia filtrante para controle da pressão intra-ocular (PIO. CONCLUSÃO: Corticóide de depósito periocular pode representar alto risco para desenvolvimento de glaucoma secundário, de difícil controle em crianças. Excisão cirúrgica do corticóide de depósito pode resultar em controle da PIO, porém, em alguns casos, a realização de cirurgia filtrante é necessária.

  11. The effects of the COMT Val108/158Met polymorphism on BOLD activation during working memory, planning, and response inhibition: a role for the posterior cingulate cortex?

    Science.gov (United States)

    Stokes, Paul R A; Rhodes, Rebecca A; Grasby, Paul M; Mehta, Mitul A

    2011-03-01

    Catechol-O-methyl transferase (COMT) val(108/158)met polymorphism impacts on cortical dopamine levels and may influence functional magnetic resonance (fMRI) measures of task-related neuronal activity. Here, we investigate whether COMT genotype influences cortical activations, particularly prefrontal activations, by interrogating its effect across three tasks that have been associated with the dopaminergic system in a large cohort of healthy volunteers. A total of 50 participants (13 met/met, 23 val/met, and 14 val/val) successfully completed N-Back, Go-NoGo, and Tower of London fMRI tasks. Image analysis was performed using statistical parametric mapping. No significant relationships between COMT genotype groups and frontal lobe activations were observed for any contrast of the three tasks studied. However, the val/val group produced significantly greater deactivation of the right posterior cingulate cortex in two tasks: the Go-NoGo (NoGo vs Go deactivation contrast) and N-Back (2-back vs rest deactivation contrast). For the N-Back task, the modulated deactivation cluster was functionally connected to the precuneus, left middle occipital lobe, and cerebellum. These results do not support findings of prefrontal cortical modulation of activity with COMT genotype, but instead suggest that COMT val/val genotype can modulate the activity of the posterior cingulate and may indicate the potential network effects of COMT genotype on the default mode network.

  12. Cortical gyrification is abnormal in children with prenatal alcohol exposure

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    Timothy J. Hendrickson

    2017-01-01

    Conclusions: Abnormalities in cortical development were seen across the brain in children with PAE compared to controls. Cortical gyrification and IQ were strongly correlated, suggesting that examining mechanisms by which alcohol disrupts cortical formation may yield clinically relevant insights and potential directions for early intervention.

  13. Impaired visual short-term memory capacity is distinctively associated with structural connectivity of the posterior thalamic radiation and the splenium of the corpus callosum in preterm-born adults.

    Science.gov (United States)

    Menegaux, Aurore; Meng, Chun; Neitzel, Julia; Bäuml, Josef G; Müller, Hermann J; Bartmann, Peter; Wolke, Dieter; Wohlschläger, Afra M; Finke, Kathrin; Sorg, Christian

    2017-04-15

    Preterm birth is associated with an increased risk for lasting changes in both the cortico-thalamic system and attention; however, the link between cortico-thalamic and attention changes is as yet little understood. In preterm newborns, cortico-cortical and cortico-thalamic structural connectivity are distinctively altered, with increased local clustering for cortico-cortical and decreased integrity for cortico-thalamic connectivity. In preterm-born adults, among the various attention functions, visual short-term memory (vSTM) capacity is selectively impaired. We hypothesized distinct associations between vSTM capacity and the structural integrity of cortico-thalamic and cortico-cortical connections, respectively, in preterm-born adults. A whole-report paradigm of briefly presented letter arrays based on the computationally formalized Theory of Visual Attention (TVA) was used to quantify parameter vSTM capacity in 26 preterm- and 21 full-term-born adults. Fractional anisotropy (FA) of posterior thalamic radiations and the splenium of the corpus callosum obtained by diffusion tensor imaging were analyzed by tract-based spatial statistics and used as proxies for cortico-thalamic and cortico-cortical structural connectivity. The relationship between vSTM capacity and cortico-thalamic and cortico-cortical connectivity, respectively, was significantly modified by prematurity. In full-term-born adults, the higher FA in the right posterior thalamic radiation the higher vSTM capacity; in preterm-born adults this FA-vSTM-relationship was inversed. In the splenium, higher FA was correlated with higher vSTM capacity in preterm-born adults, whereas no significant relationship was evident in full-term-born adults. These results indicate distinct associations between cortico-thalamic and cortico-cortical integrity and vSTM capacity in preterm-and full-term-born adults. Data suggest compensatory cortico-cortical fiber re-organization for attention deficits after preterm delivery

  14. Aspectos clínicos e concentração sérica da creatina-quinase e lactato-desidrogenase em cães submetidos à fisioterapia após atrofia muscular induzida Clinical aspects and serum concentration creatina kinase and lactate dehydrogenase in dogs submitted to physiotherapy after induced muscle atrophy

    Directory of Open Access Journals (Sweden)

    Soraia Figueiredo de Souza

    2011-07-01

    Full Text Available Avaliou-se a resposta de diferentes protocolos fisioterapêuticos em cães após a indução de atrofia muscular por meio da imobilização do joelho por 30 dias. Os grupos foram denominados grupo C ou controle, grupo E (massagem, movimentação passiva e eletroterapia, grupo H (massagem, movimentação passiva e hidroterapia em esteira aquática e grupo EH (massagem, movimentação passiva, eletroterapia e hidroterapia em esteira aquática. Foram mensurados os graus de claudicação, arco do movimento, circunferência da coxa e a variação sérica das enzimas creatina-quinase e lactato-desidrogenase. De acordo com os resultados encontrados, foi possível concluir que as modalidades terapêuticas de massagem, movimentação passiva da articulação, estimulação elétrica neuromuscular e hidroterapia por caminhada em esteira aquática aceleram a recuperação clínica em cães com atrofia muscular induzida.The response of different physiotherapeutic treatment protocols was evaluated in dogs after muscle atrophy induced by joint immobilization for 30 days. Groups were named C group or control, E group (massage, passive range of motion and neuromuscular electrical stimulation, H group (massage, passive range of motion and aquatic therapy in underwater treadmill and EH group (massage, passive range of motion, neuromuscular electrical stimulation and aquatic therapy in underwater treadmill. It was measured the degree of lameness, range motion, thigh circumference and range of serum creatine kinase (CK and lactate dehydrogenase (LDH. According to the results, it was possible to conclude that associated therapeutics modalities such as massage, passive range of motion of the joint, neuromuscular electrical stimulation and aquatic therapy by walking on underwater treadmill accelerate clinical recovery in dogs with induced muscle atrophy.

  15. Minimal-invasive posterior approach in the treatment of the posterior wall fractures of the acetabulum.

    Science.gov (United States)

    Spagnolo, Rosario; Bonalumi, Matteo; Pace, Fabrizio; Capitani, Dario

    2009-05-01

    We examined patients affected by a posterior wall fracture of the acetabulum treated with a minimally invasive posterior approach (from 12 to 18 cm). During 2004-2006 19 patients were treated by this approach. 4 patients had a combined surgery by the ileo-inguinal approach. Fracture fixation was performed using reconstruction plates and screws. All the patients were studied with typical X-rays projection for pelvis and iliac oblique view and obturator oblique view (Judet view) and CT scan with 3D reconstruction. After 3 months a CT scan was performed on about 30% of our patients, which demonstrated the perfect healing of the fractures. The most important advantages we observed using this approach were a lesser split of the gluteus maximus and no risk of damage for the superior gluteal nerve. In the early post-operative rehabilitation we examined the trophism of the gluteus maximus, which was found to be better than in patients treated with the typical Kocher-Langenbeck approach. The only absolute contraindication for this technique is in obese patients. The post-operative complications include one case of heterotypic ossification of the gluteus minimus and one case of peroneal-nerve palsy with the spontaneous and complete recovery within 6 months. According to our experience this kind of approach could be used for posterior wall fracture of the pelvis and it can be extended to transverse fractures. In the post-operative period the greatest advantage is the lesser muscle damage and therefore a most effective rehabilitation.

  16. Causal evidence for frontal involvement in memory target maintenance by posterior brain areas during distracter interference of visual working memory.

    Science.gov (United States)

    Feredoes, Eva; Heinen, Klaartje; Weiskopf, Nikolaus; Ruff, Christian; Driver, Jon

    2011-10-18

    Dorsolateral prefrontal cortex (DLPFC) is recruited during visual working memory (WM) when relevant information must be maintained in the presence of distracting information. The mechanism by which DLPFC might ensure successful maintenance of the contents of WM is, however, unclear; it might enhance neural maintenance of memory targets or suppress processing of distracters. To adjudicate between these possibilities, we applied time-locked transcranial magnetic stimulation (TMS) during functional MRI, an approach that permits causal assessment of a stimulated brain region's influence on connected brain regions, and evaluated how this influence may change under different task conditions. Participants performed a visual WM task requiring retention of visual stimuli (faces or houses) across a delay during which visual distracters could be present or absent. When distracters were present, they were always from the opposite stimulus category, so that targets and distracters were represented in distinct posterior cortical areas. We then measured whether DLPFC-TMS, administered in the delay at the time point when distracters could appear, would modulate posterior regions representing memory targets or distracters. We found that DLPFC-TMS influenced posterior areas only when distracters were present and, critically, that this influence consisted of increased activity in regions representing the current memory targets. DLPFC-TMS did not affect regions representing current distracters. These results provide a new line of causal evidence for a top-down DLPFC-based control mechanism that promotes successful maintenance of relevant information in WM in the presence of distraction.

  17. Femoroacetabular impingement predisposes to traumatic posterior hip dislocation.

    Science.gov (United States)

    Steppacher, Simon D; Albers, Christoph E; Siebenrock, Klaus A; Tannast, Moritz; Ganz, Reinhold

    2013-06-01

    Traumatic posterior hip dislocation in adults is generally understood to be the result of a high-energy trauma. Aside from reduced femoral antetorsion, morphologic risk factors for dislocation are unknown. We previously noticed that some hips with traumatic posterior dislocations had evidence of morphologic features of femoroacetabular impingement (FAI), therefore, we sought to evaluate that possibility more formally. We asked whether hips with a traumatic posterior hip dislocation present with (1) a cam-type deformity and/or (2) a retroverted acetabulum. We retrospectively compared the morphologic features of 53 consecutive hips (53 patients) after traumatic posterior hip dislocation with 85 normal hips (44 patients) based on AP pelvic and crosstable axial radiographs. We measured the axial and the lateral alpha angle for detection of a cam deformity and the crossover sign, ischial spine sign, posterior wall sign, retroversion index, and ratio of anterior to posterior acetabular coverage to describe the acetabular orientation. Hips with traumatic posterior traumatic dislocation were more likely to have cam deformities than were normal hips, in that the hips with dislocation had increased axial and lateral alpha angles. Hips with posterior dislocation also were more likely to be retroverted; dislocated hips had a higher prevalence of a positive crossover sign, ischial spine sign, and posterior wall sign, and they had a higher retroversion index and increased ratio of anterior to posterior acetabular coverage. Hips with posterior traumatic dislocation typically present with morphologic features of anterior FAI, including a cam-type deformity and retroverted acetabulum. An explanation for these findings could be that the early interaction between the aspherical femoral head and the prominent acetabular rim acts as a fulcrum, perhaps making these hips more susceptible to traumatic dislocation.

