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Sample records for left cerebral hemisphere

  1. Right hemispheric reversible cerebral vasoconstriction syndrome in a patient with left hemispheric partial seizures.

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    Perez, Gina S; McCaslin, Justin; Shamim, Sadat

    2017-04-01

    We report a right-handed 19-year-old girl who developed reversible cerebral vasoconstriction syndrome (RCVS) lateralized to the right hemisphere with simultaneous new-onset left hemispheric seizures. RCVS, typically more diffuse, was lateralized to one of the cerebral hemispheres.

  2. Testing the Language of German Cerebral Palsy Patients with Right Hemispheric Language Organization after Early Left Hemispheric Damage

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    Schwilling, Eleonore; Krageloh-Mann, Ingeborg; Konietzko, Andreas; Winkler, Susanne; Lidzba, Karen

    2012-01-01

    Language functions are generally represented in the left cerebral hemisphere. After early (prenatally acquired or perinatally acquired) left hemispheric brain damage language functions may be salvaged by reorganization into the right hemisphere. This is different from brain lesions acquired in adulthood which normally lead to aphasia. Right…

  3. Oxygenation and hemodynamics in left and right cerebral hemispheres during induction of veno-arterial extracorporeal membrane oxygenation.

    NARCIS (Netherlands)

    Heyst, A.F.J. van; Liem, D.; Hopman, J.C.W.; Staak, F.H.J.M. van der; Sengers, R.C.A.

    2004-01-01

    OBJECTIVE: Oxygenation and hemodynamics in the left and right cerebral hemispheres were measured during induction of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). STUDY DESIGN: Using near infrared spectrophotometry, effects of right common carotid artery (RCCA) and right internal

  4. Moral judgement by the disconnected left and right cerebral hemispheres: a split-brain investigation.

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    Steckler, Conor M; Hamlin, J Kiley; Miller, Michael B; King, Danielle; Kingstone, Alan

    2017-07-01

    Owing to the hemispheric isolation resulting from a severed corpus callosum, research on split-brain patients can help elucidate the brain regions necessary and sufficient for moral judgement. Notably, typically developing adults heavily weight the intentions underlying others' moral actions, placing greater importance on valenced intentions versus outcomes when assigning praise and blame. Prioritization of intent in moral judgements may depend on neural activity in the right hemisphere's temporoparietal junction, an area implicated in reasoning about mental states. To date, split-brain research has found that the right hemisphere is necessary for intent-based moral judgement. When testing the left hemisphere using linguistically based moral vignettes, split-brain patients evaluate actions based on outcomes, not intentions. Because the right hemisphere has limited language ability relative to the left, and morality paradigms to date have involved significant linguistic demands, it is currently unknown whether the right hemisphere alone generates intent-based judgements. Here we use nonlinguistic morality plays with split-brain patient J.W. to examine the moral judgements of the disconnected right hemisphere, demonstrating a clear focus on intent. This finding indicates that the right hemisphere is not only necessary but also sufficient for intent-based moral judgement, advancing research into the neural systems supporting the moral sense.

  5. Meningiomatosis restricted to the left cerebral hemisphere with acute clinical deterioration: Case presentation and discussion of treatment options.

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    Ohla, Victoria; Scheiwe, Christian

    2015-01-01

    True multiple meningiomas are defined as meningiomas occurring at several intracranial locations simultaneously without the presence of neurofibromatosis. Though the prognosis does not differ from benign solitary meningiomas, the simultaneous occurrence of different grades of malignancy has been reported in one-third of patients with multiple meningiomas. Due to its rarity, unclear etiology, and questions related to proper management, we are presenting our case of meningiomatosis and discuss possible pathophysiological mechanisms. We illustrate the case of a 55-year-old female with multiple meningothelial meningeomas exclusively located in the left cerebral hemisphere. The patient presented with acute vigilance decrement, aphasia, and vomiting. Further deterioration with sopor and nondirectional movements required oral intubation. Emergent magnetic resonance imaging (MRI) with MR-angiography disclosed a massive midline shift to the right due to widespread, plaque-like lesions suspicious for meningeomatosis, purely restricted to the left cerebral hemisphere. Emergency partial tumor resection was performed. Postoperative computed tomography (CT) scan showed markedly reduction of cerebral edema and midline shift. After tapering the sedation a right-sided hemiparesis resolved within 2 weeks, leaving the patient neurologically intact. Although multiple meningeomas are reported frequently, the presence of meningeomatosis purely restricted to one cerebral hemisphere is very rare. As with other accessible and symptomatic lesions, the treatment of choice is complete resection with clean margins to avoid local recurrence. In case of widespread distribution a step-by-step resection with the option of postoperative radiation of tumor remnants may be an option.

  6. Greater left cerebral hemispheric metabolism in bulimia assessed by positron emission tomography

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    Wu, J.C.; Hagman, J.; Buchsbaum, M.S.; Blinder, B.; Derrfler, M.; Tai, W.Y.; Hazlett, E.; Sicotte, N. (Univ. of California, Irvine (USA))

    1990-03-01

    Eight women with bulimia and eight age- and sex-matched normal control subjects were studied with positron emission tomography using (18F)-fluorodeoxyglucose (FDG) as a tracer of brain metabolic rate. Subjects performed a visual vigilance task during FDG uptake. In control subjects, the metabolic rate was higher in the right hemisphere than in the left, but patients with bulimia did not have this normal asymmetry. Lower metabolic rates in the basal ganglia, found in studies of depressed subjects, and higher rates in the basal ganglia, reported in a study of anorexia nervosa, were not found. This is consistent with the suggestion that bulimia is a diagnostic grouping distinct from these disorders.

  7. Selected Gray Matter Volumes and Gender but Not Basal Ganglia nor Cerebellum Gyri Discriminate Left Versus Right Cerebral Hemispheres: Multivariate Analyses in human Brains at 3T.

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    Roldan-Valadez, Ernesto; Suarez-May, Marcela A; Favila, Rafael; Aguilar-Castañeda, Erika; Rios, Camilo

    2015-07-01

    Interest in the lateralization of the human brain is evident through a multidisciplinary number of scientific studies. Understanding volumetric brain asymmetries allows the distinction between normal development stages and behavior, as well as brain diseases. We aimed to evaluate volumetric asymmetries in order to select the best gyri able to classify right- versus left cerebral hemispheres. A cross-sectional study performed in 47 right-handed young-adults healthy volunteers. SPM-based software performed brain segmentation, automatic labeling and volumetric analyses for 54 regions involving the cerebral lobes, basal ganglia and cerebellum from each cerebral hemisphere. Multivariate discriminant analysis (DA) allowed the assembling of a predictive model. DA revealed one discriminant function that significantly differentiated left vs. right cerebral hemispheres: Wilks' λ = 0.008, χ(2) (9) = 238.837, P brain gyri are able to accurately classify left vs. right cerebral hemispheres by using a multivariate approach; the selected regions correspond to key brain areas involved in attention, internal thought, vision and language; our findings favored the concept that lateralization has been evolutionary favored by mental processes increasing cognitive efficiency and brain capacity. © 2015 Wiley Periodicals, Inc.

  8. When left-hemisphere reading is compromised: Comparing reading ability in participants after left cerebral hemispherectomy and participants with developmental dyslexia.

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    Katzir, Tami; Christodoulou, Joanna A; de Bode, Stella

    2016-10-01

    We investigated reading skills in individuals who have undergone left cerebral hemispherectomy and in readers with developmental dyslexia to understand diverse characteristics contributing to reading difficulty. Although dyslexia is a developmental disorder, left hemispherectomy requires that patients (re)establish the language process needed to perform the language-based tasks in the nondominant (right) hemisphere to become readers. Participants with developmental dyslexia (DD; n = 11) and participants who had undergone left hemispherectomy (HEMI; n = 11) were matched on age and gender, and were compared on timed and untimed measures of single word and pseudo-word reading. The hemispherectomy group was subdivided into prenatal (in utero) and postnatal (>3 years) insult groups, indicating the timing of the primary lesion that ultimately required surgical intervention. On an untimed reading measure, the readers with DD were comparable to individuals who had undergone left hemispherectomy due to prenatal insult, but both scored higher than the postnatal hemispherectomy group. Timed word reading differed across groups. The hemispherectomy prenatal subgroup had low average scores on both timed and untimed tests. The group with dyslexia had average scores on untimed measures and below average scores on timed reading. The hemispherectomy postnatal group had the lowest scores among the groups by a significant margin, and the most pronounced reading difficulty. Patients with prenatal lesions leading to an isolated right hemisphere (RH) have the potential to develop reading to a degree comparable to that in persons with dyslexia for single word reading. This potential sharply diminishes in individuals who undergo hemispherectomy due to postnatal insult. The higher scores of the prenatal hemispherectomy group on timed reading suggest that under these conditions, individuals with an isolated RH can compensate to a significant degree. Wiley Periodicals, Inc. © 2016

  9. A case of expressive-vocal amusia in a right-handed patient with left hemispheric cerebral infarction.

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    Uetsuki, Shizuka; Kinoshita, Hiroshi; Takahashi, Ryuichi; Obata, Satoshi; Kakigi, Tatsuya; Wada, Yoshiko; Yokoyama, Kazumasa

    2016-03-01

    A 53-year-old right-handed woman had an extensive lesion in the left hemisphere due to an infarction caused by vasospasm secondary to subarachnoid bleeding. She exhibited persistent expressive-vocal amusia with no symptoms of aphasia. Evaluation of the patient's musical competence using the Montreal Battery for Evaluation of Amusia, rhythm reproduction tests, acoustic analysis of pitch upon singing familiar music, Japanese standard language tests, and other detailed clinical examinations revealed that her amusia was more dominantly related to pitch production. The intactness of her speech provided strong evidence that the right hemisphere played a major role in her linguistic processing. Data from functional magnetic resonance imaging while she was singing a familiar song, a scale, and reciting lyrics indicated that perilesional residual activation in the left hemisphere was associated with poor pitch production, while right hemispheric activation was involved in linguistic processing. The localization of infarction more anterior to the left Sylvian fissure might be related to the dominant deficits in expressive aspects of the singing of the patient. Compromised motor programming producing a single tone may have made a major contribution to her poor singing. Imperfect auditory feedback due to borderline perceptual ability or improper audio-motor associations might also have played a role. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Changes in regional cerebral blood flow in the right cortex homologous to left language areas are directly affected by left hemispheric damage in aphasic stroke patients: evaluation by Tc-ECD SPECT and novel analytic software.

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    Uruma, G; Kakuda, W; Abo, M

    2010-03-01

    The objective of this study was to clarify the influence of regional cerebral blood flow (rCBF) changes in language-relevant areas of the dominant hemisphere on rCBF in each region in the non-dominant hemisphere in post-stroke aphasic patients. The study subjects were 27 aphasic patients who suffered their first symptomatic stroke in the left hemisphere. In each subject, we measured rCBF by means of 99mTc-ethylcysteinate dimmer single photon emission computed tomography (SPECT). The SPECT images were analyzed by the statistical imaging analysis programs easy Z-score Imaging System (eZIS) and voxel-based stereotactic extraction estimation (vbSEE). Segmented into Brodmann Area (BA) levels, Regions of Interest (ROIs) were set in language-relevant areas bilaterally, and changes in the relative rCBF as average negative and positive Z-values were computed fully automatically. To assess the relationship between rCBF changes of each ROIs in the left and right hemispheres, the Spearman ranked correlation analysis and stepwise multiple regression analysis were applied. Globally, a negative and asymmetric influence of rCBF changes in the language-relevant areas of the dominant hemisphere on the right hemisphere was found. The rCBF decrease in left BA22 significantly influenced the rCBF increase in right BA39, BA40, BA44 and BA45. The results suggested that the chronic increase in rCBF in the right language-relevant areas is due at least in part to reduction in the trancallosal inhibitory activity of the language-dominant left hemisphere caused by the stroke lesion itself and that these relationships are not always symmetric.

  11. Reorganization of the Cerebro-Cerebellar Network of Language Production in Patients with Congenital Left-Hemispheric Brain Lesions

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    Lidzba, K.; Wilke, M.; Staudt, M.; Krageloh-Mann, I.; Grodd, W.

    2008-01-01

    Patients with congenital lesions of the left cerebral hemisphere may reorganize language functions into the right hemisphere. In these patients, language production is represented homotopically to the left-hemispheric language areas. We studied cerebellar activation in five patients with congenital lesions of the left cerebral hemisphere to assess…

  12. Enhanced activation of the left hemisphere promotes normative decision making.

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    Corser, Ryan; Jasper, John D

    2014-01-01

    Previous studies have reported that enhanced activation of the left cerebral hemisphere reduces risky-choice, attribute, and goal-framing effects relative to enhanced activation of the right cerebral hemisphere. The present study sought to extend these findings and show that enhanced activation of the left hemisphere also reduces violations of other normative principles, besides the invariance principle. Participants completed ratio bias (Experiment 1, N = 296) and base rate neglect problems (Experiment 2, N = 145) under normal (control) viewing or with the right or left hemisphere primarily activated by imposing a unidirectional gaze. In Experiment 1 we found that enhanced left hemispheric activation reduced the ratio bias relative to normal viewing and a group experiencing enhanced right hemispheric activation. In Experiment 2 enhanced left hemispheric activation resulted in using base rates more than normal viewing, but not significantly more than enhanced right hemispheric activation. Results suggest that hemispheric asymmetries can affect higher-order cognitive processes, such as decision-making biases. Possible theoretical accounts are discussed as well as implications for dual-process theories.

  13. Bilateral cerebral hemispheric infarction associated with sildenafil citrate (Viagra) use.

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    Kim, K-K; Kim, D G; Ku, Y H; Lee, Y J; Kim, W-C; Kim, O J; Kim, H S

    2008-03-01

    Sildenafil citrate (Viagra) is one of the frequently prescribed drugs for men with erectile dysfunction. We describe a 52-year-old man with bilateral middle cerebral artery (MCA) territory infarction after sildenafil use. He ingested 100 mg of sildenafil and about 1 h later, he complained of chest discomfort, palpitation and dizziness followed by mental obtundation, global aphasia and left hemiparesis. Brain magnetic resonance imaging documented acute bilateral hemispheric infarction, and cerebral angiography showed occluded bilateral MCA. Despite significant bilateral MCA stenosis and cerebral infarction, systemic hypotension persisted for a day. We presume that cerebral infarction was caused by cardioembolism with sildenafil use.

  14. Interaction of cerebral hemispheres and artistic thinking

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    Nikolaenko, Nikolay N.

    1998-07-01

    Study of drawings by patients with local lesions of the right or left hemisphere allows to understand how artistic thinking is supported by brain structures. The role of the right hemisphere is significant at the early stage of creative process. The right hemisphere is a generator of nonverbal visuo-spatial thinking. It operates with blurred nonverbal images and arrange them in a visual space. With the help of iconic signs the right hemisphere reflects the world and creates perceptive visual standards which are stored in the long-term right hemisphere memory. The image, which appeared in the `inner' space, should be transferred into a principally different language, i.e. a left hemispheric sign language. This language operates with a number of discrete units, logical succession and learned grammar rules. This process can be explained by activation (information) transfer from the right hemisphere to the left one. Thus, natural and spontaneous creative process, which is finished by a conscious effort, can be understood as an activation impulse transfer from the right hemisphere to the left one and back.

  15. Split-brain reveals separate but equal self-recognition in the two cerebral hemispheres.

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    Uddin, Lucina Q; Rayman, Jan; Zaidel, Eran

    2005-09-01

    To assess the ability of the disconnected cerebral hemispheres to recognize images of the self, a split-brain patient (an individual who underwent complete cerebral commissurotomy to relieve intractable epilepsy) was tested using morphed self-face images presented to one visual hemifield (projecting to one hemisphere) at a time while making "self/other" judgments. The performance of the right and left hemispheres of this patient as assessed by a signal detection method was not significantly different, though a measure of bias did reveal hemispheric differences. The right and left hemispheres of this patient independently and equally possessed the ability to self-recognize, but only the right hemisphere could successfully recognize familiar others. This supports a modular concept of self-recognition and other-recognition, separately present in each cerebral hemisphere.

  16. Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage.

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    Lidzba, Karen; de Haan, Bianca; Wilke, Marko; Krägeloh-Mann, Ingeborg; Staudt, Martin

    2017-10-01

    Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development. Copyright © 2017. Published by Elsevier Inc.

  17. Cerebral hemisphere astrocytoma: Treatment results

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    Boyages, J.; Tiver, K.W.

    1987-01-01

    Eighty two adult patients with histologically proven cerebral astrocytomas of grades I to IV received post-operative radiotherapy at Westmead Hospital between January 1980 and February 1985. Seventy one patients completed a course of megavoltage irradiation, the majority having received a tumour dose of at least 60 Gy. Patients who underwent surgical resection had a greater median survival than those undergoing biopsy, but the difference was not statistically significant. By grade, the difference reached statistical significance only for grade III tumours. Patients with high grade tumours had a significantly lower survival than those patients with tumours of low grade. After adjustment for grade, various dosage levels did not significantly affect survival, although there was a trend towards improved median survival with higher doses in grade III tumours. When included in a multivariate analysis, the extent of surgery did not significantly influence survival, but increasing tumour grade and increasing age were significant adverse prognostic factors. (Auth.)

  18. Split Fovea Theory and the Role of the Two Cerebral Hemispheres in Reading: A Review of the Evidence

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    Ellis, Andrew W.; Brysbaert, Marc

    2010-01-01

    Split fovea theory proposes that when the eyes are fixated within a written word, visual information about the letters falling to the left of fixation is projected initially to the right cerebral hemisphere while visual information about the letters falling to the right of fixation is projected to the left cerebral hemisphere. The two parts of the…

  19. Priming vs. Rhyming: Orthographic and Phonological Representations in the Left and Right Hemispheres

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    Lindell, Annukka K.; Lum, Jarrad A. G.

    2008-01-01

    The right cerebral hemisphere has long been argued to lack phonological processing capacity. Recently, however, a sex difference in the cortical representation of phonology has been proposed, suggesting discrete left hemisphere lateralization in males and more distributed, bilateral representation of function in females. To evaluate this…

  20. Behavioral evidence for left-hemisphere specialization of motor planning

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    Janssen, L.; Meulenbroek, R.G.; Steenbergen, B.

    2011-01-01

    Recent studies suggest that the left hemisphere is dominant for the planning of motor actions. This left-hemisphere specialization hypothesis was proposed in various lines of research, including patient studies, motor imagery studies, and studies involving neurophysiological techniques. However,

  1. Temporal processing asymmetries between the cerebral hemispheres: evidence and implications.

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    Nicholls, M E

    1996-07-01

    This paper reviews a large body of research which has investigated the capacities of the cerebral hemispheres to process temporal information. This research includes clinical, non-clinical, and electrophysiological experimentation. On the whole, the research supports the notion of a left hemisphere advantage for temporal resolution. The existence of such an asymmetry demonstrates that cerebral lateralisation is not limited to the higher-order functions such as language. The capacity for the resolution of fine temporal events appears to play an important role in other left hemisphere functions which require a rapid sequential processor. The functions that are facilitated by such a processor include verbal, textual, and fine movement skills. The co-development of these functions with an efficient temporal processor can be accounted for with reference to a number of evolutionary scenarios. Physiological evidence favours a temporal processing mechanism located within the left temporal cortex. The function of this mechanism may be described in terms of intermittency or travelling moment models of temporal processing. The travelling moment model provides the most plausible account of the asymmetry.

  2. Metabolite changes in the ipsilateral and contralateral cerebral hemispheres in rats with middle cerebral artery occlusion

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    Lei Ruan

    2017-01-01

    Full Text Available Cerebral ischemia not only causes pathological changes in the ischemic areas but also induces a series of secondary changes in more distal brain regions (such as the contralateral cerebral hemisphere. The impact of supratentorial lesions, which are the most common type of lesion, on the contralateral cerebellum has been studied in patients by positron emission tomography, single photon emission computed tomography, magnetic resonance imaging and diffusion tensor imaging. In the present study, we investigated metabolite changes in the contralateral cerebral hemisphere after supratentorial unilateral ischemia using nuclear magnetic resonance spectroscopy-based metabonomics. The permanent middle cerebral artery occlusion model of ischemic stroke was established in rats. Rats were randomly divided into the middle cerebral artery occlusion 1-, 3-, 9- and 24-hour groups and the sham group. 1H nuclear magnetic resonance spectroscopy was used to detect metabolites in the left and right cerebral hemispheres. Compared with the sham group, the concentrations of lactate, alanine, γ-aminobutyric acid, choline and glycine in the ischemic cerebral hemisphere were increased in the acute stage, while the concentrations of N-acetyl aspartate, creatinine, glutamate and aspartate were decreased. This demonstrates that there is an upregulation of anaerobic glycolysis (shown by the increase in lactate, a perturbation of choline metabolism (suggested by the increase in choline, neuronal cell damage (shown by the decrease in N-acetyl aspartate and neurotransmitter imbalance (evidenced by the increase in γ-aminobutyric acid and glycine and by the decrease in glutamate and aspartate in the acute stage of cerebral ischemia. In the contralateral hemisphere, the concentrations of lactate, alanine, glycine, choline and aspartate were increased, while the concentrations of γ-aminobutyric acid, glutamate and creatinine were decreased. This suggests that there is a

  3. Homotopic Language Reorganization in the Right Hemisphere after Early Left Hemisphere Injury

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    Tivarus, Madalina E.; Starling, Sarah J.; Newport, Elissa L.; Langfitt, John T.

    2012-01-01

    To determine the areas involved in reorganization of language to the right hemisphere after early left hemisphere injury, we compared fMRI activation patterns during four production and comprehension tasks in post-surgical epilepsy patients with either left (LH) or right hemisphere (RH) speech dominance (determined by Wada testing) and healthy…

  4. An unusual association of headache, epilepsy, and late-onset Kleist’s pseudodepression syndrome in frontal lobe cavernoma of the cerebral left hemisphere

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    Chirchiglia D

    2017-05-01

    Full Text Available Domenico Chirchiglia,1 Attilio Della Torre,1 Domenico Murrone,2 Pasquale Chirchiglia,3 Rosa Marotta4 1Department of Neurosurgery, Neurophysiopathology Unit, University of Catanzaro “Magna Graecia”, Catanzaro, 2Neurosurgery Department, Di Venere Hospital, Bari, 3School of Medicine, University of Catanzaro, Catanzaro, 4Department of Medical and Surgical Sciences, University of Catanzaro, Catanzaro, Italy Abstract: Cerebral cavernous angioma or cavernoma is a benign vascular malformation, usually asymptomatic. It is infrequent and often its discovery is incidental, a so-called incidentaloma. However, these lesions can be symptomatic, causing headaches, epilepsy, cerebral hemorrhage and other neurological signs depending on the brain area involved. Frontal localization is responsible for psychiatric disorders, particularly the prefrontal region, leading to prefrontal syndrome, a condition common in all frontal lobe tumors. Psychopathological syndrome can be depression-type, pseudodepression syndrome or maniac-type, pseudomaniac syndrome. Surgical treatment of lesions like this may not always be possible due to their location in eloquent areas. In this study, we describe an unusual association of migraine-like headache, epilepsy and frontal lobe pseudodepression late-onset syndrome in the same patient. We have considered this case interesting mainly for the rarity of both a headache with migraine features and for the late onset of pseudodepression syndrome. Pathophysiology underlying migraine-like headache and that concerning the late-onset pseudodepression frontal lobe syndrome seems to be unclear. This case leads to further hypotheses about the mechanisms responsible for headache syndromes and psychopathological disorders, in the specific case when caused by a cerebral frontal lobe lesion. Keywords: cerebral cavernoma, cavernous angioma, headache, frontal syndrome, pseudodepression syndrome 

  5. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke

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    Xing, Shihui; Lacey, Elizabeth H.; Skipper-Kallal, Laura M.; Jiang, Xiong; Harris-Love, Michelle L.; Zeng, Jinsheng

    2016-01-01

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor’s lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion–symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  6. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.

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    Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E

    2016-01-01

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  7. Hand movements with a phase structure and gestures that depict action stem from a left hemispheric system of conceptualization.

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    Helmich, I; Lausberg, H

    2014-10-01

    The present study addresses the previously discussed controversy on the contribution of the right and left cerebral hemispheres to the production and conceptualization of spontaneous hand movements and gestures. Although it has been shown that each hemisphere contains the ability to produce hand movements, results of left hemispherically lateralized motor functions challenge the view of a contralateral hand movement production system. To examine hemispheric specialization in hand movement and gesture production, ten right-handed participants were tachistoscopically presented pictures of everyday life actions. The participants were asked to demonstrate with their hands, but without speaking what they had seen on the drawing. Two independent blind raters evaluated the videotaped hand movements and gestures employing the Neuropsychological Gesture Coding System. The results showed that the overall frequency of right- and left-hand movements is equal independent of stimulus lateralization. When hand movements were analyzed considering their Structure, the presentation of the action stimuli to the left hemisphere resulted in more hand movements with a phase structure than the presentation to the right hemisphere. Furthermore, the presentation to the left hemisphere resulted in more right and left-hand movements with a phase structure, whereas the presentation to the right hemisphere only increased contralateral left-hand movements with a phase structure as compared to hand movements without a phase structure. Gestures that depict action were primarily displayed in response to stimuli presented in the right visual field than in the left one. The present study shows that both hemispheres possess the faculty to produce hand movements in response to action stimuli. However, the left hemisphere dominates the production of hand movements with a phase structure and gestures that depict action. We therefore conclude that hand movements with a phase structure and gestures that

  8. Caffeine improves left hemisphere processing of positive words.

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    Kuchinke, Lars; Lux, Vanessa

    2012-01-01

    A positivity advantage is known in emotional word recognition in that positive words are consistently processed faster and with fewer errors compared to emotionally neutral words. A similar advantage is not evident for negative words. Results of divided visual field studies, where stimuli are presented in either the left or right visual field and are initially processed by the contra-lateral brain hemisphere, point to a specificity of the language-dominant left hemisphere. The present study examined this effect by showing that the intake of caffeine further enhanced the recognition performance of positive, but not negative or neutral stimuli compared to a placebo control group. Because this effect was only present in the right visual field/left hemisphere condition, and based on the close link between caffeine intake and dopaminergic transmission, this result points to a dopaminergic explanation of the positivity advantage in emotional word recognition.

  9. Caffeine improves left hemisphere processing of positive words.

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    Lars Kuchinke

    Full Text Available A positivity advantage is known in emotional word recognition in that positive words are consistently processed faster and with fewer errors compared to emotionally neutral words. A similar advantage is not evident for negative words. Results of divided visual field studies, where stimuli are presented in either the left or right visual field and are initially processed by the contra-lateral brain hemisphere, point to a specificity of the language-dominant left hemisphere. The present study examined this effect by showing that the intake of caffeine further enhanced the recognition performance of positive, but not negative or neutral stimuli compared to a placebo control group. Because this effect was only present in the right visual field/left hemisphere condition, and based on the close link between caffeine intake and dopaminergic transmission, this result points to a dopaminergic explanation of the positivity advantage in emotional word recognition.

  10. Apraxia and spatial inattention dissociate in left hemisphere stroke.

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    Timpert, David C; Weiss, Peter H; Vossel, Simone; Dovern, Anna; Fink, Gereon R

    2015-10-01

    Theories of lateralized cognitive functions propose a dominance of the left hemisphere for motor control and of the right hemisphere for spatial attention. Accordingly, spatial attention deficits (e.g., neglect) are more frequently observed after right-hemispheric stroke, whereas apraxia is a common consequence of left-hemispheric stroke. Clinical reports of spatial attentional deficits after left hemisphere (LH) stroke also exist, but are often neglected. By applying parallel analysis (PA) and voxel-based lesion-symptom mapping (VLSM) to data from a comprehensive neuropsychological assessment of 74 LH stroke patients, we here systematically investigate the relationship between spatial inattention and apraxia and their neural bases. PA revealed that apraxic (and language comprehension) deficits loaded on one common component, while deficits in attention tests were explained by another independent component. Statistical lesion analyses with the individual component scores showed that apraxic (and language comprehension) deficits were significantly associated with lesions of the left superior longitudinal fascicle (SLF). Data suggest that in LH stroke spatial attention deficits dissociate from apraxic (and language comprehension) deficits. These findings contribute to models of lateralised cognitive functions in the human brain. Moreover, our findings strongly suggest that LH stroke patients should be assessed systematically for spatial attention deficits so that these can be included in their rehabilitation regime. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Choosing words: left hemisphere, right hemisphere, or both? Perspective on the lateralization of word retrieval

    Science.gov (United States)

    Ries, Stephanie K.; Dronkers, Nina F.; Knight, Robert T.

    2015-01-01

    Language is considered to be one of the most lateralized human brain functions. Left hemisphere dominance for language has been consistently confirmed in clinical and experimental settings and constitutes one of the main axioms of neurology and neuroscience. However, functional neuroimaging studies are finding that the right hemisphere also plays a role in diverse language functions. Critically, the right hemisphere may also compensate for the loss or degradation of language functions following extensive stroke-induced damage to the left hemisphere. Here, we review studies that focus on our ability to choose words as we speak. Although fluidly performed in individuals with intact language, this process is routinely compromised in aphasic patients. We suggest that parceling word retrieval into its sub-processes—lexical activation and lexical selection—and examining which of these can be compensated for after left hemisphere stroke can advance the understanding of the lateralization of word retrieval in speech production. In particular, the domain-general nature of the brain regions associated with each process may be a helpful indicator of the right hemisphere's propensity for compensation. PMID:26766393

  12. Developmental dyslexia: dysfunction of a left hemisphere reading network

    Directory of Open Access Journals (Sweden)

    Fabio eRichlan

    2012-05-01

    Full Text Available This mini-review summarizes and integrates findings from recent meta-analyses and original neuroimaging studies on functional brain abnormalities in dyslexic readers. Surprisingly, there is little empirical support for the standard neuroanatomical model of developmental dyslexia, which localizes the primary phonological decoding deficit in left temporo-parietal regions. Rather, recent evidence points to a dysfunction of a left hemisphere reading network, which includes occipito-temporal, inferior frontal, and inferior parietal regions.

  13. Effect of unilateral dominance of the cerebral hemispheres on the radiographic appearance of the cervical spine

    Energy Technology Data Exchange (ETDEWEB)

    Jirout, J

    1980-10-01

    The results of dynamic radiographic studies of the cervical spine following isometric exercise of the shoulders and the upper extremities appear to indicate that the commonly seen asymmetries of the joints in the craniocervical and cervicothoracic junction are due to asymmetry in the function of the muscles. The obvious dominance of the muscles on the right side demonstrates the dominance of the left cerebral hemisphere. The clinical importance of this is pointed out.

  14. Left Hemisphere Regions Are Critical for Language in the Face of Early Left Focal Brain Injury

    Science.gov (United States)

    Beharelle, Anjali Raja; Dick, Anthony Steven; Josse, Goulven; Solodkin, Ana; Huttenlocher, Peter R.; Levine, Susan C.; Small, Steven L.

    2010-01-01

    A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we…

  15. Left hemisphere regions are critical for language in the face of early left focal brain injury

    OpenAIRE

    Raja Beharelle, Anjali; Dick, Anthony Steven; Josse, Goulven; Solodkin, Ana; Huttenlocher, Peter R.; Levine, Susan C.; Small, Steven L.

    2010-01-01

    A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we used functional magnetic resonance imaging to examine brain activity during category fluency in participants who had sustained pre- or perinatal left h...

  16. Hydrocephalus after decompressive craniectomy for malignant hemispheric cerebral infarction.

    Science.gov (United States)

    Wang, Qiang-Ping; Ma, Jun-Peng; Zhou, Zhang-Ming; Yang, Min; You, Chao

    2016-08-01

    Several studies have investigated the incidence and risk factors of hydrocephalus after decompressive craniectomy (DC) for malignant hemispheric cerebral infarction. However, the results are controversial. Therefore, the following is a retrospective cohort study to determine the incidence and risk factors of hydrocephalus after DC for malignant hemispheric cerebral infarction. From January 2004 to June 2014, patients at two medical centres in south-west China, who underwent DC for malignant hemispheric cerebral infarction, were included. The patients' clinical and radiologic findings were retrospectively reviewed. A chi-square test, Mann-Whitney U-test and logistic regression model were used to identify the risk factors. A total of 128 patients were included in the study. The incidence of ventriculomegaly and shunt-dependent hydrocephalus were 42.2% (54/128) and 14.8% (19/128), respectively. Lower preoperative Glasgow Coma Scale (GCS) score and presence of subarachnoid haemorrhage (SAH) were factors significantly associated with the development of post-operative hydrocephalus after DC. Cerebral infarction patients receiving DC have a moderate tendency to suffer from post-operative hydrocephalus. A poor GCS score and the presence of SAH were significantly associated with the development of hydrocephalus after DC.

  17. Left-right cortical asymmetries of regional cerebral blood flow during listening to words

    DEFF Research Database (Denmark)

    Nishizawa, Y; Olsen, T S; Larsen, B

    1982-01-01

    1. Regional cerebral blood flow (rCBF) was measured during rest and during listening to simple words. The xenon-133 intracarotid technique was used and results were obtained from 254 regions of seven right hemispheres and seven left hemispheres. The measurements were performed just after carotid...... of the entire hemisphere. The focal rCBF increases were localized to the superior part of the temporal regions, the prefrontal regions, the frontal eye fields, and the orbitofrontal regions. Significant asymmetries were found in particular in the superior temporal region with the left side showing a more...

  18. Hemispheric distribution of middle cerebral artery ischemic strokes in patients admitted to military hospital rawalpindi

    International Nuclear Information System (INIS)

    Tariq, M.; Ishtiaq, S.; Zulfiqar, S.O.

    2016-01-01

    Objective: To determine the difference in the frequency of middle cerebral artery (MCA) ischemic strokes between left and right cerebral hemispheres in the adult patients admitted to the Military Hospital (MH) Rawalpindi. Study Design: A descriptive study. Place and Duration of Study: MH Rawalpindi from 01 Dec 2013 to 30 Mar 2014. Patients and Methods: Seventy eight adult patients admitted to MH Rawalpindi with neurologic deficits consistent with MCA strokes and having no evidence of intracerebral haemorrhage on Computed Tomographic (CT) scan of brain. Descriptive Statistics were calculated using SPSS version 17. Results: A total of 78 patients met the inclusion criteria of the study; 35 (45 percent) patients had right MCA stroke while 43 (55 percent) had left MCA stroke. Conclusion: Left MCA ischemic strokes are more common than right MCA ischemic strokes. (author)

  19. Taxonomic and ad hoc categorization within the two cerebral hemispheres.

    Science.gov (United States)

    Shen, Yeshayahu; Aharoni, Bat-El; Mashal, Nira

    2015-01-01

    A typicality effect refers to categorization which is performed more quickly or more accurately for typical than for atypical members of a given category. Previous studies reported a typicality effect for category members presented in the left visual field/right hemisphere (RH), suggesting that the RH applies a similarity-based categorization strategy. However, findings regarding the typicality effect within the left hemisphere (LH) are less conclusive. The current study tested the pattern of typicality effects within each hemisphere for both taxonomic and ad hoc categories, using words presented to the left or right visual fields. Experiment 1 tested typical and atypical members of taxonomic categories as well as non-members, and Experiment 2 tested typical and atypical members of ad hoc categories as well as non-members. The results revealed a typicality effect in both hemispheres and in both types of categories. Furthermore, the RH categorized atypical stimuli more accurately than did the LH. Our findings suggest that both hemispheres rely on a similarity-based categorization strategy, but the coarse semantic coding of the RH seems to facilitate the categorization of atypical members.

  20. Comparison of the two cerebral hemispheres in inhibitory processes operative during movement preparation

    Science.gov (United States)

    Klein, Pierre-Alexandre; Duque, Julie; Labruna, Ludovica; Ivry, Richard B.

    2015-01-01

    was a global difference in CS excitability across experiments between the two hemispheres. When the intensity of stimulation was set to 115% of the resting threshold, MEPs were larger when the TMS probe was applied over the M1LEFT than over M1RIGHT. In summary, while the latter result suggests that M1LEFT is more excitable than M1RIGHT, the recruitment of preparatory inhibitory mechanisms is similar within the two cerebral hemispheres. PMID:26458519

  1. Hemispheric lateralization in an analysis of speech sounds. Left hemisphere dominance replicated in Japanese subjects.

    Science.gov (United States)

    Koyama, S; Gunji, A; Yabe, H; Oiwa, S; Akahane-Yamada, R; Kakigi, R; Näätänen, R

    2000-09-01

    Evoked magnetic responses to speech sounds [R. Näätänen, A. Lehtokoski, M. Lennes, M. Cheour, M. Huotilainen, A. Iivonen, M. Vainio, P. Alku, R.J. Ilmoniemi, A. Luuk, J. Allik, J. Sinkkonen and K. Alho, Language-specific phoneme representations revealed by electric and magnetic brain responses. Nature, 385 (1997) 432-434.] were recorded from 13 Japanese subjects (right-handed). Infrequently presented vowels ([o]) among repetitive vowels ([e]) elicited the magnetic counterpart of mismatch negativity, MMNm (Bilateral, nine subjects; Left hemisphere alone, three subjects; Right hemisphere alone, one subject). The estimated source of the MMNm was stronger in the left than in the right auditory cortex. The sources were located posteriorly in the left than in the right auditory cortex. These findings are consistent with the results obtained in Finnish [R. Näätänen, A. Lehtokoski, M. Lennes, M. Cheour, M. Huotilainen, A. Iivonen, M.Vainio, P.Alku, R.J. Ilmoniemi, A. Luuk, J. Allik, J. Sinkkonen and K. Alho, Language-specific phoneme representations revealed by electric and magnetic brain responses. Nature, 385 (1997) 432-434.][T. Rinne, K. Alho, P. Alku, M. Holi, J. Sinkkonen, J. Virtanen, O. Bertrand and R. Näätänen, Analysis of speech sounds is left-hemisphere predominant at 100-150 ms after sound onset. Neuroreport, 10 (1999) 1113-1117.] and English [K. Alho, J.F. Connolly, M. Cheour, A. Lehtokoski, M. Huotilainen, J. Virtanen, R. Aulanko and R.J. Ilmoniemi, Hemispheric lateralization in preattentive processing of speech sounds. Neurosci. Lett., 258 (1998) 9-12.] subjects. Instead of the P1m observed in Finnish [M. Tervaniemi, A. Kujala, K. Alho, J. Virtanen, R.J. Ilmoniemi and R. Näätänen, Functional specialization of the human auditory cortex in processing phonetic and musical sounds: A magnetoencephalographic (MEG) study. Neuroimage, 9 (1999) 330-336.] and English [K. Alho, J. F. Connolly, M. Cheour, A. Lehtokoski, M. Huotilainen, J. Virtanen, R. Aulanko

  2. Agents with left and right dominant hemispheres and quantum statistics

    Science.gov (United States)

    Ezhov, Alexandr A.; Khrennikov, Andrei Yu.

    2005-01-01

    We present a multiagent model illustrating the emergence of two different quantum statistics, Bose-Einstein and Fermi-Dirac, in a friendly population of individuals with the right-brain dominance and in a competitive population of individuals with the left-brain hemisphere dominance, correspondingly. Doing so, we adduce the arguments that Lefebvre’s “algebra of conscience” can be used in a natural way to describe decision-making strategies of agents simulating people with different brain dominance. One can suggest that the emergence of the two principal statistical distributions is able to illustrate different types of society organization and also to be used in order to simulate market phenomena and psychic disorders, when a switching of hemisphere dominance is involved.

  3. Beyond Hemispheric Dominance: Brain Regions Underlying the Joint Lateralization of Language and Arithmetic to the Left Hemisphere

    Science.gov (United States)

    Pinel, Philippe; Dehaene, Stanislas

    2010-01-01

    Language and arithmetic are both lateralized to the left hemisphere in the majority of right-handed adults. Yet, does this similar lateralization reflect a single overall constraint of brain organization, such an overall "dominance" of the left hemisphere for all linguistic and symbolic operations? Is it related to the lateralization of specific…

  4. Reorganization of syntactic processing following left-hemisphere brain damage: does right-hemisphere activity preserve function?

    Science.gov (United States)

    Tyler, Lorraine K; Wright, Paul; Randall, Billi; Marslen-Wilson, William D; Stamatakis, Emmanuel A

    2010-11-01

    The extent to which the human brain shows evidence of functional plasticity across the lifespan has been addressed in the context of pathological brain changes and, more recently, of the changes that take place during healthy ageing. Here we examine the potential for plasticity by asking whether a strongly left-lateralized system can successfully reorganize to the right-hemisphere following left-hemisphere brain damage. To do this, we focus on syntax, a key linguistic function considered to be strongly left-lateralized, combining measures of tissue integrity, neural activation and behavioural performance. In a functional neuroimaging study participants heard spoken sentences that differentially loaded on syntactic and semantic information. While healthy controls activated a left-hemisphere network of correlated activity including Brodmann areas 45/47 and posterior middle temporal gyrus during syntactic processing, patients activated Brodmann areas 45/47 bilaterally and right middle temporal gyrus. However, voxel-based morphometry analyses showed that only tissue integrity in left Brodmann areas 45/47 was correlated with activity and performance; poor tissue integrity in left Brodmann area 45 was associated with reduced functional activity and increased syntactic deficits. Activity in the right-hemisphere was not correlated with damage in the left-hemisphere or with performance. Reduced neural integrity in the left-hemisphere through brain damage or healthy ageing results in increased right-hemisphere activation in homologous regions to those left-hemisphere regions typically involved in the young. However, these regions do not support the same linguistic functions as those in the left-hemisphere and only indirectly contribute to preserved syntactic capacity. This establishes the unique role of the left hemisphere in syntax, a core component in human language.

  5. Neural correlates supporting sensory discrimination after left hemisphere stroke

    Science.gov (United States)

    Borstad, Alexandra; Schmalbrock, Petra; Choi, Seongjin; Nichols-Larsen, Deborah S.