  18. Ultrastructure of the posterior corneal stroma.

    Science.gov (United States)

    Schlötzer-Schrehardt, Ursula; Bachmann, Bjoern O; Tourtas, Theofilos; Torricelli, Andre A M; Singh, Arun; González, Sheyla; Mei, Hua; Deng, Sophie X; Wilson, Steven E; Kruse, Friedrich E

    2015-04-01

    To reinvestigate the ultrastructure of the posterior stroma of the human cornea and to correlate the findings with the stromal behavior after big-bubble creation. Observational consecutive 3-center case series. Fresh corneoscleral buttons from human donors (n = 19) and organ-cultured corneoscleral buttons (n = 10) obtained after Descemet's membrane endothelial keratoplasty. Corneal specimens were divided into central (3 mm), mid peripheral (8 mm), and peripheral parts by trephination and processed for transmission electron microscopic and immunohistochemical analyses. A big bubble was created by air injection into the stroma of organ-cultured corneas before fixation. The distance of keratocytes to Descemet's membrane, number of collagen lamellae between keratocytes and Descemet's membrane, diameter and arrangement of collagen fibrils, thickness of stromal lamella created by air injection, and immunopositivity for collagen types III, IV, and VI. Stromal keratocytes were observed at variable distances from Descemet's membrane, increasing from 1.5 to 12 μm (mean, 4.97±2.19 μm) in the central, 3.5 to 14 μm (mean, 8.03±2.47 μm) in the midperipheral, and 4.5 to 18 μm (mean, 9.77±2.90 μm) in the peripheral regions. The differences in mean distances were significant (P collagen lamellae between Descemet's membrane and most posterior keratocytes varied from 2 to 10 and the diameter of collagen fibrils averaged 23.5±1.8 nm and corresponded with that of the remaining stroma. A thin layer (0.5-1.0 μm thick) of randomly arranged, unaligned collagen fibers, which was positive for collagen types III and VI, was observed at the Descemet-stroma interface. The residual stromal sheet separated by air injection in 8 of 10 donor corneas varied in thickness from 4.5 to 27.5 μm, even within individual corneas (≤3-fold), and was composed of 5 to 11 collagen lamellae that revealed keratocytes on their anterior surface and in between. Barring an anchoring zone of interwoven

  19. Cortical activation changes during repeated laser stimulation: a magnetoencephalographic study.

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    Andrej Stancak

    Full Text Available Repeated warm laser stimuli produce a progressive increase of the sensation of warmth and heat and eventually that of a burning pain. The pain resulting from repetitive warm stimuli is mediated by summated C fibre responses. To shed more light on the cortical changes associated with pain during repeated subnoxious warm stimulation, we analysed magnetoencephalographic (MEG evoked fields in eleven subjects during application of repetitive warm laser stimuli to the dorsum of the right hand. One set of stimuli encompassed 10 laser pulses occurring at 2.5 s intervals. Parameters of laser stimulation were optimised to elicit a pleasant warm sensation upon a single stimulus with a rise of skin temperature after repeated stimulation not exceeding the threshold of C mechano-heat fibres. Subjects reported a progressive increase of the intensity of heat and burning pain during repeated laser stimulation in spite of only mild (4.8°C increase of skin temperature from the first stimulus to the tenth stimulus. The mean reaction time, evaluated in six subjects, was 1.33 s, confirming involvement of C fibres. The neuromagnetic fields were modelled by five equivalent source dipoles located in the occipital cortex, cerebellum, posterior cingulate cortex, and left and right operculo-insular cortex. The only component showing statistically significant changes during repetitive laser stimulation was the late component of the contralateral operculo-insular source peaking at 1.05 s after stimulus onset. The amplitude increases of the late component of the contralateral operculo-insular source dipole correlated with the subjects' numerical ratings of warmth and pain. Results point to a pivotal role of the contralateral operculo-insular region in processing of C-fibre mediated pain during repeated subnoxious laser stimulation.

  20. Cortical Activation Changes during Repeated Laser Stimulation: A Magnetoencephalographic Study

    Science.gov (United States)

    Stancak, Andrej; Alghamdi, Jamaan; Nurmikko, Turo J.

    2011-01-01

    Repeated warm laser stimuli produce a progressive increase of the sensation of warmth and heat and eventually that of a burning pain. The pain resulting from repetitive warm stimuli is mediated by summated C fibre responses. To shed more light on the cortical changes associated with pain during repeated subnoxious warm stimution, we analysed magnetoencephalographic (MEG) evoked fields in eleven subjects during application of repetitive warm laser stimuli to the dorsum of the right hand. One set of stimuli encompassed 10 laser pulses occurring at 2.5 s intervals. Parameters of laser stimulation were optimised to elicit a pleasant warm sensation upon a single stimulus with a rise of skin temperature after repeated stimulation not exceeding the threshold of C mechano-heat fibres. Subjects reported a progressive increase of the intensity of heat and burning pain during repeated laser stimulation in spite of only mild (4.8°C) increase of skin temperature from the first stimulus to the tenth stimulus. The mean reaction time, evaluated in six subjects, was 1.33 s, confirming involvement of C fibres. The neuromagnetic fields were modelled by five equivalent source dipoles located in the occipital cortex, cerebellum, posterior cingulate cortex, and left and right operculo-insular cortex. The only component showing statistically significant changes during repetitive laser stimulation was the late component of the contralateral operculo-insular source peaking at 1.05 s after stimulus onset. The amplitude increases of the late component of the contralateral operculo-insular source dipole correlated with the subjects' numerical ratings of warmth and pain. Results point to a pivotal role of the contralateral operculo-insular region in processing of C-fibre mediated pain during repeated subnoxious laser stimulation. PMID:21572954

  1. Properties of bilateral spinocerebellar activation of cerebellar cortical neurons

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    Pontus eGeborek

    2014-10-01

    Full Text Available We aimed to explore the cerebellar cortical inputs from two spinocerebellar pathways, the spinal border cell-component of the ventral spinocerebellar tract (SBC-VSCT and the dorsal spinocerebellar tract (DSCT, respectively, in the sublobule C1 of the cerebellar posterior lobe. The two pathways were activated by electrical stimulation of the contralateral lateral funiculus (coLF and the ipsilateral LF (iLF at lower thoracic levels. Most granule cells in sublobule C1 did not respond at all but part of the granule cell population displayed high-intensity responses to either coLF or iLF stimulation. As a rule, Golgi cells and Purkinje cell simple spikes responded to input from both LFs, although Golgi cells could be more selective. In addition, a small population of granule cells responded to input from both the coLF and the iLF. However, in these cases, similarities in the temporal topography and magnitude of the responses suggested that the same axons were stimulated from the two LFs, i.e. that the axons of individual spinocerebellar neurons could be present in both funiculi. This was also confirmed for a population of spinal neurons located within known locations of SBC-VSCT neurons and dorsal horn DSCT neurons. We conclude that bilateral spinocerebellar responses can occur in cerebellar granule cells, but the VSCT and DSCT systems that provide the input can also be organized bilaterally. The implications for the traditional functional separation of VSCT and DSCT systems and the issue whether granule cells primarily integrate functionally similar information or not are discussed.

  2. Posterior glenoid wear in total shoulder arthroplasty: eccentric anterior reaming is superior to posterior augment.

    Science.gov (United States)

    Wang, Tim; Abrams, Geoffrey D; Behn, Anthony W; Lindsey, Derek; Giori, Nicholas; Cheung, Emilie V

    2015-12-01

    Uncorrected glenoid retroversion during total shoulder arthroplasty may lead to an increased likelihood of glenoid prosthetic loosening. Augmented glenoid components seek to correct retroversion to address posterior glenoid bone loss, but few biomechanical studies have evaluated their performance. We compared the use of augmented glenoid components with eccentric reaming with standard glenoid components in a posterior glenoid wear model. The primary outcome for biomechanical stability in this model was assessed by (1) implant edge displacement in superior and inferior edge loading at intervals up to 100,000 cycles, with secondary outcomes including (2) implant edge load during superior and inferior translation at intervals up to 100,000 cycles, and (3) incidence of glenoid fracture during implant preparation and after cyclic loading. A 12°-posterior glenoid defect was created in 12 composite scapulae, and the specimens were divided in two equal groups. In the posterior augment group, glenoid version was corrected to 8° and an 8°-augmented polyethylene glenoid component was placed. In the eccentric reaming group, anterior glenoid reaming was performed to neutral version and a standard polyethylene glenoid component was placed. Specimens were cyclically loaded in the superoinferior direction to 100,000 cycles. Superior and inferior glenoid edge displacements were recorded. Surviving specimens in the posterior augment group showed greater displacement than the eccentric reaming group of superior (1.01 ± 0.02 [95% CI, 0.89-1.13] versus 0.83 ± 0.10 [95% CI, 0.72-0.94 mm]; mean difference, 0.18 mm; p = 0.025) and inferior markers (1.36 ± 0.05 [95% CI, 1.24-1.48] versus 1.20 ± 0.09 [95% CI, 1.09-1.32 mm]; mean difference, 0.16 mm; p = 0.038) during superior edge loading and greater displacement of the superior marker during inferior edge loading (1.44 ± 0.06 [95% CI, 1.28-1.59] versus 1.16 ± 0.11 [95% CI, 1.02-1.30 mm]; mean difference, 0.28 mm; p = 0.009) at 100

  3. Fetal MRI for characterising a variety of posterior fossa anomalies ...

    African Journals Online (AJOL)

    Fetal MRI is increasingly being used to more accurately assess abnormalities detected on screening ultrasound. The procedure is more pertinent when the initial ultrasound is done late in the third trimester and when the abnormality involves the posterior fossa of the brain. Four cases with a variety of unusual posterior fossa ...

  4. Posterior epidural migration of lumbar intervertebral fragment: case ...

    African Journals Online (AJOL)

    Posterior epidural migrated lumbar disc fragments are often confused with other posterior epidural space-occupying lesions (cysts, abscesses, tumors, and hematomas). We reported the case of a 52- year-old man presented with progressive not systematizes bilateral radiculopathy complicated one week before admission a ...

  5. Possibly Ill-behaved Posteriors in Econometric Models

    NARCIS (Netherlands)

    L.F. Hoogerheide (Lennart); H.K. van Dijk (Herman)

    2008-01-01

    textabstractHighly non-elliptical posterior distributions may occur in several econometric models, in particular, when the likelihood information is allowed to dominate and data information is weak. We explain the issue of highly non-elliptical posteriors in a model for the effect of education on

  6. Comparison of Medial and Posterior Surgical Approaches in ...

    African Journals Online (AJOL)

    When evaluated patients according to Flynn's criteria, for medial group, 31 cases (93.9%) had good–perfect result regarding ROM loss, whereas for posterior group 33 cases (97%) had good–perfect result. Regarding carrying angle change and posterior group were slightly better than medial group (perfect result observed ...

  7. 16 determination of posterior tibia slope and slope deterioration with ...

    African Journals Online (AJOL)

    Cruciate Ligament (ACL) injuries due to increased anterior tibia translation (2, 3). Although some authors have reported increased stability of posterior cruciate ligament deficient knees with deepened posterior tibial slopes (4). Therefore, the slope should be maintained or corrected to maintain normal kinematics. These.

  8. Evaluation of the mechanical and physical properties of a posterior ...

    African Journals Online (AJOL)

    To evaluate the mechanical and physical properties of a micro-hybrid resin composite used in adult posterior restorations A micro-hybrid, light curing resin composite Unolux BCS Composite Restorative, (UnoDent, England) was used to restore 74 carious classes I and II cavities on posterior teeth of 62 adult patients.

  9. Posterior tibial tendon dysfunction by bone imprisonment | Zejjari ...

    African Journals Online (AJOL)

    The radiological assessment finds imprisonment of posterior tibial tendon in the internal retromalleolar bony canal. The patient received a release of the tendon with resection of the bony canal in full. The posterior tibial tendon showed longitudinal laceration was sutured and the internal retromalleolar canal was closed.

  10. Vascular Anomalies of Posterior Fossa and Their Implications.

    Science.gov (United States)

    Singh, Rajani; Kumar, Raj; Kumar, Arushi

    2017-11-01

    Posterior fossa houses very vital and sensitive structures namely midbrain, pons, medulla, and cerebellum. These structures are irrigated by vertebral, posterior inferior cerebellar, anterior inferior cerebellar, and superior cerebellar arteries. Parts of brain located in posterior fossa control important parts of body so any variation pertaining to stenosis, atresia, hypoplasia, fenestration, agenesis, and duplication in the arteries supplying these parts alter the irrigation pattern culminating into various morbid and mortal neurologic disorders. Therefore, a sound understanding and thorough knowledge of posterior circulation vascular variant anatomy builds the foundation for the accurate diagnosis and appropriate management of neurovascular ischemic and hemorrhagic diseases of posterior fossa. To aid in addressing these complex neurologic disorders and neurosurgical treatment to be carried out successfully, updating and consolidating the knowledge of all the variations/insults of these arteries becomes essential. Therefore, review study has been carried out.Literature search was carried out using databases, including Scielo, Scopmed, Medline, PubMed, and Wiley online library. Papers containing original data were selected and secondary references retrieved from bibliographies. Search terms used were posterior fossa, anomalies of vertebral, posterior inferior cerebellar, anterior inferior cerebellar, and superior cerebellar arteries.The study will be of paramount importance to angiographers in interpreting angiographs, neurologists in diagnosis and treatment of neurologic disorders, and neurosurgeons in performing surgery in posterior fossa and craniovertebral region particularly dealing with tumors and vascular malformations.

  11. Defect in Posterior Arch of Atlas in Myelomeningocele

    NARCIS (Netherlands)

    G. Blaauw (Gerhard)

    1971-01-01

    textabstractThe posterior arches of the cervical vertebrae of 30 children who died with a myelomeningocele in the lower thoracic, lumbar or sacral region were examined; in 70 per cent of these cases a defect was found in the posterior arch of the atlas, which was bridged by a firm fibrous band.

  12. Topography of The Posterior Communicating Artery in a Kenyan ...

    African Journals Online (AJOL)

    Objective To determine the prevalence of various configurations and branching pattern of the posterior communication artery in a Kenyan population. Materials and Methods Eighty four posterior communicating arteries obtained from Department of Human Anatomy were studied. The configuration and number of branches ...

  13. Posterior perforation of gastric ulcer: a rare surgical emergency ...

    African Journals Online (AJOL)

    BACKGROUND:Gastric ulcer perforation is a rare surgical emergency.Posterior gastric ulcer is even rarer and usually has a delayed presentation with attendant greater morbidity and mortality. AIM:To report a case of posterior perforation of gastric ulcer and review the literature. CASE REPORT:A 65yr old driver was seen in ...

  14. Hindfoot endoscopy for posterior ankle impingement. Surgical technique

    NARCIS (Netherlands)

    van Dijk, C.N.; de Leeuw, P.A.J.; Scholten, P.E.

    2009-01-01

    BACKGROUND: The surgical treatment of posterior ankle impingement is associated with a high rate of complications and a substantial time to recover. An endoscopic approach to the posterior ankle (hindfoot endoscopy) may lack these disadvantages. We hypothesized that hindfoot endoscopy causes less

  15. Posterior Debridement with Trans-Pedicular Screw Fixation For ...

    African Journals Online (AJOL)

    Methods: This retrospective study was conducted to evaluate the outcome of 15 cases of idiopathic lumbar spondylo-discitis treated with posterior debridement combined with single-stage posterior instrumentation and grafting. All patients were followed up for up to 1 year post-operative. We evaluated operative time, blood ...

  16. Monte Carlo analysis of skew posterior distributions: an econometric example

    NARCIS (Netherlands)

    H.K. van Dijk (Herman); T. Kloek (Teun)

    1983-01-01

    textabstractThe posterior distribution of a small-scale illustrative econometric model is used to compare symmetric simple importance sampling with asymmetric simple importance sampling. The numerical results include posterior first and second order moments, numerical error estimates of the first

  17. Correction of posterior crossbites: diagnosis and treatment.

    Science.gov (United States)

    Binder, Robert E

    2004-01-01

    The correction of posterior crossbites is more complex than it appears. To develop an appropriate treatment plan, it is first necessary to determine if: (1) there is a functional jaw shift on closing; (2) the crossbite is unilateral or bilateral; (3) it is dental, skeletal, or a combination of both; and (4) it is related only to the maxilla or both jaws. Once the problem's apparent cause has been defined, it is then necessary to select the appropriate modality of treatment, which, in the maxilla, is: (1) usually a removable acrylic-based appliance with 1 or more transverse screws; or (2) a fixed Hyrax-type or Hass-type appliance. In the mandible, if dental expansion is required, the appliances most frequently used are the lip bumper or a removable acrylic-based appliance with a single screw lingual to the incisors. Once the appliance has been placed, it must be determined when adequate expansion has been achieved and how best to retain it.

  18. Posterior endoscopic discectomy: Results in 300 patients

    Directory of Open Access Journals (Sweden)

    Mohinder Kaushal

    2012-01-01

    Full Text Available Background: Posterior endoscopic discectomy is an established method for treatment of lumbar disc herniation. Many studies have not been reported in literature for lumbar discectomy by Destandau Endospine System. We report a series of 300 patients operated for lumbar dissectomy by Destandau Endospine system. Materials and Methods: A total of 300 patients suffering from lumbar disc herniations were operated between January 2002 and December 2008. All patients were operated as day care procedure. Technique comprised localization of symptomatic level followed by insertion of an endospine system devise through a 15 mm skin and fascial incision. Endoscopic discectomy is then carried out by conventional micro disc surgery instruments by minimal invasive route. The results were evaluated by Macnab′s criteria after a minimum followup of 12 months and maximum up to 24 months. Results: Based on modified Macnab′s criteria, 90% patients had excellent to good, 8% had fair, and 2% had poor results. The complications observed were discitis and dural tear in five patients each and nerve root injury in two patients. 90% patients were able to return to light and sedentary work with an average delay of 3 weeks and normal physical activities after 2 months. Conclusion: Edoscopic discectomy provides a safe and minimal access corridor for lumbar discectomy. The technique also allows early postoperative mobilization and faster return to work.

  19. Decision salience signals in posterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Sarah eHeilbronner

    2011-04-01

    Full Text Available Despite its phylogenetic antiquity and clinical importance, the posterior cingulate cortex (CGp remains an enigmatic nexus of attention, memory, motivation, and decision making. Here we show that CGp neurons track decision salience—the degree to which an option differs from a standard—but not the subjective value of a decision. To do this, we recorded the spiking activity of CGp neurons in monkeys choosing between options varying in reward-related risk, delay to reward, and social outcomes, each of which varied in level of decision salience. Firing rates were higher when monkeys chose the risky option, consistent with their risk-seeking preferences, but were also higher when monkeys chose the delayed and social options, contradicting their preferences. Thus, across decision contexts, neuronal activity was uncorrelated with how much monkeys valued a given option, as inferred from choice. Instead, neuronal activity signaled the deviation of the chosen option from the standard, independently of how it differed. The observed decision salience signals suggest a role for CGp in the flexible allocation of neural resources to motivationally significant information, akin to the role of attention in selective processing of sensory inputs.

  20. Ultrasound of the posterior circumflex humeral artery.

    Science.gov (United States)

    Robinson, D J; Marks, P; Schneider-Kolsky, M E

    2010-06-01

    Quadrilateral space syndrome (QSS) is described as compression neuropathy of the axillary neurovascular bundle in the quadrilateral space of the shoulder. This neurovascular bundle includes the posterior circumflex humeral artery (PCHA). Historically, angiography and more recently magnetic resonance angiography have been used to assess occlusion and stenosis of the PCHA in cases of suspected QSS. These traditional imaging techniques have a number of disadvantages in terms of cost, availability, invasiveness and patient comfort. We undertook to examine the ability of ultrasound to reliably visualise the PCHA. Asymptomatic adult volunteers were recruited from staff, and patients attending the radiology department who presented for pathologies unrelated to the shoulder. We used a new technique to assess blood flow in the PCHA, performing the scan from a posterolateral approach on the upper arm just above the level of the surgical neck of the humerus. This technique enabled the scan to be undertaken with the patient seated comfortably. Fifty volunteers were recruited into the study. The mean (+/-SD) age was 35 (+/-14 years). The PCHA was visualised in all patients. Our method was able to maximise Doppler sensitivity and visualisation of the artery without discomfort to the patient in less than 10 min. Ultrasound can be used to reliably visualise the PCHA. Ultrasound has potential to be used in the assessment of the PCHA in cases of QSS.