    2012-01-01

    Background Nearly half of stroke patients have impaired sensory discrimination, however, the neural structures that support post-stroke sensory function have not been described. Objectives 1) To evaluate the role of the primary somatosensory (S1) cortex in post-stroke sensory discrimination and 2) To determine the relationship between post-stroke sensory discrimination and structural integrity of the sensory component of the superior thalamic radiation (sSTR). Methods 10 healthy adults and 10 individuals with left hemisphere stroke participated. Stroke participants completed sensory discrimination testing. An fMRI was conducted during right, impaired hand sensory discrimination. Fractional anisotropy and volume of the sSTR were quantified using diffusion tensor tractography. Results Sensory discrimination was impaired in 60% of participants with left stroke. Peak activation in the left (S1) did not correlate with sensory discrimination ability, rather a more distributed pattern of activation was evident in post-stroke subjects with a positive correlation between peak activation in the parietal cortex and discrimination ability (r=.70, p=.023). The only brain region in which stroke participants had significantly different cortical activation than control participants was the precuneus. Region of interest analysis of the precuneus across stroke participants revealed a positive correlation between peak activation and sensory discrimination ability (r=.77, p=.008). The L/R ratio of sSTR fractional anisotropy also correlated with right hand sensory discrimination (r=.69, p=.027). Conclusions Precuneus cortex, distributed parietal lobe activity, and microstructure of the sSTR support sensory discrimination after left hemisphere stroke. PMID:22592076

  6. A dual task priming investigation of right hemisphere inhibition for people with left hemisphere lesions

    Directory of Open Access Journals (Sweden)

    Smith-Conway Erin R

    2012-03-01

    Full Text Available Abstract Background During normal semantic processing, the left hemisphere (LH is suggested to restrict right hemisphere (RH performance via interhemispheric suppression. However, a lesion in the LH or the use of concurrent tasks to overload the LH's attentional resource balance has been reported to result in RH disinhibition with subsequent improvements in RH performance. The current study examines variations in RH semantic processing in the context of unilateral LH lesions and the manipulation of the interhemispheric processing resource balance, in order to explore the relevance of RH disinhibition to hemispheric contributions to semantic processing following a unilateral LH lesion. Methods RH disinhibition was examined for nine participants with a single LH lesion and 13 matched controls using the dual task paradigm. Hemispheric performance on a divided visual field lexical decision semantic priming task was compared over three verbal memory load conditions, of zero-, two- and six-words. Related stimuli consisted of categorically related, associatively related, and categorically and associatively related prime-target pairs. Response time and accuracy data were recorded and analyzed using linear mixed model analysis, and planned contrasts were performed to compare priming effects in both visual fields, for each of the memory load conditions. Results Control participants exhibited significant bilateral visual field priming for all related conditions (p Conclusions The results from the control group are consistent with suggestions of an age related hemispheric asymmetry reduction and indicate that in healthy aging compensatory bilateral activation may reduce the impact of inhibition. In comparison, the results for the LHD group indicate that following a LH lesion RH semantic processing can be manipulated and enhanced by the introduction of a verbal memory task designed to engage LH resources and allow disinhibition of RH processing.

  7. [Effects of acupuncture at left and right Hegu (LI 4) for cerebral function laterality].

    Science.gov (United States)

    Wang, Linying; Xu, Chunsheng; Zhu, Yifang; Li, Chuanfu; Yang, Jun

    2015-08-01

    To explore the cerebral function laterality of acupuncture at left and right Hegu (LI 4) by using functional magnetic resonance imaging (fMRI) and provide objective evidences for side selection of Hegu (LI 4) in the clinical application. Eighty healthy volunteers were randomly divided into a left-acupoint group and a right-acupoint group, and they were treated with acupuncture at left Hegu (LI 4) and right Hegu (LI 4) respectively. After the arrival of qi, the task-state fMRI data in both groups was collected, and analysis of functional neuroimages (AFNI) software was used to perform intra-group and between-group comparisons. After acupuncture, acupuncture feelings were recorded and MGH acupuncture sensation scale (MASS) was recorded. The difference of MASS between the two groups was not significant (P>0. 05). The result of left-acupoint group showed an increased signal on right cerebral hemisphere, while the right-acupoint group showed extensive signal changes in both cerebral hemispheres. The analysis between left-acupoint group and retroflex right-acupoint group showed differences in brain areas. The central effect of acupuncture at left and right Hegu (LI 4) is dissymmetry, indicating right hemisphere laterality. The right lobus insularis and cingulate gyrus may be the key regions in the acupuncture at Hegu (LI 4).

  8. Differences in lateral hemispheric asymmetries of cerebral blood flow measured by SPECT in dementia of Alzheimer type

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Nahoko [Niigata Univ. (Japan). School of Medicine

    1993-12-01

    We studied 21 right-handed patients clinically diagnosed as dementia of Alzheimer type (8 men, 13 women; aged 53-85, mean 71.1 years). The average duration of symptoms was 2.7 years. Dementia ranged from mild to moderately severe. None had clinical or laboratory evidence of cerebro-vascular disease (Hachinski ischemic scores for all patients were 4 or below). All received the Wechsler Adult Intelligence Scale (WAIS), Mini-mental State Test (MMS) and Western Aphasia Battery (WAB, First Japanese edition, 1986). Regional cerebral blood flow was evaluated by single photon emission CT (SPECT) with [sup 123]I-N-isopropyl-p-iodoamphetamine ([sup 123]I-IMP), using the Matsuda's quantitative method. The subjects were divided into three groups on the basis of right-left hemispheric asymmetry of cerebral blood flow (leftleft, n=3; left=right, n=12). General scores (MMS, T-IQ) were not correlated with asymmetry of cerebral blood flow. Verbal IQ in patients with predominant hypoperfusion of left temporal and parietal lobe were significantly lower than in other groups, while performance IQ and WAB constructive scores were lower in those with right hemispheric hypoperfusion (p<0.05). We concluded that cerebral blood flow asymmetry detected by SPECT was related significantly to the deficit of language and constructive function in patients with dementia of Alzheimer type. (author).

  9. Differences in lateral hemispheric asymmetries of cerebral blood flow measured by SPECT in dementia of Alzheimer type

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Nahoko (Niigata Univ. (Japan). School of Medicine)

    1993-12-01

    We studied 21 right-handed patients clinically diagnosed as dementia of Alzheimer type (8 men, 13 women; aged 53-85, mean 71.1 years). The average duration of symptoms was 2.7 years. Dementia ranged from mild to moderately severe. None had clinical or laboratory evidence of cerebro-vascular disease (Hachinski ischemic scores for all patients were 4 or below). All received the Wechsler Adult Intelligence Scale (WAIS), Mini-mental State Test (MMS) and Western Aphasia Battery (WAB, First Japanese edition, 1986). Regional cerebral blood flow was evaluated by single photon emission CT (SPECT) with [sup 123]I-N-isopropyl-p-iodoamphetamine ([sup 123]I-IMP), using the Matsuda's quantitative method. The subjects were divided into three groups on the basis of right-left hemispheric asymmetry of cerebral blood flow (leftleft, n=3; left=right, n=12). General scores (MMS, T-IQ) were not correlated with asymmetry of cerebral blood flow. Verbal IQ in patients with predominant hypoperfusion of left temporal and parietal lobe were significantly lower than in other groups, while performance IQ and WAB constructive scores were lower in those with right hemispheric hypoperfusion (p<0.05). We concluded that cerebral blood flow asymmetry detected by SPECT was related significantly to the deficit of language and constructive function in patients with dementia of Alzheimer type. (author).

  10. Differences in lateral hemispheric asymmetries of cerebral blood flow measured by SPECT in dementia of Alzheimer type

    International Nuclear Information System (INIS)

    Yoshimura, Nahoko

    1993-01-01

    We studied 21 right-handed patients clinically diagnosed as dementia of Alzheimer type (8 men, 13 women; aged 53-85, mean 71.1 years). The average duration of symptoms was 2.7 years. Dementia ranged from mild to moderately severe. None had clinical or laboratory evidence of cerebro-vascular disease (Hachinski ischemic scores for all patients were 4 or below). All received the Wechsler Adult Intelligence Scale (WAIS), Mini-mental State Test (MMS) and Western Aphasia Battery (WAB, First Japanese edition, 1986). Regional cerebral blood flow was evaluated by single photon emission CT (SPECT) with 123 I-N-isopropyl-p-iodoamphetamine ( 123 I-IMP), using the Matsuda's quantitative method. The subjects were divided into three groups on the basis of right-left hemispheric asymmetry of cerebral blood flow (left< right, n=6; right< left, n=3; left=right, n=12). General scores (MMS, T-IQ) were not correlated with asymmetry of cerebral blood flow. Verbal IQ in patients with predominant hypoperfusion of left temporal and parietal lobe were significantly lower than in other groups, while performance IQ and WAB constructive scores were lower in those with right hemispheric hypoperfusion (p<0.05). We concluded that cerebral blood flow asymmetry detected by SPECT was related significantly to the deficit of language and constructive function in patients with dementia of Alzheimer type. (author)

  11. Phonotactic awareness deficit following left-hemisphere stroke

    Directory of Open Access Journals (Sweden)

    Maryam Ghaleh

    2015-04-01

    Likert-type scale responses were z-transformed and coded accurate for positive z-values in condition 3 and negative z-values in condition 1 trials. Accuracy was analyzed using binomial mixed effects models and z-transformed scale responses were analyzed using linear mixed effects models. For both analyses, the fixed effects of stimulus, trial number, group (patient/control, education, age, response time, phonotactic regularity (1/3, and gender were examined along with all relevant interactions. Random effects for participant and stimuli as well as random slopes were also included. Model fitting was performed in a backward-stepwise iterative fashion, followed by forward fitting of maximal random effects structure. Models were evaluated by model fitness comparisons using Akaike Information Criterion and Bayesian Information Criterion. Accuracy analysis revealed that healthy participants were significantly more accurate than patients [β = 0.47, p<0.001] in Englishness rating. Scale response analysis revealed a significant effect of phonotactic regularity [β = 1.65, p<0.0001] indicating that participants were sensitive to phonotactic regularity differences among non-words. However, the significant interaction of group and phonotactic regularity [β = -0.5, p= 0.02] further demonstrated that, compared to healthy adults, patients were less able to recognize the phonotactic regularity differences between non-words. Results suggest that left-hemisphere lesions cause impaired phonotactic processing and that the left hemisphere might be necessary for phonotactic awareness. These preliminary findings will be followed up by further analyses investigating the interactions between phonotactic processing and participants’ scores on other linguistic/cognitive tasks as well as lesion-symptom mapping.

  12. [Evolution of superolateral surface of the cerebral hemisphere on 16-21 weeks fetus].

    Science.gov (United States)

    Varlam, H; St Antohe, D

    2002-01-01

    Edification of neocortex is accompanied by the development and growth of the cerebral hemisphere, both processes being part of the more complex one, known under the name of telencephalization. The expression of this process is more acute on the superolateral surface of the cerebral hemisphere that expands laterally by growth of the frontal, temporal and parietal lobes. We describe the modifications of shape and deepness of the lateral cerebral fossa including the stages of its closure. We consider this event as the beginning of the appearance of gyri and sulci on the superolateral surface of the cerebral hemisphere.

  13. Reorganization of syntactic processing following left-hemisphere brain damage: does right-hemisphere activity preserve function?

    OpenAIRE

    Tyler, Lorraine K.; Wright, Paul; Randall, Billi; Marslen-Wilson, William D.; Stamatakis, Emmanuel A.

    2010-01-01

    The extent to which the human brain shows evidence of functional plasticity across the lifespan has been addressed in the context of pathological brain changes and, more recently, of the changes that take place during healthy ageing. Here we examine the potential for plasticity by asking whether a strongly left-lateralized system can successfully reorganize to the right-hemisphere following left-hemisphere brain damage. To do this, we focus on syntax, a key linguistic function considered to b...

  14. Cerebral specialization. [greater performance efficiency for certain mental abilities or processes by one cerebral hemisphere over another

    Science.gov (United States)

    Morris, Robin D.; Hopkins, William D.; Rumbaugh, Duane M.

    1991-01-01

    The concept of greater performance efficiency for certain mental abilities or processes in one cerebral hemisphere rather than the other is referred to as 'cerebral lateralization'. The experimental paradigm for lateralization research involves the study of patients with one damaged hemisphere, which prevents their performance of a certain task or function; this approach, however, presents many difficulties in extrapolating to brain function in normal patients. Attention is presently given to gender differences in lateralization, cerebral asymmetries in other species, and the evolutionary bases of hemispheric specialization.

  15. The effects of left and right monocular viewing on hemispheric activation.

    Science.gov (United States)

    Wang, Chao; Burtis, D Brandon; Ding, Mingzhou; Mo, Jue; Williamson, John B; Heilman, Kenneth M

    2018-03-01

    Prior research has revealed that whereas activation of the left hemisphere primarily increases the activity of the parasympathetic division of the autonomic nervous system, right-hemisphere activation increases the activity of the sympathetic division. In addition, each hemisphere primarily receives retinocollicular projections from the contralateral eye. A prior study reported that pupillary dilation was greater with left- than with right-eye monocular viewing. The goal of this study was to test the alternative hypotheses that this asymmetric pupil dilation with left-eye viewing was induced by activation of the right-hemispheric-mediated sympathetic activity, versus a reduction of left-hemisphere-mediated parasympathetic activity. Thus, this study was designed to learn whether there are changes in hemispheric activation, as measured by alteration of spontaneous alpha activity, during right versus left monocular viewing. High-density electroencephalography (EEG) was recorded from healthy participants viewing a crosshair with their right, left, or both eyes. There was a significantly less alpha power over the right hemisphere's parietal-occipital area with left and binocular viewing than with right-eye monocular viewing. The greater relative reduction of right-hemisphere alpha activity during left than during right monocular viewing provides further evidence that left-eye viewing induces greater increase in right-hemisphere activation than does right-eye viewing.

  16. The effect of unilateral dominance of the cerebral hemispheres on the radiographic appearance of the cervical spine

    International Nuclear Information System (INIS)

    Jirout, J.

    1980-01-01

    The results of dynamic radiographic studies of the cervical spine following isometric exercise of the shoulders and the upper extremities appear to indicate that the commonly seen asymmetries of the joints in the craniocervical and cervicothoracic junction are due to asymmetry in the function of the muscles. The obvious dominance of the muscles on the right side demonstrates the dominance of the left cerebral hemisphere. The clinical importance of this is pointed out. (orig.) [de

  17. Complex syntax in the isolated right hemisphere: Receptive grammatical abilities after cerebral hemispherectomy.

    Science.gov (United States)

    de Bode, Stella; Smets, Lieselotte; Mathern, Gary W; Dubinsky, Stanley

    2015-10-01

    In this study, we explored the syntactic competence of the right hemisphere (RH) after left cerebral hemispherectomy, on the premise that it (syntactic competence) is known to be one of the most strongly left-lateralized language functions. As basic syntactic development for individuals in this subject pool has already been extensively explored, we focused instead on the investigation of complex syntactic constructions that are normally acquired later in childhood, i.e., between 7 and 9years of age. Grammatical competence in 10 participants who had undergone left cerebral hemispherectomy was compared to that of a group of normally developing children, with the two groups matched by the size of their vocabulary. The two tests we used for this research were created by the 1st language acquisition linguists and were designed to test sets of constructions categorized and differentiated by the order in which they are normally acquired and by the type of grammatical competence that they involve. We found that both groups followed the same developmental sequence of syntactic development with five (50%) postsurgical participants (all with prenatal etiologies) reaching nearly mature command of sentence grammar. Seizures negatively impacted performance on all tests. The isolated RH has the potential to support the complex grammatical categories that emerge relatively late in the normal acquisition of English by native speakers. Successful performance may be related to the timing of the initial insult and seizure control following hemispherectomy. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. The association between hemispheric specialization for language production and for spatial attention depends on left-hand preference strength.

    Science.gov (United States)

    Zago, Laure; Petit, Laurent; Mellet, Emmanuel; Jobard, Gaël; Crivello, Fabrice; Joliot, Marc; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie

    2016-12-01

    Cerebral lateralization for language production and spatial attention and their relationships with manual preference strength (MPS) were assessed in a sample of 293 healthy volunteers, including 151 left-handers, using fMRI during covert sentence production (PROD) and line bisection judgment (LBJ) tasks, as compared to high- and low-level reference tasks. At the group level, we found the expected complementary hemispheric specialization (HS) with leftward asymmetries for PROD within frontal and temporal regions and rightward asymmetries for LBJ within frontal and posterior occipito-parieto-temporal regions. Individual hemispheric (HLI) and regional (frontal and occipital) lateralization indices (LI) were then calculated on the activation maps for PROD and LBJ. We found a correlation between the degree of rightward cerebral asymmetry and the leftward behavioral attentional bias recorded during LBJ task. This correlation was found when LBJ-LI was computed over the hemispheres, in the frontal lobes, but not in the occipital lobes. We then investigated whether language production and spatial attention cerebral lateralization relate to each other, and whether manual preference was a variable that impacted the complementary HS of these functions. No correlation was found between spatial and language LIs in the majority of our sample of participants, including right-handers with a strong right-hand preference (sRH, n=97) and mixed-handers (MH, n=97), indicating that these functions lateralized independently. By contrast, in the group of left-handers with a strong left-hand preference (sLH, n= 99), a negative correlation was found between language and spatial lateralization. This negative correlation was found when LBJ-LI and PROD-LI were computed over the hemispheres, in the frontal lobes and between the occipital lobes for LBJ and the frontal lobes for PROD. These findings underline the importance to include sLH in the study sample to reveal the underlying mechanisms of

  19. Efficacy of strategy training in left hemisphere stroke patients with apraxia : A randomised clinical trial

    NARCIS (Netherlands)

    Donkervoort, M; Dekker, J; Stehmann-Saris, FC; Deelman, B. G.

    2001-01-01

    The objective of the present study was to determine in a controlled study the efficacy of strategy training in left hemisphere stroke patients with apraxia. A total of 113 left hemisphere stroke patients with apraxia were randomly assigned to two treatment groups; (1) strategy training integrated

  20. Efficacy of strategy training in left hemisphere stroke patients with apraxia: a randomised clinical trial.

    NARCIS (Netherlands)

    Donkervoort, M.; Dekker, J.; Stehmann-Saris, F.C.; Deelman, B.G.

    2001-01-01

    The objective of the present study was to determine in a controlled study the efficacy of strategy training in left hemisphere stroke patients with apraxia. A total of 113 left hemisphere stroke patients with apraxia were randomly assigned to two treatment groups; (1) strategy training integrated

  1. Efficacy of strategy training in left hemisphere stroke patients with apraxia: a randomized clinical trial.

    NARCIS (Netherlands)

    Dekker, J.; Donkervoort, M.; Stehman, F.C.; Deelman, B.G.

    2001-01-01

    The objective of the present study was to determine in a controlled study the efficacy of strategy training in left hemisphere stroke patients with apraxia. 113 Left hemisphere assigned to two treatment groups: i) strategy training integrated into usual occupational therapy and ii) usual

  2. Posed versus spontaneous facial expressions are modulated by opposite cerebral hemispheres.

    Science.gov (United States)

    Ross, Elliott D; Pulusu, Vinay K

    2013-05-01

    Clinical research has indicated that the left face is more expressive than the right face, suggesting that modulation of facial expressions is lateralized to the right hemisphere. The findings, however, are controversial because the results explain, on average, approximately 4% of the data variance. Using high-speed videography, we sought to determine if movement-onset asymmetry was a more powerful research paradigm than terminal movement asymmetry. The results were very robust, explaining up to 70% of the data variance. Posed expressions began overwhelmingly on the right face whereas spontaneous expressions began overwhelmingly on the left face. This dichotomy was most robust for upper facial expressions. In addition, movement-onset asymmetries did not predict terminal movement asymmetries, which were not significantly lateralized. The results support recent neuroanatomic observations that upper versus lower facial movements have different forebrain motor representations and recent behavioral constructs that posed versus spontaneous facial expressions are modulated preferentially by opposite cerebral hemispheres and that spontaneous facial expressions are graded rather than non-graded movements. Published by Elsevier Ltd.

  3. anomalous left anterior cerebral artery with hypoplastic right anterior ...

    African Journals Online (AJOL)

    2018-02-28

    Feb 28, 2018 ... We report an extremely rare anomalous variation of left anterior cerebral artery arising from the ... paraclinoid internal carotid artery and right ... Studies on the arteries of the brain: II-The anterior cerebral artery: Some anatomic ...

  4. Hemispheric Lateralization, Cerebral Dominance, Conjugate Saccadic Behavior and Their Use in Identifying the Creatively Gifted.

    Science.gov (United States)

    Rekdal, C. K.

    1979-01-01

    In an effort to establish new means of locating the gifted creative productive thinker, an investigation of current brain research in the areas of hemispheric lateralization, cerebral dominance and conjugate saccadic behavior is analyzed. (Author/PHR)

  5. Left Atrium Papillary Fibroelastomas: A Cause of Cerebral Emboli

    Directory of Open Access Journals (Sweden)

    A. G. Ciss

    2012-01-01

    Full Text Available Papillary fibroelastomas are cardiac benign tumours. Among the benign cardiac tumor, papillary fibroelastomas are reported second after myxomas. Most often diagnosed incidentally, papillary fibroelastomas may embolize to cerebral circulation. Valvular locations are predominant; location in left atrium is rare. In this paper, we present a case of papillary fibroelastoma located in left atrium with symptoms of cerebral embolization. Transoesophageal echocardiography diagnosed a mobile mass. The patient was treated with surgical resection without further embolic complication.

  6. Ipsilateral deficits in 1-handed shoe tying after left or right hemisphere stroke.

    Science.gov (United States)

    Poole, Janet L; Sadek, Joseph; Haaland, Kathleen Y

    2009-10-01

    Poole JL, Sadek J, Haaland KY. Ipsilateral deficits in 1-handed shoe tying after left or right hemisphere stroke. To examine 1-handed shoe tying performance and whether cognitive deficits more associated with left or right hemisphere damage differentially affect it after unilateral stroke. Observational cohort comparing ipsilesional shoe tying, spatial and language skills, and limb praxis. Primary care Veterans Affairs and private medical center. Not applicable. Volunteer right-handed sample of adults with left or right hemisphere damage and healthy demographically matched adults. The number of correct trials and the total time to complete 10 trials tying a shoe using the 1-handed method. Both stroke groups had fewer correct trials and were significantly slower tying the shoe than the control group. Spatial skills predicted accuracy and speed after right hemisphere damage. After left hemisphere damage, accuracy was predicted by spatial skills and limb praxis, while speed was predicted by limb praxis only. Ipsilesional shoe tying is similarly impaired after left or right hemisphere damage, but for different reasons. Spatial deficits had a greater influence after right hemisphere damage, and limb apraxia had a greater influence after left hemisphere damage. Language deficits did not affect performance, indicating that aphasia does not preclude using this therapy approach. These results suggest that rehabilitation professionals should consider assessment of limb apraxia and ipsilesional skill training in the performance of everyday tasks.

  7. Neuropragmatics: Extralinguistic Pragmatic Ability is Better Preserved in Left-Hemisphere-Damaged Patients than in Right-Hemisphere-Damaged Patients

    Science.gov (United States)

    Cutica, Ilaria; Bucciarelli, Monica; Bara, Bruno G.

    2006-01-01

    The aim of the present study is to compare the pragmatic ability of right- and left-hemisphere-damaged patients excluding the possible interference of linguistic deficits. To this aim, we study extralinguistic communication, that is communication performed only through gestures. The Cognitive Pragmatics Theory provides the theoretical framework:…

  8. Cerebral perfusion and metabolism in relation to the evolution of unilateral spatial neglect due to cerebral infarction. Contribution of bilateral hemispheres in appearance and recovery

    International Nuclear Information System (INIS)

    Kato, Haruhisa

    2006-01-01

    To investigate the mechanisms underlying the evolution of unilateral spatial neglect (USN) due to cerebral infarction, the cerebral oxygen metabolism was measured quantitatively by positron emission tomography (PET). Out of 189 consecutive patients with right hemisphere lesions who underwent PET, we recruited 13 patients (group A) who exhibited USN at the time of PET examination, 11 patients (group B) who had already recovered from USN, and 27 patients (group C) with right hemisphere infarction who failed to present with USN throughout. Eight normal volunteers (group NV) served as controls. Statistical comparisons were performed on the local values of the cerebral metabolic rate of oxygen (CMRO 2 ) from the region of interest (ROI) in the right dorsolateral frontal lobe, superior temporal gyrus, inferior parietal lobule, cingulate gyrus, basal ganglia and thalamus which are associated with USN. We also obtained CMRO 2 values for the contralateral areas. As compared with group C or NV, there were significant decreases in CMRO 2 in the right frontal, right temporal and right parietal lobes, right basal ganglia, right thalamus and bilateral cingulate gyri in groups A and B. Except for the left inferior parietal lobule, no significant differences in regional CMRO 2 were noted between groups A and B. These findings indicate that extensive right hemisphere lesions may produce USN, but no specific brain region is associated with its recovery. Different from aphasics, no definite relationship is evident between recovery from USN and the role of the contralateral left hemisphere. This could be explained partly by the complexity of the pathogenetic mechanisms underlying USN. (author)

  9. Left and Right Memory Revisited: Electrophysiological Investigations of Hemispheric Asymmetries at Retrieval

    Science.gov (United States)

    Evans, Karen M.; Federmeier, Kara D.

    2009-01-01

    Hemispheric differences in the use of memory retrieval cues were examined in a continuous recognition design, using visual half-field presentation to bias the processing of test words. A speeded recognition task revealed general accuracy and response time advantages for items whose test presentation was biased to the left hemisphere. A second…

  10. Influence of the language dominant hemisphere on the activation region of the cerebral cortex during mastication

    International Nuclear Information System (INIS)

    Matsushima, Yasuhiko

    2005-01-01

    We used functional magnetic resonance imaging (fMRI) to examine the relationship of the activation region of the cerebral cortex during mastication with the language dominant hemisphere. Twelve healthy subjects were asked to chew a special gum 50 times on each side of the mouth, the gum changed color, becoming a deeper red, as it was chewed. The depth of red of the chewed gum was used to ascertain the habitual masticatory side. Measurements were also performed on a conventional whole body 1.5 T clinical scanner using a single shot, multislice echo-planar imaging sequence. The subjects were asked to masticate first on the right side, and then on the left side. As well, they were instructed to do a shiritori test, which is a word game. Computer analysis of the fMRI was done using statistical parametric mapping (SPM) 99 software (p<0.001, paired t-test). We found that the sensorimotor cortex activated by masticatory movements always contains language dominant hemisphere. (author)

  11. Differences in trace element concentrations between the right and left hemispheres of human brain using INAA

    International Nuclear Information System (INIS)

    Panayi, A.E.; Surrey Univ.; Spyrou, N.M.; Akanle, O.A.; Ubertalli, L.C.; Part, P.

    2000-01-01

    Very few publications have quoted differences between the same regions in both the right and left hemispheres of the human brain. It may be possible that the two hemispheres have different trace elemental concentrations, since it is known that they both have different functions. In this study, three brain regions from both the right and left hemispheres of the cortex have been sampled from five elderly individuals (three 'normal' and two Alzheimer's disease) and their elemental concentrations have been determined by instrumental neutron activation analysis (INAA). (author)

  12. Left hemispheric dominance during auditory processing in a noisy environment

    Directory of Open Access Journals (Sweden)

    Ross Bernhard

    2007-11-01

    Full Text Available Abstract Background In daily life, we are exposed to different sound inputs simultaneously. During neural encoding in the auditory pathway, neural activities elicited by these different sounds interact with each other. In the present study, we investigated neural interactions elicited by masker and amplitude-modulated test stimulus in primary and non-primary human auditory cortex during ipsi-lateral and contra-lateral masking by means of magnetoencephalography (MEG. Results We observed significant decrements of auditory evoked responses and a significant inter-hemispheric difference for the N1m response during both ipsi- and contra-lateral masking. Conclusion The decrements of auditory evoked neural activities during simultaneous masking can be explained by neural interactions evoked by masker and test stimulus in peripheral and central auditory systems. The inter-hemispheric differences of N1m decrements during ipsi- and contra-lateral masking reflect a basic hemispheric specialization contributing to the processing of complex auditory stimuli such as speech signals in noisy environments.

  13. The Role of Left Hemispheric Structures for Emotional Processing as a Monitor of Bodily Reaction and Felt Chill - a Case-Control Functional Imaging Study.

    Science.gov (United States)

    Grunkina, Viktoria; Holtz, Katharina; Klepzig, Kai; Neubert, Jörg; Horn, Ulrike; Domin, Martin; Hamm, Alfons O; Lotze, Martin

    2016-01-01

    Background: The particular function of the left anterior human insula on emotional arousal has been illustrated with several case studies. Only after left hemispheric insula lesions, patients lose their pleasure in habits such as listening to joyful music. In functional magnetic resonance imaging studies (fMRI) activation in the left anterior insula has been associated with both processing of emotional valence and arousal. Tight interactions with different areas of the prefrontal cortex are involved in bodily response monitoring and cognitive appraisal of a given stimulus. Therefore, a large left hemispheric lesion including the left insula should impair the bodily response of chill experience (objective chill response) but leave the cognitive aspects of chill processing (subjective chill response) unaffected. Methods: We investigated a patient (MC) with a complete left hemispheric media cerebral artery stroke, testing fMRI representation of pleasant (music) and unpleasant (harsh sounds) chill response. Results: Although chill response to both pleasant and unpleasant rated sounds was confirmed verbally at passages also rated as chilling by healthy participants, skin conductance response was almost absent in MC. For a healthy control (HC) objective and subjective chill response was positively associated. Bilateral prefrontal fMRI-response to chill stimuli was sustained in MC whereas insula activation restricted to the right hemisphere. Diffusion imaging together with lesion maps revealed that left lateral tracts were completely damaged but medial prefrontal structures were intact. Conclusion: With this case study we demonstrate how bodily response and cognitive appraisal are differentially participating in the internal monitor of chill response.

  14. The right hemisphere supports but does not replace left hemisphere auditory function in patients with persisting aphasia.

    Science.gov (United States)

    Teki, Sundeep; Barnes, Gareth R; Penny, William D; Iverson, Paul; Woodhead, Zoe V J; Griffiths, Timothy D; Leff, Alexander P

    2013-06-01

    In this study, we used magnetoencephalography and a mismatch paradigm to investigate speech processing in stroke patients with auditory comprehension deficits and age-matched control subjects. We probed connectivity within and between the two temporal lobes in response to phonemic (different word) and acoustic (same word) oddballs using dynamic causal modelling. We found stronger modulation of self-connections as a function of phonemic differences for control subjects versus aphasics in left primary auditory cortex and bilateral superior temporal gyrus. The patients showed stronger modulation of connections from right primary auditory cortex to right superior temporal gyrus (feed-forward) and from left primary auditory cortex to right primary auditory cortex (interhemispheric). This differential connectivity can be explained on the basis of a predictive coding theory which suggests increased prediction error and decreased sensitivity to phonemic boundaries in the aphasics' speech network in both hemispheres. Within the aphasics, we also found behavioural correlates with connection strengths: a negative correlation between phonemic perception and an inter-hemispheric connection (left superior temporal gyrus to right superior temporal gyrus), and positive correlation between semantic performance and a feedback connection (right superior temporal gyrus to right primary auditory cortex). Our results suggest that aphasics with impaired speech comprehension have less veridical speech representations in both temporal lobes, and rely more on the right hemisphere auditory regions, particularly right superior temporal gyrus, for processing speech. Despite this presumed compensatory shift in network connectivity, the patients remain significantly impaired.

  15. Hemispheric metacontrol and cerebral dominance in healthy individuals investigated by means of chimeric faces.

    Science.gov (United States)

    Urgesi, Cosimo; Bricolo, Emanuela; Aglioti, Salvatore M

    2005-08-01

    Cerebral dominance and hemispheric metacontrol were investigated by testing the ability of healthy participants to match chimeric, entire, or half faces presented tachistoscopically. The two hemi-faces compounding chimeric or entire stimuli were presented simultaneously or asynchronously at different exposure times. Participants did not consciously detect chimeric faces for simultaneous presentations lasting up to 40 ms. Interestingly, a 20 ms separation between each half-chimera was sufficient to induce detection of conflicts at a conscious level. Although the presence of chimeric faces was not consciously perceived, performance on chimeric faces was poorer than on entire- and half-faces stimuli, thus indicating an implicit processing of perceptual conflicts. Moreover, the precedence of hemispheric stimulation over-ruled the right hemisphere dominance for face processing, insofar as the hemisphere stimulated last appeared to influence the response. This dynamic reversal of cerebral dominance, however, was not caused by a shift in hemispheric specialization, since the level of performance always reflected the right hemisphere specialization for face recognition. Thus, the dissociation between hemispheric dominance and specialization found in the present study hints at the existence of hemispheric metacontrol in healthy individuals.

  16. Acquired dysgraphia in adults following right or left-hemisphere stroke

    Directory of Open Access Journals (Sweden)

    Jaqueline de Carvalho Rodrigues

    Full Text Available OBJECTIVE: This study aimed to assess the strengths and difficulties in word and pseudoword writing in adults with left- and right-hemisphere strokes, and discuss the profiles of acquired dysgraphia in these individuals.METHODS: The profiles of six adults with acquired dysgraphia in left- or right-hemisphere strokes were investigated by comparing their performance on word and pseudoword writing tasks against that of neurologically healthy adults. A case series analysis was performed on the patients whose impairments on the task were indicative of acquired dysgraphia.RESULTS: Two patients were diagnosed with lexical dysgraphia (one with left hemisphere damage, and the other with right hemisphere damage, one with phonological dysgraphia, another patient with peripheral dysgraphia, one patient with mixed dysgraphia and the last with dysgraphia due to damage to the graphemic buffer. The latter patients all had left-hemisphere damage (LHD. The patterns of impairment observed in each patient were discussed based on the dual-route model of writing.CONCLUSION: The fact that most patients had LHD rather than right-hemisphere damage (RHD highlights the importance of the former structure for word processing. However, the fact that lexical dysgraphia was also diagnosed in a patient with RHD suggests that these individuals may develop writing impairments due to damage to the lexical route, leading to heavier reliance on phonological processing. Our results are of significant importance to the planning of writing interventions in neuropsychology.

  17. Volumetric Analysis of Cerebral Peduncles and Cerebellar Hemispheres for Predicting Hemiparesis After Hemispherectomy.

    Science.gov (United States)

    Mullin, Jeffrey P; Soni, Pranay; Lee, Sungho; Jehi, Lara; Naduvil Valappi, Ahsan Moosa; Bingaman, William; Gonzalez-Martinez, Jorge

    2016-09-01

    In some cases of refractory epilepsy, hemispherectomy is the final invasive treatment option. However, predictors of postoperative hemiparesis in these patients have not been widely studied. To investigate how the volumetric analysis of cerebral peduncles and cerebellar hemispheres in patients who have undergone hemispherectomy may determine prognostic implications for postoperative hemiparesis. Twenty-two patients who underwent hemispherectomy at our institution were retrospectively included. Using iPlan/BrainLAB (BrainLAB, Feldkirchen, Germany) imaging software and a semiautomatic voxel-based segmentation method, we calculated the preoperative cerebral peduncle and cerebellar hemisphere volumes. Cerebral peduncle and cerebellar hemisphere ratios were compared between patients with worsened or unchanged/better hemiparesis postoperatively. The ratios of ipsilateral/contralateral cerebral peduncles (0.570 vs 0.828; P = .02) and contralateral/ipsilateral cerebellar hemispheres (0.885 vs 1.031; P = .009) were significantly lower in patients who had unchanged/improved hemiparesis postoperatively compared with patients who had worsened hemiparesis. Relative risk of worsening hemiparesis was significantly higher in patients with a cerebral peduncle ratio hemiparesis using only standard volumetric magnetic resonance imaging. This information could be used in preoperative discussions with patients and families to help better understand that chance of retaining baseline motor function. CST, corticospinal tractfMRI, functional magnetic resonance imagingTMS, transcranial magnetic stimulation.

  18. When Left Means Right: An Explanation of the Left Cradling Bias in Terms of Right Hemisphere Specializations

    Science.gov (United States)

    Bourne, Victoria J.; Todd, Brenda K.

    2004-01-01

    Previous research has indicated that 70-85% of women and girls show a bias to hold infants, or dolls, to the left side of their body. This bias is not matched in males (e.g. deChateau, Holmberg & Winberg, 1978; Todd, 1995). This study tests an explanation of cradling preferences in terms of hemispheric specialization for the perception of facial…

  19. Right-ear precedence and vocal emotion contagion: The role of the left hemisphere.

    Science.gov (United States)

    Schepman, Astrid; Rodway, Paul; Cornmell, Louise; Smith, Bethany; de Sa, Sabrina Lauren; Borwick, Ciara; Belfon-Thompson, Elisha

    2018-05-01

    Much evidence suggests that the processing of emotions is lateralized to the right hemisphere of the brain. However, under some circumstances the left hemisphere might play a role, particularly for positive emotions and emotional experiences. We explored whether emotion contagion was right-lateralized, lateralized valence-specifically, or potentially left-lateralized. In two experiments, right-handed female listeners rated to what extent emotionally intoned pseudo-sentences evoked target emotions in them. These sound stimuli had a 7 ms ear lead in the left or right channel, leading to stronger stimulation of the contralateral hemisphere. In both experiments, the results revealed that right ear lead stimuli received subtly but significantly higher evocation scores, suggesting a left hemisphere dominance for emotion contagion. A control experiment using an emotion identification task showed no effect of ear lead. The findings are discussed in relation to prior findings that have linked the processing of emotional prosody to left-hemisphere brain regions that regulate emotions, control orofacial musculature, are involved in affective empathy processing areas, or have an affinity for processing emotions socially. Future work is needed to eliminate alternative interpretations and understand the mechanisms involved. Our novel binaural asynchrony method may be useful in future work in auditory laterality.

  20. Hemispheric Dominance for Stereognosis in a Patient With an Infarct of the Left Postcentral Sensory Hand Area.

    Science.gov (United States)

    Moll, Jorge; de Oliveira-Souza, Ricardo

    2017-09-01

    The concept of left hemispheric dominance for praxis, speech, and language has been one of the pillars of neurology since the mid-19th century. In 1906, Hermann Oppenheim reported a patient with bilateral stereoagnosia (astereognosis) caused by a left parietal lobe tumor and proposed that the left hemisphere was also dominant for stereognosis. Surprisingly, few cases of bilateral stereoagnosia caused by a unilateral cerebral lesion have been documented in the literature since then. Here we report a 75-year-old right-handed man who developed bilateral stereoagnosia after suffering a small infarct in the crown of the left postcentral gyrus. He could not recognize objects with either hand, but retained the ability to localize stimuli applied to the palm of his left (ipsilesional) hand. He was severely disabled in ordinary activities requiring the use of his hands. The lesion corresponded to Brodmann area 1, where probabilistic anatomic, functional, and electrophysiologic studies have located one of the multiple somatosensory representations of the hand. The lesion was in a strategic position to interrupt both the processing of afferent tactile information issuing from the primary somatosensory cortex (areas 3a and 3b) and the forward higher-order processing in area 2, the secondary sensory cortex, and the contralateral area 1. The lesion also deprived the motor hand area of its afferent regulation from the sensory hand area (grasping), while leaving intact the visuomotor projections from the occipital cortex (reaching). Our patient supports Oppenheim's proposal that the left postcentral gyrus of some individuals is dominant for stereognosis.

  1. Laterality of cerebral hemispheres on CT scan and gross motor function in severely handicapped children

    Energy Technology Data Exchange (ETDEWEB)

    Iwasaki, Nobuaki; Hamano, Kenzo; Nakamoto, Natsue; Okada, Yusuke [Tsukuba Univ., Ibaraki (Japan); Takeya, Toshiki

    1997-06-01

    The relation between brain damage and gross motor function in severely handicapped children (spastic type) was studied. The subjects were fifteen cases with laterality in their cerebral hemisphere CT scans (laterality group) and 28 cases with no laterality (control group). All cases were divided into four groups according to the level of gross motor function. The grade of brain damage was estimated based on CT scan analysis using the following parameters and index: maximum frontal extracerebral space (ES), maximum width of Sylvian fissure (SY), Evans` ratio, and cella media index. In the laterality group, the parameters and index were measured for both cerebral hemispheres, respectively. In the more severely disturbed hemisphere of the laterality group, ES and SY were significantly enlarged compared with those of the cases with the same level of motor function in the control group (p<0.01). In the less severely disturbed hemisphere of the laterality group, the ES, SY, Evans` ratio and cell media index were not significantly enlarged compared to cases with the same level of motor function as the control group. These findings may indicate that gross motor function of severely handicapped children is closely related to the less severely disturbed cerebral hemisphere. (author)

  2. Laterality of cerebral hemispheres on CT scan and gross motor function in severely handicapped children

    International Nuclear Information System (INIS)

    Iwasaki, Nobuaki; Hamano, Kenzo; Nakamoto, Natsue; Okada, Yusuke; Takeya, Toshiki.

    1997-01-01

    The relation between brain damage and gross motor function in severely handicapped children (spastic type) was studied. The subjects were fifteen cases with laterality in their cerebral hemisphere CT scans (laterality group) and 28 cases with no laterality (control group). All cases were divided into four groups according to the level of gross motor function. The grade of brain damage was estimated based on CT scan analysis using the following parameters and index: maximum frontal extracerebral space (ES), maximum width of Sylvian fissure (SY), Evans' ratio, and cella media index. In the laterality group, the parameters and index were measured for both cerebral hemispheres, respectively. In the more severely disturbed hemisphere of the laterality group, ES and SY were significantly enlarged compared with those of the cases with the same level of motor function in the control group (p<0.01). In the less severely disturbed hemisphere of the laterality group, the ES, SY, Evans' ratio and cell media index were not significantly enlarged compared to cases with the same level of motor function as the control group. These findings may indicate that gross motor function of severely handicapped children is closely related to the less severely disturbed cerebral hemisphere. (author)

  3. Prevalence of apraxia among patients with a first left hemisphere stroke in rehabilitation centres and nursing homes.

    OpenAIRE

    Donkervoort, M.; Dekker, J.; Ende, E. van den; Stehmann-Saris, J.C.; Deelman, B.G.

    2000-01-01

    OBJECTIVE: To investigate the prevalence of apraxia in patients with a first left hemisphere stroke. SUBJECTS: Left hemisphere stroke patients staying at an inpatient care unit of a rehabilitation centre or nursing home and receiving occupational therapy (n = 600). MEASURES: A short questionnaire on general patient characteristics and stroke-related aspects was completed by occupational therapists for every left hemisphere stroke patient they treated. A diagnosis of apraxia or nonapraxia was ...

  4. Computed tomographic findings in cerebral palsy: Analysis of hemisphere and lateral ventricular volume

    International Nuclear Information System (INIS)

    Cho, Seoung Hwan; Kim, Hak Jin; Sol, Chang Hyo; Kim, Byung Soo

    1989-01-01

    Authors analysed the CT findings of 28 cerebral palsy patients at Pusan National University Hospital from January, 1984 to December, 1987. Volumes of hemispheres, lateral ventricles and paranchymes were measured in patients who showed no remarkable abnormality on CT film, and compared with those of normal control group. 1. Among the 28 cerebral palsy patients, there were 6 cases of diffuse atrophy in CT findings, and unilateral atrophy in 2 cases and encephalomalacia and diffuse white matter low density in 1 case and generalized symmetrical white matter low density in 1 case, but remaining 18 cases had no specific abnormal finding on CT. 2. Difference in volumes of brain parenchyma and lateral ventricles of each hemisphere was greater than that of control group. 3. There were more enlarged lateral ventricles and prominent unilateral brain atrophy in 18 cases of cerebral palsy who showed no specific abnormality on CT as compared with normal control group

  5. Homotopic organization of essential language sites in right and bilateral cerebral hemispheric dominance.

    Science.gov (United States)

    Chang, Edward F; Wang, Doris D; Perry, David W; Barbaro, Nicholas M; Berger, Mitchel S

    2011-04-01

    Language dominance in the right hemisphere is rare. Therefore, the organization of essential language sites in the dominant right hemisphere is unclear, especially compared with cases involving the more prevalent left dominant hemisphere. The authors reviewed the medical records of 15 patients who underwent awake craniotomy for tumor or epilepsy surgery and speech mapping of right hemisphere perisylvian language areas at the University of California, San Francisco. All patients were determined to have either complete right-sided or bilateral language dominance by preoperative Wada testing. All patients but one were left-handed. Of more than 331 total stimulation sites, 27 total sites were identified as essential for language function (14 sites for speech arrest/anarthria; 12 for anomia; and 1 for alexia). While significant interindividual variability was observed, the general pattern of language organization was similar to classic descriptions of frontal language production and posterior temporal language integration for the left hemisphere. Speech arrest sites were clustered in the ventral precentral gyrus and pars opercularis. Anomia sites were more widely distributed, but were focused in the posterior superior and middle temporal gyri as well as the inferior parietal gyrus. One alexia site was found over the superior temporal gyrus. Face sensory and motor cortical sites were also identified along the ventral sensorimotor strip. The prevalence and specificity of essential language sites were greater in unilateral right hemisphere-dominant patients, compared with those with bilateral dominance by Wada testing. The authors' results suggest that the organization of language in right hemisphere dominance mirrors that of left hemisphere dominance. Awake speech mapping is a safe and reliable surgical adjunct in these rare clinical cases and should be done in the setting of right hemisphere dominance to avoid preventable postoperative aphasia.

  6. Characteristics and dynamics of cognitive impairment in patients with primary and recurrent cerebral ischemic hemispheric stroke

    Directory of Open Access Journals (Sweden)

    A. A. Kozyolkin

    2014-08-01

    Full Text Available Acute cerebrovascular disease is a global medical and social problem of the modern angioneurology, occupying leading positions in the structure of morbidity and mortality among adult population of the world. Ischemic stroke – is one of the most common pathology. Today this disease took out the world pandemic. More than 16 million new cases of cerebral infarction recorded in the world each year and it “kills” about 7 million of people. About 111,953 cases of cerebral stroke were registered in 2013 in Ukraine. Cognitive impairment, t hat significantly disrupt daily activities and life of the patient, is one of the most significant post-stroke complications that have social, medical and biological significance. Aim. The purpose of this investigation was to study features and dynamics of cognitive impairments in patients with primary and recurrent cerebral hemispheric ischemic stroke (CHIS in the acute stage of the disease. Materials and methods. To achieve the aim, and the decision of tasks in the clinic of nervous diseases Zaporozhye State Medical University (supervisor - Doctor of Medicine, Professor Kozelkin A. based on the department of acute cerebrovascular disease were performed comparative, prospective cohort study, which included comprehensive clinical and paraclinical examinations of 41 patients (26 men and 15 women aged 45 to 85 years (mean age 66,4 ± 1,4 years with acute left-hemispheric (2 patients and right - hemispheric (39 patients CHIS . First up was a group of 28 patients (19 men and 9 women, mean age 65,6 ± 1,6 years, who suffered from primary CHIS. The second group consisted of 13 patients (7 men and 6 women, mean age 68,1 ± 2,5 years with recurrent CHIS. The groups were matched by age, sex, localization of the lesion and the initial level of neurological deficit. All patients underwent physical examination, neurological examination. Dynamic clinical neurological examination assessing the severity of stroke was conducted

  7. Left hemispheric dominance of vestibular processing indicates lateralization of cortical functions in rats.

    Science.gov (United States)

    Best, Christoph; Lange, Elena; Buchholz, Hans-Georg; Schreckenberger, Mathias; Reuss, Stefan; Dieterich, Marianne

    2014-11-01

    Lateralization of cortical functions such as speech dominance, handedness and processing of vestibular information are present not only in humans but also in ontogenetic older species, e.g. rats. In human functional imaging studies, the processing of vestibular information was found to be correlated with the hemispherical dominance as determined by the handedness. It is located mainly within the right hemisphere in right handers and within the left hemisphere in left handers. Since dominance of vestibular processing is unknown in animals, our aim was to study the lateralization of cortical processing in a functional imaging study applying small-animal positron emission tomography (microPET) and galvanic vestibular stimulation in an in vivo rat model. The cortical and subcortical network processing vestibular information could be demonstrated and correlated with data from other animal studies. By calculating a lateralization index as well as flipped region of interest analyses, we found that the vestibular processing in rats follows a strong left hemispheric dominance independent from the "handedness" of the animals. These findings support the idea of an early hemispheric specialization of vestibular cortical functions in ontogenetic older species.

  8. Effects of mental rotation on acalculia: differences in the direction of mental rotation account for the differing characteristics of acalculia induced by right and left hemispheric brain injury.

    Science.gov (United States)

    Asada, Tomohiko; Takayama, Yoshihiro; Oita, Jiro; Fukuyama, Hidenao

    2014-04-01

    We observed a 59-year-old right-handed man with an infarction in his right-middle cerebral artery that included the parietal lobe, who abnormally manipulated mental images in the horizontal direction, resulting in calculation disturbances. Three years later, the patient suffered an infarction in the left parietal lobe and displayed abnormalities during the creation of mental images; i.e., he rotated them in the vertical direction, which again resulted in calculation disturbances. These mental imagery disturbances might indicate that a common acalculia mechanism exists between the right and left hemispheres.

  9. Left and Right Hemisphere Brain Functions and Symbolic vs. Spontaneous Communication Processes.

    Science.gov (United States)

    Buck, Ross

    Recent findings on the communicative functions of the left versus the right hemisphere of the brain may suggest that there is a distinction between the intentional use of symbols for the sending of specific messages or propositions (language, signing, pantomime) and spontaneous expressive behaviors that signal their meaning through a natural…

  10. Left hemisphere EEG coherence in infancy predicts infant declarative pointing and preschool epistemic language.

    Science.gov (United States)

    Kühn-Popp, N; Kristen, S; Paulus, M; Meinhardt, J; Sodian, B

    2016-01-01

    Pointing plays a central role in preverbal communication. While imperative pointing aims at influencing another person's behavior, declarative gestures serve to convey epistemic information and to share interest in an object. Further, the latter are hypothesized to be a precursor ability of epistemic language. So far, little is known about their underlying brain maturation processes. Therefore, the present study investigated the relation between brain maturation processes and the production of imperative and declarative motives as well as epistemic language in N = 32 infants. EEG coherence scores were measured at 14 months, imperative and declarative point production at 15 months and epistemic language at 48 months. Results of correlational analyses suggest distinct behavioral and neural patterns for imperative and declarative pointing, with declarative pointing being associated with the maturation of the left hemisphere. Further, EEG coherence measures of the left hemisphere at 14 months and declarative pointing at 15 months are related to individual differences in epistemic language skills at 48 months, independently of child IQ. In regression analyses, coherence measures of the left hemisphere prove to be the most important predictor of epistemic language skills. Thus, neural processes of the left hemisphere seem particularly relevant to social communication.

  11. Estimation of blood volume difference between bilateral cerebral hemispheres by means of subtraction method

    International Nuclear Information System (INIS)

    Ueno, Ichiro

    1983-01-01

    It would be admitted that by measuring radioactivity of the head after intravenous injection of RI some information could be afforded concerning the cerebral vascular bed. After intravenous injection of sup(99m)Tc-pertechnetate (15mCi), an anterior view scintiscanning was made using a gamma camera combined with a computer system. Two ROIs of about 30 cm 2 were set bilateral symmetrically and a count rate curve of each ROI was obtained. The brain transit time (BTT) was calculated from first derivative of the initial count rate courve. As an index devoting difference between vascular bed of each hemisphere, the vascular bed difference index (VBDI) was introduced BTT and VBDI were calculated in 104 subjects including 11 normal controls. In most of brain tumor, cerebral hemorrhage, severe head injury and cerebral aneurysm BTTs were prolonged in affected hemispheres. However, in a half of cerebral infarction cases BTTs were rather shortened on the affected side. In normal controls, the absolute value of VBDI was [0.16 +- 0.06(S.D.)]. In cases of brain tumor, cerebral hemorrhage and severe head injury, VBDI showed a significant deviation from the normal range, taking plus value. This results suggest, according to the definition of VBDI, vascular beds of the affected hemisphere are abnormally decreased compared with those of non-affected side. In cases of arteriovenous malformation VBDIs were increased on the affected side, reflecting enlarged tangle of arteriols and venous vessels. On the other hand, in cases of cerebral infarction, VBDI varied from case to case, making it difficult to get some conclusion from the present data. VBDI, however, invariably decreased in cases in which the occlusion of arteries were definitely confirmed by angiography

  12. Schizophrenia as failure of left hemispheric dominance for the phonological component of language.

    Science.gov (United States)

    Angrilli, Alessandro; Spironelli, Chiara; Elbert, Thomas; Crow, Timothy J; Marano, Gianfranco; Stegagno, Luciano

    2009-01-01

    T. J. Crow suggested that the genetic variance associated with the evolution in Homo sapiens of hemispheric dominance for language carries with it the hazard of the symptoms of schizophrenia. Individuals lacking the typical left hemisphere advantage for language, in particular for phonological components, would be at increased risk of the typical symptoms such as auditory hallucinations and delusions. Twelve schizophrenic patients treated with low levels of neuroleptics and twelve matched healthy controls participated in an event-related potential experiment. Subjects matched word-pairs in three tasks: rhyming/phonological, semantic judgment and word recognition. Slow evoked potentials were recorded from 26 scalp electrodes, and a laterality index was computed for anterior and posterior regions during the inter stimulus interval. During phonological processing individuals with schizophrenia failed to achieve the left hemispheric dominance consistently observed in healthy controls. The effect involved anterior (fronto-temporal) brain regions and was specific for the Phonological task; group differences were small or absent when subjects processed the same stimulus material in a Semantic task or during Word Recognition, i.e. during tasks that typically activate more widespread areas in both hemispheres. We show for the first time how the deficit of lateralization in the schizophrenic brain is specific for the phonological component of language. This loss of hemispheric dominance would explain typical symptoms, e.g. when an individual's own thoughts are perceived as an external intruding voice. The change can be interpreted as a consequence of "hemispheric indecision", a failure to segregate phonological engrams in one hemisphere.

  13. Schizophrenia as failure of left hemispheric dominance for the phonological component of language.

    Directory of Open Access Journals (Sweden)

    Alessandro Angrilli

    Full Text Available BACKGROUND: T. J. Crow suggested that the genetic variance associated with the evolution in Homo sapiens of hemispheric dominance for language carries with it the hazard of the symptoms of schizophrenia. Individuals lacking the typical left hemisphere advantage for language, in particular for phonological components, would be at increased risk of the typical symptoms such as auditory hallucinations and delusions. METHODOLOGY/PRINCIPAL FINDINGS: Twelve schizophrenic patients treated with low levels of neuroleptics and twelve matched healthy controls participated in an event-related potential experiment. Subjects matched word-pairs in three tasks: rhyming/phonological, semantic judgment and word recognition. Slow evoked potentials were recorded from 26 scalp electrodes, and a laterality index was computed for anterior and posterior regions during the inter stimulus interval. During phonological processing individuals with schizophrenia failed to achieve the left hemispheric dominance consistently observed in healthy controls. The effect involved anterior (fronto-temporal brain regions and was specific for the Phonological task; group differences were small or absent when subjects processed the same stimulus material in a Semantic task or during Word Recognition, i.e. during tasks that typically activate more widespread areas in both hemispheres. CONCLUSIONS/SIGNIFICANCE: We show for the first time how the deficit of lateralization in the schizophrenic brain is specific for the phonological component of language. This loss of hemispheric dominance would explain typical symptoms, e.g. when an individual's own thoughts are perceived as an external intruding voice. The change can be interpreted as a consequence of "hemispheric indecision", a failure to segregate phonological engrams in one hemisphere.

  14. Prevalence of apraxia among patients with a first left hemisphere stroke in rehabilitation centres and nursing homes

    NARCIS (Netherlands)

    Donkervoort, M; Dekker, J; van den Ende, E; Stehmann-Saris, J. C.; Deelman, B. G.

    Objective: To investigate the prevalence of apraxia in patients with a first left hemisphere stroke. Subjects. Left hemisphere stroke patients staying at an inpatient care unit of a rehabilitation centre or nursing home and receiving occupational therapy (n = 600). Measures: A short questionnaire on

  15. The course of apraxia and ADL functioning in left hemisphere stroke patients treated in rehabilitation centres and nursing homes.

    NARCIS (Netherlands)

    Donkervoort, M.; Dekker, J.; Deelman, B.

    2006-01-01

    OBJECTIVE: To study the course of apraxia and daily life functioning (ADL) in left hemisphere stroke patients with apraxia. DESIGN: Prospective cohort study. SETTING: Rehabilitation centres and nursing homes. SUBJECTS: One hundred and eight left hemisphere stroke patients with apraxia, hospitalized

  16. Prevalence of apraxia among patients with a first left hemisphere stroke in rehabilitation centres and nursing homes.

    NARCIS (Netherlands)

    Donkervoort, M.; Dekker, J.; Ende, E. van den; Stehmann-Saris, J.C.; Deelman, B.G.

    2000-01-01

    OBJECTIVE: To investigate the prevalence of apraxia in patients with a first left hemisphere stroke. SUBJECTS: Left hemisphere stroke patients staying at an inpatient care unit of a rehabilitation centre or nursing home and receiving occupational therapy (n = 600). MEASURES: A short questionnaire on

  17. Síndromes del hemisferio no dominante Syndrome of cerebral non-dominant hemisphere

    Directory of Open Access Journals (Sweden)

    Newra Rotta

    2007-01-01

    Full Text Available En este trabajo de revisión se discute lo que entendemos de las funciones hemisféricas y se abordan los principales hallazgos que forman parte del síndrome del hemisferio cerebral no dominante, que en la mayor parte de los casos es el derecho, con énfasis en las alteraciones de la sustancia blanca o sea de las fibras comisurales, de asociación y de proyección. Los diferentes aspectos de los síndromes tienen relación con la etiología, localización, extensión y etapa del desarrollo en que el daño ocurrió. Se observan: hemiplejía izquierda; alteración de la prosodia, así como alteraciones en la comunicación no verbal; percepción visuo-espacial; organización, secuenciación de actividades e interacción social. Estos comportamientos se observan también en trastornos del desarrollo, tales como disturbio de déficit de atención/hiperactividad, y síndrome de Asperger. Con el objetivo de destacar cuáles son los hallazgos más frecuentes y más persistentes en niños con lesión adquirida en el hemisferio derecho, presentamos siete casos de accidente vascular isquémico. Todos los pacientes fueron controlados por más de dos años y se les realizó examen neurológico, examen neurológico evolutivo y evaluación psicológica. Con el seguimiento de los siete casos fue posible observar que las alteraciones motoras son menos severas y menos definitivas que las alteraciones cognitivas, afectivas y conductuales.In this review the meaning of cerebral hemispheric function is discussed with special emphasis in non-dominant cerebral hemisphere and particularly in the lesion of commissural, association, projection of white matter fibers. Clinical characteristics depend on etiology, localization, extension and particularly the period of brain development. The following are common findings in these patients: left hemiplegia, abnormal prosody and non verbal communication, anomalies visiospatial perception, organization, and social interaction

  18. Prevalence of apraxia among patients with a first left hemisphere stroke in rehabilitation centres and nursing homes.

    Science.gov (United States)

    Donkervoort, M; Dekker, J; van den Ende, E; Stehmann-Saris, J C; Deelman, B G

    2000-04-01

    To investigate the prevalence of apraxia in patients with a first left hemisphere stroke. Left hemisphere stroke patients staying at an inpatient care unit of a rehabilitation centre or nursing home and receiving occupational therapy (n = 600). A short questionnaire on general patient characteristics and stroke-related aspects was completed by occupational therapists for every left hemisphere stroke patient they treated. A diagnosis of apraxia or nonapraxia was made in every patient, on the basis of a set of clinical criteria. The prevalence of apraxia among 492 first left hemisphere stroke patients in rehabilitation centres was 28% (96/338) and in nursing homes 37% (57/154). No relationship was found between the prevalence of apraxia and age, gender or type of stroke (haemorrhage or infarct). This study shows that approximately one-third of left hemisphere stroke patients has apraxia.

  19. Cortical motor representation of the rectus femoris does not differ between the left and right hemisphere.

    Science.gov (United States)

    Ward, Sarah; Bryant, Adam L; Pietrosimone, Brian; Bennell, Kim L; Clark, Ross; Pearce, Alan J

    2016-06-01

    Transcranial magnetic stimulation (TMS) involves non-invasive magnetic stimulation of the brain, and can be used to explore the corticomotor excitability and motor representations of skeletal muscles. However there is a lack of motor mapping studies in the lower limb and few conducted in healthy cohorts. The cortical motor representations of muscles can vary between individuals in terms of center position and area despite having a general localized region within the motor cortex. It is important to characterize the normal range for these variables in healthy cohorts to be able to evaluate changes in clinical populations. TMS was used in this cross-sectional study to assess the active motor threshold (AMT) and cortical representation area for rectus femoris in 15 healthy individuals (11M/4F 27.3±5.9years). No differences were found between hemispheres (Left vs. Right P=0.130) for AMT. In terms of y-axis center position no differences were found between hemispheres (Left vs. Right P=0.539), or for the x-axis center position (Left vs. Right P=0.076). Similarly, no differences in calculated area of the motor representation were found (Left vs. Right P=0.699) indicating symmetry between hemispheres. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

    Energy Technology Data Exchange (ETDEWEB)

    Maeshima, S.; Matsumoto, T.; Ueyoshi, A. [Department of Physical Medicine and Rehabilitation, Wakayama Medical University, Wakayama (Japan); Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H. [Department of Neurological Surgery, Hidaka General Hospital, Wakayama (Japan); Roger, P. [School of Communication Sciences and Disorders, University of Sydney, Sydney, NSW (Australia)

    2002-02-01

    We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

  1. Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

    International Nuclear Information System (INIS)

    Maeshima, S.; Matsumoto, T.; Ueyoshi, A.; Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H.; Roger, P.

    2002-01-01

    We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

  2. Why the Left Hemisphere Is Dominant for Speech Production: Connecting the Dots

    Directory of Open Access Journals (Sweden)

    Harvey Martin Sussman

    2015-12-01

    Full Text Available Evidence from seemingly disparate areas of speech/language research is reviewed to form a unified theoretical account for why the left hemisphere is specialized for speech production. Research findings from studies investigating hemispheric lateralization of infant babbling, the primacy of the syllable in phonological structure, rhyming performance in split-brain patients, rhyming ability and phonetic categorization in children diagnosed with developmental apraxia of speech, rules governing exchange errors in spoonerisms, organizational principles of neocortical control of learned motor behaviors, and multi-electrode recordings of human neuronal responses to speech sounds are described and common threads highlighted. It is suggested that the emergence, in developmental neurogenesis, of a hard-wired, syllabically-organized, neural substrate representing the phonemic sound elements of one’s language, particularly the vocalic nucleus, is the crucial factor underlying the left hemisphere’s dominance for speech production.

  3. Better together: Left and right hemisphere engagement to reduce age-related memory loss.

    Science.gov (United States)

    Brambilla, Michela; Manenti, Rosa; Ferrari, Clarissa; Cotelli, Maria

    2015-10-15

    Episodic memory is a cognitive function that appears more susceptible than others to the effects of aging. The main aim of this study is to investigate if the magnitude of functional hemispheric lateralization during episodic memory test was positively correlated with memory performance, proving the presence of a beneficial pattern of neural processing in high-performing older adults but not in low-performing participants. We have applied anodal transcranial Direct Current Stimulation (tDCS) or sham stimulation over left and right hemisphere in a group of young subjects and in high-performing and low-performing older participants during an experimental verbal episodic memory task. Remarkably, young individuals and high-performing older adults exhibited similar performances on episodic memory tasks and both groups showed symmetrical recruitment of left and right areas during memory retrieval. In contrast, low-performing older adults, who obtained lower scores on the memory tasks, demonstrated a greater engagement of the left hemisphere during verbal memory task. Furthermore, structural equation model was performed for analyzing the interrelations between the index of interhemispheric asymmetry and several neuropsychological domains. We found that the bilateral engagement of dorsolateral prefrontal cortex and parietal cortex regions had a direct correlation with memory and executive functions evaluated as latent constructs. These findings drew attention to brain maintenance hypothesis. The potential of neurostimulation in cognitive enhancement is particularly promising to prevent memory loss during aging. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Clinico-anatomical correlations of left posterior cerebral artery occlusion

    International Nuclear Information System (INIS)

    Isono, Osamu; Shiota, Junichi; Kawamura, Mitsuru; Hirayama, Keizou; Maki, Toshiyuki.

    1988-01-01

    The relation between neurological signs and symptoms and computed tomography (CT) and magnetic resonance imaging (MRI) was examined in 11 cases of occlusion of the left posterior cerebral artery. All the patients were righthanded. Right homonimous hemianopia was noted in 8 cases, right upper quadrantanopia in 2 cases, and right lower quadrantanopia in 1 case. Of the 11 cases, alexia without agraphia was noted in 9 cases, all 9 of which showed lesions of inferior occipital cortex (lingual and fusiform gyri) and subjacent white matter. Lesions of splenium were found in only 5 of the cases of alexia without agraphia. In 2 cases with neither alexia nor agraphia, lesions were seen in the medial occipital cortex and the subjacent white matter but not in the inferior occipital lobe. Three patients had color anomia which was accompanied by memory disturbances and alexia without agraphia. In 2 of these 3, lesions were widespread in the region of the left posterior cerebral artery. Memory disturbances were observed in 6 cases, all of which also showed alexia without agraphia. The lesions extended not only of the inferior surface of the occipital lobe and along the interhemispheric fissure, but also of hippocampal and parahippocampal gyri. In 3 cases of alexia without agraphia in which no memory distrubance was found, the symptoms of alexia were slight and disappeared at an early stage. (J.P.N.)

  5. Increased spatial granularity of left brain activation and unique age/gender signatures: a 4D frequency domain approach to cerebral lateralization at rest.

    Science.gov (United States)

    Agcaoglu, O; Miller, R; Mayer, A R; Hugdahl, K; Calhoun, V D

    2016-12-01

    Cerebral lateralization is a well-studied topic. However, most of the research to date in functional magnetic resonance imaging (fMRI) has been carried out on hemodynamic fluctuations of voxels, networks, or regions of interest (ROIs). For example, cerebral differences can be revealed by comparing the temporal activation of an ROI in one hemisphere with the corresponding homotopic region in the other hemisphere. While this approach can reveal significant information about cerebral organization, it does not provide information about the full spatiotemporal organization of the hemispheres. The cerebral differences revealed in literature suggest that hemispheres have different spatiotemporal organization in the resting state. In this study, we evaluate cerebral lateralization in the 4D spatiotemporal frequency domain to compare the hemispheres in the context of general activation patterns at different spatial and temporal scales. We use a gender-balanced resting fMRI dataset comprising over 600 healthy subjects ranging in age from 12 to 71, that have previously been studied with a network specific voxel-wise and global analysis of lateralization (Agcaoglu, et al. NeuroImage, 2014). Our analysis elucidates significant differences in the spatiotemporal organization of brain activity between hemispheres, and generally more spatiotemporal fluctuation in the left hemisphere especially in the high spatial frequency bands, and more power in the right hemisphere in the low and middle spatial frequencies. Importantly, the identified effects are not visible in the context of a typical assessment of voxelwise, regional, or even global laterality, thus our study highlights the value of 4D spatiotemporal frequency domain analyses as a complementary and powerful tool for studying brain function.

  6. Case-control study of six genes asymmetrically expressed in the two cerebral hemispheres: association of BAIAP2 with attention-deficit/hyperactivity disorder

    DEFF Research Database (Denmark)

    Ribasés, Marta; Bosch, Rosa; Hervás, Amaia

    2009-01-01

    BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset neuropsychiatric disease that persists into adulthood in at least 30% of patients. There is evidence suggesting that abnormal left-right brain asymmetries in ADHD patients may be involved in a variety of ADHD......-related cognitive processes, including sustained attention, working memory, response inhibition and planning. Although mechanisms underlying cerebral lateralization are unknown, left-right cortical asymmetry has been associated with transcriptional asymmetry at embryonic stages and several genes differentially...... expressed between hemispheres have been identified. METHODS: We selected six functional candidate genes showing at least 1.9-fold differential expression between hemispheres (BAIAP2, DAPPER1, LMO4, NEUROD6, ATP2B3, and ID2) and performed a case-control association study in an initial Spanish sample of 587...

  7. Cognitive alterations in motor imagery process after left hemispheric ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Jing Yan

    Full Text Available BACKGROUND: Motor imagery training is a promising rehabilitation strategy for stroke patients. However, few studies had focused on the neural mechanisms in time course of its cognitive process. This study investigated the cognitive alterations after left hemispheric ischemic stroke during motor imagery task. METHODOLOGY/PRINCIPAL FINDINGS: Eleven patients with ischemic stroke in left hemisphere and eleven age-matched control subjects participated in mental rotation task (MRT of hand pictures. Behavior performance, event-related potential (ERP and event-related (desynchronization (ERD/ERS in beta band were analyzed to investigate the cortical activation. We found that: (1 The response time increased with orientation angles in both groups, called "angle effect", however, stoke patients' responses were impaired with significantly longer response time and lower accuracy rate; (2 In early visual perceptual cognitive process, stroke patients showed hypo-activations in frontal and central brain areas in aspects of both P200 and ERD; (3 During mental rotation process, P300 amplitude in control subjects decreased while angle increased, called "amplitude modulation effect", which was not observed in stroke patients. Spatially, patients showed significant lateralization of P300 with activation only in contralesional (right parietal cortex while control subjects showed P300 in both parietal lobes. Stroke patients also showed an overall cortical hypo-activation of ERD during this sub-stage; (4 In the response sub-stage, control subjects showed higher ERD values with more activated cortical areas particularly in the right hemisphere while angle increased, named "angle effect", which was not observed in stroke patients. In addition, stroke patients showed significant lower ERD for affected hand (right response than that for unaffected hand. CONCLUSIONS/SIGNIFICANCE: Cortical activation was altered differently in each cognitive sub-stage of motor imagery after

  8. Left hemisphere lateralization for lexical and acoustic pitch processing in Cantonese speakers as revealed by mismatch negativity.

    Science.gov (United States)

    Gu, Feng; Zhang, Caicai; Hu, Axu; Zhao, Guoping

    2013-12-01

    For nontonal language speakers, speech processing is lateralized to the left hemisphere and musical processing is lateralized to the right hemisphere (i.e., function-dependent brain asymmetry). On the other hand, acoustic temporal processing is lateralized to the left hemisphere and spectral/pitch processing is lateralized to the right hemisphere (i.e., acoustic-dependent brain asymmetry). In this study, we examine whether the hemispheric lateralization of lexical pitch and acoustic pitch processing in tonal language speakers is consistent with the patterns of function- and acoustic-dependent brain asymmetry in nontonal language speakers. Pitch contrast in both speech stimuli (syllable /ji/ in Experiment 1) and nonspeech stimuli (harmonic tone in Experiment 1; pure tone in Experiment 2) was presented to native Cantonese speakers in passive oddball paradigms. We found that the mismatch negativity (MMN) elicited by lexical pitch contrast was lateralized to the left hemisphere, which is consistent with the pattern of function-dependent brain asymmetry (i.e., left hemisphere lateralization for speech processing) in nontonal language speakers. However, the MMN elicited by acoustic pitch contrast was also left hemisphere lateralized (harmonic tone in Experiment 1) or showed a tendency for left hemisphere lateralization (pure tone in Experiment 2), which is inconsistent with the pattern of acoustic-dependent brain asymmetry (i.e., right hemisphere lateralization for acoustic pitch processing) in nontonal language speakers. The consistent pattern of function-dependent brain asymmetry and the inconsistent pattern of acoustic-dependent brain asymmetry between tonal and nontonal language speakers can be explained by the hypothesis that the acoustic-dependent brain asymmetry is the consequence of a carryover effect from function-dependent brain asymmetry. Potential evolutionary implication of this hypothesis is discussed. © 2013.

  9. Right cerebral hemisphere and central auditory processing in children with developmental dyslexia

    Directory of Open Access Journals (Sweden)

    Paulina C. Murphy-Ruiz

    2013-11-01

    Full Text Available Objective We hypothesized that if the right hemisphere auditory processing abilities can be altered in children with developmental dyslexia (DD, we can detect dysfunction using specific tests. Method We performed an analytical comparative cross-sectional study. We studied 20 right-handed children with DD and 20 healthy right-handed control subjects (CS. Children in both groups were age, gender, and school-grade matched. Focusing on the right hemisphere’s contribution, we utilized tests to measure alterations in central auditory processing (CAP, such as determination of frequency patterns; sound duration; music pitch recognition; and identification of environmental sounds. We compared results among the two groups. Results Children with DD showed lower performance than CS in all CAP subtests, including those that preferentially engaged the cerebral right hemisphere. Conclusion Our data suggests a significant contribution of the right hemisphere in alterations of CAP in children with DD. Thus, right hemisphere CAP must be considered for examination and rehabilitation of children with DD.

  10. The course of apraxia and ADL functioning in left hemisphere stroke patients treated in rehabilitation centres and nursing homes.

    OpenAIRE

    Donkervoort, M.; Dekker, J.; Deelman, B.

    2006-01-01

    OBJECTIVE: To study the course of apraxia and daily life functioning (ADL) in left hemisphere stroke patients with apraxia. DESIGN: Prospective cohort study. SETTING: Rehabilitation centres and nursing homes. SUBJECTS: One hundred and eight left hemisphere stroke patients with apraxia, hospitalized in rehabilitation centres and nursing homes. MEASURES: ADL-observations, Barthel ADL Index, Apraxia Test, Motricity Index. RESULTS: During the study period of 20 weeks, patients showed small improv...

  11. The significance of clumsy gestures in apraxia following a left hemisphere stroke.

    Science.gov (United States)

    Kangas, Maria; Tate, Robyn L

    2006-02-01

    Individuals who sustain a cerebrovascular accident (CVA) in the dominant (typically left) hemisphere, are at increased risk of developing motor skill deficits due to motor-sensory impairments, as well as cognitive impairments (e.g., apraxia). Clumsiness is a central component affecting motor skills in individuals with a left hemisphere CVA (LCVA). The term "clumsiness" however, has not been adequately operationalised in the apraxia literature in clinical terms, thereby making diagnosis difficult and its contribution to apraxic disorders uncertain. Accordingly, in this study "clumsiness" was explicitly defined by establishing a set of four criteria. The non-dominant (left) hand movements of three groups of participants were examined: 10 individuals with limb-apraxia (APX); 8 individuals without limb apraxia who had sustained a LCVA (NAPX); and 19 healthy individuals without a history of brain impairment (NBD). Performance was examined on four sets of motor tasks, including a conventional praxis test, basic perceptual-motor co-ordination and fine movement tasks, and a naturalistic actions test. A striking finding that emerged was that clumsy errors occurred frequently in all groups, including the NBD group, particularly on the praxis and fine motor tasks. In terms of quantity of clumsy errors emitted, the APX group made significantly more clumsy gestures across all four tasks in comparison to the NBD group. No differences emerged between the two clinical groups, however, in terms of total clumsy gestures emitted on the naturalistic action tasks, or the type of clumsy errors emitted on the fine motor tasks. Thus, frequency and types of clumsy gestures were partly determined by task demands. These results highlight the need to consider the contribution of clumsy gestures in limb functioning following hemispheric brain damage. In broad terms, these findings emphasise the importance of adopting more detailed analyses of movement errors in apraxia and assessments of

  12. Reading laterally: the cerebral hemispheric use of spatial frequencies in visual word recognition.

    Science.gov (United States)

    Tadros, Karine; Dupuis-Roy, Nicolas; Fiset, Daniel; Arguin, Martin; Gosselin, Frédéric

    2013-01-04

    It is generally accepted that the left hemisphere (LH) is more capable for reading than the right hemisphere (RH). Left hemifield presentations (initially processed by the RH) lead to a globally higher error rate, slower word identification, and a significantly stronger word length effect (i.e., slower reaction times for longer words). Because the visuo-perceptual mechanisms of the brain for word recognition are primarily localized in the LH (Cohen et al., 2003), it is possible that this part of the brain possesses better spatial frequency (SF) tuning for processing the visual properties of words than the RH. The main objective of this study is to determine the SF tuning functions of the LH and RH for word recognition. Each word image was randomly sampled in the SF domain using the SF bubbles method (Willenbockel et al., 2010) and was presented laterally to the left or right visual hemifield. As expected, the LH requires less visual information than the RH to reach the same level of performance, illustrating the well-known LH advantage for word recognition. Globally, the SF tuning of both hemispheres is similar. However, these seemingly identical tuning functions hide important differences. Most importantly, we argue that the RH requires higher SFs to identify longer words because of crowding.

  13. Left hemisphere dysfunction during verbal dichotic listening tests in patients who have social phobia with or without comorbid depressive disorder.

    Science.gov (United States)

    Bruder, Gerard E; Schneier, Franklin R; Stewart, Jonathan W; McGrath, Patrick J; Quitkin, Frederic

    2004-01-01

    Behavioral, electrophysiological, and imaging studies have found evidence that anxiety disorders are associated with left hemisphere dysfunction or higher than normal activation of right hemisphere regions. Few studies, however, have examined hemispheric asymmetries of function in social phobia, and the influence of comorbidity with depressive disorders is unknown. The present study used dichotic listening tests to assess lateralized cognitive processing in patients with social phobia, depression, or comorbid social phobia and depression. The study used a two-by-two factorial design in which one factor was social phobia (present versus absent) and the second factor was depressive disorder (present versus absent). A total of 125 unmedicated patients with social phobia, depressive disorder, or comorbid social phobia and depressive disorder and 44 healthy comparison subjects were tested on dichotic fused-words, consonant-vowel syllable, and complex tone tests. Patients with social phobia with or without a comorbid depressive disorder had a smaller left hemisphere advantage for processing words and syllables, compared with subjects without social phobia, whereas no difference between groups was found in the right hemisphere advantage for processing complex tones. Depressed women had a larger left hemisphere advantage for processing words, compared with nondepressed women, but this difference was not seen among men. The results support the hypothesis that social phobia is associated with dysfunction of left hemisphere regions mediating verbal processing. Given the importance of verbal processes in social interactions, this dysfunction may contribute to the stress and difficulty experienced by patients with social phobia in social situations.

  14. Cerebral Lateralization of Face-Selective and Body-Selective Visual Areas Depends on Handedness

    NARCIS (Netherlands)

    Willems, R.M.; Peelen, M.V.; Hagoort, P.

    2010-01-01

    The left-hemisphere dominance for language is a core example of the functional specialization of the cerebral hemispheres. The degree of left-hemisphere dominance for language depends on hand preference: Whereas the majority of right-handers show left-hemispheric language lateralization, this number

  15. Cerebral lateralization of face-selective and body-selective visual areas depends on handedness

    NARCIS (Netherlands)

    Willems, R.M.; Peelen, M.V.; Hagoort, P.

    2010-01-01

    The left-hemisphere dominance for language is a core example of the functional specialization of the cerebral hemispheres. The degree of left-hemisphere dominance for language depends on hand preference: Whereas the majority of right-handers show left-hemispheric language lateralization, this number

  16. Damage to white matter bottlenecks contributes to language impairments after left hemispheric stroke

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    Joseph C. Griffis

    2017-01-01

    Full Text Available Damage to the white matter underlying the left posterior temporal lobe leads to deficits in multiple language functions. The posterior temporal white matter may correspond to a bottleneck where both dorsal and ventral language pathways are vulnerable to simultaneous damage. Damage to a second putative white matter bottleneck in the left deep prefrontal white matter involving projections associated with ventral language pathways and thalamo-cortical projections has recently been proposed as a source of semantic deficits after stroke. Here, we first used white matter atlases to identify the previously described white matter bottlenecks in the posterior temporal and deep prefrontal white matter. We then assessed the effects of damage to each region on measures of verbal fluency, picture naming, and auditory semantic decision-making in 43 chronic left hemispheric stroke patients. Damage to the posterior temporal bottleneck predicted deficits on all tasks, while damage to the anterior bottleneck only significantly predicted deficits in verbal fluency. Importantly, the effects of damage to the bottleneck regions were not attributable to lesion volume, lesion loads on the tracts traversing the bottlenecks, or damage to nearby cortical language areas. Multivariate lesion-symptom mapping revealed additional lesion predictors of deficits. Post-hoc fiber tracking of the peak white matter lesion predictors using a publicly available tractography atlas revealed evidence consistent with the results of the bottleneck analyses. Together, our results provide support for the proposal that spatially specific white matter damage affecting bottleneck regions, particularly in the posterior temporal lobe, contributes to chronic language deficits after left hemispheric stroke. This may reflect the simultaneous disruption of signaling in dorsal and ventral language processing streams.

  17. Independent and Collaborative Contributions of the Cerebral Hemispheres to Emotional Processing

    Science.gov (United States)

    Shobe, Elizabeth R.

    2014-01-01

    Presented is a model suggesting that the right hemisphere (RH) directly mediates the identification and comprehension of positive and negative emotional stimuli, whereas the left hemisphere (LH) contributes to higher level processing of emotional information that has been shared via the corpus callosum. RH subcortical connections provide initial processing of emotional stimuli, and their innervation to cortical structures provides a secondary pathway by which the hemispheres process emotional information more fully. It is suggested that the LH contribution to emotion processing is in emotional regulation, social well-being, and adaptation, and transforming the RH emotional experience into propositional and verbal codes. Lastly, it is proposed that the LH has little ability at the level of emotion identification, having a default positive bias and no ability to identify a stimulus as negative. Instead, the LH must rely on the transfer of emotional information from the RH to engage higher-order emotional processing. As such, either hemisphere can identify positive emotions, but they must collaborate for complete processing of negative emotions. Evidence presented draws from behavioral, neurological, and clinical research, including discussions of subcortical and cortical pathways, callosal agenesis, commissurotomy, emotion regulation, mood disorders, interpersonal interaction, language, and handedness. Directions for future research are offered. PMID:24795597

  18. Left hemisphere structural connectivity abnormality in pediatric hydrocephalus patients following surgery

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    Weihong Yuan

    2016-01-01

    Full Text Available Neuroimaging research in surgically treated pediatric hydrocephalus patients remains challenging due to the artifact caused by programmable shunt. Our previous study has demonstrated significant alterations in the whole brain white matter structural connectivity based on diffusion tensor imaging (DTI and graph theoretical analysis in children with hydrocephalus prior to surgery or in surgically treated children without programmable shunts. This study seeks to investigate the impact of brain injury on the topological features in the left hemisphere, contratelateral to the shunt placement, which will avoid the influence of shunt artifacts and makes further group comparisons feasible for children with programmable shunt valves. Three groups of children (34 in the control group, 12 in the 3-month post-surgery group, and 24 in the 12-month post-surgery group, age between 1 and 18 years were included in the study. The structural connectivity data processing and analysis were performed based on DTI and graph theoretical analysis. Specific procedures were revised to include only left brain imaging data in normalization, parcellation, and fiber counting from DTI tractography. Our results showed that, when compared to controls, children with hydrocephalus in both the 3-month and 12-month post-surgery groups had significantly lower normalized clustering coefficient, lower small-worldness, and higher global efficiency (all p < 0.05, corrected. At a regional level, both patient groups showed significant alteration in one or more regional connectivity measures in a series of brain regions in the left hemisphere (8 and 10 regions in the 3-month post-surgery and the 12-month post-surgery group, respectively, all p < 0.05, corrected. No significant correlation was found between any of the global or regional measures and the contemporaneous neuropsychological outcomes [the General Adaptive Composite (GAC from the Adaptive Behavior Assessment System, Second

  19. Diffusion tensor imaging of early changes in corpus callosum after acute cerebral hemisphere lesions in newborns

    International Nuclear Information System (INIS)

    Righini, Andrea; Doneda, Chiara; Parazzini, Cecilia; Arrigoni, Filippo; Triulzi, Fabio; Matta, Ursula

    2010-01-01

    The main purpose was to investigate any early diffusion tensor imaging (DTI) changes in corpus callosum (CC) associated with acute cerebral hemisphere lesions in term newborns. We retrospectively analysed 19 cases of term newborns acutely affected by focal or multi-focal lesions: hypoxic-ischemic encephalopathy, hypoglycaemic encephalopathy, focal ischemic stroke and deep medullary vein associated lesions. DTI was acquired at 1.5 Tesla with dedicated neonatal coil. DTI metrics (apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial λ parallel and radial λ diffusivity) were measured in the hemisphere lesions and in the CC. The control group included seven normal newborns. The following significant differences were found between patients and normal controls in the CC: mean ADC was lower in patients (0.88 SD 0.23 versus 1.18 SD 0.07 μm 2 /s) and so was mean FA (0.50 SD 0.1 versus 0.67 SD 0.05) and mean λ parallel value (1.61 SD 0.52 versus 2.36 SD 0.14 μm 2 /s). In CC the percentage of ADC always diminished independently of lesion age (with one exception), whereas in hemisphere lesions, it was negative in earlier lesions, but exceeded normal values in the older lesions. CC may undergo early DTI changes in newborns with acute focal or multi-focal hemisphere lesions of different aetiology. Although a direct insult to CC cannot be totally ruled out, DTI changes in CC (in particular λ parallel ) may also be compatible with very early Wallerian degeneration or pre-Wallerian degeneration. (orig.)