  1. MRI of the posterior lobe in diabetes insipidus

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, Ichiro; Nishimura, Kazumasa; Asato, Reinin and others

    1987-08-01

    Characteristic MR findings in diabetes insipidus (DI) are described. The posterior lobe of the pituitary gland on high-field (1.5 Tesla) magnetic resonance (MR) imaging was evaluated in 5 patients, including one primary (idiopathic) and four secondary DI due to two germinomas, teratoma, and histiocytosis X. A normal posterior lobe is demonstrated as a high signal indistinguishable from fatty tissue on T/sub 1/ WI (a short T/sub 1/ value). In all 5 DI cases, the normal high signal of the posterior lobe was not detected in the pituitary fossa on T/sub 1/ WI. MR imaging is a great help in the diagnosis of DI, and this characteristic finding suggests that the short T/sub 1/ value of the posterior lobe is closely related to the functional integrity of the posterior lobe and may be due to the neurosecretory materials in the axons of the hypothalamo-hypophyseal tract.

  2. Posterior Corneal Surface Stability after Femtosecond Laser-Assisted Keratomileusis

    Directory of Open Access Journals (Sweden)

    Carlo Cagini

    2015-01-01

    Full Text Available The purpose of this study was to evaluate posterior corneal surface variation after femtosecond laser-assisted keratomileusis in patients with myopia and myopic astigmatism. Patients were evaluated by corneal tomography preoperatively and at 1, 6, and 12 months. We analyzed changes in the posterior corneal curvature, posterior corneal elevation, and anterior chamber depth. Moreover, we explored correlation between corneal ablation depth, residual corneal thickness, percentage of ablated corneal tissue, and preoperative corneal thickness. During follow-up, the posterior corneal surface did not have a significant forward corneal shift: no significant linear relationships emerged between the anterior displacement of the posterior corneal surface and corneal ablation depth, residual corneal thickness, or percentage of ablated corneal tissue.

  3. Posterior distributions for likelihood ratios in forensic science.

    Science.gov (United States)

    van den Hout, Ardo; Alberink, Ivo

    2016-09-01

    Evaluation of evidence in forensic science is discussed using posterior distributions for likelihood ratios. Instead of eliminating the uncertainty by integrating (Bayes factor) or by conditioning on parameter values, uncertainty in the likelihood ratio is retained by parameter uncertainty derived from posterior distributions. A posterior distribution for a likelihood ratio can be summarised by the median and credible intervals. Using the posterior mean of the distribution is not recommended. An analysis of forensic data for body height estimation is undertaken. The posterior likelihood approach has been criticised both theoretically and with respect to applicability. This paper addresses the latter and illustrates an interesting application area. Copyright © 2016 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Eclamptogenic Gerstmann's syndrome in combination with cortical agnosia and cortical diplopia.

    Science.gov (United States)

    Käsmann, B; Ruprecht, K W

    1995-07-01

    Cortical blindness is defined as a loss of vision due to bilateral retrogeniculate lesions (geniculocalcarine blindness). Gerstmann's syndrome is a combination of disorientation for left and right, finger agnosia, and profound agraphia, alexia, and acalculia. It is due to a lesion in the left angular gyrus, situated at the confluence of the temporal, parietal, and occipital lobes. We report on a patient who suffered from severe underdiagnosed eclampsia and who developed bilateral extensive medial temporal, parietal, and calcarine ischemic infarctions during an eclamptic fit. In addition, ischemia destroyed the left angular gyrus. The combination of these lesions led to Gerstmann's syndrome with additional cortical agnosia and cortical diplopia. For the first few months following the ischemic insult, the patient had been cortically blind. Thereafter, the patient slowly regained a visual acuity of 0.1 in both eyes. She then experienced monocular and binocular diplopia. Her ocular motility was normal; there was no phoria or tropia. Monocular and binocular diplopia slowly became less severe over the following year. Now, 2 years after the incident, the patient has a visual acuity of 0.2 in both eyes and no double vision. However, the handicapping symptoms of Gerstmann's syndrome, which make leading a normal life impossible, have persisted--the patient still cannot cope alone, mainly due to the severe disorientation for left and right. The picture of cortical agnosia, cortical diplopia, and Gerstmann's syndrome is a very rare combination. Visual recovery and rehabilitation in cortical blindness are severely affected and made difficult by the symptoms of Gerstmann's syndrome. In our case the reason for such a dramatic clinical picture was eclampsia, whose prodomes had not been diagnosed in time.

  5. Rab3A, a possible marker of cortical granules, participates in cortical granule exocytosis in mouse eggs.

    Science.gov (United States)

    Bello, Oscar Daniel; Cappa, Andrea Isabel; de Paola, Matilde; Zanetti, María Natalia; Fukuda, Mitsunori; Fissore, Rafael A; Mayorga, Luis S; Michaut, Marcela A

    2016-09-10

    Fusion of cortical granules with the oocyte plasma membrane is the most significant event to prevent polyspermy. This particular exocytosis, also known as cortical reaction, is regulated by calcium and its molecular mechanism is still not known. Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in calcium-dependent exocytosis and is not yet clear whether Rab3A participates in cortical granules exocytosis. Here, we examine the involvement of Rab3A in the physiology of cortical granules, particularly, in their distribution during oocyte maturation and activation, and their participation in membrane fusion during cortical granule exocytosis. Immunofluorescence and Western blot analysis showed that Rab3A and cortical granules have a similar migration pattern during oocyte maturation, and that Rab3A is no longer detected after cortical granule exocytosis. These results suggested that Rab3A might be a marker of cortical granules. Overexpression of EGFP-Rab3A colocalized with cortical granules with a Pearson correlation coefficient of +0.967, indicating that Rab3A and cortical granules have almost a perfect colocalization in the egg cortical region. Using a functional assay, we demonstrated that microinjection of recombinant, prenylated and active GST-Rab3A triggered cortical granule exocytosis, indicating that Rab3A has an active role in this secretory pathway. To confirm this active role, we inhibited the function of endogenous Rab3A by microinjecting a polyclonal antibody raised against Rab3A prior to parthenogenetic activation. Our results showed that Rab3A antibody microinjection abolished cortical granule exocytosis in parthenogenetically activated oocytes. Altogether, our findings confirm that Rab3A might function as a marker of cortical granules and participates in cortical granule exocytosis in mouse eggs. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Posterior Probability Matching and Human Perceptual Decision Making.

    Directory of Open Access Journals (Sweden)

    Richard F Murray

    2015-06-01

    Full Text Available Probability matching is a classic theory of decision making that was first developed in models of cognition. Posterior probability matching, a variant in which observers match their response probabilities to the posterior probability of each response being correct, is being used increasingly often in models of perception. However, little is known about whether posterior probability matching is consistent with the vast literature on vision and hearing that has developed within signal detection theory. Here we test posterior probability matching models using two tools from detection theory. First, we examine the models' performance in a two-pass experiment, where each block of trials is presented twice, and we measure the proportion of times that the model gives the same response twice to repeated stimuli. We show that at low performance levels, posterior probability matching models give highly inconsistent responses across repeated presentations of identical trials. We find that practised human observers are more consistent across repeated trials than these models predict, and we find some evidence that less practised observers more consistent as well. Second, we compare the performance of posterior probability matching models on a discrimination task to the performance of a theoretical ideal observer that achieves the best possible performance. We find that posterior probability matching is very inefficient at low-to-moderate performance levels, and that human observers can be more efficient than is ever possible according to posterior probability matching models. These findings support classic signal detection models, and rule out a broad class of posterior probability matching models for expert performance on perceptual tasks that range in complexity from contrast discrimination to symmetry detection. However, our findings leave open the possibility that inexperienced observers may show posterior probability matching behaviour, and our methods

  7. Posterior Probability Matching and Human Perceptual Decision Making

    Science.gov (United States)

    Murray, Richard F.; Patel, Khushbu; Yee, Alan

    2015-01-01

    Probability matching is a classic theory of decision making that was first developed in models of cognition. Posterior probability matching, a variant in which observers match their response probabilities to the posterior probability of each response being correct, is being used increasingly often in models of perception. However, little is known about whether posterior probability matching is consistent with the vast literature on vision and hearing that has developed within signal detection theory. Here we test posterior probability matching models using two tools from detection theory. First, we examine the models’ performance in a two-pass experiment, where each block of trials is presented twice, and we measure the proportion of times that the model gives the same response twice to repeated stimuli. We show that at low performance levels, posterior probability matching models give highly inconsistent responses across repeated presentations of identical trials. We find that practised human observers are more consistent across repeated trials than these models predict, and we find some evidence that less practised observers more consistent as well. Second, we compare the performance of posterior probability matching models on a discrimination task to the performance of a theoretical ideal observer that achieves the best possible performance. We find that posterior probability matching is very inefficient at low-to-moderate performance levels, and that human observers can be more efficient than is ever possible according to posterior probability matching models. These findings support classic signal detection models, and rule out a broad class of posterior probability matching models for expert performance on perceptual tasks that range in complexity from contrast discrimination to symmetry detection. However, our findings leave open the possibility that inexperienced observers may show posterior probability matching behaviour, and our methods provide new tools

  8. Genetic Animal Models of Malformations of Cortical Development and Epilepsy

    Science.gov (United States)

    Wong, Michael; Roper, Steven N.

    2015-01-01

    Malformations of cortical development constitute a variety of pathological brain abnormalities that commonly cause severe, medically-refractory epilepsy, including focal lesions, such as focal cortical dysplasia, hetereotopias, and tubers of tuberous sclerosis complex, and diffuse malformations, such as lissencephaly. Although some cortical malformations result from environmental insults during cortical development in utero, genetic factors are increasingly recognized as primary pathogenic factors across the entire spectrum of malformations. Genes implicated in causing different cortical malformations are involved in a variety of physiological functions, but many are focused on regulation of cell proliferation, differentiation, and neuronal migration. Advances in molecular genetic methods have allowed the engineering of increasingly sophisticated animal models of cortical malformations and associated epilepsy. These animal models have identified some common mechanistic themes shared by a number of different cortical malformations, but also revealed the diversity and complexity of cellular and molecular mechanisms that lead to the development of the pathological lesions and resulting epileptogenesis. PMID:25911067

  9. Control and amplification of cortical neurodynamics

    Science.gov (United States)

    Liljenstroem, Hans; Aronsson, P.