  20. Diffusion tensor imaging of early changes in corpus callosum after acute cerebral hemisphere lesions in newborns

    Energy Technology Data Exchange (ETDEWEB)

    Righini, Andrea; Doneda, Chiara; Parazzini, Cecilia; Arrigoni, Filippo; Triulzi, Fabio [Children' s Hospital V. Buzzi, ICP, Radiology and Neuroradiology Department, Milan (Italy); Matta, Ursula [University of Milan, Radiology Institute, Milan (Italy)

    2010-11-15

    The main purpose was to investigate any early diffusion tensor imaging (DTI) changes in corpus callosum (CC) associated with acute cerebral hemisphere lesions in term newborns. We retrospectively analysed 19 cases of term newborns acutely affected by focal or multi-focal lesions: hypoxic-ischemic encephalopathy, hypoglycaemic encephalopathy, focal ischemic stroke and deep medullary vein associated lesions. DTI was acquired at 1.5 Tesla with dedicated neonatal coil. DTI metrics (apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial {lambda} {sub parallel} and radial {lambda} diffusivity) were measured in the hemisphere lesions and in the CC. The control group included seven normal newborns. The following significant differences were found between patients and normal controls in the CC: mean ADC was lower in patients (0.88 SD 0.23 versus 1.18 SD 0.07 {mu}m{sup 2}/s) and so was mean FA (0.50 SD 0.1 versus 0.67 SD 0.05) and mean {lambda} {sub parallel} value (1.61 SD 0.52 versus 2.36 SD 0.14 {mu}m{sup 2}/s). In CC the percentage of ADC always diminished independently of lesion age (with one exception), whereas in hemisphere lesions, it was negative in earlier lesions, but exceeded normal values in the older lesions. CC may undergo early DTI changes in newborns with acute focal or multi-focal hemisphere lesions of different aetiology. Although a direct insult to CC cannot be totally ruled out, DTI changes in CC (in particular {lambda} {sub parallel}) may also be compatible with very early Wallerian degeneration or pre-Wallerian degeneration. (orig.)

  1. Altered functional connectivity differs in stroke survivors with impaired touch sensation following left and right hemisphere lesions

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    Peter Goodin

    Full Text Available One in two survivors experience impairment in touch sensation after stroke. The nature of this impairment is likely associated with changes associated with the functional somatosensory network of the brain; however few studies have examined this. In particular, the impact of lesioned hemisphere has not been investigated. We examined resting state functional connectivity in 28 stroke survivors, 14 with left hemisphere and 14 with right hemisphere lesion, and 14 healthy controls. Contra-lesional hands showed significantly decreased touch discrimination. Whole brain functional connectivity (FC data was extracted from four seed regions, i.e. primary (S1 and secondary (S2 somatosensory cortices in both hemispheres. Whole brain FC maps and Laterality Indices (LI were calculated for subgroups. Inter-hemispheric FC was greater in healthy controls compared to the combined stroke cohort from the left S1 seed and bilateral S2 seeds. The left lesion subgroup showed decreased FC, relative to controls, from left ipsi-lesional S1 to contra-lesional S1 and to distributed temporal, occipital and parietal regions. In comparison, the right lesion group showed decreased connectivity from contra-lesional left S1 and bilateral S2 to ipsi-lesional parietal operculum (S2, and to occipital and temporal regions. The right lesion group also showed increased intra-hemispheric FC from ipsi-lesional right S1 to inferior parietal regions compared to controls. In comparison to the left lesion group, those with right lesion showed greater intra-hemispheric connectivity from left S1 to left parietal and occipital regions and from right S1 to right angular and parietal regions. Laterality Indices were significantly greater for stroke subgroups relative to matched controls for contra-lesional S1 (left lesion group and contra-lesional S2 (both groups. We provide evidence of altered functional connectivity within the somatosensory network, across both hemispheres, and to other

  2. Altered functional connectivity differs in stroke survivors with impaired touch sensation following left and right hemisphere lesions.

    Science.gov (United States)

    Goodin, Peter; Lamp, Gemma; Vidyasagar, Rishma; McArdle, David; Seitz, Rüdiger J; Carey, Leeanne M

    2018-01-01

    One in two survivors experience impairment in touch sensation after stroke. The nature of this impairment is likely associated with changes associated with the functional somatosensory network of the brain; however few studies have examined this. In particular, the impact of lesioned hemisphere has not been investigated. We examined resting state functional connectivity in 28 stroke survivors, 14 with left hemisphere and 14 with right hemisphere lesion, and 14 healthy controls. Contra-lesional hands showed significantly decreased touch discrimination. Whole brain functional connectivity (FC) data was extracted from four seed regions, i.e. primary (S1) and secondary (S2) somatosensory cortices in both hemispheres. Whole brain FC maps and Laterality Indices (LI) were calculated for subgroups. Inter-hemispheric FC was greater in healthy controls compared to the combined stroke cohort from the left S1 seed and bilateral S2 seeds. The left lesion subgroup showed decreased FC, relative to controls, from left ipsi-lesional S1 to contra-lesional S1 and to distributed temporal, occipital and parietal regions. In comparison, the right lesion group showed decreased connectivity from contra-lesional left S1 and bilateral S2 to ipsi-lesional parietal operculum (S2), and to occipital and temporal regions. The right lesion group also showed increased intra-hemispheric FC from ipsi-lesional right S1 to inferior parietal regions compared to controls. In comparison to the left lesion group, those with right lesion showed greater intra-hemispheric connectivity from left S1 to left parietal and occipital regions and from right S1 to right angular and parietal regions. Laterality Indices were significantly greater for stroke subgroups relative to matched controls for contra-lesional S1 (left lesion group) and contra-lesional S2 (both groups). We provide evidence of altered functional connectivity within the somatosensory network, across both hemispheres, and to other networks in stroke

  3. Multimodality language mapping in patients with left-hemispheric language dominance on Wada test.

    Science.gov (United States)

    Kojima, Katsuaki; Brown, Erik C; Rothermel, Robert; Carlson, Alanna; Matsuzaki, Naoyuki; Shah, Aashit; Atkinson, Marie; Mittal, Sandeep; Fuerst, Darren; Sood, Sandeep; Asano, Eishi

    2012-10-01

    We determined the utility of electrocorticography (ECoG) and stimulation for detecting language-related sites in patients with left-hemispheric language-dominance on Wada test. We studied 13 epileptic patients who underwent language mapping using event-related gamma-oscillations on ECoG and stimulation via subdural electrodes. Sites showing significant gamma-augmentation during an auditory-naming task were defined as language-related ECoG sites. Sites at which stimulation resulted in auditory perceptual changes, failure to verbalize a correct answer, or sensorimotor symptoms involving the mouth were defined as language-related stimulation sites. We determined how frequently these methods revealed language-related sites in the superior-temporal, inferior-frontal, dorsolateral-premotor, and inferior-Rolandic regions. Language-related sites in the superior-temporal and inferior-frontal gyri were detected by ECoG more frequently than stimulation (p hemispheric language-dominance. Measurement of language-related gamma-oscillations is warranted in presurgical evaluation of epileptic patients. Copyright © 2012 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Frequency-difference MIT imaging of cerebral haemorrhage with a hemispherical coil array: numerical modelling.

    Science.gov (United States)

    Zolgharni, M; Griffiths, H; Ledger, P D

    2010-08-01

    The feasibility of detecting a cerebral haemorrhage with a hemispherical MIT coil array consisting of 56 exciter/sensor coils of 10 mm radius and operating at 1 and 10 MHz was investigated. A finite difference method combined with an anatomically realistic head model comprising 12 tissue types was used to simulate the strokes. Frequency-difference images were reconstructed from the modelled data with different levels of the added phase noise and two types of a priori boundary errors: a displacement of the head and a size scaling error. The results revealed that a noise level of 3 m degrees (standard deviation) was adequate for obtaining good visualization of a peripheral stroke (volume approximately 49 ml). The simulations further showed that the displacement error had to be within 3-4 mm and the scaling error within 3-4% so as not to cause unacceptably large artefacts on the images.

  5. Heterogeneity in semantic priming effect with a lexical decision task in patients after left hemisphere stroke

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    Candice Steffen Holderbaum

    Full Text Available ABSTRACT Investigations on the semantic priming effect (SPE in patients after left hemisphere (LH lesions have shown disparities that may be explained by the variability in performance found among patients. The aim of the present study was to verify the existence of subgroups of patients after LH stroke by searching for dissociations between performance on the lexical decision task based on the semantic priming paradigm and performance on direct memory, semantic association and language tasks. All 17 patients with LH lesions after stroke (ten non-fluent aphasics and seven non aphasics were analyzed individually. Results indicated the presence of three groups of patients according to SPE: one exhibiting SPE at both stimulus onset asynchronies (SOAs, one with SPE only at long SOA, and another, larger group with no SPE.

  6. Post-stroke acquired amusia: A comparison between right- and left-brain hemispheric damages.

    Science.gov (United States)

    Jafari, Zahra; Esmaili, Mahdiye; Delbari, Ahmad; Mehrpour, Masoud; Mohajerani, Majid H

    2017-01-01

    Although extensive research has been published about the emotional consequences of stroke, most studies have focused on emotional words, speech prosody, voices, or facial expressions. The emotional processing of musical excerpts following stroke has been relatively unexplored. The present study was conducted to investigate the effects of chronic stroke on the recognition of basic emotions in music. Seventy persons, including 25 normal controls (NC), 25 persons with right brain damage (RBD) from stroke, and 20 persons with left brain damage (LBD) from stroke between the ages of 31-71 years were studied. The Musical Emotional Bursts (MEB) test, which consists of a set of short musical pieces expressing basic emotional states (happiness, sadness, and fear) and neutrality, was used to test musical emotional perception. Both stroke groups were significantly poorer than normal controls for the MEB total score and its subtests (p right hemisphere dominance in processing negative emotions.

  7. Left-hemisphere activation is associated with enhanced vocal pitch error detection in musicians with absolute pitch

    Science.gov (United States)

    Behroozmand, Roozbeh; Ibrahim, Nadine; Korzyukov, Oleg; Robin, Donald A.; Larson, Charles R.

    2014-01-01

    The ability to process auditory feedback for vocal pitch control is crucial during speaking and singing. Previous studies have suggested that musicians with absolute pitch (AP) develop specialized left-hemisphere mechanisms for pitch processing. The present study adopted an auditory feedback pitch perturbation paradigm combined with ERP recordings to test the hypothesis whether the neural mechanisms of the left-hemisphere enhance vocal pitch error detection and control in AP musicians compared with relative pitch (RP) musicians and non-musicians (NM). Results showed a stronger N1 response to pitch-shifted voice feedback in the right-hemisphere for both AP and RP musicians compared with the NM group. However, the left-hemisphere P2 component activation was greater in AP and RP musicians compared with NMs and also for the AP compared with RP musicians. The NM group was slower in generating compensatory vocal reactions to feedback pitch perturbation compared with musicians, and they failed to re-adjust their vocal pitch after the feedback perturbation was removed. These findings suggest that in the earlier stages of cortical neural processing, the right hemisphere is more active in musicians for detecting pitch changes in voice feedback. In the later stages, the left-hemisphere is more active during the processing of auditory feedback for vocal motor control and seems to involve specialized mechanisms that facilitate pitch processing in the AP compared with RP musicians. These findings indicate that the left hemisphere mechanisms of AP ability are associated with improved auditory feedback pitch processing during vocal pitch control in tasks such as speaking or singing. PMID:24355545

  8. Multi-tasking uncovers right spatial neglect and extinction in chronic left-hemisphere stroke patients.

    Science.gov (United States)

    Blini, Elvio; Romeo, Zaira; Spironelli, Chiara; Pitteri, Marco; Meneghello, Francesca; Bonato, Mario; Zorzi, Marco

    2016-11-01

    Unilateral Spatial Neglect, the most dramatic manifestation of contralesional space unawareness, is a highly heterogeneous syndrome. The presence of neglect is related to core spatially lateralized deficits, but its severity is also modulated by several domain-general factors (such as alertness or sustained attention) and by task demands. We previously showed that a computer-based dual-task paradigm exploiting both lateralized and non-lateralized factors (i.e., attentional load/multitasking) better captures this complex scenario and exacerbates deficits for the contralesional space after right hemisphere damage. Here we asked whether multitasking would reveal contralesional spatial disorders in chronic left-hemisphere damaged (LHD) stroke patients, a population in which impaired spatial processing is thought to be uncommon. Ten consecutive LHD patients with no signs of right-sided neglect at standard neuropsychological testing performed a computerized spatial monitoring task with and without concurrent secondary tasks (i.e., multitasking). Severe contralesional (right) space unawareness emerged in most patients under attentional load in both the visual and auditory modalities. Multitasking affected the detection of contralesional stimuli both when presented concurrently with an ipsilesional one (i.e., extinction for bilateral targets) and when presented in isolation (i.e., left neglect for right-sided targets). No spatial bias emerged in a control group of healthy elderly participants, who performed at ceiling, as well as in a second control group composed of patients with Mild Cognitive Impairment. We conclude that the pathological spatial asymmetry in LHD patients cannot be attributed to a global reduction of cognitive resources but it is the consequence of unilateral brain damage. Clinical and theoretical implications of the load-dependent lack of awareness for contralesional hemispace following LHD are discussed. Copyright © 2016. Published by Elsevier Ltd.

  9. Detectability and detection rate of acute cerebral hemisphere infarcts on CT and diffusion-weighted MRI

    International Nuclear Information System (INIS)

    Urbach, H.; Flacke, S.; Keller, E.; Textor, J.; Berlis, A.; Reul, J.; Schild, H.H.; Hartmann, A.; Solymosi, L.

    2000-01-01

    Our purpose was to compare the detectability and detection rate of acute ischaemic cerebral hemisphere infarcts on CT and diffusion-weighted MRI (DWI). We investigated 32 consecutive patients with acute hemisphere stroke with unenhanced CT and DWI within 6 h of stroke onset. The interval between CT and DWI ranged from 15 to 180 min (mean 60 min). Infarct detectability on CT and DWI was determined by comparing the initial CT, DWI and later reference images in a consensus reading of five independent examiners. The ''true'' detection rate was assessed by analysing all single readings. Two patients had intracerebral haematomas on DWI and CT and were excluded. There were 27 patients with ischaemic infarcts; all were visible on DWI and proven by follow-up. DWI was negative in three patients without a final diagnosis of infarct (100 % sensitivity, 100 % specificity, χ 2 = 30, P 2 = 1.48, P = 0.224). With regard to the single readings (30 examinations x 5 examiners = 150 readings), 63 CT readings were true positive and 72 false negative (sensitivity 47 %, specificity 86 %, χ 2 = 2.88, P = 0.089). Of the DWI readings 128 were true positive and 7 false negative (sensitivity 95 %, specificity 87 %, χ 2 = 70.67, P < 0.0001). Interobserver agreement was substantial for CT (χ= 0.72, 95 % confidence interval, 0.6-0.84) and DWI (χ= 0.82, 95 % confidence interval, 0.46-1). Taken together, detectability and detection rate of acute (< 6 h) hemisphere infarcts are significantly higher with DWI than with CT. (orig.)

  10. Left hemisphere structural connectivity abnormality in pediatric hydrocephalus patients following surgery.

    Science.gov (United States)

    Yuan, Weihong; Meller, Artur; Shimony, Joshua S; Nash, Tiffany; Jones, Blaise V; Holland, Scott K; Altaye, Mekibib; Barnard, Holly; Phillips, Jannel; Powell, Stephanie; McKinstry, Robert C; Limbrick, David D; Rajagopal, Akila; Mangano, Francesco T

    2016-01-01

    Neuroimaging research in surgically treated pediatric hydrocephalus patients remains challenging due to the artifact caused by programmable shunt. Our previous study has demonstrated significant alterations in the whole brain white matter structural connectivity based on diffusion tensor imaging (DTI) and graph theoretical analysis in children with hydrocephalus prior to surgery or in surgically treated children without programmable shunts. This study seeks to investigate the impact of brain injury on the topological features in the left hemisphere, contratelateral to the shunt placement, which will avoid the influence of shunt artifacts and makes further group comparisons feasible for children with programmable shunt valves. Three groups of children (34 in the control group, 12 in the 3-month post-surgery group, and 24 in the 12-month post-surgery group, age between 1 and 18 years) were included in the study. The structural connectivity data processing and analysis were performed based on DTI and graph theoretical analysis. Specific procedures were revised to include only left brain imaging data in normalization, parcellation, and fiber counting from DTI tractography. Our results showed that, when compared to controls, children with hydrocephalus in both the 3-month and 12-month post-surgery groups had significantly lower normalized clustering coefficient, lower small-worldness, and higher global efficiency (all p  hydrocephalus surgically treated with programmable shunts.

  11. Cognitive outcome after awake surgery for left and right hemisphere tumours

    Directory of Open Access Journals (Sweden)

    Elke De Witte

    2015-04-01

    Full Text Available INTRODUCTION: Awake surgery in eloquent brain regions is performed to preserve language and other cognitive functions. Although in general, no major permanent cognitive deficits are found after awake brain surgery, clinically relevant impairments are detected and cognitive recovery takes longer than generally assumed (3 months (Santini et al., 2012; Satoer et al., 2014; Talacchi et al., 2012. However, as there is a lack of extensive cognitive follow-up data it is unknown when recovery takes place. In addition, the influence of critical language sites identified by direct electrical stimulation (DES and tumour variables (e.g. left/right tumour location, tumour grade on long-term cognitive findings remains unclear. METHODS: In this longitudinal study the short-term and long-term effects of awake surgery on cognition were investigated in 40 patients (29 patients with left and 11 with right hemisphere tumours. Language, memory, attentional, executive and visuospatial functions were assessed in the preoperative phase, at short-term follow-up (6 weeks postsurgery and at long-term follow-up (6 months postsurgery with a neuropsychological protocol. In addition, the effect of intraoperative critical language sites, left/right tumour location, hemispheric language dominance, extent of resection and adjuvant treatment on cognitive change was studied. RESULTS: Both pre- and postoperatively, the mean performance of the patients was worse (impairment = z-score below -2 than the performance of the normal population in the language domain, the memory domain, the attentional and executive domain (p .05. Awake surgery negatively affected language, attentional and executive functions but not memory and visuospatial functions. At 6 weeks postsurgery, performance on all language, attentional and executive tasks deteriorated (object/action naming, semantic/phonological fluency from DuLIP, Token test; Trail Making Test A & B, Stroop I, II, & III. At 6 months

  12. Crossed aphasia: an analysis of the symptoms, their frequency, and a comparison with left-hemisphere aphasia symptomatology.

    Science.gov (United States)

    Coppens, Patrick; Hungerford, Suzanne; Yamaguchi, Satoshi; Yamadori, Atsushi

    2002-12-01

    This study presents a thorough analysis of published crossed aphasia (CA) cases, including for the first time the cases published in Japanese. The frequency of specific symptoms was determined, and symptomatology differences based on gender, familial sinistrality, and CA subtype were investigated. Results suggested that the CA population is comparable to the left-hemisphere patient population. However, male were significantly more likely than female CA subjects to show a positive history of familial sinistrality. Typical right-hemisphere (i.e., nonlanguage-dominant) symptoms were frequent but rarely carefully reported or assessed. Results are compared with previous CA reviews and left-hemisphere aphasia. Suggestions for a more systematic assessment of the CA symptomatology are presented.

  13. Neural Networks Mediating High-Level Mentalizing in Patients With Right Cerebral Hemispheric Gliomas

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    Riho Nakajima

    2018-03-01

    Full Text Available Mentalizing is the ability to understand others’ mental state through external cues. It consists of two networks, namely low-level and high-level metalizing. Although it is an essential function in our daily social life, surgical resection of right cerebral hemisphere disturbs mentalizing processing with high possibility. In the past, little was known about the white matter related to high-level mentalizing, and the conservation of high-level mentalizing during surgery has not been a focus of attention. Therefore, the main purpose of this study was to examine the neural networks underlying high-level mentalizing and then, secondarily, investigate the usefulness of awake surgery in preserving the mentalizing network. A total of 20 patients with glioma localized in the right hemisphere who underwent awake surgery participated in this study. All patients were assigned to two groups: with or without intraoperative assessment of high-level mentalizing. Their high-level mentalizing abilities were assessed before surgery and 1 week and 3 months after surgery. At 3 months after surgery, only patients who received the intraoperative high-level mentalizing test showed the same score as normal healthy volunteers. The tract-based lesion symptom analysis was performed to confirm the severity of damage of associated fibers and high-level mentalizing accuracy. This analysis revealed the superior longitudinal fascicles (SLF III and fronto-striatal tract (FST to be associated with high-level mentalizing processing. Moreover, the voxel-based lesion symptom analysis demonstrated that resection of orbito-frontal cortex (OFC causes persistent mentalizing dysfunction. Our study indicates that damage of the OFC and structural connectivity of the SLF and FST causes the disorder of mentalizing after surgery, and assessing high-level mentalizing during surgery may be useful to preserve these pathways.

  14. Gait Patterns in Hemiplegic Children with Cerebral Palsy: Comparison of Right and Left Hemiplegia

    Science.gov (United States)

    Galli, Manuela; Cimolin, Veronica; Rigoldi, Chiara; Tenore, Nunzio; Albertini, Giorgio

    2010-01-01

    The aims of this study are to compare quantitatively the gait strategy of the right and left hemiplegic children with Cerebral Palsy (CP) using gait analysis. The gait strategy of 28 right hemiparetic CP (RHG) and 23 left hemiparetic CP (LHG) was compared using gait analysis (spatio-temporal and kinematic parameters) and considering the hemiplegic…

  15. Diffusion tensor imaging correlates with lesion volume in cerebral hemisphere infarctions

    International Nuclear Information System (INIS)

    Rossi, Maija E; Jason, Eeva; Marchesotti, Silvia; Dastidar, Prasun; Ollikainen, Jyrki; Soimakallio, Seppo

    2010-01-01

    Both a large lesion volume and abnormalities in diffusion tensor imaging are independently associated with a poor prognosis after cerebral infarctions. Therefore, we assume that they are associated. This study assessed the associations between lesion volumes and diffusion tensor imaging in patients with a right-sided cerebral infarction. The lesion volumes of 33 patients (age 65.9 ± 8.7, 26 males and 7 females) were imaged using computed tomography (CT) in the acute phase (within 3-4 hours) and magnetic resonance imaging (MRI) in the chronic phase (follow-up at 12 months, with a range of 8-27 months). The chronic-phase fractional anisotropy (FA) and mean diffusivity (MD) values were measured at the site of the infarct and selected white matter tracts. Neurological tests in both the acute and chronic phases, and DTI lateralization were assessed with the Wilcoxon signed-rank test. The effects of thrombolytic therapy (n = 10) were assessed with the Mann-Whitney U test. The correlations between the measured parameters were analysed with Spearman's rho correlation. Bonferroni post-hoc correction was used to compensate for the familywise error rate in multiple comparisons. Several MD values in the right hemisphere correlated positively and FA values negatively with the lesion volumes. These correlations included both lesion area and healthy tissue. The results of the mini-mental state examination and the National Institutes of Health Stroke Scale also correlated with the lesion volume. A larger infarct volume is associated with more pronounced tissue modifications in the chronic stage as observed with the MD and FA alterations

  16. Detection of misery perfusion in the cerebral hemisphere with chronic unilateral major cerebral artery steno-occlusive disease using crossed cerebellar hypoperfusion: comparison of brain SPECT and PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yoshiyasu; Ogasawara, Kuniaki; Saito, Hideo; Takahashi, Yoshihiro; Ogasawara, Yasushi; Kobayashi, Masakazu; Ogawa, Akira [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Terasaki, Kazunori [Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Yoshida, Kenji; Beppu, Takaaki; Kubo, Yoshitaka; Fujiwara, Shunrou [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Tsushima, Eiki [Hirosaki University, Graduate School of Health Sciences, Hirosaki (Japan)

    2013-10-15

    In patients with unilateral internal carotid or middle cerebral artery (ICA or MCA) occlusive disease, the degree of crossed cerebellar hypoperfusion that is evident within a few months after the onset of stroke may reflect cerebral metabolic rate of oxygen in the affected cerebral hemisphere relative to that in the contralateral cerebral hemisphere. The aim of the present study was to determine whether the ratio of blood flow asymmetry in the cerebellar hemisphere to blood flow asymmetry in the cerebral hemisphere on positron emission tomography (PET) and single photon emission computed tomography (SPECT) correlates with oxygen extraction fraction (OEF) asymmetry in the cerebral hemisphere on PET in patients with chronic unilateral ICA or MCA occlusive disease and whether this blood flow ratio on SPECT detects misery perfusion in the affected cerebral hemisphere in such patients. Brain blood flow and OEF were assessed using {sup 15}O-PET and N-isopropyl-p-[{sup 123}I]iodoamphetamine ({sup 123}I-IMP) SPECT, respectively. All images were anatomically standardized using SPM2. A region of interest (ROI) was automatically placed in the bilateral MCA territories and in the bilateral cerebellar hemispheres using a three-dimensional stereotaxic ROI template, and affected-to-contralateral asymmetry in the MCA territory or contralateral-to-affected asymmetry in the cerebellar hemisphere was calculated. Sixty-three patients with reduced blood flow in the affected cerebral hemisphere on {sup 123}I-IMP SPECT were enrolled in this study. A significant correlation was observed between MCA ROI asymmetry of PET OEF and the ratio of cerebellar hemisphere asymmetry of blood flow to MCA ROI asymmetry of blood flow on PET (r = 0.381, p = 0.0019) or SPECT (r = 0.459, p = 0.0001). The correlation coefficient was higher when reanalyzed in a subgroup of 43 patients undergoing a PET study within 3 months after the last ischemic event (r = 0.541, p = 0.0001 for PET; r = 0.609, p < 0

  17. You may now kiss the bride: Interpretation of social situations by individuals with right or left hemisphere injury.

    Science.gov (United States)

    Baldo, Juliana V; Kacinik, Natalie A; Moncrief, Amber; Beghin, Francesca; Dronkers, Nina F

    2016-01-08

    While left hemisphere damage (LHD) has been clearly shown to cause a range of language impairments, patients with right hemisphere damage (RHD) also exhibit communication deficits, such as difficulties processing prosody, discourse, and social contexts. In the current study, individuals with RHD and LHD were directly compared on their ability to interpret what a character in a cartoon might be saying or thinking, in order to better understand the relative role of the right and left hemisphere in social communication. The cartoon stimuli were manipulated so as to elicit more or less formulaic responses (e.g., a scene of a couple being married by a priest vs. a scene of two people talking, respectively). Participants' responses were scored by blind raters on how appropriately they captured the gist of the social situation, as well as how formulaic and typical their responses were. Results showed that RHD individuals' responses were rated as significantly less appropriate than controls and were also significantly less typical than controls and individuals with LHD. Individuals with RHD produced a numerically lower proportion of formulaic expressions than controls, but this difference was only a trend. Counter to prediction, the pattern of performance across participant groups was not affected by how constrained/formulaic the social situation was. The current findings expand our understanding of the roles that the right and left hemispheres play in social processing and communication and have implications for the potential treatment of social communication deficits in individuals with RHD. Published by Elsevier Ltd.

  18. Pre-surgical evaluation of the cerebral tumor in the left language related areas by functional MRI

    International Nuclear Information System (INIS)

    Zou Zhitong; Ma Lin; Weng Xuchu

    2010-01-01

    Objective: To evaluate the application of combination of BOLD-fMRI and diffusion tensor tractography (DTT) in pre-operative evaluation of cerebral tumors located at the left language related areas. Methods: A non-vocal button pressing semantic judging paradigm was developed and validated in 10 right-handed volunteers at 3 T. After validation, this protocol combined with DTI were applied to 15 patients with left cerebral tumor prior to surgical resection, and 3 of them had aphasia. fMRI data analysis was on subject-specific basis by one-sampled t-test. The distance from the tumor to Broca area and pre-central 'hand-knot' area were measured separately. Functional language laterality index (LI) was calculated by taking out Broca area and Wernicke area. Three dimensional architecture of frontal lobe white matter fibers, especially arcuate fasciculus, were visualized using diffusion tensor tractography on Volume-one software. The images demonstrating relationship among tumor, language activation areas and white matter fibers were reviewed by neurosurgeons as part of pre-operative planning. One year after the operation, patients were followed up with MRI and language function test. Results: The non-vocal semantic judging paradigm successfully detect Broca area, Wernicke area and pre-central 'hand-knot' area. In 12 of 15 patients, the relationship of Broca area and pre-central motor area to the left brain tumor in language related areas was identified, which make the pre-operative neurosurgical plan applicable to minimize the disruption of language and motor. 8 patients had the left language dominant hemisphere, 3 patients with the right language dominant hemisphere and 1 patient with bilateral dominance. The other 3 patients' fMRI data were corrupted by patients' motion. Diffusion tensor images were corrupted by motion in 1 patient but demonstrated the impact of tumor on left accouter fasciculus in 14 patients. Diffusion tensor tractography showed disruption of left

  19. Therapeutic efficacy of chemotherapy with ACNU and radiation therapy for malignant glioma in the cerebral hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Miyagami, Mitsusuke; Katayama, Yoichi; Nakamura, Saburo [Nihon Univ., Tokyo (Japan). School of Medicine

    2000-10-01

    Seventy-two patients with malignant gliomas (57 with glioblastoma and 15 with anaplastic astrocytoma) in the cerebral hemisphere were studied retrospectively to evaluate the therapeutic efficacy of chemotherapy with nimustine and radiation after surgery. Survival was analyzed with the Kaplan-Meier method in 21 patients treated with radiotherapy after surgery and 51 patients treated with nimustine and radiotherapy after surgery. Histological classification age, and the extent of resection of the tumors were significantly correlated with survival. The median survival time was 8 months in patients treated with radiotherapy and 15 months in patients treated with nimustine and radiotherapy. The 2- and 5-year survival rates were 12% and 0% in patients treated with radiotherapy and 33% and 22% in patients treated with nimustine and radiotherapy. Thus, a significant difference in survival was recognized, and chemotherapy with nimustine was found to be useful as an adjuvant therapy for glioblastoma after surgery. However, survival time did not differ between intravenous and intra-arterial infusion of nimustine. (author)

  20. The effect of viewing speech on auditory speech processing is different in the left and right hemispheres.

    Science.gov (United States)

    Davis, Chris; Kislyuk, Daniel; Kim, Jeesun; Sams, Mikko

    2008-11-25

    We used whole-head magnetoencephalograpy (MEG) to record changes in neuromagnetic N100m responses generated in the left and right auditory cortex as a function of the match between visual and auditory speech signals. Stimuli were auditory-only (AO) and auditory-visual (AV) presentations of /pi/, /ti/ and /vi/. Three types of intensity matched auditory stimuli were used: intact speech (Normal), frequency band filtered speech (Band) and speech-shaped white noise (Noise). The behavioural task was to detect the /vi/ syllables which comprised 12% of stimuli. N100m responses were measured to averaged /pi/ and /ti/ stimuli. Behavioural data showed that identification of the stimuli was faster and more accurate for Normal than for Band stimuli, and for Band than for Noise stimuli. Reaction times were faster for AV than AO stimuli. MEG data showed that in the left hemisphere, N100m to both AO and AV stimuli was largest for the Normal, smaller for Band and smallest for Noise stimuli. In the right hemisphere, Normal and Band AO stimuli elicited N100m responses of quite similar amplitudes, but N100m amplitude to Noise was about half of that. There was a reduction in N100m for the AV compared to the AO conditions. The size of this reduction for each stimulus type was same in the left hemisphere but graded in the right (being largest to the Normal, smaller to the Band and smallest to the Noise stimuli). The N100m decrease for the Normal stimuli was significantly larger in the right than in the left hemisphere. We suggest that the effect of processing visual speech seen in the right hemisphere likely reflects suppression of the auditory response based on AV cues for place of articulation.

  1. Hemispheric specialization in affective responses, cerebral dominance for language, and handedness: Lateralization of emotion, language, and dexterity.

    Science.gov (United States)

    Costanzo, Elsa Yolanda; Villarreal, Mirta; Drucaroff, Lucas Javier; Ortiz-Villafañe, Manuel; Castro, Mariana Nair; Goldschmidt, Micaela; Wainsztein, Agustina Edith; Ladrón-de-Guevara, María Soledad; Romero, Carlos; Brusco, Luis Ignacio; Camprodon, Joan A; Nemeroff, Charles; Guinjoan, Salvador Martín

    2015-07-15

    Hemispheric specialization in affective responses has received little attention in the literature. This is a fundamental variable to understand circuit dynamics of networks subserving emotion. In this study we put to test a modified "valence" hypothesis of emotion processing, considering that sadness and happiness are processed by each hemisphere in relation to dominance for language and handedness. Mood induction and language activation during functional magnetic resonance imaging (fMRI) were used in 20 right-handed and 20 nonright-handed subjects, focusing on interconnected regions known to play critical roles in affective responses: subgenual cingulate cortex, amygdala, and anterior insular cortex. We observed a consistent relationship between lateralization of affective processing, motor dexterity, and language in individuals with clear right-handedness. Sadness induces a greater activation of right-hemisphere cortical structures in right-handed, left-dominant individuals, which is not evident in nonright-handed subjects who show no consistent hemispheric dominance for language. In anterior insula, right-handed individuals displayed reciprocal activation of either hemisphere depending upon mood valence, whereas amygdala activation was predominantly left-sided regardless of mood valence. Nonright-handed individuals exhibited less consistent brain lateralization of affective processing regardless of language and motor dexterity lateralization. In contrast with traditional views on emotion processing lateralization, hemispheric specialization in affective responses is not a unitary process but is specific to the brain structure being activated. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Size of Left Cardiac Chambers Correlates with Cerebral Microembolic Load in Open Heart Operations

    Directory of Open Access Journals (Sweden)

    Elena Z. Golukhova

    2010-01-01

    Full Text Available Background. Microemboli are a widely recognized etiological factor of cerebral complications in cardiac surgery patients. The present study was aimed to determine if size of left cardiac chambers relates to cerebral microembolic load in open heart operations. Methods. Thirty patients participated in the study. Echocardiography was performed in 2-3 days before surgery. A transcranial Doppler system was used for registering intraoperative microemboli. Results. Preoperative left atrium and left ventricular end-systolic and end-diastolic sizes significantly correlated with intraoperative microembolic load (s=0.48, 0.57 and 0.53, s≺.01, resp.. The associations between left ventricular diameters and number of cerebral microemboli remained significant when cardiopulmonary bypass time was included as a covariate into the analysis. Conclusions. The present results demonstrate that increased size of left heart chambers is an influential risk factor for elevated cerebral microembolic load during open heart operations. Mini-invasive surgery and carbon dioxide insufflation into wound cavity may be considered as neuroprotective approaches in patients with high risk of cerebral microembolism.

  3. Regional cerebral blood volume (rCBV) in the cerebral and cerebellar hemispheres in nomal 52 healthy adults. Measurement with contrast-enhanced dynamic echo-planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Muroi, Kenzo; Kurihara, Hiroaki; Amauchi, Hiroshi; Nozawa, Takeo; Matsubara, Sho; Yamamoto, Isao [Yokohama City Univ. (Japan). Hospital; Iwasawa, Tae

    2001-05-01

    The aim of this study was to investigate the possibility of absolute quantification of mean transit time (MTT) and rCBV in normal 52 healthy adults using contrast-enhanced dynamic echo-planar imaging, changes in signals in the middle cerebral arteries (MCAs) in the Sylvian fissures as AIF. MR was performed with a 1.5 T magnet (Horizon, GE Medical System, Milwaukee, WI). Dynamic susceptibility contrast-enhanced imaging was obtained every 1.8 second using echo-planar imaging (EPI) sequence (TE=42 msec, matrices=128 x 128) in six slices (6 mm slice thickness with 10 mm gap) including the cerebellar hemisphere at the level of middle cerebellar peduncles. The regional cerebral blood volume (rCBV) was calculated based on dilution theory. We calculated rCBV of the cerebral white matter (WM), cortical gray matter (GM), and cerebellar hemispheres (CH), and the effect of age on MTT and rCBV were evaluated linear regression analyses. The MTT of MCAs did not change with age, and the area under the curve of MCAs declined slightly with age. The mean rCBV of cortical GM, cerebral WM and cerebellar hemispheres were 8.2{+-}2.8, 2.0{+-}0.8 and 8.8{+-}2.1 respectively. The rCBV of cortical GM and the CH decreased slightly with age, however, that of WM remained to be a greater extent than those in GM. From these results, the method using AIF determined in bilateral MCAs was considered as an practical approach for the quantification of rCBV. Further clinical and/or comparative studies with other modalities will be necessary for the application of this method for patients with atherosclerosis and/or major vessel occlusion. (author)

  4. Chemotherapy with ACNU and radiation therapy for malignant glioma in cerebral hemisphere of adult

    Energy Technology Data Exchange (ETDEWEB)

    Miyagami, Mitsusuke; Tsubokawa, Takashi (Nihon Univ., Tokyo (Japan). School of Medicine)

    1990-08-01

    Fifty four cases of malignant gliomas in adults localized in the cerebral hemisphere including the location of basal ganglia and corpus callosum in 26% were survived over one month and followed more than 2 years after operation for 10 years recently. Histologically they had 40 cases of glioblastoma multiform and 14 cases of anaplastic astrocytoma. All malignant gliomas were given an operation and radiation, classifying 4 groups due to chemotherapeutic methods: Group I (20 cases) was treated by intraarterial infusion of ACNU with 20% mannitol. The others were Group II (8 cases) treated by intraarterial infusion of ACNU only, Group III (13 cases) by intravenous infusion of ACNU only and Group IV (13 cases) by no chemotherapy. Post-operative survival rates in the malignant gliomas of Group I were that 1 year survival rate was in 16 out of 20 cases (80%), 2 years in 55%, and 5 years in 25%. In glioblastoma multiform, 1 year survival rate of Group I was recognized in 70% and 2 years in 36%, a little better than the other treatments. Two year survival rate of other treatments demonstrated 17% in Group II, 25% in Group III, and 11% in Group IV. CT findings of glioblastoma multiform in Group I showed no rest tumor in 4 cases and one case of CR, and 3 cases of PR in the follow up study of 10 cases with rest tumor on CT after operation. There were no permanent complications except for temporary mild neurological deficit in 7% of Group I improving within 2 to 3 days after intraarterial infusion of ACNU and 20% mannitol. It is suggested that chemotherapy of Group I by intraarterial infusion of ACNU and 20% mannitol demonstrated a little better therapeutic efficacy than the other Groups, at least within 2 years after operation. (author).

  5. Is a lone right hemisphere enough? Neurolinguistic architecture in a case with a very early left hemispherectomy.

    Science.gov (United States)

    Danelli, Laura; Cossu, Giuseppe; Berlingeri, Manuela; Bottini, Gabriella; Sberna, Maurizio; Paulesu, Eraldo

    2013-01-01

    We studied the linguistic profile and neurolinguistic organization of a 14-year-old adolescent (EB) who underwent a left hemispherectomy at the age of 2.5 years. After initial aphasia, his language skills recovered within 2 years, with the exception of some word finding problems. Over the years, the neuropsychological assessments showed that EB's language was near-to-normal, with the exception of lexical competence, which lagged slightly behind for both auditory and written language. Moreover, EB's accuracy and speed in both reading and writing words and non-words were within the normal range, whereas difficulties emerged in reading loan words and in tasks with homophones. EB's functional magnetic resonance imaging (fMRI) patterns for several linguistic and metalinguistic tasks were similar to those observed in the dominant hemisphere of controls, suggesting that his language network conforms to a left-like linguistic neural blueprint. However, a stronger frontal recruitment suggests that linguistic tasks are more demanding for him. Finally, no specific reading activation was found in EB's occipitotemporal region, a finding consistent with the surface dyslexia-like behavioral pattern of the patient. While a lone right hemisphere may not be sufficient to guarantee full blown linguistic competences after early hemispherectomy, EB's behavioral and fMRI patterns suggest that his lone right hemisphere followed a left-like blueprint of the linguistic network.