    1999-03-01

    We investigate different mechanisms for the control and amplification of cortical neurodynamics, using a neural network model of a three layered cortical structure. We show that different dynamical states can be obtained by changing a control parameter of the input-output relation, or by changing the noise level. Point attractor, limit cycle, and strange attractor dynamics occur at different values of the control parameter. For certain, optimal noise levels, system performance is maximized, analogous to stochastic resonance phenomena. Noise can also be used to induce different dynamical states. A few noisy network units distributed in a network layer can result in global synchronous oscillations, or waves of activity moving across the network. We further demonstrate that fast synchronization of network activity can be obtained by implementing electromagnetic interactions between network units.

  10. Plasticity of Cortical Excitatory-Inhibitory Balance

    Science.gov (United States)

    Froemke, Robert C.

    2015-01-01

    Synapses are highly plastic and are modified by changes in patterns of neural activity or sensory experience. Plasticity of cortical excitatory synapses is thought to be important for learning and memory, leading to alterations in sensory representations and cognitive maps. However, these changes must be coordinated across other synapses within local circuits to preserve neural coding schemes and the organization of excitatory and inhibitory inputs, i.e., excitatory-inhibitory balance. Recent studies indicate that inhibitory synapses are also plastic and are controlled directly by a large number of neuromodulators, particularly during episodes of learning. Many modulators transiently alter excitatory-inhibitory balance by decreasing inhibition, and thus disinhibition has emerged as a major mechanism by which neuromodulation might enable long-term synaptic modifications naturally. This review examines the relationships between neuromodulation and synaptic plasticity, focusing on the induction of long-term changes that collectively enhance cortical excitatory-inhibitory balance for improving perception and behavior. PMID:25897875

  11. Reduced cortical thickness in gambling disorder

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Chamberlain, Samuel R

    2015-01-01

    Gambling disorder has recently been recognized as a prototype 'behavioral addiction' by virtue of its inclusion in the DSM-5 category of 'Substance-Related and Addictive Disorders.' Despite its newly acquired status and prevalence rate of 1-3 % globally, relatively little is known regarding...... the neurobiology of this disorder. The aim of this study was to explore cortical morphometry in untreated gambling disorder, for the first time. Subjects with gambling disorder (N = 16) free from current psychotropic medication or psychiatric comorbidities, and healthy controls (N = 17), were entered...... into the study and undertook magnetic resonance imaging (3T MRI). Cortical thickness was quantified using automated segmentation techniques (FreeSurfer), and group differences were identified using permutation cluster analysis, with stringent correction for multiple comparisons. Gambling disorder was associated...

  12. Massive cortical reorganization in sighted Braille readers.

    Science.gov (United States)

    Siuda-Krzywicka, Katarzyna; Bola, Łukasz; Paplińska, Małgorzata; Sumera, Ewa; Jednoróg, Katarzyna; Marchewka, Artur; Śliwińska, Magdalena W; Amedi, Amir; Szwed, Marcin

    2016-03-15

    The brain is capable of large-scale reorganization in blindness or after massive injury. Such reorganization crosses the division into separate sensory cortices (visual, somatosensory...). As its result, the visual cortex of the blind becomes active during tactile Braille reading. Although the possibility of such reorganization in the normal, adult brain has been raised, definitive evidence has been lacking. Here, we demonstrate such extensive reorganization in normal, sighted adults who learned Braille while their brain activity was investigated with fMRI and transcranial magnetic stimulation (TMS). Subjects showed enhanced activity for tactile reading in the visual cortex, including the visual word form area (VWFA) that was modulated by their Braille reading speed and strengthened resting-state connectivity between visual and somatosensory cortices. Moreover, TMS disruption of VWFA activity decreased their tactile reading accuracy. Our results indicate that large-scale reorganization is a viable mechanism recruited when learning complex skills.

  13. Behavioral modulation of gustatory cortical activity.

    Science.gov (United States)

    Fontanini, Alfredo; Katz, Donald B

    2009-07-01

    Our perception of the sensory world is constantly modulated by the environment surrounding us and by our psychological state; each encounter with the same stimulus can in fact evoke very different perceptions. This phenomenological richness correlates well with the plasticity and the state-dependency observed in neural responses to sensory stimuli. This article reviews recent results on how the processing of sensory inputs varies depending on the internal state of the animal. Specifically it focuses on the gustatory system and on data showing that levels of attention and expectation modulate taste processing and gustatory cortical activity in meaningful ways. Mounting experimental evidence suggesting that expectation-dependent changes in gustatory cortical activity result from changes in the coupling between the amygdala and the cortex will also be discussed. The results presented here begin to paint a complex picture of taste, which goes beyond the framework of classical coding theories.

  14. Bilateral Renal Cortical Necrosis in Meningococcal Meningitis

    Directory of Open Access Journals (Sweden)

    C. Kennedy

    2011-01-01

    Full Text Available Bacterial meningitis is a relatively common infection of the cerebrospinal fluid (CSF and leptomeninges. The clinical picture evolves rapidly and, if treatment is delayed, can result in a variety of long-term sequelae, including death. Acute kidney injury in the setting of bacterial meningitis usually results from hypotension and volume depletion and resolves with appropriate treatment. Meningococcaemia with profound hypotension, and/or disseminated intravascular coagulopathy (DIC may very rarely lead to bilateral renal cortical necrosis. In this context, renal recovery is extremely unlikely. We present two cases of meningococcaemia complicated by bilateral renal cortical necrosis and, ultimately, end stage kidney disease. We also present a review of the literature on the subject. The cases outline the importance of early aggressive intervention by a multidisciplinary team.

  15. Expertise with artificial nonspeech sounds recruits speech-sensitive cortical regions.

    Science.gov (United States)

    Leech, Robert; Holt, Lori L; Devlin, Joseph T; Dick, Frederic

    2009-04-22

    Regions of the human temporal lobe show greater activation for speech than for other sounds. These differences may reflect intrinsically specialized domain-specific adaptations for processing speech, or they may be driven by the significant expertise we have in listening to the speech signal. To test the expertise hypothesis, we used a video-game-based paradigm that tacitly trained listeners to categorize acoustically complex, artificial nonlinguistic sounds. Before and after training, we used functional MRI to measure how expertise with these sounds modulated temporal lobe activation. Participants' ability to explicitly categorize the nonspeech sounds predicted the change in pretraining to posttraining activation in speech-sensitive regions of the left posterior superior temporal sulcus, suggesting that emergent auditory expertise may help drive this functional regionalization. Thus, seemingly domain-specific patterns of neural activation in higher cortical regions may be driven in part by experience-based restructuring of high-dimensional perceptual space.

  16. Hiperostosis cortical infantil (enfermedad de Caffey)

    OpenAIRE

    Delgado-Azañero, Wilson A.; Facultad de Estomatología, Universidad Peruana Cayetano Heredia. Lima,; Arrascue Dulanto, Manuel; Facultad de Estomatología, Universidad Peruana Cayetano Heredia. Lima,

    2014-01-01

    Se presenta un caso de hiperostosis cortical infantil o enfermedad de Caffey diagnosticado enuna niña de 5 meses de edad. El cuadro se caracterizó por hinchazón asintomática de la hemicaraizquierda debido a engrosamiento periostal del cuerpo y rama ascendente del maxilar inferior. Serevisa la literatura, el diagnóstico diferencial y el manejo de esta rara enfermedad ósea.

  17. Perinatal cortical growth and childhood neurocognitive abilities.

    Science.gov (United States)

    Rathbone, R; Counsell, S J; Kapellou, O; Dyet, L; Kennea, N; Hajnal, J; Allsop, J M; Cowan, F; Edwards, A D

    2011-10-18

    This observational cohort study addressed the hypothesis that after preterm delivery brain growth between 24 and 44 weeks postmenstrual age (PMA) is related to global neurocognitive ability in later childhood. Growth rates for cerebral volume and cortical surface area were estimated in 82 infants without focal brain lesions born before 30 weeks PMA by using 217 magnetic resonance images obtained between 24 and 44 weeks PMA. Abilities were assessed at 2 years using the Griffiths Mental Development Scale and at 6 years using the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R), the Developmental Neuropsychological Assessment (NEPSY), and the Movement Assessment Battery for Children (MABC). Analysis was by generalized least-squares regression. Mean test scores approximated population averages. Cortical growth was directly related to the Griffiths Developmental Quotient (DQ), the WPPSI-R full-scale IQ, and a NEPSY summary score but not the MABC score and in exploration of subtests to attention, planning, memory, language, and numeric and conceptual abilities but not motor skills. The mean (95% confidence interval) estimated reduction in cortical surface area at term corrected age associated with a 1 SD fall in test score was as follows: DQ 7.0 (5.8-8.5); IQ 6.0 (4.9-7.3); and NEPSY 9.1 (7.5-11.0) % · SD(-1). Total brain volume growth was not correlated with any test score. The rate of cerebral cortical growth between 24 and 44 weeks PMA predicts global ability in later childhood, particularly complex cognitive functions but not motor functions.

  18. Epilepsy, Acquired Aphasia with Focal Cortical Dysplasia

    Directory of Open Access Journals (Sweden)

    Girija A.S

    1999-01-01

    Full Text Available A six year old boy having complex partial seizures with secondary generalization of four months duration developing isolated expressive dysphasia, later progressing to global aphasia is being reported. His awake EEG showed a left temporal spike wave discharge and sleep EEG showed continuous spike and ware discharges. MR imaging demonstrated focal cortical dysplasia in the left frontal and opercular region, a combination that has not been reported earlier.

  19. Combined Anterior-Posterior Surgery Versus Posterior Surgery for Thoracolumbar Burst Fractures: A Systematic Review of the Literature

    NARCIS (Netherlands)

    P.P. Oprel (Pim); W.E. Tuinebreijer (Wim); P. Patka (Peter); D. den Hartog (Dennis)

    2010-01-01

    textabstractAbstract: Study Design: A systematic quantitative review of the literature. Objective: To compare combined anterior-posterior surgery versus posterior surgery for thoracolumbar fractures in order to identify better treatments. Summary of Background Data: Axial load of the anterior and

  20. Unusual combination of posterior femoral head dislocation with anterior and posterior wall fractures in the ipsilateral acetabulum.