  6. Cortical activity in the left and right hemispheres during language-related brain functions

    DEFF Research Database (Denmark)

    Lassen, N A; Larsen, B

    1980-01-01

    of cortical activity seen during various language functions, emphasizing the practically symmetrical involvement in both hemispheres. A case of auditive agnosia (with complete cortical word deafness but preserved pure tone thresholds) is presented. The patient's normal speech constitutes evidence...

  7. Transient acute renal failure and functional hemispheric depression after cerebral arteriography in diabetic patients

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj; Lund, P; Praestholm, J

    1981-01-01

    Cerebral angiography was carried out in two diabetic patients in the evaluation of minor vascular ischemic episodes. A transient acute renal failure following cerebral angiography was accompanied by a transient comatose episode with severe unilateral neurological deficits. A functional depression...

  8. Electroencephalographic (eeg coherence between visual and motor areas of the left and the right brain hemisphere while performing visuomotor task with the right and the left hand

    Directory of Open Access Journals (Sweden)

    Simon Brežan

    2007-09-01

    Full Text Available Background: Unilateral limb movements are based on the activation of contralateral primary motor cortex and the bilateral activation of premotor cortices. Performance of a visuomotor task requires a visuomotor integration between motor and visual cortical areas. The functional integration (»binding« of different brain areas, is probably mediated by the synchronous neuronal oscillatory activity, which can be determined by electroencephalographic (EEG coherence analysis. We introduced a new method of coherence analysis and compared coherence and power spectra in the left and right hemisphere for the right vs. left hand visuomotor task, hypothesizing that the increase in coherence and decrease in power spectra while performing the task would be greater in the contralateral hemisphere.Methods: We analyzed 6 healthy subjects and recorded their electroencephalogram during visuomotor task with the right or the left hand. For data analysis, a special Matlab computer programme was designed. The results were statistically analysed by a two-way analysis of variance, one-way analysis of variance and post-hoc t-tests with Bonferroni correction.Results: We demonstrated a significant increase in coherence (p < 0.05 for the visuomotor task compared to control tasks in alpha (8–13 Hz in beta 1 (13–20 Hz frequency bands between visual and motor electrodes. There were no significant differences in coherence nor power spectra depending on the hand used. The changes of coherence and power spectra between both hemispheres were symmetrical.Conclusions: In previous studies, a specific increase of coherence and decrease of power spectra for the visuomotor task was found, but we found no conclusive asymmetries when performing the task with right vs. left hand. This could be explained in a way that increases in coherence and decreases of power spectra reflect symmetrical activation and cooperation between more complex visual and motor brain areas.

  9. Hemispheric Division of Function Is the Result of Independent Probabilistic Biases

    Science.gov (United States)

    Whitehouse, Andrew J. O.; Bishop, Dorothy V. M.

    2009-01-01

    Verbal and visuospatial abilities are typically subserved by different cerebral hemispheres: the left hemisphere for the former and the right hemisphere for the latter. However little is known of the origin of this division of function. Causal theories propose that functional asymmetry is an obligatory pattern of organisation, while statistical…

  10. Organizational strategy influence on visual memory performance after stroke: cortical/subcortical and left/right hemisphere contrasts.

    Science.gov (United States)

    Lange, G; Waked, W; Kirshblum, S; DeLuca, J

    2000-01-01

    To examine how organizational strategy at encoding influences visual memory performance in stroke patients. Case control study. Postacute rehabilitation hospital. Stroke patients with right hemisphere damage (n = 20) versus left hemisphere damage (n = 15), and stroke patients with cortical damage (n = 11) versus subcortical damage (n = 19). Organizational strategy scores, recall performance on the Rey-Osterrieth Complex Figure (ROCF). Results demonstrated significantly greater organizational impairment and less accurate copy performance (i.e., encoding of visuospatial information on the ROCF) in the right compared to the left hemisphere group, and in the cortical relative to the subcortical group. Organizational strategy and copy accuracy scores were significantly related to each other. The absolute amount of immediate and delayed recall was significantly associated with poor organizational strategy scores. However, relative to the amount of visual information originally encoded, memory performances did not differ between groups. These findings suggest that visual memory impairments after stroke may be caused by a lack of organizational strategy affecting information encoding, rather than an impairment in memory storage or retrieval.

  11. Co-speech hand movements during narrations: What is the impact of right vs. left hemisphere brain damage?

    Science.gov (United States)

    Hogrefe, Katharina; Rein, Robert; Skomroch, Harald; Lausberg, Hedda

    2016-12-01

    Persons with brain damage show deviant patterns of co-speech hand movement behaviour in comparison to healthy speakers. It has been claimed by several authors that gesture and speech rely on a single production mechanism that depends on the same neurological substrate while others claim that both modalities are closely related but separate production channels. Thus, findings so far are contradictory and there is a lack of studies that systematically analyse the full range of hand movements that accompany speech in the condition of brain damage. In the present study, we aimed to fill this gap by comparing hand movement behaviour in persons with unilateral brain damage to the left and the right hemisphere and a matched control group of healthy persons. For hand movement coding, we applied Module I of NEUROGES, an objective and reliable analysis system that enables to analyse the full repertoire of hand movements independent of speech, which makes it specifically suited for the examination of persons with aphasia. The main results of our study show a decreased use of communicative conceptual gestures in persons with damage to the right hemisphere and an increased use of these gestures in persons with left brain damage and aphasia. These results not only suggest that the production of gesture and speech do not rely on the same neurological substrate but also underline the important role of right hemisphere functioning for gesture production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Phonological memory in sign language relies on the visuomotor neural system outside the left hemisphere language network.

    Science.gov (United States)

    Kanazawa, Yuji; Nakamura, Kimihiro; Ishii, Toru; Aso, Toshihiko; Yamazaki, Hiroshi; Omori, Koichi

    2017-01-01

    Sign language is an essential medium for everyday social interaction for deaf people and plays a critical role in verbal learning. In particular, language development in those people should heavily rely on the verbal short-term memory (STM) via sign language. Most previous studies compared neural activations during signed language processing in deaf signers and those during spoken language processing in hearing speakers. For sign language users, it thus remains unclear how visuospatial inputs are converted into the verbal STM operating in the left-hemisphere language network. Using functional magnetic resonance imaging, the present study investigated neural activation while bilinguals of spoken and signed language were engaged in a sequence memory span task. On each trial, participants viewed a nonsense syllable sequence presented either as written letters or as fingerspelling (4-7 syllables in length) and then held the syllable sequence for 12 s. Behavioral analysis revealed that participants relied on phonological memory while holding verbal information regardless of the type of input modality. At the neural level, this maintenance stage broadly activated the left-hemisphere language network, including the inferior frontal gyrus, supplementary motor area, superior temporal gyrus and inferior parietal lobule, for both letter and fingerspelling conditions. Interestingly, while most participants reported that they relied on phonological memory during maintenance, direct comparisons between letters and fingers revealed strikingly different patterns of neural activation during the same period. Namely, the effortful maintenance of fingerspelling inputs relative to letter inputs activated the left superior parietal lobule and dorsal premotor area, i.e., brain regions known to play a role in visuomotor analysis of hand/arm movements. These findings suggest that the dorsal visuomotor neural system subserves verbal learning via sign language by relaying gestural inputs to

  13. Words, Hemispheres, and Dissociable Subsystems: The Effects of Exposure Duration, Case Alternation, Priming, and Continuity of Form on Word Recognition in the Left and Right Visual Fields

    Science.gov (United States)

    Ellis, Andrew W.; Ansorge, Lydia; Lavidor, Michal

    2007-01-01

    Three experiments explore aspects of the dissociable neural subsystems theory of hemispheric specialisation proposed by Marsolek and colleagues, and in particular a study by [Deason, R. G., & Marsolek, C. J. (2005). A critical boundary to the left-hemisphere advantage in word processing. "Brain and Language," 92, 251-261]. Experiment 1A showed…

  14. Analysis of speech sounds is left-hemisphere predominant at 100-150ms after sound onset.

    Science.gov (United States)

    Rinne, T; Alho, K; Alku, P; Holi, M; Sinkkonen, J; Virtanen, J; Bertrand, O; Näätänen, R

    1999-04-06

    Hemispheric specialization of human speech processing has been found in brain imaging studies using fMRI and PET. Due to the restricted time resolution, these methods cannot, however, determine the stage of auditory processing at which this specialization first emerges. We used a dense electrode array covering the whole scalp to record the mismatch negativity (MMN), an event-related brain potential (ERP) automatically elicited by occasional changes in sounds, which ranged from non-phonetic (tones) to phonetic (vowels). MMN can be used to probe auditory central processing on a millisecond scale with no attention-dependent task requirements. Our results indicate that speech processing occurs predominantly in the left hemisphere at the early, pre-attentive level of auditory analysis.

  15. Understanding Actions of Others: The Electrodynamics of the Left and Right Hemispheres. A High-Density EEG Neuroimaging Study

    Science.gov (United States)

    Ortigue, Stephanie; Sinigaglia, Corrado; Rizzolatti, Giacomo; Grafton, Scott T.

    2010-01-01

    Background When we observe an individual performing a motor act (e.g. grasping a cup) we get two types of information on the basis of how the motor act is done and the context: what the agent is doing (i.e. grasping) and the intention underlying it (i.e. grasping for drinking). Here we examined the temporal dynamics of the brain activations that follow the observation of a motor act and underlie the observer's capacity to understand what the agent is doing and why. Methodology/Principal Findings Volunteers were presented with two-frame video-clips. The first frame (T0) showed an object with or without context; the second frame (T1) showed a hand interacting with the object. The volunteers were instructed to understand the intention of the observed actions while their brain activity was recorded with a high-density 128-channel EEG system. Visual event-related potentials (VEPs) were recorded time-locked with the frame showing the hand-object interaction (T1). The data were analyzed by using electrical neuroimaging, which combines a cluster analysis performed on the group-averaged VEPs with the localization of the cortical sources that give rise to different spatio-temporal states of the global electrical field. Electrical neuroimaging results revealed four major steps: 1) bilateral posterior cortical activations; 2) a strong activation of the left posterior temporal and inferior parietal cortices with almost a complete disappearance of activations in the right hemisphere; 3) a significant increase of the activations of the right temporo-parietal region with simultaneously co-active left hemispheric sources, and 4) a significant global decrease of cortical activity accompanied by the appearance of activation of the orbito-frontal cortex. Conclusions/Significance We conclude that the early striking left hemisphere involvement is due to the activation of a lateralized action-observation/action execution network. The activation of this lateralized network mediates the

  16. Understanding actions of others: the electrodynamics of the left and right hemispheres. A high-density EEG neuroimaging study.

    Directory of Open Access Journals (Sweden)

    Stephanie Ortigue

    Full Text Available BACKGROUND: When we observe an individual performing a motor act (e.g. grasping a cup we get two types of information on the basis of how the motor act is done and the context: what the agent is doing (i.e. grasping and the intention underlying it (i.e. grasping for drinking. Here we examined the temporal dynamics of the brain activations that follow the observation of a motor act and underlie the observer's capacity to understand what the agent is doing and why. METHODOLOGY/PRINCIPAL FINDINGS: Volunteers were presented with two-frame video-clips. The first frame (T0 showed an object with or without context; the second frame (T1 showed a hand interacting with the object. The volunteers were instructed to understand the intention of the observed actions while their brain activity was recorded with a high-density 128-channel EEG system. Visual event-related potentials (VEPs were recorded time-locked with the frame showing the hand-object interaction (T1. The data were analyzed by using electrical neuroimaging, which combines a cluster analysis performed on the group-averaged VEPs with the localization of the cortical sources that give rise to different spatio-temporal states of the global electrical field. Electrical neuroimaging results revealed four major steps: 1 bilateral posterior cortical activations; 2 a strong activation of the left posterior temporal and inferior parietal cortices with almost a complete disappearance of activations in the right hemisphere; 3 a significant increase of the activations of the right temporo-parietal region with simultaneously co-active left hemispheric sources, and 4 a significant global decrease of cortical activity accompanied by the appearance of activation of the orbito-frontal cortex. CONCLUSIONS/SIGNIFICANCE: We conclude that the early striking left hemisphere involvement is due to the activation of a lateralized action-observation/action execution network. The activation of this lateralized network

  17. The course of apraxia and ADL functioning in left hemisphere stroke patients treated in rehabilitation centres and nursing homes.

    Science.gov (United States)

    Donkervoort, Mireille; Dekker, Joost; Deelman, Betto

    2006-12-01

    To study the course of apraxia and daily life functioning (ADL) in left hemisphere stroke patients with apraxia. Prospective cohort study. Rehabilitation centres and nursing homes. One hundred and eight left hemisphere stroke patients with apraxia, hospitalized in rehabilitation centres and nursing homes. ADL-observations, Barthel ADL Index, Apraxia Test, Motricity Index. During the study period of 20 weeks, patients showed small improvements in apraxia (standardized mean differences of 0.19 and 0.33) and medium-sized improvements in ADL functioning (standardized mean differences from 0.37 to 0.61). About 88% of the patients were still apraxic at week 20. Less improvement in apraxia was observed in initially less severe apraxic patients. Less improvement in ADL functioning was found to be associated with more severe apraxia, a more independent initial ADL score, higher age, impaired motor functioning and longer time between stroke and first assessment. Apraxia in stroke patients is a persistent disorder, which has an adverse influence on ADL recovery.

  18. Malignant Hemispheric Cerebral Infarction Associated with Idiopathic Systemic Capillary Leak Syndrome

    Directory of Open Access Journals (Sweden)

    Kei Miyata

    2013-10-01

    Full Text Available Idiopathic systemic capillary leak syndrome (ISCLS is a rare condition that is characterized by unexplained episodic capillary hyperpermeability due to a shift of fluid and protein from the intravascular to the interstitial space. This results in diffuse general swelling, fetal hypovolemic shock, hypoalbuminemia, and hemoconcentration. Although ISCLS rarely induces cerebral infarction, we experienced a patient who deteriorated and was comatose as a result of massive cerebral infarction associated with ISCLS. In this case, severe hypotensive shock, general edema, hemiparesis, and aphasia appeared after serious antecedent gastrointestinal symptoms. Progressive life-threatening ischemic cerebral edema required decompressive hemicraniectomy. The patient experienced another episode of severe hypotension and limb edema that resulted in multiple extremity compartment syndrome. Treatment entailed forearm and calf fasciotomies. Cerebral edema in the ischemic brain progresses rapidly in patients suffering from ISCLS. Strict control of fluid volume resuscitation and aggressive diuretic therapy may be needed during the post-leak phase of fluid remobilization.

  19. Electrophysiological evidence for the action of a center-surround mechanism on semantic processing in the left hemisphere

    Directory of Open Access Journals (Sweden)

    Diana eDeacon

    2013-12-01

    Full Text Available Physiological evidence was sought for a center-surround attentional mechanism (CSM, which has been proposed to assist in the retrieval of weakly activated items from semantic memory. The CSM operates by facilitating strongly related items in the center of the weakly activated area of semantic memory, and inhibiting less strongly related items in its surround. In this study weak activation was created by having subjects acquire the meanings of new words to a recall criterion of only 50%. Subjects who attained this approximate criterion level of performance were subsequently included in a semantic priming task, during which ERPs were recorded. Primes were newly learned rare words, and targets were either synonyms, nonsynonymously related words, or unrelated words. All stimuli were presented to the RVF/LH (right visual field/left hemisphere or the LVF/RH (left visual field/right hemisphere. Under RVF/LH stimulation the newly learned word primes produced facilitation on N400 for synonym targets, and inhibition for related targets. No differences were observed under LVF/RH stimulation. The LH thus, supports a CSM, whereby a synonym in the center of attention focused on the newly learned word is facilitated, whereas a related word in the surround is inhibited. The data are consistent with the view of this laboratory that semantic memory is subserved by a spreading activation system in the LH. Also consistent with our view, there was no evidence of spreading activation in the RH. The findings are discussed in the context of additional recent theories of semantic memory. Finally, the adult right hemisphere may require more learning than the LH in order to demonstrate evidence of meaning acquisition.

  20. Hemispheric specialization in dogs for processing different acoustic stimuli.

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    Marcello Siniscalchi

    Full Text Available Considerable experimental evidence shows that functional cerebral asymmetries are widespread in animals. Activity of the right cerebral hemisphere has been associated with responses to novel stimuli and the expression of intense emotions, such as aggression, escape behaviour and fear. The left hemisphere uses learned patterns and responds to familiar stimuli. Although such lateralization has been studied mainly for visual responses, there is evidence in primates that auditory perception is lateralized and that vocal communication depends on differential processing by the hemispheres. The aim of the present work was to investigate whether dogs use different hemispheres to process different acoustic stimuli by presenting them with playbacks of a thunderstorm and their species-typical vocalizations. The results revealed that dogs usually process their species-typical vocalizations using the left hemisphere and the thunderstorm sounds using the right hemisphere. Nevertheless, conspecific vocalizations are not always processed by the left hemisphere, since the right hemisphere is used for processing vocalizations when they elicit intense emotion, including fear. These findings suggest that the specialisation of the left hemisphere for intraspecific communication is more ancient that previously thought, and so is specialisation of the right hemisphere for intense emotions.

  1. Automated quantification of cerebral edema following hemispheric infarction: Application of a machine-learning algorithm to evaluate CSF shifts on serial head CTs

    OpenAIRE

    Chen, Yasheng; Dhar, Rajat; Heitsch, Laura; Ford, Andria; Fernandez-Cadenas, Israel; Carrera, Caty; Montaner, Joan; Lin, Weili; Shen, Dinggang; An, Hongyu; Lee, Jin-Moo

    2016-01-01

    Although cerebral edema is a major cause of death and deterioration following hemispheric stroke, there remains no validated biomarker that captures the full spectrum of this critical complication. We recently demonstrated that reduction in intracranial cerebrospinal fluid (CSF) volume (??CSF) on serial computed tomography (CT) scans provides an accurate measure of cerebral edema severity, which may aid in early triaging of stroke patients for craniectomy. However, application of such a volum...

  2. A tale of two hemispheres: Contrasting socioemotional dysfunction in right- versus left-lateralised semantic dementia

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    Muireann Irish

    Full Text Available ABSTRACT Objective: Semantic dementia, a subtype of frontotemporal lobar degeneration, is characterised by cross-modal loss of conceptual knowledge attributable to progressive degeneration of the left anterior temporal lobe. Much less is known regarding the clinical presentation of SD patients with predominantly right-lateralised atrophy. Recent reports emphasise marked socioemotional and behavioural disturbances in such cases. Given the importance of the right anterior temporal lobes in social cognition, we hypothesised that socioemotional functioning would be disproportionately affected in right versus left-lateralised SD cases. Methods: We assessed well-characterised cases of predominantly right (n=10 and left (n=12 SD and 20 matched healthy controls on tests of emotion processing and interpersonal functioning. Results: Right SD cases showed disproportionate difficulties in the recognition of positive and negative facial emotions, specifically happiness and anger, compared with left SD cases. Deficits in anger recognition persisted in right SD despite covarying for facial and semantic processing. On a contextually rich task of emotion recognition using multimodal videos, no subgroup differences were evident. Finally, empathic concern was rated as significantly lower by caregivers of right versus left SD cases. Overall, the extent of socioemotional disturbance was associated with the degree of behavioural changes in SD. Conclusion: Our results reveal considerable overlap in the extent to which socioemotional processes are disrupted in left and right-lateralised cases of SD. Notably, however, right SD cases show disproportionate deficits for recognition of facial emotions and the capacity for empathic concern, supporting a specialised role for the right anterior temporal lobes in mediating these cognitive functions.

  3. Improved Spatial Ability Correlated with Left Hemisphere Dysfunction in Turner's Syndrome. Implications for Mechanism.

    Science.gov (United States)

    Rovet, Joanne F.

    This study contrasts the performance of a 17-year-old female subject with Turner's syndrome before and after developing left temporal lobe seizures, as a means of identifying the mechanism responsible for the Turner's syndrome spatial impairment. The results revealed a deficit in spatial processing before onset of the seizure disorder. Results…

  4. Dyke-Davidoff-Masson syndrome: case report of fetal unilateral ventriculomegaly and hypoplastic left middle cerebral artery.

    Science.gov (United States)

    Piro, Ettore; Piccione, Maria; Marrone, Gianluca; Giuffrè, Mario; Corsello, Giovanni

    2013-05-14

    Prenatal ultrasonographic detection of unilateral cerebral ventriculomegaly arises suspicion of pathological condition related to cerebrospinal fluid flow obstruction or cerebral parenchimal pathology. Dyke-Davidoff-Masson syndrome is a rare condition characterized by cerebral hemiatrophy, calvarial thickening, skull and facial asymmetry, contralateral hemiparesis, cognitive impairment and seizures. Congenital and acquired types are recognized and have been described, mainly in late childhood, adolescence and adult ages. We describe a female infant with prenatal diagnosis of unilateral left ventriculomegaly in which early brain MRI and contrast enhanced-MRI angiography, showed cerebral left hemiatrophy associated with reduced caliber of the left middle cerebral artery revealing the characteristic findings of the Dyke-Davidoff-Masson syndrome. Prenatal imaging, cerebral vascular anomaly responsible for the cerebral hemiatrophy and the early clinical evolution have never been described before in such a young child and complete the acquired clinical descriptions in older children. Differential diagnosis, genetic investigations, neurophysiologic assessments, short term clinical and developmental follow up are described. Dyke-Davidoff-Masson syndrome must be ruled out in differential diagnosis of fetal unilateral ventriculomegaly. Early clinical assessment, differential diagnosis and cerebral imaging including cerebral MRI angiography allow the clinicians to diagnose also in early infancy this rare condition.

  5. Prevention of Cerebral Embolism Progression by Emergency Surgery of the Left Atrial Myxoma

    Directory of Open Access Journals (Sweden)

    Syuichi Tetsuka

    2015-01-01

    Full Text Available A 21-year-old woman developed left hemiparesis during work and was hospitalized. Her National Institutes of Health Stroke Scale score was 4. Hyperintense areas in the left basal ganglia, corona radiata, and cortex of the temporal lobe were found by brain diffusion-weighted magnetic resonance imaging, indicating acute cerebral infarction. Echocardiography showed a giant mass of diameter 7 × 4 cm in the left atrium. Therefore, she was diagnosed with cerebral embolism due to a left atrial myxoma. Currently, thrombolytic therapy may continue to be effective because the embolic source may be composed of tumor tissue itself. In case of atrial myxoma, we considered that the use of tPA as emergency treatment in all patients with infarction by atrial myxoma may be questioned. Thus, cardiac tumor extraction was performed the next day after hospitalization without thrombolytic therapy. The excised myxoma measured 7 × 6 × 4 cm. The patient recovered and her neurological symptoms also improved. Furthermore, her National Institutes of Health Stroke Scale score improved to 0. Thirteen days after admission, the patient was discharged from our hospital. Cardiac myxoma is often associated with a high risk of embolic episodes, which emphasizes the need for prompt surgical excision as soon as the diagnosis is confirmed.

  6. Selective attention to phonology dynamically modulates initial encoding of auditory words within the left hemisphere.

    Science.gov (United States)

    Yoncheva, Yuliya; Maurer, Urs; Zevin, Jason D; McCandliss, Bruce D

    2014-08-15

    Selective attention to phonology, i.e., the ability to attend to sub-syllabic units within spoken words, is a critical precursor to literacy acquisition. Recent functional magnetic resonance imaging evidence has demonstrated that a left-lateralized network of frontal, temporal, and posterior language regions, including the visual word form area, supports this skill. The current event-related potential (ERP) study investigated the temporal dynamics of selective attention to phonology during spoken word perception. We tested the hypothesis that selective attention to phonology dynamically modulates stimulus encoding by recruiting left-lateralized processes specifically while the information critical for performance is unfolding. Selective attention to phonology was captured by manipulating listening goals: skilled adult readers attended to either rhyme or melody within auditory stimulus pairs. Each pair superimposed rhyming and melodic information ensuring identical sensory stimulation. Selective attention to phonology produced distinct early and late topographic ERP effects during stimulus encoding. Data-driven source localization analyses revealed that selective attention to phonology led to significantly greater recruitment of left-lateralized posterior and extensive temporal regions, which was notably concurrent with the rhyme-relevant information within the word. Furthermore, selective attention effects were specific to auditory stimulus encoding and not observed in response to cues, arguing against the notion that they reflect sustained task setting. Collectively, these results demonstrate that selective attention to phonology dynamically engages a left-lateralized network during the critical time-period of perception for achieving phonological analysis goals. These findings suggest a key role for selective attention in on-line phonological computations. Furthermore, these findings motivate future research on the role that neural mechanisms of attention may

  7. Selective attention to phonology dynamically modulates initial encoding of auditory words within the left hemisphere

    Science.gov (United States)

    Yoncheva; Maurer, Urs; Zevin, Jason; McCandliss, Bruce

    2015-01-01

    Selective attention to phonology, i.e., the ability to attend to sub-syllabic units within spoken words, is a critical precursor to literacy acquisition. Recent functional magnetic resonance imaging evidence has demonstrated that a left-lateralized network of frontal, temporal, and posterior language regions, including the visual word form area, supports this skill. The current event-related potential (ERP) study investigated the temporal dynamics of selective attention to phonology during spoken word perception. We tested the hypothesis that selective atten tion to phonology dynamically modulates stimulus encoding by recruiting left-lateralized processes specifically while the information critical for performance is unfolding. Selective attention to phonology was captured by ma nipulating listening goals: skilled adult readers attended to either rhyme or melody within auditory stimulus pairs. Each pair superimposed rhyming and melodic information ensuring identical sensory stimulation. Selective attention to phonology produced distinct early and late topographic ERP effects during stimulus encoding. Data- driven source localization analyses revealed that selective attention to phonology led to significantly greater re cruitment of left-lateralized posterior and extensive temporal regions, which was notably concurrent with the rhyme-relevant information within the word. Furthermore, selective attention effects were specific to auditory stimulus encoding and not observed in response to cues, arguing against the notion that they reflect sustained task setting. Collectively, these results demonstrate that selective attention to phonology dynamically engages a left-lateralized network during the critical time-period of perception for achieving phonological analysis goals. These findings support the key role of selective attention to phonology in the development of literacy and motivate future research on the neural bases of the interaction between phonological

  8. Case Report of a 52 Year Old Hypertensive with Cerebral ...

    African Journals Online (AJOL)

    TNHJOURNALPH

    inability to move the left side of his body and other neurologic features suggestive of a right hemispheric ischaemic stroke. Brain. CT showed features of cerebral toxoplasmosis and .... Foundation for Education and Research. ofN eurological ...

  9. Understanding the Dorsal and Ventral Systems of the Human Cerebral Cortex: Beyond Dichotomies

    Science.gov (United States)

    Borst, Gregoire; Thompson, William L.; Kosslyn, Stephen M.

    2011-01-01

    Traditionally, characterizations of the macrolevel functional organization of the human cerebral cortex have focused on the left and right cerebral hemispheres. However, the idea of left brain versus right brain functions has been shown to be an oversimplification. We argue here that a top-bottom divide, rather than a left-right divide, is a more…

  10. Potenciais evocados auditivos de longa latência: um estudo comparativo entre hemisférios cerebrais Long auditory evoked potential: comparative study between cerebral hemispheres

    Directory of Open Access Journals (Sweden)

    Ana Claudia F. Frizzo

    2001-09-01

    central structures. Considering the functional differences among the cerebral hemispheres, the present study pretend to identify electrophysiologicals evidences to verify differences between hemispheres. Objective: The main objective was to verify the occurrence of possible differences among the captured potentials of the hemispheres right (Cz/A2 and left (Cz/A1 in a group of normal listeners between 8 and 18 years old. Study design: For so much, a comparative analysis of the registrations of LLAEP was performed, as for the latency as the amplitude. Results: Statistical significants differences were not observed among the measures of the derivations Cz/A1 and Cz/A2, except for the component P2 in the masculine population. However, the functional difference between the hemispheres cannot deny, and this should be considered that variable during the performance of the LLAEP‘s research. Conclusion: Future works will still be necessary, with larger populations or even with different positions of electrodes so that we can verify existence or not of electrophysiologicals evidences that identify those differences, making sure and efficients application of this method.

  11. Performance of language tasks in patients with ruptured aneurysm of the left hemisphere worses in the post-surgical evaluation

    Directory of Open Access Journals (Sweden)

    Ana Cláudia C. Vieira

    2016-08-01

    Full Text Available ABSTRACT Sub-arachnoid hemorrhage (SAH promotes impairment of upper cortical functions. However, few information is available emphasizing changes in language after aneurismal SAH and aneurysm location influence. Objective To assess the language and verbal fluency performance in aneurismal SAH pre- and post-surgery in patients caused by an aneurysm of the anterior communicating artery (AcomA, left middle cerebral artery (L-MCA and left posterior comunicating artery (L-PcomA. Methods Assessment in 79 patients with SAH, on two occasions: pre- and post surgical treatment. They were divided into three groups by the aneurysms’ location. Results Deterioration is detected in the performance of all patients during the post-surgical period; L-MCA aneurysm patients displayed a reduction in verbal naming and fluency; L-PcomA patients deteriorated in the written language and fluency tasks. Conclusion After the surgical procedure the patients decreased in various language tasks and these differences in performance being directly related to the location of the aneurysm.

  12. A case of left-sided unilateral spatial neglect owing to the cerebral infarction in the distribution of the right posterior cerebral artery

    International Nuclear Information System (INIS)

    Odagaki, Yuji; Oka, Iori; Kon, Yutaka; Asano, Yutaka

    1985-01-01

    We report a case of left-sided unilateral spatial neglect (USN) induced by the cerebral infarction in the distribution of right posterior cerebral artery (PCA). A 69-year-old, right-handed man, who had had a sudden onset of left hemiparesis in August 1983, was admitted to our hospital on January 16, 1984, because of nocturnal delirium. He became alert a few days after admission, but was euphoric and sometimes irritable. Neurologic examination disclosed left homonymous hemianopsia, dysarthria, left central facial weakness, spastic left hemiparesis, hyperactive reflexes on the left with no Babinski sign, left hemisensory loss, and left thalamic pain. On neuropsychologic examination it was revealed that he had a tendency to neglect the left half of his extrapersonal space. When asked to locate cities on a blank map of Japan, he located most of them not only on the right side of the map but also incorrectly. He also had a severe acalculia. There was gradual improvement in these neuropsychologic symptoms. CT demonstrated an area of decreased density in the territory of the right PCA, posterolateral portion of the right thalamus, and the posterior limb of right internal capsule, sparing parietal and temporal lobes. Single-photon emission computed tomography (SPECT) using the Xenon-133 inhalation method showed, however, diminished regional cerebral blood flow (rCBF) in an area larger than the area of infarction demonstrated by CT, including the right parieto-temporo-occipital junctional area, which has been considerd to be responsible for left-sided USN. The authors ascribed the patient's left-sided USN to the lesion of this area that was revealed not morphologically by CT but functionally by SPECT, although the possibility that the lesions of the medial portion of the right occipital lobe and/or subcortical lesions of such areas as the thalamus and the internal capsule more or less influenced the neuropsychologic symptoms could not be excluded. (author)

  13. The Influence of Visual and Auditory Information on the Perception of Speech and Non-Speech Oral Movements in Patients with Left Hemisphere Lesions

    Science.gov (United States)

    Schmid, Gabriele; Thielmann, Anke; Ziegler, Wolfram

    2009-01-01

    Patients with lesions of the left hemisphere often suffer from oral-facial apraxia, apraxia of speech, and aphasia. In these patients, visual features often play a critical role in speech and language therapy, when pictured lip shapes or the therapist's visible mouth movements are used to facilitate speech production and articulation. This demands…

  14. Prognostic value of proton MR spectroscopy of cerebral hemisphere tumors in children

    Energy Technology Data Exchange (ETDEWEB)

    Girard, N. [Department of Neuroradiology and Vascular Radiology, Hopital de la Timone, Marseille (France); Wang, Z.J.; Zimmerman, R.A. [Department of Radiology, Children`s Hospital of Philadelphia, PA (United States); Erbetta, A. [Department of Neuroradiology, Istituto Nazionale Neurologico C. Besta, Milan (Italy); Sutton, L.N. [Division of Neurosurgery, Children`s Hospital of Philadelphia, PA (United States); Phillips, P.C. [Neurooncology Program, Children`s Hospital of Philadelphia, PA (United States); Rorke, L.B. [Department of Neuropathology, Children`s Hospital of Philadelphia, PA (United States)

    1998-02-01

    We studied 14 young people with newly diagnosed hemisphere tumors, aged from 3 to 20 years (average 10 years). All underwent surgery following MR imaging (MRI) and spectroscopy (MRS). The tumors studied were three glioblastomas, one each of ganglio-glioblastoma, primitive neuroectodermal tumor (PNET), rhabdoid teratoid tumor, pilocytic astrocytoma, ependymoma, anaplastic ependymoma, and gliomatosis cerebri, and four gangliogliomas. Four patients died; ten patients are alive (five with stable residual tumor, five with no evident tumor). Images and spectra were acquired on a 1.5-T imager. Proton MRS was performed before gadolinium injection in all but one case. Single-voxel techniques were utilized in all cases, using a spin-echo or STEAM sequence with a long echo time (135 or 270 ms). Peak areas of N -acetyl aspartate (NAA), choline (Cho), and creatine and phosphocreatine (Cr) were assessed. The NAA/Cho peak-area ratio was very low in the patients who died (mean {+-} s. d. 0.20 {+-} 0.14), and higher in the patients who are alive (0.74 {+-} 0.47; P = 0.007 by two-tailed t -test). The Cr/Cho peak-area ratio also followed a similar trend for the two groups (mean {+-} s. d. 0.17 {+-} 0.07 and 0.49 {+-} 0.30, respectively; P = 0.01 by two-tailed t -test). (orig.) With 4 figs., 3 tabs., 22 refs.

  15. Continuous theta burst stimulation (cTBS on left cerebellar hemisphere affects mental rotation tasks during music listening.

    Directory of Open Access Journals (Sweden)

    Silvia Picazio

    Full Text Available Converging evidence suggests an association between spatial and music domains. A cerebellar role in music-related information processing as well as in spatial-temporal tasks has been documented. Here, we investigated the cerebellar role in the association between spatial and musical domains, by testing performances in embodied (EMR or abstract (AMR mental rotation tasks of subjects listening Mozart Sonata K.448, which is reported to improve spatial-temporal reasoning, in the presence or in the absence of continuous theta burst stimulation (cTBS of the left cerebellar hemisphere. In the absence of cerebellar cTBS, music listening did not influence either MR task, thus not revealing a "Mozart Effect". Cerebellar cTBS applied before musical listening made subjects faster (P = 0.005 and less accurate (P = 0.005 in performing the EMR but not the AMR task. Thus, cerebellar inhibition by TBS unmasked the effect of musical listening on motor imagery. These data support a coupling between music listening and sensory-motor integration in cerebellar networks for embodied representations.

  16. THE IMPACT OF LEFT HEMISPHERE STROKE ON FORCE CONTROL WITH FAMILIAR AND NOVEL OBJECTS: NEUROANATOMIC SUBSTRATES AND RELATIONSHIP TO APRAXIA

    Science.gov (United States)

    Dawson, Amanda M.; Buxbaum, Laurel J.; Duff, Susan V.

    2010-01-01

    Fingertip force scaling for lifting objects frequently occurs in anticipation of finger contact. An ongoing question concerns the types of memories that are used to inform predictive control. Object-specific information such as weight may be stored and retrieved when previously encountered objects are lifted again. Alternatively, visual size and shape cues may provide estimates of object density each time objects are encountered. We reasoned that differences in performance with familiar versus novel objects would provide support for the former possibility. Anticipatory force production with both familiar and novel objects was assessed in 6 left hemisphere stroke patients, 2 of whom exhibited deficient actions with familiar objects (ideomotor apraxia; IMA), along with 5 control subjects. In contrast to healthy controls and stroke participants without IMA, participants with IMA displayed poor anticipatory scaling with familiar objects. However, like the other groups, IMA participants learned to differentiate fingertip forces with repeated lifts of both familiar and novel objects. Finally, there was a significant correlation between damage to the inferior parietal and superior and middle temporal lobes, and impaired anticipatory control for familiar objects. These data support the hypotheses that anticipatory control during lifts of familiar objects in IMA patients are based on object-specific memories, and that the ventro-dorsal stream is involved in the long-term storage of internal models used for anticipatory scaling during object manipulation. PMID:19945445

  17. Different visual exploration of tool-related gestures in left hemisphere brain damaged patients is associated with poor gestural imitation.

    Science.gov (United States)

    Vanbellingen, Tim; Schumacher, Rahel; Eggenberger, Noëmi; Hopfner, Simone; Cazzoli, Dario; Preisig, Basil C; Bertschi, Manuel; Nyffeler, Thomas; Gutbrod, Klemens; Bassetti, Claudio L; Bohlhalter, Stephan; Müri, René M

    2015-05-01

    According to the direct matching hypothesis, perceived movements automatically activate existing motor components through matching of the perceived gesture and its execution. The aim of the present study was to test the direct matching hypothesis by assessing whether visual exploration behavior correlate with deficits in gestural imitation in left hemisphere damaged (LHD) patients. Eighteen LHD patients and twenty healthy control subjects took part in the study. Gesture imitation performance was measured by the test for upper limb apraxia (TULIA). Visual exploration behavior was measured by an infrared eye-tracking system. Short videos including forty gestures (20 meaningless and 20 communicative gestures) were presented. Cumulative fixation duration was measured in different regions of interest (ROIs), namely the face, the gesturing hand, the body, and the surrounding environment. Compared to healthy subjects, patients fixated significantly less the ROIs comprising the face and the gesturing hand during the exploration of emblematic and tool-related gestures. Moreover, visual exploration of tool-related gestures significantly correlated with tool-related imitation as measured by TULIA in LHD patients. Patients and controls did not differ in the visual exploration of meaningless gestures, and no significant relationships were found between visual exploration behavior and the imitation of emblematic and meaningless gestures in TULIA. The present study thus suggests that altered visual exploration may lead to disturbed imitation of tool related gestures, however not of emblematic and meaningless gestures. Consequently, our findings partially support the direct matching hypothesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Prophylactic action of Alpha-tocopherol against Gamma irradiation changes in total lipid and phospholipid contents of brain cerebral hemispheres in Rats

    Energy Technology Data Exchange (ETDEWEB)

    Mahdy, A M; Helen, N S; Roushdy, H M [National Centre for Radiation Research and Technology, Cairo (Egypt)

    1987-12-31

    Male albino rats were intraperitoneally injected with Gamma tocopherol (vitamin E) at 10 mg/100 g animal body weight, 2 hr, before irradiation exposure. exposure. Rats were then exposed to a whole body dose of gamma irradiation at 7 Gy. Rats were sacrificed 1, 3, 7 and 10 days post irradiation. The two cerebral hemispheres were taken to determine the phospholipids and total lipid contents. whole body gamma irradiation of rats at 7 Gy caused a significant decrease in the levels of both phospholipids and total lipid contents in the cerebral hemispheres on the 3 rd, 7 Th, and 10 Th days post-irradiation, the decrease was insignificant on the 1 st day post exposure. The variations were less pronounced in rats treated with vitamin E. The results obtained were discussed in view of the relevant literature. 2 tabs.

  19. X-ray computed tomography (CT) study of small, deep and recent infarcts (SDRIs) of the cerebral hemispheres in adults

    International Nuclear Information System (INIS)

    Launay, M.; N'Diaye, M.; Bories, J.

    1985-01-01

    The evolution of CT signs of small deep infarcts of the cerebral hemispheres in thirty adults, in the first five weeks, has been retrospectively studied. The relevant literature has been reviewed and an attempt has been made to present a synthesis, accompanied by a commentary. It is impossible now to give the frequency of each type of evolution, but the main data are as follows: 1. The shortest delay in apparance of an hypodense area is about 17 to 21 h, but at 27 h the densities may be still normal. 2. The evolution of the hypodense area is also variable: after a minimum attenuation is reached - at approximately 72 h - there is a risk of ''fogging effect'', which reduces the visibility of ischemic lesions; it could be seen from the end of the 1st week to the beginning of the 4th, but its frequency and its duration have yet to be better determined. 3. In our series, contrast enhancement has been found in the gray matter of the basal ganglia between the 8th and the 22nd days - but according to some observations recorded in the literature, it may be found from the second to the twenty sixth day - and there was no obvious contrast enhancement in the white matter. The significance of the evolving CT signs is discussed in connection with the clinical applications, principally in the management of these patients and with the attempts to correlate the clinical and CT findings. (orig.)

  20. Right: Left:: East: West. Evidence that individuals from East Asian and South Asian cultures emphasize right hemisphere functions in comparison to Euro-American cultures.

    Science.gov (United States)

    Rozin, Paul; Moscovitch, Morris; Imada, Sumio

    2016-09-01

    We present evidence that individuals from East or South Asian cultures (Japanese college students in Japan and East or South Asian born and raised college students in the USA) tend to exhibit default thinking that corresponds to right hemisphere holistic functions, as compared to Caucasian individuals from a Western culture (born and raised in the USA). In two lateralized tasks (locating the nose in a scrambled face, and global-local letter task), both Asian groups showed a greater right hemisphere bias than the Western group. In a third lateralized task, judging similarity in terms of visual form versus functional/semantic categorizations, there was not a reliable difference between the groups. On a classic, ambiguous face composed of vegetables, both Eastern groups displayed a greater right hemisphere (holistic face processing) bias than the Western group. These results support an "East - Right Hemisphere, West - Left Hemisphere" hypothesis, as originally proposed by Ornstein (1972). This hypothesis is open as to the degree to which social-cultural forces were involved in hemispheric specialization, or the opposite, or both. Our aim is to encourage a more thorough analysis of this hypothesis, suggesting both lateralization studies corresponding to documented East-West differences, and East-West studies corresponding to lateralization differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Free amino acids in synaptic vesicles isolated from the cerebellum and cerebral hemispheres of control and neonatally X-irradiated rats

    International Nuclear Information System (INIS)

    Valcana, T.; Hudson, D.B.; Timiras, P.S.

    1984-01-01

    X-irradiation of the rat brain (1000R, at two days of age), suppresses the normal age-related increase in the weight of the cerebellum and cerebral hemispheres and influences amino acid levels. The decrease in glutamic acid concentration, particularly in the cerebellum, supports the previously advanced proposition that this amino acid may be associated with or may be the transmitter of, the rat cerebellar granule cells. Subfractionation of the cerebellar tissue reveals that the decrease in the glutamic acid level consequent to the loss of granule cells, is reflected in the cytoplasmic fraction but not in the synaptic vesicle subfraction, where glutamic acid was increased. The reduced weight gain in the cerebral hemispheres after irradiation, is accompanied by a significant decrease of aspartate in the cytoplasmic fraction, changes which suggest that a specific cell type, with aspartic acid as its neurotransmitter (possibly in the hippocampus), may also be radiosensitive in the early postnatal period. In contrast, in the synaptic vesicle fraction from cerebral hemispheres, all free amino acids, with the exception of glutamine, increased significantly. Overall, the changes in free amino acid concentration induced by X-irradiation in the cytoplasmic fraction in both brain regions studied are opposite to those found in the synaptic vesicle fraction and although they may indicate changes in specific cell populations, as proposed above, they could also reflect changes in cellular compartmentalization and metabolism or changes in the relative axonal arborization of the affected regions

  2. Right hand, left brain: genetic and evolutionary bases of cerebral asymmetries for language and manual action.

    Science.gov (United States)

    Corballis, Michael C; Badzakova-Trajkov, Gjurgjica; Häberling, Isabelle S

    2012-01-01

    Most people are right-handed and left-cerebrally dominant for language. This pattern of asymmetry, as well as departures from it, have been reasonably accommodated in terms of a postulated gene with two alleles, one disposing to this common pattern and the other leaving the direction of handedness and language asymmetry to chance. There are some leads as to the location of the gene or genes concerned, but no clear resolution; one possibility is that the chance factor is achieved by epigenetic cancelling of the lateralizing gene rather than through a chance allele. Neurological evidence suggests that the neural basis of manual praxis, including pantomime and tool use, is more closely associated with cerebral asymmetry for language than with handedness, and is homologous with the so-called "mirror system" in the primate brain, which is specialized for manual grasping. The evidence reviewed supports the theory that language itself evolved within the praxic system, and became lateralized in humans, and perhaps to a lesser extent in our common ancestry with the great apes. WIREs Cogn Sci 2012, 3:1-17. doi: 10.1002/wcs.158 For further resources related to this article, please visit the WIREs website. Copyright © 2011 John Wiley & Sons, Ltd.

  3. Changes in regional cerebral blood flow in nondominant hemisphere during speech task in aphasics. A PET activation study

    Energy Technology Data Exchange (ETDEWEB)

    Ohyama, Masashi; Kitamura, Shin; Mishina, Masahiro; Terashi, Akiro [Nippon Medical School, Tokyo (Japan); Senda, Michio; Ishii, Kenji

    1995-08-01

    To investigate the patients with language disorder and to detect the activated areas in language processing, we measured the changes in the regional cerebral blood flow (CBF) during speech task (`counting` task) using O-15 water PET activation technique in six normal subjects (age 58.3 {+-}8.1, mean{+-}SD), ten fluent aphasics (age 60.3{+-}12.5) and six nonfluent aphasics (age 50.5{+-}8.3). In `counting` task, the subjects were instructed to count the number aloud from 1 to 10 and repeat the sequence over and over in the native language (Japanese) at the rate of one number per 2.5 sec. The data were analyzed with stereotactic intersubject averaging analysis for the normal subjects. Apart from it, the regions of interest (ROI) analysis (a circular ROI of 12 mm diameter) was performed in the language-related area for each subject. In the normal subjects, the language-related areas: posteroinferofrontal areas (PIF), posterosuperotemporal area (PST), and Rolandic areas (related to the mouth and lips) were significantly activated bilaterally in the `counting` task. PIF were activated with a dominance in the left side. In the resting state, rCBF in the left PIF and left PST was reduced in both fluent and nonfluent aphasics. In nonfluent aphasics, the magnitude of activation in the right PIF by `counting` task was significantly greater than normal subjects and patients with fluent aphasia (ANOVA). It suggests the importance of the right PIF in the simple language processing in the nonfluent aphasia. In the sixteen aphasic patients, the increase in rCBF in the right PST during the `counting` task was negatively correlated with the score of comprehension (WAB) in the Spearman ranked correlation (p<0.05). It suggests that, while the activity of the right PST is minimal for the `counting` in normal subjects, it plays an important and compensatory role in aphasic patients. (author).

  4. Changes in regional cerebral blood flow in nondominant hemisphere during speech task in aphasics. A PET activation study

    International Nuclear Information System (INIS)

    Ohyama, Masashi; Kitamura, Shin; Mishina, Masahiro; Terashi, Akiro; Senda, Michio; Ishii, Kenji.

    1995-01-01

    To investigate the patients with language disorder and to detect the activated areas in language processing, we measured the changes in the regional cerebral blood flow (CBF) during speech task ('counting' task) using O-15 water PET activation technique in six normal subjects (age 58.3 ±8.1, mean±SD), ten fluent aphasics (age 60.3±12.5) and six nonfluent aphasics (age 50.5±8.3). In 'counting' task, the subjects were instructed to count the number aloud from 1 to 10 and repeat the sequence over and over in the native language (Japanese) at the rate of one number per 2.5 sec. The data were analyzed with stereotactic intersubject averaging analysis for the normal subjects. Apart from it, the regions of interest (ROI) analysis (a circular ROI of 12 mm diameter) was performed in the language-related area for each subject. In the normal subjects, the language-related areas: posteroinferofrontal areas (PIF), posterosuperotemporal area (PST), and Rolandic areas (related to the mouth and lips) were significantly activated bilaterally in the 'counting' task. PIF were activated with a dominance in the left side. In the resting state, rCBF in the left PIF and left PST was reduced in both fluent and nonfluent aphasics. In nonfluent aphasics, the magnitude of activation in the right PIF by 'counting' task was significantly greater than normal subjects and patients with fluent aphasia (ANOVA). It suggests the importance of the right PIF in the simple language processing in the nonfluent aphasia. In the sixteen aphasic patients, the increase in rCBF in the right PST during the 'counting' task was negatively correlated with the score of comprehension (WAB) in the Spearman ranked correlation (p<0.05). It suggests that, while the activity of the right PST is minimal for the 'counting' in normal subjects, it plays an important and compensatory role in aphasic patients. (author)

  5. Assessment of arcuate fasciculus with diffusion-tensor tractography may predict the prognosis of aphasia in patients with left middle cerebral artery infarcts

    International Nuclear Information System (INIS)

    Hosomi, Akiko; Nagakane, Yoshinari; Kuriyama, Nagato; Mizuno, Toshiki; Nakagawa, Masanori; Yamada, Kei; Nishimura, Tsunehiko

    2009-01-01

    It is often clinically difficult to assess the severity of aphasia in the earliest stage of cerebral infarction. A method enabling objective assessment of verbal function is needed for this purpose. We examined whether diffusion tensor (DT) tractography is of clinical value in assessing aphasia. Thirteen right-handed patients with left middle cerebral artery infarcts who were scanned within 2 days after stroke onset were enrolled in this study. Magnetic resonance data of ten control subjects were also examined by DT tractography. Based on the severity of aphasia at discharge, patients were divided into two groups: six patients in the aphasic group and seven in the nonaphasic group. Fractional anisotropy (FA) and number of arcuate fasciculus fibers were evaluated. Asymmetry index was calculated for both FA and number of fibers. FA values for the arcuate fasciculus fibers did not differ between hemispheres in either the patient groups or the controls. Number of arcuate fasciculus fibers exhibited a significant leftward asymmetry in the controls and the nonaphasic group but not in the aphasic group. Asymmetry index of number of fibers was significantly lower (rightward) in the aphasic group than in the nonaphasic (P = 0.015) and control (P = 0.005) groups. Loss of leftward asymmetry in number of AF fibers predicted aphasia at discharge with a sensitivity of 0.83 and specificity of 0.86. Asymmetry of arcuate fasciculus fibers by DT tractography may deserve to be assessed in acute infarction for predicting the fate of vascular aphasia. (orig.)

  6. Assessment of arcuate fasciculus with diffusion-tensor tractography may predict the prognosis of aphasia in patients with left middle cerebral artery infarcts

    Energy Technology Data Exchange (ETDEWEB)

    Hosomi, Akiko; Nagakane, Yoshinari; Kuriyama, Nagato; Mizuno, Toshiki; Nakagawa, Masanori [Kyoto Prefectural University of Medicine, Department of Neurology, Graduate School of Medical Science, Kyoto (Japan); Yamada, Kei; Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science, Kyoto (Japan)

    2009-09-15

    It is often clinically difficult to assess the severity of aphasia in the earliest stage of cerebral infarction. A method enabling objective assessment of verbal function is needed for this purpose. We examined whether diffusion tensor (DT) tractography is of clinical value in assessing aphasia. Thirteen right-handed patients with left middle cerebral artery infarcts who were scanned within 2 days after stroke onset were enrolled in this study. Magnetic resonance data of ten control subjects were also examined by DT tractography. Based on the severity of aphasia at discharge, patients were divided into two groups: six patients in the aphasic group and seven in the nonaphasic group. Fractional anisotropy (FA) and number of arcuate fasciculus fibers were evaluated. Asymmetry index was calculated for both FA and number of fibers. FA values for the arcuate fasciculus fibers did not differ between hemispheres in either the patient groups or the controls. Number of arcuate fasciculus fibers exhibited a significant leftward asymmetry in the controls and the nonaphasic group but not in the aphasic group. Asymmetry index of number of fibers was significantly lower (rightward) in the aphasic group than in the nonaphasic (P = 0.015) and control (P = 0.005) groups. Loss of leftward asymmetry in number of AF fibers predicted aphasia at discharge with a sensitivity of 0.83 and specificity of 0.86. Asymmetry of arcuate fasciculus fibers by DT tractography may deserve to be assessed in acute infarction for predicting the fate of vascular aphasia. (orig.)

  7. Ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation: effects on cerebral oxygenation and hemodynamics.

    NARCIS (Netherlands)

    Heyst, A.F.J. van; Staak, F.H.J.M. van der; Hopman, J.C.W.; Tanke, R.B.; Sengers, R.C.A.; Liem, K.D.

    2003-01-01

    OBJECTIVE: To investigate the effect on cerebral oxygenation and hemodynamics of a patent ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation in a lamb model. DESIGN: Prospective intervention study in animals. SETTING: Animal research laboratory of a

  8. Where Were Those Rabbits? A New Paradigm to Determine Cerebral Lateralisation of Visuospatial Memory Function in Children

    Science.gov (United States)

    Groen, Margriet A.; Whitehouse, Andrew J. O.; Badcock, Nicholas A.; Bishop, Dorothy V. M.

    2011-01-01

    In the majority of people, functional differences are observed between the two cerebral hemispheres: language production is typically subserved by the left hemisphere and visuospatial skills by the right hemisphere. The development of this division of labour is not well understood and lateralisation of visuospatial function has received little…

  9. Does Handedness Affect the Cerebral Organization of Speech and Language in Individuals with Aphasia?

    Directory of Open Access Journals (Sweden)

    Juliana Baldo

    2014-04-01

    Although some earlier studies suggested distinct cerebral organizations for right- versus non-right-handed individuals, the neural correlates of fluency and comprehension were greatly overlapping between these groups in our sample of left hemisphere patients with aphasia.

  10. Anterior & lateral extension of optic radiation & safety of amygdalohippocampectomy through middle temporal gyrus: a cadaveric study of 11 cerebral hemispheres.

    Science.gov (United States)

    Chowdhury, F H; Khan, A H

    2010-01-01

    This is a cadaveric anatomical study on the localization of the optic radiation within the temporal lobe and to find whether surgical intervention to the temporal lobe, especially amygdalohippocampectomy, can damage the optic radiation or not. 11 cadaveric cerebral hemispheres were used for the study. A 2 cm long antero-posterior incision was done with a sharp knife, on middle temporal gyrus, starting 3 cm posterior to temporal pole. The incision was deepened perpendicular to surface of the gyrus to reach the temporal horn. The optic radiation was dissected under operating microscope using Klinger's fiber dissection technique and measurements were taken to define the anterior and lateral extension of optic radiation. The optic radiation in each hemispehere was inspected for any incision related damage. No damage to the optic radiation was found, caused by the 2 cm long anterior-posterior incision on middle temporal gyrus 3 cm posterior to temporal pole. Most anterior 9mm (8-10mm) of the Meyer loop was completely on the roof and there was no extension over lateral wall of the temporal horn. In next posterior 17.5mm (16-20 mm) it extended over lateral wall of temporal horn with gradual progression. The most anterior extension of optic radiation was 26mm (23-31mm) posterior to temporal pole. Amygdalohippocampectomy through a 2 cm long horizontal incision on the middle temporal gyrus, starting 3 cm posterior to the temporal pole, to enter into the temporal horn through the lower aspect of the lateral wall is unlikely to cause damage to the Meyer's loop. Any entry from the superior aspect of the temporal horn and any temporal lobectomy inclusive of the superior temporal gyrus to enter the temporal horn is likely to cause Meyer's loop injury. The findings support the fact that the more inferior the surgical trajectory to the temporal horn of the lateral ventricle, the lover is the risk of visual field damage.

  11. The functional organization of trial-related activity in lexical processing after early left hemispheric brain lesions: An event-related fMRI study.

    Science.gov (United States)

    Fair, Damien A; Choi, Alexander H; Dosenbach, Yannic B L; Coalson, Rebecca S; Miezin, Francis M; Petersen, Steven E; Schlaggar, Bradley L

    2010-08-01

    Children with congenital left hemisphere damage due to perinatal stroke are capable of acquiring relatively normal language functions despite experiencing a cortical insult that in adults often leads to devastating lifetime disabilities. Although this observed phenomenon is accepted, its neurobiological mechanisms are not well characterized. In this paper we examined the functional neuroanatomy of lexical processing in 13 children/adolescents with perinatal left hemispheric damage. In contrast to many previous perinatal infarct fMRI studies, we used an event-related design, which allowed us to isolate trial-related activity and examine correct and error trials separately. Using both group and single subject analysis techniques we attempt to address several methodological factors that may contribute to some discrepancies in the perinatal lesion literature. These methodological factors include making direct statistical comparisons, using common stereotactic space, using both single subject and group analyses, and accounting for performance differences. Our group analysis, investigating correct trial-related activity (separately from error trials), showed very few statistical differences in the non-involved right hemisphere between patients and performance matched controls. The single subject analysis revealed atypical regional activation patterns in several patients; however, the location of these regions identified in individual patients often varied across subjects. These results are consistent with the idea that alternative functional organization of trial-related activity after left hemisphere lesions is in large part unique to the individual. In addition, reported differences between results obtained with event-related designs and blocked designs may suggest diverging organizing principles for sustained and trial-related activity after early childhood brain injuries. 2009 Elsevier Inc. All rights reserved.

  12. Asymmetry in the brain influenced the neurological deficits and infarction volume following the middle cerebral artery occlusion in rats

    OpenAIRE

    Zhang Meizeng; Gao Huanmin

    2008-01-01

    Abstract Background Paw preference in rats is similar to human handedness, which may result from dominant hemisphere of rat brain. However, given that lateralization is the uniqueness of the humans, many researchers neglect the differences between the left and right hemispheres when selecting the middle cerebral artery occlusion (MCAO) in rats. The aim of this study was to evaluate the effect of ischemia in the dominant hemisphere on neurobehavioral function and on the cerebral infarction vol...

  13. Delayed decrease in hemispheric cerebral blood flow during Wada test demonstrated by 99mTc-HMPAO single photon emission computer tomography

    International Nuclear Information System (INIS)

    Ryding, E.; Sjoeholm, H.; Skeidsvoll, H.; Elmqvist, D.

    1989-01-01

    We describe how brain regions with a flow (and metabolism) decrease can be visualized after an injection of short-acting barbiturate in one of the internal carotid arteries during a Wada test. An intravenous administration of 99mTc-HMPAO was used to mark the relative flow distribution. The 99mTc-HMPAO distribution in the brain was recorded three-dimensionally about 1 h later, by means of a single photon emission computer tomograph. We show that the timing of the intravenous 99mTc-HMPAO administration during the Wada test is important for the visualization of the low-flow regions. The administration of the tracer substance should be delayed at least 30 s after the first signs of the barbiturate effect. The rCBF decrease in the barbiturate-injected cerebral hemisphere was associated with a simultaneous decrease in the contralateral, pharmacologically not directly affected, cerebellar hemisphere (crossed cerebellar diaschisis). (author)

  14. Posterior reversible encephalopathy syndrome mimicking a left middle cerebral artery stroke.

    Science.gov (United States)

    Terranova, Santo; Kumar, Jai Dev; Libman, Richard B

    2012-01-01

    Certain Acute Clinical presentations are highly suggestive of stroke caused by specific mechanisms. One example of this would be the sudden onset of aphasia without hemiparesis often reflecting cerebral embolism, frequently from a cardiac source. Posterior reversible encephalopathy syndrome (PRES) describes a usually reversible neurologic syndrome with a variety of presenting symptoms from headache, altered mental status, seizures, vomiting, diminished spontaneity and speech, abnormalities of visual perception and visual loss. We report a patient presenting with elevated blood pressure, CT characteristics of PRES but a highly circumscribed neurologic syndrome (Wernicke's Aphasia without hemiparesis) suggestive of a cardioembolic stroke affecting the left MCA territory. That is, PRES mimicked a focal stroke syndrome. The importance of recognizing this possibility is that his deficits resolved with blood pressure control, while other treatments, such as intensifying his anticoagulation would have been inappropriate. In addition, allowing his blood pressure to remain elevated as is often done in the setting of an acute stroke might have perpetuated the underlying pathophysiology of PRES leading to a worse clinical outcome. For this reason PRES needs to be recognized quickly and treated appropriately.

  15. Electron-beam computed tomography findings of left atrial appendage in patients with cardiogenic cerebral embolism

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Makiko; Takahashi, Satoshi; Yonezawa, Hisashi [Iwate Medical Univ., Morioka (Japan). School of Medicine

    2002-04-01

    We studied electron-beam computed tomography (EBCT) findings in the left atrial appendage of 72 patients with cerebral embolism [27 in the acute phase (<48 hours) and 45 in the chronic phase], 9 cases with nonvalvular atrial fibrillation (NVAF) but without stroke, and 13 controls. EBCT was performed in the early (during injection of contrast medium), late-1 (5 min after injection), and-2 (10 min after injection) phases. In the acute phase patients, 41% showed filling defect (FD) in the early phase alone (FDE), 15% showed FD until late phase-1 (FDL-1), and 15% showed FD until late phase-2 (FDL-2). The chronic phase patients showed FDE in 33% of cases, FDL-1 in 8% and FDL-2 11%. Only FDE was observed in 44% in NVAF cases without stroke. No FDs were observed in controls. Flow velocity in the appendage measured by transesophageal echocardiography was 23{+-}10 cm/sec in 21 FDE cases, 14{+-}3 cm/sec in 3 FDL-1 cases, 29{+-}23 cm/sec in 4 FDL-2 cases, significantly lower in comparison with 58{+-}25 cm/s in the 23 cases with no FD. FDL-1 and -2 suggested severe stasis or presence of thrombus in the appendage, which indicated high risk of embolism slower the movement of MES through the sample volume. (author)

  16. Electron-beam computed tomography findings of left atrial appendage in patients with cardiogenic cerebral embolism

    International Nuclear Information System (INIS)

    Okamoto, Makiko; Takahashi, Satoshi; Yonezawa, Hisashi

    2002-01-01

    We studied electron-beam computed tomography (EBCT) findings in the left atrial appendage of 72 patients with cerebral embolism [27 in the acute phase (<48 hours) and 45 in the chronic phase], 9 cases with nonvalvular atrial fibrillation (NVAF) but without stroke, and 13 controls. EBCT was performed in the early (during injection of contrast medium), late-1 (5 min after injection), and-2 (10 min after injection) phases. In the acute phase patients, 41% showed filling defect (FD) in the early phase alone (FDE), 15% showed FD until late phase-1 (FDL-1), and 15% showed FD until late phase-2 (FDL-2). The chronic phase patients showed FDE in 33% of cases, FDL-1 in 8% and FDL-2 11%. Only FDE was observed in 44% in NVAF cases without stroke. No FDs were observed in controls. Flow velocity in the appendage measured by transesophageal echocardiography was 23±10 cm/sec in 21 FDE cases, 14±3 cm/sec in 3 FDL-1 cases, 29±23 cm/sec in 4 FDL-2 cases, significantly lower in comparison with 58±25 cm/s in the 23 cases with no FD. FDL-1 and -2 suggested severe stasis or presence of thrombus in the appendage, which indicated high risk of embolism slower the movement of MES through the sample volume. (author)

  17. Hemispheric specialisation in selective attention and short-term memory: A fine-coarse model of left and right ear disadvantages

    Directory of Open Access Journals (Sweden)

    John E. Marsh

    2013-12-01

    Full Text Available Serial short-term memory is impaired by irrelevant sound, particularly when the sound changes acoustically. This acoustic effect is larger when the sound is presented to the left compared to the right ear (a left-ear disadvantage. Serial memory appears relatively insensitive to distraction from the semantic properties of a background sound. In contrast, short-term free recall of semantic-category exemplars is impaired by the semantic properties of background speech and relatively insensitive to the sound’s acoustic properties. This semantic effect is larger when the sound is presented to the right compared to the left ear (a right-ear disadvantage. In this paper, we outline a speculative neurocognitive fine-coarse model of these hemispheric differences in relation to short-term memory and selective attention, and explicate empirical directions in which this model can be critically evaluated.

  18. Inference comprehension in text reading: Performance of individuals with right- versus left-hemisphere lesions and the influence of cognitive functions.

    Directory of Open Access Journals (Sweden)

    Marcela Lima Silagi

    Full Text Available Right-hemisphere lesions (RHL may impair inference comprehension. However, comparative studies between left-hemisphere lesions (LHL and RHL are rare, especially regarding reading comprehension. Moreover, further knowledge of the influence of cognition on inferential processing in this task is needed.To compare the performance of patients with RHL and LHL on an inference reading comprehension task. We also aimed to analyze the effects of lesion site and to verify correlations between cognitive functions and performance on the task.Seventy-five subjects were equally divided into the groups RHL, LHL, and control group (CG. The Implicit Management Test was used to evaluate inference comprehension. In this test, subjects read short written passages and subsequently answer five types of questions (explicit, logical, distractor, pragmatic, and other, which require different types of inferential reasoning. The cognitive functional domains of attention, memory, executive functions, language, and visuospatial abilities were assessed using the Cognitive Linguistic Quick Test (CLQT.The LHL and RHL groups presented difficulties in inferential comprehension in comparison with the CG. However, the RHL group presented lower scores than the LHL group on logical, pragmatic and other questions. A covariance analysis did not show any effect of lesion site within the hemispheres. Overall, all cognitive domains were correlated with all the types of questions from the inference test (especially logical, pragmatic, and other. Attention and visuospatial abilities affected the scores of both the RHL and LHL groups, and only memory influenced the performance of the RHL group.Lesions in either hemisphere may cause difficulties in making inferences during reading. However, processing more complex inferences was more difficult for patients with RHL than for those with LHL, which suggests that the right hemisphere plays an important role in tasks with higher comprehension

  19. Inference comprehension in text reading: Performance of individuals with right- versus left-hemisphere lesions and the influence of cognitive functions.

    Science.gov (United States)

    Silagi, Marcela Lima; Radanovic, Marcia; Conforto, Adriana Bastos; Mendonça, Lucia Iracema Zanotto; Mansur, Leticia Lessa

    2018-01-01

    Right-hemisphere lesions (RHL) may impair inference comprehension. However, comparative studies between left-hemisphere lesions (LHL) and RHL are rare, especially regarding reading comprehension. Moreover, further knowledge of the influence of cognition on inferential processing in this task is needed. To compare the performance of patients with RHL and LHL on an inference reading comprehension task. We also aimed to analyze the effects of lesion site and to verify correlations between cognitive functions and performance on the task. Seventy-five subjects were equally divided into the groups RHL, LHL, and control group (CG). The Implicit Management Test was used to evaluate inference comprehension. In this test, subjects read short written passages and subsequently answer five types of questions (explicit, logical, distractor, pragmatic, and other), which require different types of inferential reasoning. The cognitive functional domains of attention, memory, executive functions, language, and visuospatial abilities were assessed using the Cognitive Linguistic Quick Test (CLQT). The LHL and RHL groups presented difficulties in inferential comprehension in comparison with the CG. However, the RHL group presented lower scores than the LHL group on logical, pragmatic and other questions. A covariance analysis did not show any effect of lesion site within the hemispheres. Overall, all cognitive domains were correlated with all the types of questions from the inference test (especially logical, pragmatic, and other). Attention and visuospatial abilities affected the scores of both the RHL and LHL groups, and only memory influenced the performance of the RHL group. Lesions in either hemisphere may cause difficulties in making inferences during reading. However, processing more complex inferences was more difficult for patients with RHL than for those with LHL, which suggests that the right hemisphere plays an important role in tasks with higher comprehension demands

  20. Use of computed tomography in the diagnosis of a cerebral abscess in a goat

    International Nuclear Information System (INIS)

    Gerros, T.C.; Mattoon, J.S.; Snyder, S.P.

    1998-01-01

    A 7-month-old La Mancha doe was presented with a right head tilt and ventral strabismus while circling to the left, History and physical examination led to a tentative diagnosis of a cerebral abscess. Computed tomography revealed a large, complex mass with ring enhancement in the left cerebral hemisphere, supporting the diagnosis. Postmortem examination confirmed the cerebral abscess. Bacterial cultures yielded heavy growth of Actinomyces pyogenes

  1. The Visual Word Form Area remains in the dominant hemisphere for language in late-onset left occipital lobe epilepsies: A postsurgery analysis of two cases.

    Science.gov (United States)

    Lopes, Ricardo; Nunes, Rita Gouveia; Simões, Mário Rodrigues; Secca, Mário Forjaz; Leal, Alberto

    2015-05-01

    Automatic recognition of words from letter strings is a critical processing step in reading that is lateralized to the left-hemisphere middle fusiform gyrus in the so-called Visual Word Form Area (VWFA). Surgical lesions in this location can lead to irreversible alexia. Very early left hemispheric lesions can lead to transfer of the VWFA to the nondominant hemisphere, but it is currently unknown if this capability is preserved in epilepsies developing after reading acquisition. In this study, we aimed to determine the lateralization of the VWFA in late-onset left inferior occipital lobe epilepsies and also the effect of surgical disconnection from the adjacent secondary visual areas. Two patients with focal epilepsies with onset near the VWFA underwent to surgery for epilepsy, with sparing of this area. Neuropsychology evaluations were performed before and after surgery, as well as quantitative evaluation of the speed of word reading. Comparison of the surgical localization of the lesion, with the BOLD activation associated with the contrast of words-strings, was performed, as well as a study of the associated main white fiber pathways using diffusion-weighted imaging. Neither of the patients developed alexia after surgery (similar word reading speed before and after surgery) despite the fact that the inferior occipital surgical lesions reached the neighborhood (less than 1cm) of the VWFA. Surgeries partly disconnected the VWFA from left secondary visual areas, suggesting that pathways connecting to the posterior visual ventral stream were severely affected but did not induce alexia. The anterior and superior limits of the resection suggest that the critical connection between the VWFA and the Wernicke's Angular Gyrus cortex was not affected, which is supported by the detection of this tract with probabilistic tractography. Left occipital lobe epilepsies developing after reading acquisition did not produce atypical localizations of the VWFA, even with foci in the

  2. Let thy left brain know what thy right brain doeth: Inter-hemispheric compensation of functional deficits after brain damage.

    Science.gov (United States)

    Bartolomeo, Paolo; Thiebaut de Schotten, Michel

    2016-12-01

    Recent evidence revealed the importance of inter-hemispheric communication for the compensation of functional deficits after brain damage. This review summarises the biological consequences observed using histology as well as the longitudinal findings measured with magnetic resonance imaging methods in brain damaged animals and patients. In particular, we discuss the impact of post-stroke brain hyperactivity on functional recovery in relation to time. The reviewed evidence also suggests that the proportion of the preserved functional network both in the lesioned and in the intact hemispheres, rather than the simple lesion location, determines the extent of functional recovery. Hence, future research exploring longitudinal changes in patients with brain damage may unveil potential biomarkers underlying functional recovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Study of cerebral blood flow and oxygen utilization in the edematous area and ipsilateral hemispheric gray matter using positron emission tomography in brain tumors

    International Nuclear Information System (INIS)

    Ikeda, Yusuke

    1990-01-01

    We measured the cerebral blood flow and oxygen utilization of the peritumoral white matter and ipsilateral hemispheric gray matter in 50 patients with brain tumors using Positron Emission Tomography (PET). The intraaxial tumors consisted of 34 cases (25 of gliomas, 6 of metastatic tumors, and 3 others), white the extraaxial tumors (all of meningiomas) were 16 cases. The cases were divided into 2 groups on the basis of the Xray CT scan findings. The cases of Edema (+) group showed moderate or large peritumoral edema in the white matter on the Xray CT scan, while Edema (-) group showed no or small edema. The method of PET study was the 15 O steady state inhalation technique by Frackoviak's method. ROIs (region of interest) were set on the peritumoral white matter and the ipsilateral hemispheric gray matter, and the mean CBF, OEF and CMRO2 values of the white and gray matter were calculated. In the Edema (+) group, the mean values of blood flow and oxygen utilization were low in the peritumoral white matter, and there were no obvious differences of values between intra and extraaxial tumors. But, the values in the ipsilateral hemispheric gray matter of intraaxial tumors were lower than those of extraaxial tumor. In the Edema (-) group, the mean values were almost normal in the white and gray matter, and there were no differences between intra and extraaxial tumors. The consideration about significance of the above stated results was discussed added with literature. (author)

  4. Compensatory cerebral motor control following presumed perinatal ischemic stroke

    NARCIS (Netherlands)

    van der Hoorn, Anouk; Potgieser, Adriaan R E; Brouwer, Oebele F; de Jong, Bauke M

    Case: A fifteen year-old left-handed girl presented with right-sided focal motor seizures. Neuroimaging showed a large left hemisphere lesion compatible with a middle cerebral artery stroke of presumed perinatal origin. She was not previously diagnosed with a motor deficit, although neurological

  5. An Attempt to Determine the Construct Validity of Measures Hypothesized to Represent an Orientation to Right, Left, or Integrated Hemispheric Brain Function for a Sample of Primary School Children.

    Science.gov (United States)

    Dumbrower, Jule; And Others

    1981-01-01

    This study attempts to obtain evidence of the construct validity of pupil ability tests hypothesized to represent orientation to right, left, or integrated hemispheric function, and of teacher observation subscales intended to reveal behaviors in school setting that were hypothesized to portray preference for right or left brain function. (Author)

  6. Effects of excision of a mass lesion of the precentral region of the left hemisphere on disturbances of graphomotor output

    NARCIS (Netherlands)

    Tucha, Oliver; Tucha, L.I.; Smely, C.; Lange, K.W.

    2012-01-01

    In the present study, the effect of neurosurgery on graphomotor output of a right-handed female patient with a mass lesion of the precentral region of the left frontal lobe was reported. For examination of handwriting movements a digitizing tablet was used. Preoperatively, the patient showed longer

  7. Crossed Aphasia in a Patient with Anaplastic Astrocytoma of the Non-Dominant Hemisphere.

    Science.gov (United States)

    Prater, Stephanie; Anand, Neil; Wei, Lawrence; Horner, Neil

    2017-09-01

    Aphasia describes a spectrum of speech impairments due to damage in the language centers of the brain. Insult to the inferior frontal gyrus of the dominant cerebral hemisphere results in Broca's aphasia - the inability to produce fluent speech. The left cerebral hemisphere has historically been considered the dominant side, a characteristic long presumed to be related to a person's "handedness". However, recent studies utilizing fMRI have shown that right hemispheric dominance occurs more frequently than previously proposed and despite a person's handedness. Here we present a case of a right-handed patient with Broca's aphasia caused by a right-sided brain tumor. This is significant not only because the occurrence of aphasia in right-handed-individuals with right hemispheric brain damage (so-called "crossed aphasia") is unusual but also because such findings support dissociation between hemispheric linguistic dominance and handedness.

  8. Cerebral lateralization for the processing of spatial coordinates and categories in left-and right-handers.

    Science.gov (United States)

    LAENG, B; PETERS, M

    1995-04-01

    Subjects judged whether a tachistoscopially lateralized drawing was identical or different to a drawing seen immediately before in free vision. The drawings depicted natural objects (e.g. animals). On half of the trials the tachistoscopic drawing presented the same objects but either the categorical or the coordinate spatial relations (according to Kosslyn's definitions [23]) between the objects were transformed. In the first experiment 38 right-handed subjects (half males and half females) were tested. Categorical judgements were faster when the match drawing appeared in the right visual field, whereas coordinate judgements were faster when the match drawing appeared in the left visual field. In the second experiment 26 right-handed and 40 left-handed subjects participated. Almost all the subjects were female. Right-handed subjects replicated the findings of the subjects in the first experiment. However, the LHs did not show any difference in response times between spatial conditions and visual fields. These findings support Kosslyn's hypothesis that the left and right hemispheres are specialized respectively for processing categorical and coordinate spatial relations. Moreover, they also suggest that this lateralization pattern is not typical of left-handers.

  9. Reduced microvascular volume and hemispherically deficient vasoreactivity to hypercapnia in acute ischemia: MRI study using permanent middle cerebral artery occlusion rat model.

    Science.gov (United States)

    Suh, J Y; Shim, Woo H; Cho, Gyunggoo; Fan, Xiang; Kwon, Seon J; Kim, Jeong K; Dai, George; Wang, Xiaoying; Kim, Young R

    2015-06-01

    Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2*-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2 gas inhalation in normal (n=5) and acute stroke rats (n=10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology.

  10. External carotid compression: a novel technique to improve cerebral perfusion during selective antegrade cerebral perfusion for aortic arch surgery.

    Science.gov (United States)

    Grocott, Hilary P; Ambrose, Emma; Moon, Mike

    2016-10-01

    Selective antegrade cerebral perfusion (SACP) involving cannulation of either the axillary or innominate artery is a commonly used technique for maintaining cerebral blood flow (CBF) during the use of hypothermic cardiac arrest (HCA) for operations on the aortic arch. Nevertheless, asymmetrical CBF with hypoperfusion of the left cerebral hemisphere is a common occurrence during SACP. The purpose of this report is to describe an adjunctive maneuver to improve left hemispheric CBF during SACP by applying extrinsic compression to the left carotid artery. A 77-yr-old male patient with a history of aortic valve replacement presented for emergent surgical repair of an acute type A aortic dissection of a previously known ascending aortic aneurysm. His intraoperative course included cannulation of the right axillary artery, which was used as the aortic inflow during cardiopulmonary bypass and also allowed for subsequent SACP during HCA. After the onset of HCA, the innominate artery was clamped at its origin to allow for SACP. Shortly thereafter, however, the left-sided cerebral oxygen saturation (SrO2) began to decrease. Augmenting the PaO2, PaCO2 and both SACP pressure and flow failed to increase left hemispheric SrO2. Following the use of ultrasound guidance to confirm the absence of atherosclerotic disease in the carotid artery, external pressure was applied partially compressing the artery. With the carotid compression, the left cerebral saturation abruptly increased, suggesting pressurization of the left cerebral hemispheric circulation and augmentation of CBF. Direct ultrasound visualization and cautious partial compression of the left carotid artery may address asymmetrical CBF that occurs with SACP during HCA for aortic arch surgery. This strategy may lead to improved symmetry of CBF and corresponding cerebral oximetry measurements during aortic arch surgery.

  11. A vision of graded hemispheric specialization.

    Science.gov (United States)

    Behrmann, Marlene; Plaut, David C

    2015-11-01

    Understanding the process by which the cerebral hemispheres reach their mature functional organization remains challenging. We propose a theoretical account in which, in the domain of vision, faces and words come to be represented adjacent to retinotopic cortex by virtue of the need to discriminate among homogeneous exemplars. Orthographic representations are further constrained to be proximal to typically left-lateralized language-related information to minimize connectivity length between visual and language areas. As reading is acquired, orthography comes to rely more heavily (albeit not exclusively) on the left fusiform region to bridge vision and language. Consequently, due to competition from emerging word representations, face representations that were initially bilateral become lateralized to the right fusiform region (albeit, again, not exclusively). We review recent research that describes constraints that give rise to this graded hemispheric arrangement. We then summarize empirical evidence from a variety of studies (behavioral, evoked response potential, functional imaging) across different populations (children, adolescents, and adults; left handers and individuals with developmental dyslexia) that supports the claims that hemispheric lateralization is graded rather than binary and that this graded organization emerges dynamically over the course of development. Perturbations of this system either during development or in adulthood provide further insights into the principles governing hemispheric organization. © 2015 New York Academy of Sciences.

  12. Headache and Central Positioning Vertigo in a Middle Aged Female-a Case of Solitary Cerebellar Tuberculoma Involving Left Cerebellar Hemisphere

    Directory of Open Access Journals (Sweden)

    Shakya Bhattacharjee

    2012-03-01

    Full Text Available A 48 year old female presented with headache and an illusory sensation of spinning of head in respect to environment for last 8 weeks. Her head spinning or vertigo had no particular direction or not precipitated by any specific head posture. Headache is non- specific in nature and intensified in last few days.Her neurological examination revealed a central positional vertigo with horizontal gaze evoked nystagmus and ataxia. Her MRI scan brain showed the presence of a large solitary ring enhancing lesion in the left cerebellar hemisphere. The lesion was surgically excised and was examined histopathologicaliy that revealed a chronic inflammatory granuloma with caseation necrosis and multinucleated giant cells suggestive of tuberculosis

  13. Case-control study of six genes asymmetrically expressed in the two cerebral hemispheres: association of BAIAP2 with attention-deficit/hyperactivity disorder

    DEFF Research Database (Denmark)

    Ribasés, Marta; Bosch, Rosa; Hervás, Amaia

    2009-01-01

    BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset neuropsychiatric disease that persists into adulthood in at least 30% of patients. There is evidence suggesting that abnormal left-right brain asymmetries in ADHD patients may be involved in a variety of ADHD...... results support the participation of BAIAP2 in the continuity of ADHD across life span, at least in some of the populations analyzed, and suggest that genetic factors potentially influencing abnormal cerebral lateralization may be involved in this disorder....

  14. Motor imagery training promotes motor learning in adolescents with cerebral palsy: comparison between left and right hemiparesis.

    Science.gov (United States)

    Cabral-Sequeira, Audrey Sartori; Coelho, Daniel Boari; Teixeira, Luis Augusto

    2016-06-01

    This experiment was designed to evaluate the effects of pure motor imagery training (MIT) and its combination with physical practice on learning an aiming task with the more affected arm in adolescents suffering from cerebral palsy. Effect of MIT was evaluated as a function of side of hemiparesis. The experiment was accomplished by 11- to 16-year-old participants (M = 13.58 years), who suffered left (n = 16) or right (n = 15) mild hemiparesis. They were exposed to pure MIT (day 1) followed by physical practice (day 2) on an aiming task demanding movement accuracy and speed. Posttraining movement kinematics of the group receiving MIT were compared with movement kinematics of the control group after receiving recreational activities (day 1) and physical practice (day 2). Kinematic analysis showed that MIT led to decreased movement time and straighter hand displacements to the target. Performance achievements from MIT were increased with further physical practice, leading to enhanced effects on motor learning. Retention evaluation indicated that performance improvement from pure MIT and its combination with physical practice were stable over time. Performance achievements were equivalent between adolescents with either right or left hemiparesis, suggesting similar capacity between these groups to achieve performance improvement from pure imagery training and from its association with physical practice. Our results suggest that motor imagery training is a procedure potentially useful to increase motor learning achievements in individuals suffering from cerebral palsy.

  15. Use of decompressive craniectomy in the treatment of hemispheric infarction Uso da craniectomia descompressiva no tratamento do acidente vascular cerebral isquêmico hemisférico

    Directory of Open Access Journals (Sweden)

    José Antonio Fiorot Jr.

    2008-06-01

    Full Text Available Decompressive craniectomy (DC has demonstrated efficacy in reducing mortality in hemispheric infarction of the middle cerebral artery. The aim of our study was to compare the outcome of patients submitted to DC to patients treated in a conservative way. Eighteen patients were submitted to DC and 14 received conservative treatment. Neurological status was assessed by the Glasgow Coma Score and National Institutes of Health Stroke Scale score. Mortality, modified Rankin Scale and Barthel Index scores were assessed at 90 days to evaluate outcome. We did not observe reduction in overall mortality and functional outcome in patients submitted to DC. The differences between our group and previously published series are probably related to the neurological status of the patients at the time of therapeutic decision.Craniectomia descompressiva (CD tem demonstrado eficácia em reduzir a mortalidade em pacientes com infarto hemisférico (IH da artéria cerebral média. Este estudo avaliou o prognóstico dos pacientes submetidos a CD comparando a pacientes com IH tratados de maneira conservadora. Dezoito pacientes foram submetidos a CD e 14 receberam tratamento conservador. Escala de Coma de Glasgow e Escala de AVC do National Institutes of Health foram utilizadas para graduar o déficit neurológico. A mortalidade, bem como os escores obtidos na escala modificada de Rankin e índice de Barthel foram avaliados em 90 dias. Não foi observada redução de mortalidade nos pacientes submetidos a CD. Essa diferença entre os nossos resultados e os estudos publicados previamente se deve, provavelmente, à decisão cirúrgica tardia em pacientes com sinais clínicos de herniação cerebral.