    Science.gov (United States)

    Chen, Wei; Su, Yanling; Zhang, Yingze; Zhang, Qi; Zheng, Zhanle; Pan, Jinshe

    2010-06-09

    Although hip dislocation combined with acetabular fracture is not an uncommon injury, anterior acetabular wall fractures rarely occur in patients who have posterior fracture-dislocations of the hip. This article presents a unique case of anterior and posterior wall fractures of the ipsilateral acetabulum in a patient who sustained traumatic posterior hip dislocation that resulted from a high-speed motor vehicle accident. The initial imaging evaluation, which did not include the obturator oblique view, revealed no concomitant anterior acetabular wall fracture. Repeated manipulative reductions were unsuccessful in reducing the displaced hip joint. Pelvic computed tomography (CT) scans revealed the initially missed anterior acetabular wall fracture fragments incarcerated in the left hip joint in addition to the hip dislocation and the posterior acetabular wall fracture. The incarcerated bone fragments lay between the anterior wall and the femoral head, and between the posterior wall and the femoral head, which appeared to derive from both anterior and posterior acetabular walls, respectively. Open reduction and internal fixation was performed to manage the posterior dislocation and associated acetabular fractures. Intraoperatively, the major anterior wall fragment was used to reconstruct the defected posterior wall. This case highlights the necessity of suspicion and pre- and postoperative monitoring of the obturator oblique view and CT scans to detect the potentially existing anterior acetabular wall fracture. Early surgical intervention is important to guarantee satisfactory outcomes of such complex fracture-dislocation injuries. Copyright 2010, SLACK Incorporated.

  1. Rab3A, a possible marker of cortical granules, participates in cortical granule exocytosis in mouse eggs

    Energy Technology Data Exchange (ETDEWEB)

    Bello, Oscar Daniel; Cappa, Andrea Isabel; Paola, Matilde de; Zanetti, María Natalia [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Fukuda, Mitsunori [Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Fissore, Rafael A. [Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA 01003 (United States); Mayorga, Luis S. [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Michaut, Marcela A., E-mail: mmichaut@gmail.com [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (Argentina)

    2016-09-10

    Fusion of cortical granules with the oocyte plasma membrane is the most significant event to prevent polyspermy. This particular exocytosis, also known as cortical reaction, is regulated by calcium and its molecular mechanism is still not known. Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in calcium-dependent exocytosis and is not yet clear whether Rab3A participates in cortical granules exocytosis. Here, we examine the involvement of Rab3A in the physiology of cortical granules, particularly, in their distribution during oocyte maturation and activation, and their participation in membrane fusion during cortical granule exocytosis. Immunofluorescence and Western blot analysis showed that Rab3A and cortical granules have a similar migration pattern during oocyte maturation, and that Rab3A is no longer detected after cortical granule exocytosis. These results suggested that Rab3A might be a marker of cortical granules. Overexpression of EGFP-Rab3A colocalized with cortical granules with a Pearson correlation coefficient of +0.967, indicating that Rab3A and cortical granules have almost a perfect colocalization in the egg cortical region. Using a functional assay, we demonstrated that microinjection of recombinant, prenylated and active GST-Rab3A triggered cortical granule exocytosis, indicating that Rab3A has an active role in this secretory pathway. To confirm this active role, we inhibited the function of endogenous Rab3A by microinjecting a polyclonal antibody raised against Rab3A prior to parthenogenetic activation. Our results showed that Rab3A antibody microinjection abolished cortical granule exocytosis in parthenogenetically activated oocytes. Altogether, our findings confirm that Rab3A might function as a marker of cortical granules and participates in cortical granule exocytosis in mouse eggs. - Highlights: • Rab3A has a similar migration pattern to cortical granules in mouse oocytes. • Rab3A can be a marker of

  2. Functional rehabilitation of partial cortical blindness?

    Science.gov (United States)

    Stoerig, Petra

    2008-01-01

    The current doctrine regards fields of partial cortical blindness as permanent once a temporally restricted window for spontaneous recovery has passed. Accordingly, neuropsychological rehabilitation mainly applies compensatory procedures that train patients to make better use of their sighted field. The more ambitious goal of functional recovery depends on the survival of pathways that continue to transmit retinal information from the blind field. Although wide-spread antero- and retrograde degeneration follows lesions that destroy or denervate the primary visual cortex and cause partial cortical blindness, several retinofugal pathways survive in cats, monkeys, and humans. In all three species, they subserve a variety of visual functions which develop and improve with practice. Post lesion plasticity is greater when the lesion occurs early in life, but changes in behavioural performance and brain responses have also been demonstrated in late lesion subjects. Although the extent of functional improvement is variable, and the most effective approaches still need to be established across cohorts, the evidence for perceptual learning in fields of cortical blindness indicates that the visual processes mediated by the surviving parts of the visual system can be harnessed to improve functional outcome.

  3. Stochastic computations in cortical microcircuit models.

    Directory of Open Access Journals (Sweden)

    Stefan Habenschuss

    Full Text Available Experimental data from neuroscience suggest that a substantial amount of knowledge is stored in the brain in the form of probability distributions over network states and trajectories of network states. We provide a theoretical foundation for this hypothesis by showing that even very detailed models for cortical microcircuits, with data-based diverse nonlinear neurons and synapses, have a stationary distribution of network states and trajectories of network states to which they converge exponentially fast from any initial state. We demonstrate that this convergence holds in spite of the non-reversibility of the stochastic dynamics of cortical microcircuits. We further show that, in the presence of background network oscillations, separate stationary distributions emerge for different phases of the oscillation, in accordance with experimentally reported phase-specific codes. We complement these theoretical results by computer simulations that investigate resulting computation times for typical probabilistic inference tasks on these internally stored distributions, such as marginalization or marginal maximum-a-posteriori estimation. Furthermore, we show that the inherent stochastic dynamics of generic cortical microcircuits enables them to quickly generate approximate solutions to difficult constraint satisfaction problems, where stored knowledge and current inputs jointly constrain possible solutions. This provides a powerful new computing paradigm for networks of spiking neurons, that also throws new light on how networks of neurons in the brain could carry out complex computational tasks such as prediction, imagination, memory recall and problem solving.

  4. Stochastic computations in cortical microcircuit models.

    Science.gov (United States)

    Habenschuss, Stefan; Jonke, Zeno; Maass, Wolfgang

    2013-01-01

    Experimental data from neuroscience suggest that a substantial amount of knowledge is stored in the brain in the form of probability distributions over network states and trajectories of network states. We provide a theoretical foundation for this hypothesis by showing that even very detailed models for cortical microcircuits, with data-based diverse nonlinear neurons and synapses, have a stationary distribution of network states and trajectories of network states to which they converge exponentially fast from any initial state. We demonstrate that this convergence holds in spite of the non-reversibility of the stochastic dynamics of cortical microcircuits. We further show that, in the presence of background network oscillations, separate stationary distributions emerge for different phases of the oscillation, in accordance with experimentally reported phase-specific codes. We complement these theoretical results by computer simulations that investigate resulting computation times for typical probabilistic inference tasks on these internally stored distributions, such as marginalization or marginal maximum-a-posteriori estimation. Furthermore, we show that the inherent stochastic dynamics of generic cortical microcircuits enables them to quickly generate approximate solutions to difficult constraint satisfaction problems, where stored knowledge and current inputs jointly constrain possible solutions. This provides a powerful new computing paradigm for networks of spiking neurons, that also throws new light on how networks of neurons in the brain could carry out complex computational tasks such as prediction, imagination, memory recall and problem solving.

  5. Coverage, continuity, and visual cortical architecture.

    Science.gov (United States)

    Keil, Wolfgang; Wolf, Fred

    2011-12-29

    The primary visual cortex of many mammals contains a continuous representation of visual space, with a roughly repetitive aperiodic map of orientation preferences superimposed. It was recently found that orientation preference maps (OPMs) obey statistical laws which are apparently invariant among species widely separated in eutherian evolution. Here, we examine whether one of the most prominent models for the optimization of cortical maps, the elastic net (EN) model, can reproduce this common design. The EN model generates representations which optimally trade of stimulus space coverage and map continuity. While this model has been used in numerous studies, no analytical results about the precise layout of the predicted OPMs have been obtained so far. We present a mathematical approach to analytically calculate the cortical representations predicted by the EN model for the joint mapping of stimulus position and orientation. We find that in all the previously studied regimes, predicted OPM layouts are perfectly periodic. An unbiased search through the EN parameter space identifies a novel regime of aperiodic OPMs with pinwheel densities lower than found in experiments. In an extreme limit, aperiodic OPMs quantitatively resembling experimental observations emerge. Stabilization of these layouts results from strong nonlocal interactions rather than from a coverage-continuity-compromise. Our results demonstrate that optimization models for stimulus representations dominated by nonlocal suppressive interactions are in principle capable of correctly predicting the common OPM design. They question that visual cortical feature representations can be explained by a coverage-continuity-compromise.

  6. Real-time EEG-based brain-computer interface to a virtual avatar enhances cortical involvement in human treadmill walking.

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    Luu, Trieu Phat; Nakagome, Sho; He, Yongtian; Contreras-Vidal, Jose L

    2017-08-21

    Recent advances in non-invasive brain-computer interface (BCI) technologies have shown the feasibility of neural decoding for both users' gait intent and continuous kinematics. However, the dynamics of cortical involvement in human upright walking with a closed-loop BCI has not been investigated. This study aims to investigate the changes of cortical involvement in human treadmill walking with and without BCI control of a walking avatar. Source localization revealed significant differences in cortical network activity between walking with and without closed-loop BCI control. Our results showed sustained α/µ suppression in the Posterior Parietal Cortex and Inferior Parietal Lobe, indicating increases of cortical involvement during walking with BCI control. We also observed significant increased activity of the Anterior Cingulate Cortex (ACC) in the low frequency band suggesting the presence of a cortical network involved in error monitoring and motor learning. Additionally, the presence of low γ modulations in the ACC and Superior Temporal Gyrus may associate with increases of voluntary control of human gait. This work is a further step toward the development of a novel training paradigm for improving the efficacy of rehabilitation in a top-down approach.

  7. Cortical Signatures of Dyslexia and Remediation: An Intrinsic Functional Connectivity Approach

    Science.gov (United States)

    Koyama, Maki S.; Di Martino, Adriana; Kelly, Clare; Jutagir, Devika R.; Sunshine, Jessica; Schwartz, Susan J.; Castellanos, Francisco X.; Milham, Michael P.