  16. Selection and application of familiar and novel tools in patients with left and right hemispheric stroke: Psychometrics and normative data.

    Science.gov (United States)

    Buchmann, Ilka; Randerath, Jennifer

    2017-09-01

    Frequently left brain damage (LBD) leads to limb apraxia, a disorder that can affect tool-use. Despite its impact on daily life, classical tests examining the pantomime of tool-use and imitation of gestures are seldom applied in clinical practice. The study's aim was to present a diagnostic approach which appears more strongly related to actions in daily life in order to sensitize applicants and patients about the relevance of the disorder before patients are discharged. Two tests were introduced that evaluate actual tool selection and tool-object-application: the Novel Tools (NTT) and the Familiar Tools (FTT) Test (parts of the DILA-S: Diagnostic Instrument for Limb Apraxia - Short Version). Normative data in healthy subjects (N = 82) was collected. Then the tests were applied in stroke patients with unilateral left brain damage (LBD: N = 33), a control right brain damage group (RBD: N = 20) as well as healthy age and gender matched controls (CL: N = 28, and CR, N = 18). The tests showed appropriate interrater-reliability and internal consistency as well as concurrent and divergent validity. To examine criterion validity based on the well-known left lateralization of limb apraxia, group comparisons were run. As expected, the LBD group demonstrated a high prevalence of tool-use apraxia (NTT: 36.4%, FTT: 48.5%) ranging from mild to severe impairment and scored worse than their control group (CL). A few RBD patients did demonstrate impairments in tool-use (NTT: 15%, FTT: 15%). On a group level they did not differ from their healthy controls (CR). Further, it was demonstrated that the selection and application of familiar and novel tools can be impaired selectively. Our study results suggest that real tool-use tests evaluating tool selection and tool application should be considered for standard diagnosis of limb apraxia in left as well as right brain damaged patients. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Bilingualism yields language-specific plasticity in left hemisphere's circuitry for learning to read in young children.

    Science.gov (United States)

    Jasińska, K K; Berens, M S; Kovelman, I; Petitto, L A

    2017-04-01

    How does bilingual exposure impact children's neural circuitry for learning to read? Theories of bilingualism suggests that exposure to two languages may yield a functional and neuroanatomical adaptation to support the learning of two languages (Klein et al., 2014). To test the hypothesis that this neural adaptation may vary as a function of structural and orthographic characteristics of bilinguals' two languages, we compared Spanish-English and French-English bilingual children, and English monolingual children, using functional Near Infrared Spectroscopy neuroimaging (fNIRS, ages 6-10, N =26). Spanish offers consistent sound-to-print correspondences ("phonologically transparent" or "shallow"); such correspondences are more opaque in French and even more opaque in English (which has both transparent and "phonologically opaque" or "deep" correspondences). Consistent with our hypothesis, both French- and Spanish-English bilinguals showed hyperactivation in left posterior temporal regions associated with direct sound-to-print phonological analyses and hypoactivation in left frontal regions associated with assembled phonology analyses. Spanish, but not French, bilinguals showed a similar effect when reading Irregular words. The findings inform theories of bilingual and cross-linguistic literacy acquisition by suggesting that structural characteristics of bilinguals' two languages and their orthographies have a significant impact on children's neuro-cognitive architecture for learning to read. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Recurrent cerebral thrombosis

    International Nuclear Information System (INIS)

    Iwamoto, Toshihiko; Abe, Shin-e; Kubo, Hideki; Hanyu, Haruo; Takasaki, Masaru

    1992-01-01

    Neuroradiological techniques were used to elucidate pathophysiology of recurrent cerebral thrombosis. Twenty-two patients with cerebral thrombosis who suffered a second attack under stable conditions more than 22 days after the initial stroke were studied. Hypertension, diabetes mellitus, and hypercholesterolemia were also seen in 20, 8, and 12 patients, respectively. The patients were divided into three groups according to their symptoms: (I) symptoms differed between the first and second strokes (n=12); (II) initial symptoms were suddenly deteriorated (n=6); and (III) symptoms occurring in groups I and II were seen (n=4). In group I, contralateral hemiparesis or suprabulbar palsy was often associated with the initial hemiparesis. The time of recurrent stroke varied from 4 months to 9 years. CT and MRI showed not only lacunae in both hemispheres, but also deep white-matter ischemia of the centrum semi-ovale. In group II, hemiparesis or visual field defect was deteriorated early after the initial stroke. In addition, neuroimaging revealed that infarction in the posterior cerebral artery was progressed on the contralateral side, or that white matter lesion in the middle artery was enlarged in spite of small lesion in the left cerebral hemisphere. All patients in group III had deterioration of right hemiparesis associated with aphasia. CT, MRI, SPECT, and angiography indicated deep white-matter ischemia caused by main trunk lesions in the left hemisphere. Group III seemed to be equivalent to group II, except for laterality of the lesion. Neuroradiological assessment of the initial stroke may help to predict the mode of recurrence, although pathophysiology of cerebral thrombosis is complicated and varies from patient to patient. (N.K.)

  19. Hemispheric Asymmetries in Processing L1 and L2 Idioms: Effects of Salience and Context

    Science.gov (United States)

    Cieslicka, Anna B.; Heredia, Roberto R.

    2011-01-01

    This study investigates the contribution of the left and right hemispheres to the comprehension of bilingual figurative language and the joint effects of salience and context on the differential cerebral involvement in idiom processing. The divided visual field and the lexical decision priming paradigms were employed to examine the activation of…

  20. Right retrograde brachial cerebral angiography with simultaneous compression of the left carotid artery

    International Nuclear Information System (INIS)

    Ericson, K.; Mosskin, M.

    1981-01-01

    Right retrograde brachial angiography with simultaneous compression of the left common carotid artery was performed in 12 patients, invariably resulting in filling of the right vertebral and the basilar artery. In all but one patient, the right carotid artery and its branches were also filled. Retrograde filling of the left internal carotid artery occurred in 8 patients. Furthermore, retrograde filling of the intracranial part of the left vertebral artery was obtained in 5 of 12 patients. A complete four-vessel cranial angiography was thus obtained in one third of the patients. The method may be considered as a safe and valuable adjunct to other angiographic techniques. (Auth.)

  1. Emotion-related hemisphere asymmetry: subjective emotional responses to laterally presented films.

    Science.gov (United States)

    Wittling, W; Roschmann, R

    1993-09-01

    To investigate whether the cerebral hemispheres differ in their subjective emotional responses 54 adult subjects were presented two films of different emotion-related qualities (positive and negative film) either to their left or right hemisphere. The films were exposed by means of a technique for the lateralization of visual input that allows prolonged viewing while permitting free ocular scanning. Subjective emotional responses were assessed by means of a continuous rating of emotional arousal experienced during the movie as well as by retrospective ratings of ten different emotional qualities. Presenting both films to the right hemisphere resulted in stronger subjective responses in the continuous emotion rating as well as in some retrospectively assessed ratings compared to left-hemispheric presentation. The effects were more pronounced for the negative film. Taken together, the findings suggest a higher responsiveness of the right hemisphere in subjective emotional experience.

  2. Cerebral circulation and metabolism with recovery of chronic poststroke aphasia

    International Nuclear Information System (INIS)

    Yamada, Tomoyuki; Kabasawa, Hidehiro; Matsubara, Michitaka; Hibino, Hiroaki; Kamimoto, Kaoru; Fukagawa, Kazutoshi

    2004-01-01

    The recruitment of cerebral circulation and oxygen metabolism in the particular brain areas responsible for poststroke aphasia are necessary for recovery. This study was undertaken to investigate changes in cerebral circulation and oxygen metabolism corresponding to improvement of aphasia. Twenty-nine right-handed chronic aphasic patients with left hemispheric stroke were studied. Aphasia was evaluated as the score of fluency, comprehension, repetition and naming by the Western Aphasia Battery (Japanese version). Concurrent with the evaluation of aphasia, positron emission tomography (PET) scans were performed. After several months of speech therapy, PET scans and evaluation of aphasia were reperformed. Both regional cerebral blood flow and the cerebral metabolic rate for oxygen significantly increased in the left upper superior and middle temporal gyri, and in the left upper inferior frontal gyrus in the fair recovery group for comprehension, repetition and naming. In the fair recovery group for fluency, the cerebral metabolic rate for oxygen significantly increased in the left upper superior and middle temporal gyri, but regional cerebral blood flow increased insignificantly in these areas. In the lower white matter of the right parietal lobe, both the regional cerebral blood flow and the cerebral metabolic rate for oxygen were significantly increased in the fair recovery group for all aphasic features. The recruitment of cerebral circulation and oxygen metabolism in the left temporo-parietal area, in the left inferior frontal area, and in the right deep parietal area are essentially responsible for the recovery of aphasia. (author)

  3. Gender and rapid alterations of hemispheric dominance during planning.

    Science.gov (United States)

    Schuepbach, Daniel; Skotchko, Tatjana; Duschek, Stefan; Theodoridou, Anastasia; Grimm, Simone; Boeker, Heinz; Seifritz, Erich

    2012-01-01

    Mental planning and carrying out a plan provoke specific cerebral hemodynamic responses. Gender aspects of hemispheric laterality using rapid cerebral hemodynamics have not been reported. Here, we applied functional transcranial Doppler sonography to examine lateralization of cerebral hemodynamics of the middle cerebral arteries of 28 subjects (14 women and 14 men) performing a standard planning task. There were easy and difficult problems, and mental planning without motor activity was separated from movement execution. Difficult mental planning elicited lateralization to the right hemisphere after 2 or more seconds, a feature that was not observed during movement execution. In females, there was a dominance to the left hemisphere during movement execution. Optimized problem solving yielded an increased laterality change to the right during mental planning. Gender-related hemispheric dominance appears to be condition-dependent, and change of laterality to the right may play a role in optimized performance. Results are of relevance when considering laterality from a perspective of performance enhancement of higher cognitive functions, and also of psychiatric disorders with cognitive dysfunctions and abnormal lateralization patterns such as schizophrenia. Copyright © 2012 S. Karger AG, Basel.

  4. Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies

    International Nuclear Information System (INIS)

    Knopman, D.S.; Rubens, A.B.; Selnes, O.A.; Klassen, A.C.; Meyer, M.W.

    1984-01-01

    In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery

  5. Does cerebral lateralisation develop? A study using functional transcranial Doppler ultrasound assessing lateralization for language production and visuaspatial memory

    NARCIS (Netherlands)

    Groen, M.A.; Whitehouse, A.J.O.; Badcock, N.A.; Bishop, D.V.M.

    2012-01-01

    In the majority of people, language production is lateralized to the left cerebral hemisphere and visuospatial skills to the right. However, questions remain as to when, how, and why humans arrive at this division of labor. In this study, we assessed cerebral lateralization for language production

  6. Hemispheric biases and the control of visuospatial attention: an ERP study

    Directory of Open Access Journals (Sweden)

    Banich Marie T

    2005-08-01

    Full Text Available Abstract Background We examined whether individual differences in hemispheric utilization can interact with the intrinsic attentional biases of the cerebral hemispheres. Evidence suggests that the hemispheres have competing biases to direct attention contralaterally, with the left hemisphere (LH having a stronger bias than the right hemisphere. There is also evidence that individuals have characteristic biases to utilize one hemisphere more than the other for processing information, which can induce a bias to direct attention to contralateral space. We predicted that LH-biased individuals would display a strong rightward attentional bias, which would create difficulty in selectively attending to target stimuli in the left visual field (LVF as compared to right in the performance of a bilateral flanker task. Results Consistent with our hypothesis, flanker interference effects were found on the N2c event-related brain potential and error rate for LH-biased individuals in the Attend-LVF condition. The error rate effect was correlated with the degree of hemispheric utilization bias for the LH-Bias group. Conclusion We conclude that hemispheric utilization bias can enhance a hemisphere's contralateral attentional bias, at least for individuals with a LH utilization bias. Hemispheric utilization bias may play an important and largely unrecognized role in visuospatial attention.

  7. Hemicraniectomy after middle cerebral artery infarction with life-threatening Edema trial (HAMLET). Protocol for a randomised controlled trial of decompressive surgery in space-occupying hemispheric infarction.

    Science.gov (United States)

    Hofmeijer, Jeannette; Amelink, G Johan; Algra, Ale; van Gijn, Jan; Macleod, Malcolm R; Kappelle, L Jaap; van der Worp, H Bart

    2006-09-11

    Patients with a hemispheric infarct and massive space-occupying brain oedema have a poor prognosis. Despite maximal conservative treatment, the case fatality rate may be as high as 80%, and most survivors are left severely disabled. Non-randomised studies suggest that decompressive surgery reduces mortality substantially and improves functional outcome of survivors. This study is designed to compare the efficacy of decompressive surgery to improve functional outcome with that of conservative treatment in patients with space-occupying supratentorial infarction The study design is that of a multi-centre, randomised clinical trial, which will include 112 patients aged between 18 and 60 years with a large hemispheric infarct with space-occupying oedema that leads to a decrease in consciousness. Patients will be randomised to receive either decompressive surgery in combination with medical treatment or best medical treatment alone. Randomisation will be stratified for the intended mode of conservative treatment (intensive care or stroke unit care). The primary outcome measure will be functional outcome, as determined by the score on the modified Rankin Scale, at one year.

  8. Awake surgery for WHO Grade II gliomas within "noneloquent" areas in the left dominant hemisphere: toward a "supratotal" resection. Clinical article.

    Science.gov (United States)

    Yordanova, Yordanka N; Moritz-Gasser, Sylvie; Duffau, Hugues

    2011-08-01

    It has been demonstrated that an extensive resection (total or subtotal) may significantly increase the overall survival in patients with WHO Grade II gliomas (low-grade gliomas [LGGs]). Yet, recent data have shown that conventional MR imaging underestimates the spatial extent of LGG, since tumor cells were found up to 20 mm around MR imaging abnormalities. Thus, it was hypothesized that an extended resection with a margin beyond MR imaging-defined abnormalities-a "supratotal" resection-might improve the outcome of LGG. However, because of the frequent location of LGG within "eloquent" brain areas, it is often difficult to achieve such a supratotal resection. This could nevertheless be possible when LGGs involve "noneloquent" areas, even in the left dominant hemisphere. The authors report on their use of awake electrical mapping to tailor the resection according to functional boundaries, that is, to pursue the resection beyond MR imaging-defined abnormalities, until corticosubcortical eloquent structures are encountered. Their aim was to apply this reliable surgical technique to LGGs located not within eloquent areas but distant from eloquent areas, to take a margin around the LGG visible on MR imaging while preserving brain function. Fifteen right-handed patients with a total of 17 tumors underwent resection of WHO Grade II gliomas involving nonfunctional areas within the left dominant hemisphere. In all patients, seizures were the initial manifestation of the tumors. Awake surgery with intraoperative electrostimulation was performed in all cases. The resection was continued until the surgeon reached cortical and subcortical areas crucial for brain function, especially language, as defined by the intrasurgical electrical mapping. The extent of resection was evaluated on postoperative FLAIR-weighted MR images. Despite transient neurological worsening in 60% of cases, all patients recovered and returned to a normal life. Seizure control was obtained in all patients

  9. Hyperlexia and ambient echolalia in a case of cerebral infarction of the left anterior cingulate cortex and corpus callosum.

    Science.gov (United States)

    Suzuki, Tadashi; Itoh, Shouichi; Hayashi, Mototaka; Kouno, Masako; Takeda, Katsuhiko

    2009-10-01

    We report the case of a 69-year-old woman with cerebral infarction in the left anterior cingulate cortex and corpus callosum. She showed hyperlexia, which was a distinctive reading phenomenon, as well as ambient echolalia. Clinical features also included complex disorders such as visual groping, compulsive manipulation of tools, and callosal disconnection syndrome. She read words written on the cover of a book and repeated words emanating from unrelated conversations around her or from hospital announcements. The combination of these two features due to a focal lesion has never been reported previously. The supplementary motor area may control the execution of established subroutines according to external and internal inputs. Hyperlexia as well as the compulsive manipulation of tools could be interpreted as faulty inhibition of preexisting essentially intact motor subroutines by damage to the anterior cingulate cortex reciprocally interconnected with the supplementary motor area.

  10. Differences in cerebral cortical anatomy of left- and right-handers

    NARCIS (Netherlands)

    Guadalupe, T.M.; Willems, R.M.; Zwiers, M.P.; Arias Vasquez, A.; Hoogman, M.; Hagoort, P.; Fernandez, G.S.E.; Buitelaar, J.K.; Franke, B.; Fisher, S.E.; Francks, C.

    2014-01-01

    The left and right sides of the human brain are specialized for different kinds of information processing, and much of our cognition is lateralized to an extent toward one side or the other. Handedness is a reflection of nervous system lateralization. Roughly ten percent of people are mixed- or

  11. Hypothalamic digoxin, hemispheric chemical dominance, and creativity.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-04-01

    The human hypothalamus produces an endogenous membrane Na(+)-K+ ATPase inhibitor, digoxin, which regulates neuronal transmission. The digoxin status and neurotransmitter patterns were studied in creative and non-creative individuals, as well as in individuals with differing hemispheric dominance, in order to find out the role of cerebral dominance in this respect. The activity of HMG CoA reductase and serum levels of digoxin, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in creative/non-creative individuals, and in individuals with differing hemispheric dominance. In creative individuals there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in creative individuals correlated with right hemispheric dominance. In non-creative individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in non-creative individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to creative tendency.

  12. Automated quantification of cerebral edema following hemispheric infarction: Application of a machine-learning algorithm to evaluate CSF shifts on serial head CTs

    Directory of Open Access Journals (Sweden)

    Yasheng Chen

    2016-01-01

    Full Text Available Although cerebral edema is a major cause of death and deterioration following hemispheric stroke, there remains no validated biomarker that captures the full spectrum of this critical complication. We recently demonstrated that reduction in intracranial cerebrospinal fluid (CSF volume (∆CSF on serial computed tomography (CT scans provides an accurate measure of cerebral edema severity, which may aid in early triaging of stroke patients for craniectomy. However, application of such a volumetric approach would be too cumbersome to perform manually on serial scans in a real-world setting. We developed and validated an automated technique for CSF segmentation via integration of random forest (RF based machine learning with geodesic active contour (GAC segmentation. The proposed RF + GAC approach was compared to conventional Hounsfield Unit (HU thresholding and RF segmentation methods using Dice similarity coefficient (DSC and the correlation of volumetric measurements, with manual delineation serving as the ground truth. CSF spaces were outlined on scans performed at baseline (<6 h after stroke onset and early follow-up (FU (closest to 24 h in 38 acute ischemic stroke patients. RF performed significantly better than optimized HU thresholding (p < 10−4 in baseline and p < 10−5 in FU and RF + GAC performed significantly better than RF (p < 10−3 in baseline and p < 10−5 in FU. Pearson correlation coefficients between the automatically detected ∆CSF and the ground truth were r = 0.178 (p = 0.285, r = 0.876 (p < 10−6 and r = 0.879 (p < 10−6 for thresholding, RF and RF + GAC, respectively, with a slope closer to the line of identity in RF + GAC. When we applied the algorithm trained from images of one stroke center to segment CTs from another center, similar findings held. In conclusion, we have developed and validated an accurate automated approach to segment CSF and calculate its shifts on serial CT scans

  13. Left hemisphere fractional anisotropy increase in noise-induced tinnitus: a diffusion tensor imaging (DTI) study of white matter tracts in the brain.

    Science.gov (United States)

    Benson, Randall R; Gattu, Ramtilak; Cacace, Anthony T

    2014-03-01

    Diffusion tensor imaging (DTI) is a contemporary neuroimaging modality used to study connectivity patterns and microstructure of white matter tracts in the brain. The use of DTI in the study of tinnitus is a relatively unexplored methodology with no studies focusing specifically on tinnitus induced by noise exposure. In this investigation, participants were two groups of adults matched for etiology, age, and degree of peripheral hearing loss, but differed by the presence or absence (+/-) of tinnitus. It is assumed that matching individuals on the basis of peripheral hearing loss, allows for differentiating changes in white matter microstructure due to hearing loss from changes due to the effects of chronic tinnitus. Alterations in white matter tracts, using the fractional anisotropy (FA) metric, which measures directional diffusion of water, were quantified using tract-based spatial statistics (TBSS) with additional details provided by in vivo probabilistic tractography. Our results indicate that 10 voxel clusters differentiated the two groups, including 9 with higher FA in the group with tinnitus. A decrease in FA was found for a single cluster in the group with tinnitus. However, seven of the 9 clusters with higher FA were in left hemisphere thalamic, frontal, and parietal white matter. These foci were localized to the anterior thalamic radiations and the inferior and superior longitudinal fasciculi. The two right-sided clusters with increased FA were located in the inferior fronto-occipital fasciculus and superior longitudinal fasciculus. The only decrease in FA for the tinnitus-positive group was found in the superior longitudinal fasciculus of the left parietal lobe. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Cerebral and cerebellar language organization in a right-handed subject with a left temporal porencephalic cyst : An fMRI study

    NARCIS (Netherlands)

    De Coninck, Mattias; Van Hecke, Wim; Crols, Roe; van Dun, Kim; Van Dam, Debby; De Deyn, Peter P.; Brysbaert, Marc; Marien, Peter

    To test the hypothesis of crossed cerebro-cerebellar language dominance (Marien, Engelborghs, Fabbro, & De Deyn, 2001) in atypical populations, the pattern of cerebral and cerebellar language organization in a right-handed woman with a large porencephalic cyst in the left temporal lobe with no

  15. Abces cerebral associe a une cardiopathie congenitale cyanogene ...

    African Journals Online (AJOL)

    Case 1: This was a 3-year-old girl with a known Fallot tetralogy who was admitted for non-febrile intracranial hypertension syndrome, evolving for 2 months, associated with a functional impotence of the right hemicorp. The cerebral tomodensitometry had objectified a left hemispherical abscess. She had received a puncture ...

  16. Cerebral asymmetries: complementary and independent processes.

    Directory of Open Access Journals (Sweden)

    Gjurgjica Badzakova-Trajkov

    Full Text Available Most people are right-handed and left-cerebrally dominant for speech, leading historically to the general notion of left-hemispheric dominance, and more recently to genetic models proposing a single lateralizing gene. This hypothetical gene can account for higher incidence of right-handers in those with left cerebral dominance for speech. It remains unclear how this dominance relates to the right-cerebral dominance for some nonverbal functions such as spatial or emotional processing. Here we use functional magnetic resonance imaging with a sample of 155 subjects to measure asymmetrical activation induced by speech production in the frontal lobes, by face processing in the temporal lobes, and by spatial processing in the parietal lobes. Left-frontal, right-temporal, and right-parietal dominance were all intercorrelated, suggesting that right-cerebral biases may be at least in part complementary to the left-hemispheric dominance for language. However, handedness and parietal asymmetry for spatial processing were uncorrelated, implying independent lateralizing processes, one producing a leftward bias most closely associated with handedness, and the other a rightward bias most closely associated with spatial attention.

  17. Right- and left-brain hemisphere. Rhythm in reaction time to light signals is task-load-dependent: age, gender, and handgrip strength rhythm comparisons.

    Science.gov (United States)

    Reinberg, Alain; Bicakova-Rocher, Alena; Mechkouri, Mohamed; Ashkenazi, Israel

    2002-11-01

    subjects. Hand-side differences in the grip strength rhythms in the same individuals were detected, the tau being ultradian rather than circadian in adolescent subjects while in mature subjects the tau frequently differed from that of the rhythm in CRT. These findings further support the hypothesis that functional biological clocks exist in both the left and right hemispheres of the human cortex.

  18. Hypothalamic digoxin, hemispheric chemical dominance, and the tridosha theory.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-05-01

    -potassium ATPase inhibition. Left hemispheric chemical dominance/Pitta state represents the reverse pattern with hypodigoxinemia and membrane sodium-potassium ATPase stimulation. The Vata state is the intermediate bihemispheric chemical dominant state. Ninety-five percent of the patients/individuals in the tridosha, pathological, and psychological groups were right-handed/left hemispheric dominant, however, their biochemical patterns were different--either left hemispheric chemical dominant or right hemispheric chemical dominant. Hemispheric chemical dominance/tridosha states had no correlation with cerebral dominance detected by handedness/dichotic listening test.

  19. Mapping number to space in the two hemispheres of the avian brain.

    Science.gov (United States)

    Rugani, Rosa; Vallortigara, Giorgio; Regolin, Lucia

    2016-09-01

    Pre-verbal infants and non-human animals associate small numbers with the left space and large numbers with the right space. Birds and primates, trained to identify a given position in a sagittal series of identical positions, whenever required to respond on a left/right oriented series, referred the given position starting from the left end. Here, we extended this evidence by selectively investigating the role of either cerebral hemisphere, using the temporary monocular occlusion technique. In birds, lacking the corpus callosum, visual input is fed mainly to the contralateral hemisphere. We trained 4-day-old chicks to identify the 4th element in a sagittal series of 10 identical elements. At test, the series was identical but left/right oriented. Test was conducted in right monocular, left monocular or binocular condition of vision. Right monocular chicks pecked at the 4th right element; left monocular and binocular chicks pecked at the 4th left element. Data on monocular chicks demonstrate that both hemispheres deal with an ordinal (sequential) task. Data on binocular chicks indicate that the left bias is linked to a right hemisphere dominance, that allocates the attention toward the left hemispace. This constitutes a first step towards understanding the neural basis of number space mapping. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. The role of cerebral hyperperfusion in postoperative neurologic dysfunction after left ventricular assist device implantation for end-stage heart failure.

    Science.gov (United States)

    Lietz, Katherine; Brown, Kevin; Ali, Syed S; Colvin-Adams, Monica; Boyle, Andrew J; Anderson, David; Weinberg, Alan D; Miller, Leslie W; Park, Soon; John, Ranjit; Lazar, Ronald M

    2009-04-01

    Cerebral hyperperfusion is a life-threatening syndrome that can occur in patients with chronically hypoperfused cerebral vasculature whose normal cerebral circulation was re-established after carotid endarterectomy or angioplasty. We sought to determine whether the abrupt restoration of perfusion to the brain after left ventricular assist device (LVAD) implantation produced similar syndromes. We studied the role of increased systemic flow after LVAD implantation on neurologic dysfunction in 69 consecutive HeartMate XVE LVAD (Thoratec, Pleasanton, Calif) recipients from October 2001 through June 2006. Neurologic dysfunction was defined as postoperative permanent or transient central change in neurologic status, including confusion, focal neurologic deficits, visual changes, seizures, or coma for more than 24 hours within 30 days after LVAD implantation. We found that 19 (27.5%) patients had neurologic dysfunction, including encephalopathy (n = 11), coma (n = 3), and other complications (n = 5). The multivariate analysis showed that an increase in cardiac index from the preoperative baseline value (relative risk, 1.33 per 25% cardiac index increase; P = .01) and a previous coronary bypass operation (relative risk, 4.53; P = .02) were the only independent predictors of neurologic dysfunction. Reduction of left ventricular assist device flow in 16 of the 19 symptomatic patients led to improvement of symptoms in 14 (87%) patients. Our findings showed that normal flow might overwhelm cerebral autoregulation in patients with severe heart failure, suggesting that cerebral hyperperfusion is possible in recipients of mechanical circulatory support with neurologic dysfunction.

  1. Multiple cerebral hydatid cysts

    Energy Technology Data Exchange (ETDEWEB)

    Banzo, J.; Pina, J.I.; Abos, M.D.; Rios, G.; Garcia, D.; Marin, F.; Diaz, F.J.

    1984-12-01

    A 39-year-old woman was admitted to hospital with headaches, vomiting, psychic impairment and diplopia. Three hydatid cysts of the lung had been previously removed. An avascular mass in the left hemisphere with left-to-right displacement of the anterior cerebral arteries was noted during a brain angioscintigraphy. A cerebralthrombosis (CT) brain scan showed two cystic lesions situated in the left-frontal and occipital regions. A CT abdominal scan showed multiple cysts in the liver, spleen and both kidneys. At operation, two brain cysts were totally extirpated without rupture. The definite pathological diagnosis was secondry hydatid cysts. The headaches, vomiting and diplopia were persistent in the post-operative period. Seven days after the operation, a CT brain scan showed an infratenrorial cyst. The patient rejected any surgical intervention.

  2. Hemispherical dominance of glucose metabolic rate in the brain of the 'normal' ageing population

    International Nuclear Information System (INIS)

    Cutts, D.A.; Spyrou, N.M.

    2004-01-01

    In the 'normal' ageing brain a decrease in the cerebral metabolic rate has been determined across many brain regions. It is determined whether age differences would affect metabolic rates in regions and different hemispheres of the brain. The regional metabolic rate of glucose (rCMRGlu) was examined in a group of 72 subjects, ages 22 to 82 years, with 36 regions of interest chosen from both hemispheres of the cortex, midbrain and cerebellum. To determine metabolic rates the in-vivo technique of positron emission tomography (PET) was employed. Three age groups were chosen to compare hemispherical differences. In both young and intermediate age groups the left hemisphere had higher rCMRGlu values than those of the right for the majority of regions with, although less pronounced in the intermediate group. Importantly, the older age group displayed little difference between hemispheres. (author)

  3. Dyke-Davidoff-Masson syndrome: case report of fetal unilateral ventriculomegaly and hypoplastic left middle cerebral artery

    OpenAIRE

    Piro, Ettore; Piccione, Maria; Marrone, Gianluca; Giuffr?, Mario; Corsello, Giovanni

    2013-01-01

    Prenatal ultrasonographic detection of unilateral cerebral ventriculomegaly arises suspicion of pathological condition related to cerebrospinal fluid flow obstruction or cerebral parenchimal pathology. Dyke-Davidoff-Masson syndrome is a rare condition characterized by cerebral hemiatrophy, calvarial thickening, skull and facial asymmetry, contralateral hemiparesis, cognitive impairment and seizures. Congenital and acquired types are recognized and have been described, mainly in late childhood...

  4. Hypothalamic digoxin, hemispheric dominance, and neurobiology of love and affection.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-05-01

    The human hypothalamus produces an endogenous membrane Na+-K+ ATPase inhibitor, digoxin, which can regulate neuronal transmission. The digoxin status and neurotransmitter patterns were studied in individuals with a predilection to fall in love. It was also studied in individuals with differing hemispheric dominance to find out the role of cerebral dominance in this respect. In individuals with a predilection to fall in love there was decreased digoxin synthesis, increased membrane Na+-K+ ATPase activity, decreased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern correlated with that obtained in left hemispheric chemical dominance. Hemispheric dominance and hypothalamic digoxin could regulate the predisposition to fall in love.

  5. Improvement of cerebral hypometabolism after resection of radiation-induced necrotic lesion in a patient with cerebral arteriovenous malformation

    International Nuclear Information System (INIS)

    Harada, Yae; Hirata, Kenji; Nakayama, Naoki; Yamaguchi, Shigeru; Yoshida, Michiharu; Onodera, Shunsuke; Manabe, Osamu; Shiga, Tohru; Terae, Satoshi; Shirato, Hiroki; Tamaki, Nagara

    2015-01-01

    A 55-year-old woman underwent radiosurgery for a left cerebral hemisphere arteriovenous malformation (AVM) and developed radiation-induced necrosis causing a massive edema in the surrounding brain tissues. Despite various therapies, the edema expanded to the ipsilateral hemisphere and induced neurological symptoms. The radiation-induced necrotic lesion was surgically removed 4 years after radiosurgery. While the preoperative FDG PET revealed severe hypometabolism in the left cerebrum, the necrotomy significantly ameliorated the brain edema, glucose metabolism (postoperative FDG PET), and symptoms. This case indicates that radiation necrosis-induced neurological deficits may be associated with brain edema and hypometabolism, which could be reversed by appropriate necrotomy

  6. Cerebral Asymmetry of fMRI-BOLD Responses to Visual Stimulation

    DEFF Research Database (Denmark)

    Hougaard, Anders; Jensen, Bettina Hagström; Amin, Faisal Mohammad

    2015-01-01

    Hemispheric asymmetry of a wide range of functions is a hallmark of the human brain. The visual system has traditionally been thought of as symmetrically distributed in the brain, but a growing body of evidence has challenged this view. Some highly specific visual tasks have been shown to depend......MRI) in 54 healthy subjects during stimulation with a black and white checkerboard visual stimulus. While carefully excluding possible non-physiological causes of left-to-right bias, we compared the activation of the left and the right cerebral hemispheres and related this to grey matter volume, handedness...... was correlated with subject age, suggesting a shift towards the left hemisphere with increasing age. Our findings suggest a right-hemispheric dominance of these areas, which could lend support to the generally observed leftward visual attentional bias and to the left hemifield advantage for some visual...

  7. Characteristics of Syntactic Comprehension Deficits Following Closed Head Injury versus Left Cerebrovascular Accident.

    Science.gov (United States)

    Butler-Hinz, Susan; And Others

    1990-01-01

    Two studies examined the ability to assign thematic roles and to coindex referentially dependent noun phrases in closed head injured adults (N=20), adult stroke patients (N=20), and normal adults (N=20). Results suggested that syntactic comprehension disturbances are similar following left cerebral hemisphere infarction and closed head injury.…

  8. Cerebral Abscess Associated With Odontogenic Bacteremias, Hypoxemia, and Iron Loading in Immunocompetent Patients With Right-to-Left Shunting Through Pulmonary Arteriovenous Malformations.

    Science.gov (United States)

    Boother, Emily J; Brownlow, Sheila; Tighe, Hannah C; Bamford, Kathleen B; Jackson, James E; Shovlin, Claire L

    2017-08-15

    Cerebral abscess is a recognized complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored. Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with computed tomography-confirmed PAVMs (including 403 [90.5%] with hereditary hemorrhagic telangiectasia) were recruited to a prospective series. Multivariate logistic regression was performed and detailed periabscess histories were evaluated to identify potential associations with cerebral abscess. Rates were compared to an earlier nonoverlapping series. Thirty-seven of the 445 (8.3%) patients experienced a cerebral abscess at a median age of 50 years (range, 19-76 years). The rate adjusted for ascertainment bias was 27 of 435 (6.2%). Twenty-nine of 37 (78.4%) patients with abscess had no PAVM diagnosis prior to their abscess, a rate unchanged from earlier UK series. Twenty-one of 37 (56.7%) suffered residual neurological deficits (most commonly memory/cognition impairment), hemiparesis, and visual defects. Isolation of periodontal microbes, and precipitating dental and other interventional events, emphasized potential sources of endovascular inoculations. In multivariate logistic regression, cerebral abscess was associated with low oxygen saturation (indicating greater right-to-left shunting); higher transferrin iron saturation index; intravenous iron use for anemia (adjusted odds ratio, 5.4 [95% confidence interval, 1.4-21.1]); male sex; and venous thromboemboli. There were no relationships with anatomic attributes of PAVMs, or red cell indices often increased due to secondary polycythemia. Greater appreciation of the risk of cerebral abscess in undiagnosed PAVMs is required. Lower oxygen saturation and intravenous iron may be modifiable risk factors. © The Author 2017. Published by Oxford University Press

  9. Cerebral Abscess Associated With Odontogenic Bacteremias, Hypoxemia, and Iron Loading in Immunocompetent Patients With Right-to-Left Shunting Through Pulmonary Arteriovenous Malformations

    Science.gov (United States)

    Boother, Emily J.; Brownlow, Sheila; Tighe, Hannah C.; Bamford, Kathleen B.; Jackson, James E.

    2017-01-01

    Abstract Background Cerebral abscess is a recognized complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored. Methods Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with computed tomography–confirmed PAVMs (including 403 [90.5%] with hereditary hemorrhagic telangiectasia) were recruited to a prospective series. Multivariate logistic regression was performed and detailed periabscess histories were evaluated to identify potential associations with cerebral abscess. Rates were compared to an earlier nonoverlapping series. Results Thirty-seven of the 445 (8.3%) patients experienced a cerebral abscess at a median age of 50 years (range, 19–76 years). The rate adjusted for ascertainment bias was 27 of 435 (6.2%). Twenty-nine of 37 (78.4%) patients with abscess had no PAVM diagnosis prior to their abscess, a rate unchanged from earlier UK series. Twenty-one of 37 (56.7%) suffered residual neurological deficits (most commonly memory/cognition impairment), hemiparesis, and visual defects. Isolation of periodontal microbes, and precipitating dental and other interventional events, emphasized potential sources of endovascular inoculations. In multivariate logistic regression, cerebral abscess was associated with low oxygen saturation (indicating greater right-to-left shunting); higher transferrin iron saturation index; intravenous iron use for anemia (adjusted odds ratio, 5.4 [95% confidence interval, 1.4–21.1]); male sex; and venous thromboemboli. There were no relationships with anatomic attributes of PAVMs, or red cell indices often increased due to secondary polycythemia. Conclusions Greater appreciation of the risk of cerebral abscess in undiagnosed PAVMs is required. Lower oxygen saturation and intravenous iron may be modifiable risk factors. PMID

  10. Cerebral and Renal Oxygen Saturation Are Not Compromised in the Presence of Retrograde Blood Flow in either the Ascending or Descending Aorta in Term or Near-Term Infants with Left-Sided Obstructive Lesions

    NARCIS (Netherlands)

    van der Laan, Michelle E.; Mebius, Mirthe J.; Roofthooft, Marcus T. R.; Bos, Arend F.; Berger, Rolf M. F.; Kooi, Elisabeth M. W.

    2017-01-01

    Background: In infants with left-sided obstructive lesions (LSOL), the presence of retrograde blood flow in either the ascending or descending aorta may lead to diminished cerebral and renal blood flow, respectively. Objectives: Our aim was to compare cerebral and renal tissue oxygen saturation

  11. Regional cerebral blood flow during the auditory oddball task measured by positron emission tomography

    International Nuclear Information System (INIS)

    Mochida, Masahiko

    1997-01-01

    Regional cerebral blood flow (rCBF) was measured by employing PET in nine healthy right-handed male subjects, while they simultaneously performed the auditory oddball task using tone bursts. Results showed that the rCBF value was highest in the transverse gyrus of Heschl in both right and left hemispheres. When comparing the rCBF values between right and left hemispheres, four areas had higher rCBF values in the left hemisphere and eight areas had higher rCBF values in the right hemisphere. Of these, the anterior and posterior parts of the superior temporal gyrus, especially, showed significant differences. The hemispheric differences in the rCBF values of the auditory areas can be attributed to the performance of the oddball task which requires higher processing of non verbal auditory input. The P300 amplitude which reflects the amount of the allocated information processing resources correlated positively with rCBF in the following areas: left piriform cortex, the transverse gyrus of Heschl in both left and right hemispheres. Mean-while, P300 amplitude correlated negatively with rCBF in the nucleus accumbens septi in both right and left hemispheres. The N100 amplitude evoked by frequent stimulus did not correlate with rCBF in almost all ROIs. (K.H.)

  12. Interindividual variability in the hemispheric organization for speech.

    Science.gov (United States)

    Tzourio-Mazoyer, N; Josse, G; Crivello, F; Mazoyer, B

    2004-01-01

    A PET activation study was designed to investigate hemispheric specialization during speech comprehension and production in right- and left-handed subjects. Normalized regional cerebral blood flow (NrCBF) was repeatedly monitored while subjects either listened to factual stories (Story) or covertly generated verbs semantically related to heard nouns (Gener), using silent resting (Rest) as a common control condition. NrCBF variations in each task, as compared to Rest, as well as functional asymmetry indices (FAI = right minus left NrCBF variations), were computed in anatomical regions of interest (AROIs) defined on the single-subject MNI template. FAIs were predominantly leftward in all regions during both tasks, although larger FAIs were observed during Gener. Subjects were declared "typical" for language hemispheric specialization based on the presence of significant leftward asymmetries (FAI Gener, and in the middle and inferior temporal AROIs during Story. Six subjects (including five LH) showed an atypical language representation. Among them, one presented a right hemisphere specialization during both tasks, another a shift in hemispheric specialization from production to comprehension (left during Gener, right during Story). The group of 14 typical subjects showed significant positive correlation between homologous left and right AROIs NrCBF variations in temporal areas during Story, and in temporal and inferior frontal areas during Gener, almost all regions presenting a leftward FAI. Such correlations were also present in deactivated areas with strong leftward asymmetry (supramarginalis gyrus, inferior parietal region). These results suggest that entry into a language task translates into a hemispheric reconfiguration of lateral cortical areas with global NrCBF increase in the dominant hemisphere and decrease in the minor hemisphere. This can be considered as the setting up of a "language mode", under the control of a mechanism that operates at a perisylvian

  13. Dynamic digitized cerebral parenchymography

    International Nuclear Information System (INIS)

    Theron, J.; Alachkar, F.; Nelson, M.; Mazia, D.

    1992-01-01

    Aortic arch injections centred on the head have been performed routinely in patients with cerebral ischaemia. Digital angiograms with modified windowing (low and narrow) have been used. This 'cerebral' arch injection allows much improved analysis of the cerebral parenchymal vascularization, giving better understanding of hemispheric ischaemia and making the decision about revascularization more rational. (orig.)