    2013-01-01

    This observational, cross-sectional study investigates cortical signatures of developmental dyslexia, particularly from the perspective of behavioral remediation. We employed resting-state fMRI, and compared intrinsic functional connectivity (iFC) patterns of known reading regions (seeds) among three dyslexia groups characterized by (a) no remediation (current reading and spelling deficits), (b) partial remediation (only reading deficit remediated), and (c) full remediation (both reading and spelling deficits remediated), and a group of age- and IQ-matched typically developing children (TDC) (total N = 44, age range = 7–15 years). We observed significant group differences in iFC of two seeds located in the left posterior reading network – left intraparietal sulcus (L.IPS) and left fusiform gyrus (L.FFG). Specifically, iFC between L.IPS and left middle frontal gyrus was significantly weaker in all dyslexia groups, irrespective of remediation status/literacy competence, suggesting that persistent dysfunction in the fronto-parietal attention network characterizes dyslexia. Additionally, relative to both TDC and the no remediation group, the remediation groups exhibited stronger iFC between L.FFG and right middle occipital gyrus (R.MOG). The full remediation group also exhibited stronger negative iFC between the same L.FFG seed and right medial prefrontal cortex (R.MPFC), a core region of the default network These results suggest that behavioral remediation may be associated with compensatory changes anchored in L.FFG, which reflect atypically stronger coupling between posterior visual regions (L.FFG-R.MOG) and greater functional segregation between task-positive and task-negative regions (L.FFG-R.MPFC). These findings were bolstered by significant relationships between the strength of the identified functional connections and literacy scores. We conclude that examining iFC can reveal cortical signatures of dyslexia with particular promise for monitoring

  8. Configuration and corticalization of the mandibular bifid canal in a Taiwanese adult population: a computed tomography study.

    Science.gov (United States)

    Shen, E-Chin; Fu, Earl; Fu, Martin Ming-Jen; Peng, Michelle

    2014-01-01

    The configuration and degree of corticalization of bifid mandibular canals were examined using medical computed tomography (CT) images from 170 hemimandibles obtained from 308 Taiwanese adults. The configurations of the bifid canals were assessed according to their anatomical position in relation to the ramus, molars, premolars, and mental foramen; their course (anterior/posterior or superior/inferior); the presence or absence of confluence with the main mandibular canal; and the presence or absence of penetration through the mandible to form an accessory foramen. The percentage of the canal length that was corticalized was measured. Two different classifications of bifid canals were also briefly summarized and compared. When bifid canals are present (41.2% of patients; 27.6% of hemimandibles), the bifid canals were primarily located in the ramus and retromolar regions (67.7%) running anteriorly (95.9%) and superiorly (95.9%) without confluence with the main mandibular canal (91.1%). Up to 16.5% of bifid canals form accessory foramina on the cortical surface of the mandible. Approximately 78% of the bifid canals have varied degrees of corticalization around the bifid canals. The configuration and course of 170 mandibular bifid canals were evaluated with CT images. The bifid canals were primarily located in the ramus and retromolar regions; however, 32.4% of the bifid canals were located in potential positions for dental implant placement. Most of the bifid canals ran anteriorly superior to the main mandibular canal, did not rejoin with the main mandibular canal, and diminished within the mandibular body. Approximately half of the bifid canals (45%) were completely corticated.

  9. Total bladder and posterior urethral reconstruction: salvage technique for defunctionalized bladder with recalcitrant posterior urethral stenosis.

    Science.gov (United States)

    Patil, Mukul B; Hannoun, Donald; Reyblat, Polina; Boyd, Stuart D

    2015-05-01

    Recalcitrant posterior urethral stenosis is a challenging disease. When combined with a defunctionalized bladder, cutaneous urinary diversion is the most common surgical option. We present a novel technique of total lower urinary tract reconstruction, combining salvage cystectomy, ileal neobladder formation and urethral pull-through, as an orthotopic alternative in patients with a defunctionalized bladder and recalcitrant posterior urethral stenosis. We completed a retrospective review of 8 patients who underwent salvage cystectomy, orthotopic ileal neobladder formation and urethral pull-through. Artificial urinary sphincter placement was performed in a staged fashion. Six patients received prostate cancer treatment including radiation therapy, 1 had urethral disruption after robotic radical prostatectomy, and 1 experienced bladder rupture and urethral distraction injury during a motorcycle accident. Patient demographics, operative variables and postoperative outcomes were examined. No high grade complications were observed after salvage cystectomy, orthotopic neobladder formation and urethral pull-through. After staged artificial urinary sphincter placement, a median of 2 revision surgeries (range 0 to 4) was required to establish social continence. All patients maintained functional urinary storage, urethral patency and social continence at a median followup of 58 months. No patient had complications related to orthotopic neobladder formation, including ureteroileal anastomotic stricture or pyelonephritis, and no patient required cutaneous diversion. Total lower urinary tract reconstruction with cystectomy, ileal neobladder formation and urethral pull-through offers an orthotopic alternative for patients with recalcitrant posterior urethral stenosis and defunctionalized bladders. Although it requires staged placement of an artificial urinary sphincter, this approach can offer functional urinary storage, durable urethral patency and avoidance of cutaneous urinary

  10. Anterior Commissure-posterior commissure revisited

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sang Han; Chi, Je Geun; Kim, Young Bo; Cho, Zang Hee [Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon (Korea, Republic of)

    2013-08-15

    The anterior commissure (AC) and posterior commissure (PC) are the two distinct anatomic structures in the brain which are difficult to observe in detail with conventional MRI, such as a 1.5T MRI system. However, recent advances in ultra-high resolution MRI have enabled us to examine the AC and PC directly. The objective of the present study is to standardize the shape and size of the AC and PC using a 7.0T MRI and to propose a new brain reference line. Thirty-four, 21 males and 13 females, healthy volunteers were enrolled in this study. After determining the center of each AC and PC, we defined the connection of these centers as the central intercommissural line (CIL). We compared the known extra- and intra-cerebral reference lines with the CIL to determine the difference in the angles. Additionally, we obtained horizontal line from flat ground line of look front human. The difference in angle of the CIL and the tangential intercommissural line (TIL) from the horizontal line was 8.7 ± 5.1 (11 ± 4.8) and 17.4 ± 5.2 (19.8 ± 4.8) degrees in males and females, respectively. The difference in angle between the CIL and canthomeatal line was 10.1 in both male and female, and there was no difference between both sexes. Likewise, there was no significant difference in angle between the CIL and TIL between both sexes (8.3 +/- 1.1 in male and 8.8 +/- 0.7 in female). In this study, we have used 7.0T MRI to define the AC and PC quantitatively and in a more robust manner. We have showed that the CIL is a reproducible reference line and serves as a standard for the axial images of the human brain.

  11. An evaluation of Microleakage of Posterior Composites

    Directory of Open Access Journals (Sweden)

    Mohammadi N

    1999-12-01

    Full Text Available Polymerization contraction may produce defects in the composite - tooth bond. This may lead to bond failure and microleakage. The aim of this study was to reduce microleakage of posterior composites using different methods. 45 molar and premolars extracted teeth were choosen. The cavities were randomly assigned into 5 groups of 9. Box-shaped cavities were prepared on each side of proximal surfaces and restored by five different methods. Group 1 was filled by a light-cured composite and dentin bonding agents (DBAs with light curing from the occlusal area. Group 2 was filled by a light-cured {LC} composite and DBA, in addition the angle between the light source and occlusal area was 45 degree. After conditioning of teeth in-group 3, LC glass ionomer was placed on the gingival floor and then filled by a light-cured composite and DBA. In group 4, after conditioning, the teeth were lined by a LC glass ionomer and then self-cured composite was placed on gingival floor. This group was filled with LC composite. In Group 5 DBA was used followed by placing a self-curing composite on gingival floor and filled by LC composite. The teeth were subjected to 500 thermocycling (5°C and 55°C with dowel time 30 s and stored in 0.5% basic fushin for 24 hours. Dye penetration was evaluated by light microscope. The results were tested by Kruskat-Wallis one-way analysis of variance by rank. The comparison between treatment groups showed highly significant difference {P<0.0001. No significant difference was found between groups 3 versus 4 and groups 1,2,5 versus 3,4. Group 3 showed the least microleakage score. Therefore least microleakage was obtained by the group which used L C glass ionomer and DBA followed by filling a composite.

  12. [Patient satisfaction after posterior lamellar keratoplasty (DSAEK)].

    Science.gov (United States)

    Bachmann, B O; Pogorelov, P; Kruse, F E; Cursiefen, C

    2008-06-01

    The advantages of posterior lamellar keratoplasty (DSAEK) compared to conventional full thickness keratoplasty are faster visual rehabilitation, little change in astigmatism and the absence of suture-associated complications. The current study evaluated the satisfaction of the first 15 patients who underwent DSAEK at our clinic. Evaluation of patient satisfaction was conducted via a telephone survey and by means of a written patient questionnaire. The patients were asked to answer questions on a scale from 1 (very bad) to 10 (very good) about their overall satisfaction with this procedure, their satisfaction with the achieved postoperative visual acuity, their satisfaction with the progress of the healing process and the extent of the perceived burden. The patients were also asked whether they would opt again for the operation. Pre- and postoperative visual acuity, IOP, topographic astigmatism and corneal pachymetry were analysed. 15 eyes of 15 patients were analysed (12 women and 3 men). Average age at the time of operation was 75 +/- 7 years. Visual acuity increased and corneal thickness decreased primarily within the first three months. During that time there was an increase in overall patient satisfaction which finally reached 6.9 +/- 1.8 on the scale. Postoperative visual acuity was awarded with 7.2 +/- 2.0, progress of the healing process with 7.4 +/- 2.3. The procedure was not perceived as a big burden (8.0 +/- 1.9) and most patients would have decided again for the operation (8.2 +/- 2.0). There was no pre- and postoperative difference in IOP and corneal astigmatism. Like in our group patients with diseases of the corneal endothelium are of higher age and therefore benefit from a fast restitution of visual acuity and a low burden of operation. DSAEK represents a secure and practical procedure to rehabilitate elderly patients with diseases of the corneal endothelium.

  13. Ultrasonographic findings of posterior interosseous nerve syndrome

    Directory of Open Access Journals (Sweden)

    Youdong Kim

    2017-10-01

    Full Text Available Purpose The purpose of this study was to evaluate the ultrasonographic findings associated with posterior interosseous nerve (PIN syndrome. Methods Approval from the Institutional Review Board was obtained. A retrospective review of 908 patients' sonographic images of the upper extremity from January 2001 to October 2010 revealed 10 patients suspicious for a PIN abnormality (7 male and 3 female patients; mean age of 51.8±13.1 years; age range, 32 to 79 years. The ultrasonographic findings of PIN syndrome, including changes in the PIN and adjacent secondary changes, were evaluated. The anteroposterior diameter of the pathologic PIN was measured in eight patients and the anteroposterior diameter of the contralateral asymptomatic PIN was measured in six patients, all at the level immediately proximal to the proximal supinator border. The size of the pathologic nerves and contralateral asymptomatic nerves was compared using the Mann-Whitney U test. Results Swelling of the PIN proximal to the supinator canal by compression at the arcade of Fröhse was observed in four cases. Swelling of the PIN distal to the supinator canal was observed in one case. Loss of the perineural fat plane in the supinator canal was observed in one case. Four soft tissue masses were noted. Secondary denervation atrophy of the supinator and extensor muscles was observed in two cases. The mean anteroposterior diameter of the pathologic nerves (n=8, 1.79±0.43 mm was significantly larger than that of the contralateral asymptomatic nerves (n=6, 1.02±0.22 mm (P=0.003. Conclusion Ultrasonography provides high-resolution images of the PIN and helps to diagnose PIN syndrome through visualization of its various causes and adjacent secondary changes.

  14. Ultrasonographic findings of posterior interosseous nerve syndrome.

    Science.gov (United States)

    Kim, Youdong; Ha, Doo Hoe; Lee, Sang Min

    2017-10-01

    The purpose of this study was to evaluate the ultrasonographic findings associated with posterior interosseous nerve (PIN) syndrome. Approval from the Institutional Review Board was obtained. A retrospective review of 908 patients' sonographic images of the upper extremity from January 2001 to October 2010 revealed 10 patients suspicious for a PIN abnormality (7 male and 3 female patients; mean age of 51.8±13.1 years; age range, 32 to 79 years). The ultrasonographic findings of PIN syndrome, including changes in the PIN and adjacent secondary changes, were evaluated. The anteroposterior diameter of the pathologic PIN was measured in eight patients and the anteroposterior diameter of the contralateral asymptomatic PIN was measured in six patients, all at the level immediately proximal to the proximal supinator border. The size of the pathologic nerves and contralateral asymptomatic nerves was compared using the Mann-Whitney U test. Swelling of the PIN proximal to the supinator canal by compression at the arcade of Fröhse was observed in four cases. Swelling of the PIN distal to the supinator canal was observed in one case. Loss of the perineural fat plane in the supinator canal was observed in one case. Four soft tissue masses were noted. Secondary denervation atrophy of the supinator and extensor muscles was observed in two cases. The mean anteroposterior diameter of the pathologic nerves (n=8, 1.79±0.43 mm) was significantly larger than that of the contralateral asymptomatic nerves (n=6, 1.02±0.22 mm) (P=0.003). Ultrasonography provides high-resolution images of the PIN and helps to diagnose PIN syndrome through visualization of its various causes and adjacent secondary changes.

  15. Ultrasonographic findings of posterior interosseous nerve syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kim, You Dong; Ha, Doo Hoe; Lee, Sang Min [Dept. of Radiology, CHA Bundang Medical Center, CHA University, Seongnam (Korea, Republic of)

    2017-10-15

    The purpose of this study was to evaluate the ultrasonographic findings associated with posterior interosseous nerve (PIN) syndrome. Approval from the Institutional Review Board was obtained. A retrospective review of 908 patients' sonographic images of the upper extremity from January 2001 to October 2010 revealed 10 patients suspicious for a PIN abnormality (7 male and 3 female patients; mean age of 51.8±13.1 years; age range, 32 to 79 years). The ultrasonographic findings of PIN syndrome, including changes in the PIN and adjacent secondary changes, were evaluated. The anteroposterior diameter of the pathologic PIN was measured in eight patients and the anteroposterior diameter of the contralateral asymptomatic PIN was measured in six patients, all at the level immediately proximal to the proximal supinator border. The size of the pathologic nerves and contralateral asymptomatic nerves was compared using the Mann-Whitney U test. Swelling of the PIN proximal to the supinator canal by compression at the arcade of Fröhse was observed in four cases. Swelling of the PIN distal to the supinator canal was observed in one case. Loss of the perineural fat plane in the supinator canal was observed in one case. Four soft tissue masses were noted. Secondary denervation atrophy of the supinator and extensor muscles was observed in two cases. The mean anteroposterior diameter of the pathologic nerves (n=8, 1.79±0.43 mm) was significantly larger than that of the contralateral asymptomatic nerves (n=6, 1.02±0.22 mm) (P=0.003). Ultrasonography provides high-resolution images of the PIN and helps to diagnose PIN syndrome through visualization of its various causes and adjacent secondary changes.

  16. Transsphenoidal Posterior Pituitary Lobe Biopsy in Patients with Neurohypophysial Lesions.

    Science.gov (United States)

    Kinoshita, Yasuyuki; Yamasaki, Fumiyuki; Tominaga, Atsushi; Usui, Satoshi; Arita, Kazunori; Sakoguchi, Tetsuhiko; Sugiyama, Kazuhiko; Kurisu, Kaoru

    2017-03-01

    The differential diagnosis of neurohypophysial lesions is difficult, and surgical biopsies are indispensable in the histologic diagnosis of some patients. Although pituitary stalk biopsies are uniformly performed, there is a considerable risk that they will result in impaired hormonal secretion. We attempt to clarify the usefulness and safety of posterior pituitary lobe biopsy by transsphenoidal surgery (TSS). The cases of 11 consecutive patients who underwent posterior pituitary lobe biopsies by TSS were retrospectively studied. Patients with cystic sellar lesions were excluded. We examined the clinical findings, endocrinologic data, magnetic resonance imaging findings, and histologic diagnoses of the patients. The locations of neurohypophysial lesions and the histologic diagnoses by posterior pituitary lobe biopsies were examined. The major preoperative clinical symptoms were diabetes insipidus (DI) (90.9%), followed by anterior pituitary lobe dysfunction (hypopituitarism) (54.5%). In all the patients, the lesions occupied the pituitary stalk and the posterior pituitary lobe, and the bright spot, which would indicate a normal posterior pituitary gland, disappeared on T1-weighted imaging. The posterior pituitary lobe specimens could be histologically diagnosed in all these cases. DI persisted in 10 patients with preoperative DI after the biopsy, whereas the 1 patient without preoperative DI did not suffer from DI after the biopsy. A posterior pituitary lobe biopsy by TSS may be an alternative to pituitary stalk biopsy in patients with neurohypophysial lesions. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Radiographic measurement of the posterior femoral offset is not precise.

    Science.gov (United States)

    Jenny, Jean-Yves; Honecker, Sophie; Chammai, Yves

    2017-08-01

    The posterior femoral offset may significantly impact the final flexion range after total knee arthroplasty (TKA). The purpose of the present study was to compare a conventional, radiologic-based technique with an intra-operative, surgical navigation-based technique for the measurement of posterior femoral offset. The tested hypothesis was that the two measurement techniques produce different results both before and after TKA. One-hundred consecutive cases referred for end-stage knee osteoarthritis have been studied. Posterior femoral offsets, measured pre- and post-TKA from radiographs, as well as those measured from a navigation system intra-operatively, were analysed. The pre-TKA measured offsets, post-TKA measured offsets and the changes (pre- vs. post-TKA) in the offsets were statistically compared between the radiologic and the navigated measurement techniques at a 0.05 level of significance. The mean paired difference between pre-TKA radiologic and navigated measurement was 4 ± 4 mm (p measurements. The mean paired difference between post-TKA radiologic and navigated measurement was 6 ± 5 mm (p measurements. The conventional radiologic technique for the measurement of the posterior femoral offset cannot be reliably used either for pre-TKA planning of the posterior femoral resection and antero-posterior sizing of the femoral component, or for post-TKA quality control of the reconstruction of the posterior femoral offset. Level IV.

  18. CT findings of traumatic posterior hip dislocation after reduction

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    Moon, Sung Kyoung; Park, Ji Seon; Ryu, Kyung Nam; Jin, Wook [Kyung Hee University Medical Center, Seoul (Korea, Republic of); Jin Wook

    2008-06-15

    To evaluate the CT images of reduced hips after posterior hip dislocation and to propose specific diagnostic criteria based on the CT results. We retrospectively reviewed the CT findings on 18 reduced hips from 17 patients with radiographs and clinical histories of traumatic posterior hip dislocations by evaluating 18 corresponding CT scans for joint space asymmetry, intra-articular abnormalities (intra-articular fat obliteration, loose bodies, and joint effusion), changes in posterior soft tissue (capsule, muscles, and adjacent fat), the presence, and location of fractures (acetabulum and femoral head). All 18 hips (100%) showed posterior soft tissue changes. In total, 17 hips (94.4%) had intra-articular abnormalities and 15 hips (83.3%) had joint space asymmetries. In addition, 17 hips (94.4%) had fractures involving the acetabula (15 cases, 88.2%) the femoral head (13 cases, 76.5%), or on both sides (11 cases, 64.7%). The most frequent fracture location was in he posterior wall (13/15, 86.7%) of the acetabulum and in the anterior aspect (10/13, 76.9%) of the femoral head. Patients with a prior history of posterior hip dislocation showed specific CT findings after reduction, suggesting the possibility of previous posterior hip dislocations in patients.

  19. Posterior quadrant disconnection for refractory epilepsy: A case series

    Directory of Open Access Journals (Sweden)

    Javeria Nooraine

    2014-01-01

    Full Text Available Objective: To analyze the surgical outcome and safety of posterior quadrant disconnection in medically refractory epilepsy arising from the posterior head region from a level IV tertiary care center over a period of three years. Materials and Methods: Seven consecutive patients who underwent posterior quadrant disconnection for refractory epilepsy were analyzed. Results: We analyzed the data of seven (n = 7 consecutive posterior quadrant epilepsy patients who underwent posterior quadrant disconnection with a mean age of 8.5 years over the last three years of which 4 were male and 3 females. All patients underwent extensive pre-surgical evaluation including detailed history, examination, prolonged video EEG recordings, neuropsychological testing, MRI brain, DTI, PET scan (n = 6, fMRI (n = 4, WADA test (n = 1 and invasive recording (n = 1, Of seven patients four had left sided pathology and three had right sided pathology. All patients except one underwent pure disconnection and one underwent partial resection. Conclusion: Posterior quadrant disconnection is effective surgical procedure for medically refractory epilepsy arising from the posterior quadrant in carefully selected patients without morbidity or functional disability across various age groups especially in children. In our series, all seven patient had good seizure outcome and none had functional disabilities.

  20. Cerebello-Cortical Differences in Effective Connectivity of the Dominant and Non-dominant Hand during a Visuomotor Paradigm of Grip Force Control

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    Eric Moulton

    2017-10-01

    Full Text Available Structural and functional differences are known to exist within the cortical sensorimotor networks with respect to the dominant vs. non-dominant hand. Similarly, the cerebellum, a key structure in the sensorimotor network with its cerebe