  14. Human cerebral asymmetries evaluated by computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Chang Chui, H; Damasio, A R [Iowa Univ., Iowa City (USA)

    1980-10-01

    The handedness of seventy-five persons without evidence of neurological disease, was assessed with a standardised test. An analysis of the CT scans of the same persons was performed to determine (1) presence and lateralisation of frontal and occipital 'petalia', (2) width of frontal and occipital lobes of each hemisphere, (3) direction of straight sinus deviation. Results suggest that handedness and cerebral asymmetries are independent variables. There were no significant differences between right-handers and non-right handers. Also there was no significant differences between strongly left-handed and ambidextrous individuals, nor were there differences between right-handers with or without family history of left-handedness. Irrespective of handedness, left occipital 'petalia' was more common than right (p<0.01), right frontal petalia was more common than left (p<0.01), and straight sinus deviation was more commonly toward the right. The study does not support the concept that cerebral 'symmetry' or 'reverse asymmetry' are associated with left-handedness or ambidexterity. The noted asymmetries are more likely to be direct correlates of cerebral language dominance, than of handedness. Outside forces acting on the bone may also contribute to the asymmetries. CT scan may be of value as a direct predictor of cerebral dominance.

  15. Cerebral perfusion in homogeneity in normal volunteers

    International Nuclear Information System (INIS)

    Gruenwald, S.M.; Larcos, G.

    1998-01-01

    Full text: In the interpretation of cerebral perfusion scans, it is important to know the normal variation in perfusion which may occur between the cerebral hemispheres. For this reason 24 normal volunteers with no neurological or psychiatric history, and who were on no medications, had 99m Tc-HMPAO brain SPECT studies using a single headed gamma camera computer system. Oblique, coronal and sagittal images were reviewed separately by two experienced observers and any differences were resolved by consensus. Semi-quantitation was performed by summing two adjacent oblique slices and drawing right and left mirror image ROIs corresponding to the mid section level of anterior and posterior frontal lobes, anterior and posterior parietal lobes, temporal lobes and cerebellum. From the mean counts per pixel, right: left ROI ratios and ROI: cerebellar ratios were calculated. On qualitative review 6/24 subjects had mild asymmetry in tracer distribution between right and left cerebral lobes. Semi-quantitation revealed a 5-10% difference in counts between right and left ROIs in 12/24 subjects and an additional three subjects had 10-20% difference in counts between right and left temporal lobes. This study demonstrates the presence of mild asymmetry of cerebral perfusion in a significant minority of normal subjects

  16. Human cerebral asymmetries evaluated by computed tomography

    International Nuclear Information System (INIS)

    Chang Chui, H.; Damasio, A.R.

    1980-01-01

    The handedness of seventy-five persons without evidence of neurological disease, was assessed with a standardised test. An analysis of the CT scans of the same persons was performed to determine (1) presence and lateralisation of frontal and occipital 'petalia', (2) width of frontal and occipital lobes of each hemisphere, (3) direction of straight sinus deviation. Results suggest that handedness and cerebral asymmetries are independent variables. There were no significant differences between right-handers and non-right handers. Also there was no significant differences between strongly left-handed and ambidextrous individuals, nor were there differences between right-handers with or without family history of left-handedness. Irrespective of handedness, left occipital 'petalia' was more common than right (p<0.01), right frontal petalia was more common than left (p<0.01), and straight sinus deviation was more commonly toward the right. The study does not support the concept that cerebral 'symmetry' or 'reverse asymmetry' are associated with left-handedness or ambidexterity. The noted asymmetries are more likely to be direct correlates of cerebral language dominance, than of handedness. Outside forces acting on the bone may also contribute to the asymmetries. CT scan may be of value as a direct predictor of cerebral dominance. (author)

  17. Measurement of cerebral blood flow by single photon emission tomography: principles and application to functional studies of the language areas

    International Nuclear Information System (INIS)

    Tran Dinh, Y.R.; Seylaz, J.

    1989-01-01

    Quantitative measurement of cerebral blood flow by single photon emission computerized tomography (SPECT) is a new technique which is particularly suitable for routine studies of cerebro-vascular diseases. SPECT can be used to examine the deep structures of the brain and cerebellum. The functional areas of the brain, which have hitherto been only accessible by clinical-anatomical methods, can be imaged by this technique, based on the correlation between cerebral blood flow and metabolism. The demonstration of preferential activation of temporal and frontal zones in the left hemisphere by active speech stimulation confirms the general principles of hemispheric lateralization of cerebral functions. In addition to this role in studying the physiology of normal subjects, the technique has practical pathological applications. Knowledge of hemispheric lateralization of spoken language should be a pre-operative test for cerebral lesion when there is a risk that surgical intervention may produce irreversible neuropsychological lesions [fr

  18. Cerebral asymmetry in a selected Chinese population

    International Nuclear Information System (INIS)

    Wang, Y.X.; He, G.X.; Tong, G.H.; Wang, D.B.; Xu, K.Y.

    1999-01-01

    Previous studies have demonstrated anatomical differences between the two cerebral hemispheres and ethnic differences in cerebral asymmetry. This study examined asymmetry of Chinese living in Shanghai. Measurements were taken across the frontal, mid-cerebral and occipital regions from normal head computed tomography (CT) scans of 200 Chinese Shanghai residents (100 male and 100 female, aged 6-73 years, average 48.7 years). The results were compared with reported data in the literature. The following results were found: (i) In the frontal region the right side was larger than the left in 57.5% of cases, equal in 10.5% and smaller in 32% of cases; in the mid-cerebral region the right side was larger than the left in 65.5% of cases, equal in 12.5% and smaller in 22% of cases; in the occipital regions the right side was larger than the left in 34.5% of cases, equal in 8.5% and smaller in 57% of cases. The average right-left differences between the frontal, mid-cerebral and occipital regions were 0.43 mm, 0.9 mm and 0.4 mm respectively. No difference in cerebral asymmetry existed between males and females. The occipital lobes showed the greatest individual asymmetry. The distribution of cerebral asymmetry of Chinese in Shanghai showed similarity to North American Whites rather than North American Blacks, but the average right-left differences were smaller than those of Whites. Copyright (1999) Blackwell Science Pty Ltd

  19. Utility of the cerebral SPECT in schizophrenia

    International Nuclear Information System (INIS)

    Heuguerot, C.H.; Lopez-Lerena, J.J.; Quagliata, A.; Hermida, J.C.; Oliveira, M.C.; Anastasia, H.

    2002-01-01

    Objective: To compare cortical and subcortical cerebral perfusion in schizophrenics patients with normal controls, and analyze the relation to clinical patterns and neuroleptic treatment. Method: 18 patients meeting DSM-IV criteria for schizophrenia under neuroleptic treatment (except 3 cases), evaluated with clinical scales (BPRS and PANSS). The control group included 5 subjects in good health. All subjects were studied with single photon emission computed tomography (SPECT) using technetium-99 etilencisteinato (99mTc-ECD) as a tracer. Region of interest (ROI) were defined in cerebral cortex and thalamus-basal ganglia areas. The cortical cerebral blood flow was measured with a quantitative analysis, expressed as a ratio of regional tracer uptake to occipital cortex uptake. In basal ganglia and thalamus, regional blood flow was evaluated with a semiquantitative methodology, defining categories. Results: Schizophrenics patients showed a significant reduction of perfusion on a left anterior frontal cortex ('hipofrontality') and global decrease of perfusion on left hemisphere. The interhemispheric (left/right) ratio of perfusion was incremented respect control group. In thalamic-basal ganglia complex, a significant hypoperfusion was found in neuroleptic-free patients and control group. On the other hand, neuroleptic-treated patients revealed normal or increased regional blood flow in thalamus and basal ganglia. Only the clinical item 'thought disorder' had significant high correlation with perfusion on left structures (left anterior frontal, left lateral frontal, left temporo-parietal); the other items correlated with right structures. Conclusions: The findings suggest a pattern o left cerebral hypoperfusion in patients with an incremented interhemispheric ratio of cerebral blood flow. The pivotal role of thalamic and basal ganglia areas in the pathophysiology of schizophrenia and neuroleptic action was reaffirmed; apparently, perfusion in thalamic-basal ganglia

  20. Investigation of cerebral metabolism by positron CT in Japanese following musical stimulation

    International Nuclear Information System (INIS)

    Wakasugi, Naotoshi

    1994-01-01

    Cerebral metabolic responses to Japanese and Western instrumental music were examined using 11 C-glucose and positron CT. Eight right-handed subjects were studied in both Japanese and Western music-stimulated states. Biaural musical stimulation with a Japanese instrument, the 'shakuhachi', produced diffuse metabolic changes in the left temporal lobe in all subjects. Biaural musical stimulation with a Western instrument, the 'violin', produced metabolic changes in the right temporal lobe in 3 subjects, changes in the left in 4, and changes on both sides in one. It was considered previously that all musical stimulation led to hypermetabolism in the right hemisphere of human beings. However, the present results indicated that Japanese music produced activation of the left hemisphere in Japanese. On the other hand, Western music produced right hemispheric hypermetabolism in Japanese with no emotion. The laterality of the hemisphere stimulated by Western music was apparently incidentally changed according to the state of mind the Japanese subjects. (author)

  1. Asymmetry of cerebral glucose metabolism in very low-birth-weight infants without structural abnormalities.

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    Jae Hyun Park

    Full Text Available Thirty-six VLBW infants who underwent F-18 fluorodeoxyglucose (F-18 FDG brain PET and MRI were prospectively enrolled, while infants with evidence of parenchymal brain injury on MRI were excluded. The regional glucose metabolic ratio and asymmetry index were calculated. The asymmetry index more than 10% (right > left asymmetry or less than -10% (left > right asymmetry were defined as abnormal. Regional cerebral glucose metabolism were compared between right and left cerebral hemispheres, and between the following subgroups: multiple gestations, premature rupture of membrane, bronchopulmonary dysplasia, and low-grade intraventricular hemorrhage.In the individual analysis, 21 (58.3% of 36 VLBW infants exhibited asymmetric cerebral glucose metabolism. Fifteen infants (41.7% exhibited right > left asymmetry, while six (16.7% exhibited left > right asymmetry. In the regional analysis, right > left asymmetry was more extensive than left > right asymmetry. The metabolic ratio in the right frontal, temporal, and occipital cortices and right thalamus were significantly higher than those in the corresponding left regions. In the subgroup analyses, the cerebral glucose metabolism in infants with multiple gestations, premature rupture of membrane, bronchopulmonary dysplasia, or low-grade intraventricular hemorrhage were significantly lower than those in infants without these.VLBW infants without structural abnormalities have asymmetry of cerebral glucose metabolism. Decreased cerebral glucose metabolism are noted in infants with neurodevelopmental risk factors. F-18 FDG PET could show microstructural abnormalities not detected by MRI in VLBW infants.

  2. Repeated measurements of cerebral blood flow in the left superior temporal gyrus reveal tonic hyperactivity in patients with auditory verbal hallucinations: A possible trait marker

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    Philipp eHoman

    2013-06-01

    Full Text Available Background: The left superior temporal gyrus (STG has been suggested to play a key role in auditory verbal hallucinations in patients with schizophrenia. Methods: Eleven medicated subjects with schizophrenia and medication-resistant auditory verbal hallucinations and 19 healthy controls underwent perfusion magnetic resonance imaging with arterial spin labeling. Three additional repeated measurements were conducted in the patients. Patients underwent a treatment with transcranial magnetic stimulation (TMS between the first 2 measurements. The main outcome measure was the pooled cerebral blood flow (CBF, which consisted of the regional CBF measurement in the left superior temporal gyrus (STG and the global CBF measurement in the whole brain.Results: Regional CBF in the left STG in patients was significantly higher compared to controls (p < 0.0001 and to the global CBF in patients (p < 0.004 at baseline. Regional CBF in the left STG remained significantly increased compared to the global CBF in patients across time (p < 0.0007, and it remained increased in patients after TMS compared to the baseline CBF in controls (p < 0.0001. After TMS, PANSS (p = 0.003 and PSYRATS (p = 0.01 scores decreased significantly in patients.Conclusions: This study demonstrated tonically increased regional CBF in the left STG in patients with schizophrenia and auditory hallucinations despite a decrease in symptoms after TMS. These findings were consistent with what has previously been termed a trait marker of auditory verbal hallucinations in schizophrenia.

  3. Crossed aphasia following cerebral infarction in a right-handed patient with atypical cerebral language dominance.

    Science.gov (United States)

    Tan, Xiaoping; Guo, Yang; Dun, Saihong; Sun, Hongzan

    2018-05-18

    Crossed aphasia (CA), usually referred to as an acquired language disturbance, is caused by a lesion in the cerebral hemisphere ipsilateral to the dominant hand, and the exact mechanism is not clear. The development of handedness is influenced by education and training and the impact of habitualization, while language is more susceptible to the impact of speech habits, and it is not absolutely accurate to judge cerebral language dominance by the degree of hand preference. We describe a case of CA after right hemispheric stroke in a right-handed patient with atypical language dominance and attempt to analyze the mechanism of CA based on functional imaging methods, including arterial spin labeling (ASL) and positron emission tomography/magnetic resonance imaging (PET-MRI). Brain MRI at 24 h after admission showed a large cerebral infarction in the right cerebral hemisphere, including the posteroinferior part of Broca's area in the right frontal lobe, the right temporal lobe, and the right occipital lobe. The patient exhibited a non-fluent aphasia on a standard language test (the Aphasia Battery of Chinese [ABC]) performed on the 7th day after onset. Thus, atypical language dominance was suspected. One week after admission, ASL imaging showed high perfusion in the infarct core zone and low perfusion in the left cerebellar hemisphere. Two months later, PET/MRI demonstrated low metabolism in the posterior frontal lobe, temporal lobe, temporal occipital junction area, and the right basal ganglia. The findings suggest that the patient has right-sided cerebral language dominance, or that both hemispheres have linguistic functions. Not all patients show linguistic capabilities on the side opposite hand preference. The language dominance should be predicted by a combination of clinical manifestations and functional imaging techniques.

  4. Cerebral Asymmetry of fMRI-BOLD Responses to Visual Stimulation.

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    Anders Hougaard

    Full Text Available Hemispheric asymmetry of a wide range of functions is a hallmark of the human brain. The visual system has traditionally been thought of as symmetrically distributed in the brain, but a growing body of evidence has challenged this view. Some highly specific visual tasks have been shown to depend on hemispheric specialization. However, the possible lateralization of cerebral responses to a simple checkerboard visual stimulation has not been a focus of previous studies. To investigate this, we performed two sessions of blood-oxygenation level dependent (BOLD functional magnetic resonance imaging (fMRI in 54 healthy subjects during stimulation with a black and white checkerboard visual stimulus. While carefully excluding possible non-physiological causes of left-to-right bias, we compared the activation of the left and the right cerebral hemispheres and related this to grey matter volume, handedness, age, gender, ocular dominance, interocular difference in visual acuity, as well as line-bisection performance. We found a general lateralization of cerebral activation towards the right hemisphere of early visual cortical areas and areas of higher-level visual processing, involved in visuospatial attention, especially in top-down (i.e., goal-oriented attentional processing. This right hemisphere lateralization was partly, but not completely, explained by an increased grey matter volume in the right hemisphere of the early visual areas. Difference in activation of the superior parietal lobule was correlated with subject age, suggesting a shift towards the left hemisphere with increasing age. Our findings suggest a right-hemispheric dominance of these areas, which could lend support to the generally observed leftward visual attentional bias and to the left hemifield advantage for some visual perception tasks.

  5. Right Hemisphere Dominance in Visual Statistical Learning

    Science.gov (United States)

    Roser, Matthew E.; Fiser, Jozsef; Aslin, Richard N.; Gazzaniga, Michael S.

    2011-01-01

    Several studies report a right hemisphere advantage for visuospatial integration and a left hemisphere advantage for inferring conceptual knowledge from patterns of covariation. The present study examined hemispheric asymmetry in the implicit learning of new visual feature combinations. A split-brain patient and normal control participants viewed…

  6. MRI diagnosis of the cerebral schistosomiasis

    International Nuclear Information System (INIS)

    Liu Hanqiu; Chen Yuanjun

    2002-01-01

    Objective: To discuss MRI appearance of the cerebral schistosomiasis and its clinical value through analyzing the MRI features and post-surgery pathological findings. Methods: MRI features of the cerebral schistosomiasis in 16, pathologically (n = 6) or clinically (n = 10) proved cases were analyzed retrospectively, and compared with the post-surgery pathological findings in 6 cases. Results: Single masses were found in 11 cases (11/16), and multiple masses in 5 eases (5/16), amounting to 23 masses . fifteen masses (15/23) were located in right cerebral hemisphere, including frontal lobe (n = 2), frontoparietal lobe (n = 5) , and occipitoparietal lobe (n 8), while 8 masses (8/23) in left cerebral hemisphere, including frontal lobe (n = 1), frontoparietal lobe (n = 3), and occipitoparietal lobe (n = 4). The nodular masses were isointense with the gray mass like 'island', and 12 cases (12/16) show the 'gigantic hand' form of edema around them. After IV administration of Gd-DTPA, 15 cases (15/16) revealed multiple closely spaced, intensely enhancing modules, 1-3 mm in diameter, distributed throughout the mass. Seven cases misdiagnosed by CT were revised by MRl. Conclusion: The MRI appearance of the cerebral schistosomiasis is characteristic, and MRI is the most valuable tool to diagnose it without injury

  7. Hemispheric processing asymmetries: implications for memory.

    Science.gov (United States)

    Funnell, M G; Corballis, P M; Gazzaniga, M S

    2001-01-01

    Recent research has demonstrated that memory for words elicits left hemisphere activation, faces right hemisphere activation, and nameable objects bilateral activation. This pattern of results was attributed to dual coding of information, with the left hemisphere employing a verbal code and the right a nonverbal code. Nameable objects can be encoded either verbally or nonverbally and this accounts for their bilateral activation. We investigated this hypothesis in a callosotomy patient. Consistent with dual coding, the left hemisphere was superior to the right in memory for words, whereas the right was superior for faces. Contrary to prediction, performance on nameable pictures was not equivalent in the two hemispheres, but rather resulted in a right hemisphere superiority. In addition, memory for pictures was significantly better than for either words or faces. These findings suggest that the dual code hypothesis is an oversimplification of the processing capabilities of the two hemispheres.

  8. Network-wise cerebral blood flow redistribution after 20 Hz rTMS on left dorso-lateral prefrontal cortex.

    Science.gov (United States)

    Shang, Yuan-Qi; Xie, Jun; Peng, Wei; Zhang, Jian; Chang, Da; Wang, Ze

    2018-04-01

    The repetitive application of transcranial magnetic stimulation (rTMS) on left dorsolateral prefrontal cortex (DLPFC) has been consistently shown to be beneficial for treating various neuropsychiatric or neuropsychological disorders, but its neural mechanisms still remain unclear. The purpose of this study was to measure the effects of high-frequency left DLPFC rTMS using cerebral blood flow (CBF) collected from 40 young healthy subjects before and after applying 20 Hz left DLPFC rTMS or SHAM stimulations. Relative CBF (rCBF) changes before and after 20 Hz rTMS or SHAM were assessed with paired-t test. The results show that 20 Hz DLPFC rTMS induced CBF redistribution in the default mode network, including increased rCBF in left medial temporal cortex (MTC)/hippocampus, but reduced rCBF in precuneus and cerebellum. Meanwhile, SHAM stimulation didn't produce any rCBF changes. After controlling SHAM effects, only the rCBF increase in MTC/hippocampus remained. Those data suggest that the beneficial effects of high-frequency rTMS may be through a within-network rCBF redistribution. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Effect of NMDA Receptor Antagonist on Local Cerebral Glucose Metabolic Rate in Focal Cerebral Ischemia

    International Nuclear Information System (INIS)

    Kim, Sang Eun; Hong, Seung Bong; Yoon, Byung Woo

    1995-01-01

    There has recently been increasing interest in the use of NMDA receptor antagonists as potential neuroprotective agents for the treatment of ischemic stroke. To evaluate the neuroprotective effect of the selective non-competitive NMDA receptor antagonist MK-801 in focal cerebral ischemia, local cerebral glucose utilization (1CGU) was examined in 15 neuroanatomically discrete regions of the conscious rat brain using the 2-deoxy-D[14C]glucose quantitative autoradiographic technique 24 hr after left middle cerebral artery occlusion (MCAO). Animals received MK-801 (5 mg/kg i.v.) or saline vehicle before (20-30 min) or after (30 min) MCAO. Both pretreatment and posttreatment of MK-801 increased occluded/non-occluded 1CGU ratio in 7 and 5 of the 15 regions measured, respectively(most notably in cortical structures). Following MK-801 pretreatment, there was evidence of widespread increases in 1CCPU not only in the non-occluded hemisphere (12 of the 15 areas studied) but also in the occluded hemisphere (13 of the 15 areas studied), while MK-801 posttreatment did not significantly increase 1CGU both in the normal and occluded hemispheres. These data indicate that MK-801 has a neuroprotective effect in focal cerebral ischemia and demonstrate that MK-801 provides widespread alterations of glucose utilization in conscious animals.

  10. Pseudotumoral delayed cerebral radionecrosis

    International Nuclear Information System (INIS)

    Ciaudo-Lacroix, C.; Lapresle, J.

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. γEG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed [fr

  11. Pseudotumoral delayed cerebral radionecrosis

    Energy Technology Data Exchange (ETDEWEB)

    Ciaudo-Lacroix, C; Lapresle, J [Centre Hospitalier de Bicetre, 94 - Le Kremlin-Bicetre (France)

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. ..gamma..EG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed.

  12. Handedness results from Complementary Hemispheric Dominance, not Global Hemispheric Dominance: Evidence from Mechanically Coupled Bilateral Movements.

    Science.gov (United States)

    Woytowicz, Elizabeth J; Westlake, Kelly P; Whitall, Jill; Sainburg, Robert L

    2018-05-09

    Two contrasting views of handedness can be described as 1) complementary dominance, in which each hemisphere is specialized for different aspects of motor control, and 2) global dominance, in which the hemisphere contralateral to the dominant arm is specialized for all aspects of motor control. The present study sought to determine which motor lateralization hypothesis best predicts motor performance during common bilateral task of stabilizing an object (e.g. bread) with one hand while applying forces to the object (e.g. slicing) using the other hand. We designed an experimental equivalent of this task, performed in a virtual environment with the unseen arms supported by frictionless air-sleds. The hands were connected by a spring, and the task was to maintain the position of one hand, while moving the other hand to a target. Thus, the reaching hand was required to take account of the spring load to make smooth and accurate trajectories, while the stabilizer hand was required to impede the spring load to keep a constant position. Right-handed subjects performed two task sessions (right hand reach and left hand stabilize; left hand reach and right hand stabilize) with the order of the sessions counterbalanced between groups. Our results indicate a hand by task-component interaction, such that the right hand showed straighter reaching performance while the left showed more stable holding performance. These findings provide support for the complementary dominance hypothesis and suggest that the specializations of each cerebral hemisphere for impedance and dynamic control mechanisms are expressed during bilateral interactive tasks.

  13. Quantitative Analysis of Regional Cerebral Blood Flow using 99mTc-HMPAO SPECT in Parkinson's Disease

    International Nuclear Information System (INIS)

    Lee, Myung Chul; Bae, Sang Kyun; Chung, June Key; Koh, Chang Soon; Roh, Jae Kyu; Myung, Ho Jin; Lee, Myung Hae

    1992-01-01

    Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using 99m Tc-HMPAO SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were 0.082 ± 0.033 and 0.108 ± 0.062, respectively and PIA were -0.4 ± 0.7% and -0.7 ± 1.0%, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

  14. Quantitative Analysis of Regional Cerebral Blood Flow using {sup 99m}Tc-HMPAO SPECT in Parkinson's Disease

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myung Chul; Bae, Sang Kyun; Chung, June Key; Koh, Chang Soon; Roh, Jae Kyu; Myung, Ho Jin [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Myung Hae [Asan Medical Center, Seoul (Korea, Republic of)

    1992-07-15

    Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using {sup 99m}Tc-HMPAO SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were 0.082 +- 0.033 and 0.108 +- 0.062, respectively and PIA were -0.4 +- 0.7% and -0.7 +- 1.0%, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

  15. A review of theories of dominat hemisphere and cerebral lateralization%优势半球或脑功能偏侧化学说的评价

    Institute of Scientific and Technical Information of China (English)

    杨建霞; 张桂青; 胡浴桓

    2002-01-01

    To review the theory of dominant hemisphere from the literature of western world intend to find the inadeguacies of it.Inadequacies of the theory:⑴ The theory of dominane hemisphere are only from the results of studies of phonograhic language.⑵ Most literature about the theory are only from the results of clinical studies.There were scanty of large scale of patients by community or popural based studies.The transcultural or transethnical studies were still more scanty.⑶ The results of experiments were perplexed.Look forward to the future: ⑴ Must pay attention of basic research of epidemiologic transcultural and transethnical studies.(2)Experimental studies must be suitable for language itself, traditional culture and ethical condition of the country and nationality.⑶ Some mcdern means such as fMRI and TMS etc.are difficult to popularize at present time.They may also be difficult to cumulate a large sample of patients.

  16. Regional cerebral blood flow in psychiatry: The resting and activated brains of schizophrenic patients

    International Nuclear Information System (INIS)

    Gur, R.E.

    1984-01-01

    The investigation of regional brain functioning in schizophrenia has been based on behavioral techniques. Although results are sometimes inconsistent, the behavioral observations suggest left hemispheric dysfunction and left hemispheric overreaction. Recent developments in neuroimaging technology make possible major refinements in assessing regional brain function. Both anatomical and physiological information now be used to study regional brain development in psychiatric disorders. This chapter describes the application of one method - the xenon-133 technique for measuring regional cerebral blood flow (rCBF) - in studying the resting and activated brains of schizoprenic patients

  17. Alteration of Interictal Brain Activity in Patients with Temporal Lobe Epilepsy in the Left Dominant Hemisphere: A Resting-State MEG Study

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    Haitao Zhu

    2014-01-01

    Full Text Available Resting MEG activities were compared between patients with left temporal lobe epilepsy (LTLE and normal controls. Using SAMg2, the activities of MEG data were reconstructed and normalized. Significantly elevated SAMg2 signals were found in LTLE patients in the left temporal lobe and medial structures. Marked decreases of SAMg2 signals were found in the wide extratemporal lobe regions, such as the bilateral visual cortex. The study also demonstrated a positive correlation between the seizure frequency and brain activities of the abnormal regions after the multiple linear regression analysis. These results suggested that the aberrant brain activities not only were related to the epileptogenic zones, but also existed in other extratemporal regions in patients with LTLE. The activities of the aberrant regions could be further damaged with the increase of the seizure frequency. Our findings indicated that LTLE could be a multifocal disease, including complex epileptic networks and brain dysfunction networks.

  18. Delayed recovery of adipsic diabetes insipidus (ADI) caused by elective clipping of anterior communicating artery and left middle cerebral artery aneurysms.

    Science.gov (United States)

    Tan, Jeffrey; Ndoro, Samuel; Okafo, Uchenna; Garrahy, Aoife; Agha, Amar; Rawluk, Danny

    2016-12-16

    Adipsic diabetes insipidus (ADI) is an extremely rare complication following microsurgical clipping of anterior communicating artery aneurysm (ACoA) and left middle cerebral artery (MCA) aneurysm. It poses a significant challenge to manage due to an absent thirst response and the co-existence of cognitive impairment in our patient. Recovery from adipsic DI has hitherto been reported only once. A 52-year-old man with previous history of clipping of left posterior communicating artery aneurysm 20 years prior underwent microsurgical clipping of ACoA and left MCA aneurysms without any intraoperative complications. Shortly after surgery, he developed clear features of ADI with adipsic severe hypernatraemia and hypotonic polyuria, which was associated with cognitive impairment that was confirmed with biochemical investigations and cognitive assessments. He was treated with DDAVP along with a strict intake of oral fluids at scheduled times to maintain eunatremia. Repeat assessment at six months showed recovery of thirst and a normal water deprivation test. Management of ADI with cognitive impairment is complex and requires a multidisciplinary approach. Recovery from ADI is very rare, and this is only the second report of recovery in this particular clinical setting.

  19. Correlations of cerebral blood flow with language function in aphasic patients following cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Eriko; Nagata, Ken; Uemura, Kazuo [Research Inst. for Brain and Blood Vessels, Akita (Japan)

    1997-04-01

    To elucidate the participation of the brain regions in language function, cerebral blood flow (CBF) which were measured with positron emission tomography (PET) were compared with the language scores based on the standard language test for aphasics in 97 right-handed patients with aphasia due to cerebral infarction. PET studies were performed on 71.4{+-}107.3 days after onset. By the linear regression analysis, the aphasic scores were correlated with the regional CBF from 55 brain regions. CBF from the left frontal, left temporal, and left parietal lobes significantly correlated with language scores of auditory comprehension, speaking, reading, writing, calculation, and repetition. Highly significant correlation was obtained from the left posterior inferior frontal, superior temporal, supramarginal and angular gyri. CBF from the right inferior frontal, right superior temporal, right parahippocampal and right anterior cingulate gyri also correlated with the auditory comprehension, speaking and reading. Accordingly, in addition to the classical language areas which play an essential roles in language function, the extensive areas in the left hemisphere and some part of the right hemisphere may be related to the language processing and recovery from aphasia. (author)

  20. Correlations of cerebral blood flow with language function in aphasic patients following cerebral infarction

    International Nuclear Information System (INIS)

    Yokoyama, Eriko; Nagata, Ken; Uemura, Kazuo

    1997-01-01

    To elucidate the participation of the brain regions in language function, cerebral blood flow (CBF) which were measured with positron emission tomography (PET) were compared with the language scores based on the standard language test for aphasics in 97 right-handed patients with aphasia due to cerebral infarction. PET studies were performed on 71.4±107.3 days after onset. By the linear regression analysis, the aphasic scores were correlated with the regional CBF from 55 brain regions. CBF from the left frontal, left temporal, and left parietal lobes significantly correlated with language scores of auditory comprehension, speaking, reading, writing, calculation, and repetition. Highly significant correlation was obtained from the left posterior inferior frontal, superior temporal, supramarginal and angular gyri. CBF from the right inferior frontal, right superior temporal, right parahippocampal and right anterior cingulate gyri also correlated with the auditory comprehension, speaking and reading. Accordingly, in addition to the classical language areas which play an essential roles in language function, the extensive areas in the left hemisphere and some part of the right hemisphere may be related to the language processing and recovery from aphasia. (author)

  1. Expression of glial fibrillar acidic protein in the sensorimotor cortex of the cerebral hemispheres in the modeling of transient ischemia against the background of previous sensitization by brain antigen and immunocorrection

    Directory of Open Access Journals (Sweden)

    L. M. Yaremenko

    2017-12-01

    Full Text Available Aim. In order to analyze the dynamics of expression of glial fibrillar acidic protein in the sensorimotor cortex of the large hemispheres in the simulation of transient ischemia against the background of previous sensitization by brain antigen and immunocorrection. Materials and methods. The study is conducted on 185 male mature white rats from Wistar line weighing 260-290 g, in which the damage of the brain was modulated. The brain for study was taken on the 1st, 3rd, 10th, 30th and 90th days after the start of the experiment. The histological, immunohistochemical, morphometric and statistical methods were used. Results. Observations have shown that sensitization by the brain antigen causes neurodegenerative changes in the sensorimotor cortex and a moderate increase in the number of GFAP+-gliocytes, which is gradually increasing. The discirculatory changes that occurred with PO and BCA against the background of previous sensitization practically do not lead to changes in the number of GFAP+-cells. Against the background of sensitization by brain antigen, brain ischemia leads to an increase in the number of gliocytes that are GFAP labeled. In the affected hemisphere, their number reaches a maximum in the end of the acute period of ischemia, after which it decreases. But even in 3 months after transient vascular lesion, there are almost twice as many as in conditionally intact rats. This can be a factor that will significantly affect the function of brain regions after a vascular accident. The increase in the number of GFAP+-gliocytes in the contralateral hemisphere allows us to speak about a certain systemic response of astrocytic glia after ischemic trauma. An early reaction to increase of the number of labeled astrocytes just a day after ischemic attack suggests that some of this type of gliocytes does not expresses GFAP under normal conditions. The action of Imunofan in MEAs results in a less significant decrease in manifestations of

  2. The importance of bilateral monitoring of cerebral oxygenation (NIRS): Clinical case of asymmetry during cardiopulmonary bypass secondary to previous cerebral infarction.

    Science.gov (United States)

    Matcan, S; Sanabria Carretero, P; Gómez Rojo, M; Castro Parga, L; Reinoso-Barbero, F

    2018-03-01

    Cerebral oximetry based on near infrared spectroscopy (NIRS) technology is used to determine cerebral tissue oxygenation. We hereby present the clinical case of a 12-month old child with right hemiparesis secondary to prior left middle cerebral artery stroke 8 months ago. The child underwent surgical enlargement of the right ventricular outflow tract (RVOT) with cardiopulmonary bypass. During cardiopulmonary bypass, asymmetric NIRS results were detected between both hemispheres. The utilization of multimodal neuromonitoring (NIRS-BIS) allowed acting on both perfusion pressure and anesthetic depth to balance out the supply and demand of cerebral oxygen consumption. No new neurological sequelae were observed postoperatively. We consider bilateral NIRS monitoring necessary in order to detect asymmetries between cerebral hemispheres. Although asymmetries were not present at baseline, they can arise intraoperatively and its monitoring thus allows the detection and treatment of cerebral ischemia-hypoxia in the healthy hemisphere, which if undetected and untreated would lead to additional neurological damage. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Cortical disconnection of the ipsilesional primary motor cortex is associated with gait speed and upper extremity motor impairment in chronic left hemispheric stroke.

    Science.gov (United States)

    Peters, Denise M; Fridriksson, Julius; Stewart, Jill C; Richardson, Jessica D; Rorden, Chris; Bonilha, Leonardo; Middleton, Addie; Gleichgerrcht, Ezequiel; Fritz, Stacy L

    2018-01-01

    Advances in neuroimaging have enabled the mapping of white matter connections across the entire brain, allowing for a more thorough examination of the extent of white matter disconnection after stroke. To assess how cortical disconnection contributes to motor impairments, we examined the relationship between structural brain connectivity and upper and lower extremity motor function in individuals with chronic stroke. Forty-three participants [mean age: 59.7 (±11.2) years; time poststroke: 64.4 (±58.8) months] underwent clinical motor assessments and MRI scanning. Nonparametric correlation analyses were performed to examine the relationship between structural connectivity amid a subsection of the motor network and upper/lower extremity motor function. Standard multiple linear regression analyses were performed to examine the relationship between cortical necrosis and disconnection of three main cortical areas of motor control [primary motor cortex (M1), premotor cortex (PMC), and supplementary motor area (SMA)] and motor function. Anatomical connectivity between ipsilesional M1/SMA and the (1) cerebral peduncle, (2) thalamus, and (3) red nucleus were significantly correlated with upper and lower extremity motor performance (P ≤ 0.003). M1-M1 interhemispheric connectivity was also significantly correlated with gross manual dexterity of the affected upper extremity (P = 0.001). Regression models with M1 lesion load and M1 disconnection (adjusted for time poststroke) explained a significant amount of variance in upper extremity motor performance (R 2  = 0.36-0.46) and gait speed (R 2  = 0.46), with M1 disconnection an independent predictor of motor performance. Cortical disconnection, especially of ipsilesional M1, could significantly contribute to variability seen in locomotor and upper extremity motor function and recovery in chronic stroke. Hum Brain Mapp 39:120-132, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. Hemispheric asymmetries in discourse processing: evidence from false memories for lists and texts.

    Science.gov (United States)

    Ben-Artzi, Elisheva; Faust, Miriam; Moeller, Edna

    2009-01-01

    Previous research suggests that the right hemisphere (RH) may contribute uniquely to discourse and text processing by activating and maintaining a wide range of meanings, including more distantly related meanings. The present study used the word-lists false memory paradigm [Roediger, H. L., III, & McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803-814.] to examine the hypothesis that difference between the two cerebral hemispheres in discourse processing may be due, at least partly, to memory representations for implicit text-related semantic information. Specifically, we tested the susceptibility of the left hemisphere (LH) and RH to unpresented target words following the presentation of semantically related words appearing in either word lists or short texts. Findings showed that the RH produced more false alarms than the LH for unpresented target words following either word lists or texts. These findings reveal hemispheric differences in memory for semantically related information and suggest that RH advantage in long-term maintenance of a wide range of text-related word meanings may be one aspect of its unique contribution to the construction of a discourse model. The results support the RH coarse semantic coding theory [Beeman, M. (1998). Coarse semantic coding and discourse comprehension. In M. Beeman & C. Chiarello (Eds.), Right hemisphere language comprehension: Perspectives from cognitive neuroscience (pp. 255-284). Mahwah, NJ: Erlbaum.] and suggest that hemispheric differences in semantic processing during language comprehension extend also to verbal memory.

  5. ERP evidence for hemispheric asymmetries in exemplar-specific explicit memory access.

    Science.gov (United States)

    Küper, Kristina; Zimmer, Hubert D

    2015-11-02

    The right cerebral hemisphere (RH) appears to be more effective in representing visual objects as distinct exemplars than the left hemisphere (LH) which is presumably biased towards coding objects at the level of abstract prototypes. As of yet, relatively little is known about the role that asymmetries in exemplar-specificity play at the level of explicit memory retrieval. In the present study, we addressed this issue by examining hemispheric asymmetries in the putative event-related potential (ERP) correlates of familiarity (FN400) and recollection (LPC). In an incidental study phase, pictures of familiar objects were presented centrally. At test, participants performed a memory inclusion task on identical repetitions and different exemplars of study items as well as new items which were presented in only one visual hemifield using the divided visual field technique. With respect to familiarity, we observed exemplar-specific FN400 old/new effects that were more pronounced for identical repetitions than different exemplars, irrespective of the hemisphere governing initial stimulus processing. In contrast, LPC old/new effects were subject to some hemispheric asymmetries indicating that exemplar-specific recollection was more extensive in the RH than in the LH. This further corroborates the idea that hemispheric asymmetries should not be generalized but need to be distinguished not only in different domains but also at different levels of processing. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Defective imitation of finger configurations in patients with damage in the right or left hemispheres: An integration disorder of visual and somatosensory information?

    Science.gov (United States)

    Okita, Manabu; Yukihiro, Takashi; Miyamoto, Kenzo; Morioka, Shu; Kaba, Hideto

    2017-04-01

    To explore the mechanism underlying the imitation of finger gestures, we devised a simple imitation task in which the patients were instructed to replicate finger configurations in two conditions: one in which they could see their hand (visual feedback: VF) and one in which they could not see their hand (non-visual feedback: NVF). Patients with left brain damage (LBD) or right brain damage (RBD), respectively, were categorized into two groups based on their scores on the imitation task in the NVF condition: the impaired imitation groups (I-LBD and I-RBD) who failed two or more of the five patterns and the control groups (C-LBD and C-RBD) who made one or no errors. We also measured the movement-production times for imitation. The I-RBD group performed significantly worse than the C-RBD group even in the VF condition. In contrast, the I-LBD group was selectively impaired in the NVF condition. The I-LBD group performed the imitations at a significantly slower rate than the C-LBD group in both the VF and NVF conditions. These results suggest that impaired imitation in patients with LBD is partly due to an abnormal integration of visual and somatosensory information based on the task specificity of the NVF condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Cerebral haemodynamics in female teenagers exposed to ionizing irradiation in low doses and living in 'clean' areas

    International Nuclear Information System (INIS)

    Naumova, G.I.; Naumov, A.D.

    1999-01-01

    Thirty seven girls living in various districts of the Mogilev Region and having received absorbed irradiation dose at thyroid gland owing to iodine 131 more than 1 Gy and 65 ones living in relatively free from radionuclide areas were examined. The results indicated changes in cerebral haemodynamics in the first group. Vegetative vessels dystonia syntrom had been revealed at 31 exposed to iodine 131 irradiation patients (83%) and at 16 patients (25%) from the control group. The changes tended to induce hypotonia of small cerebral peripheral blood vessels with indices asymmetry of left and right cerebral hemispheres

  8. Asymmetry in the brain influenced the neurological deficits and infarction volume following the middle cerebral artery occlusion in rats

    Directory of Open Access Journals (Sweden)

    Zhang Meizeng

    2008-12-01

    Full Text Available Abstract Background Paw preference in rats is similar to human handedness, which may result from dominant hemisphere of rat brain. However, given that lateralization is the uniqueness of the humans, many researchers neglect the differences between the left and right hemispheres when selecting the middle cerebral artery occlusion (MCAO in rats. The aim of this study was to evaluate the effect of ischemia in the dominant hemisphere on neurobehavioral function and on the cerebral infarction volume following MCAO in rats. Methods The right-handed male Sprague-Dawley rats asserted by the quadrupedal food-reaching test were subjected to 2 hours MCA occlusion and then reperfusion. Results The neurological scores were significantly worse in the left MCAO group than that in the right MCAO group at 1 h, 24 h, 48 h and 72 h (p 0.05 respectively. There was a trend toward better neurobehavioral function recovery in the right MCAO group than in the left MCAO group. The total infarct volume in left MCAO was significantly larger than that in the right (p Conclusion The neurobehavioral function result and the pathological result were consistent with the hypothesis that paw preference in rats is similar to human handedness, and suggested that ischemia in dominant hemisphere caused more significant neurobehavioral consequence than in another hemisphere following MCAO in adult rats. Asymmetry in rat brain should be considered other than being neglected in choice of rat MCAO model.

  9. Systematization, description and territory of the caudal cerebral artery of the brain in broad-snouted Caiman (Caiman latirostris

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    Lygia Almeida

    2011-09-01

    Full Text Available Thirty heads with the neck segment of Caiman latirostris were used. The animals were provided from a creation center called Mister Caiman, under the authorization of the Brazilian Institute of Environment and Renewable Natural Resources (Ibama. Animals were sacrificed according to the slaughtering routine of the abattoir, and the heads were sectioned at the level of the third cervical vertebra. The arterial system was washed with cold saline solution, with drainage through jugular veins. Subsequently, the system was filled with red colored latex injection. Pieces were than fixed in 20% formaldehyde, for seven days. The brains were removed, with a spinal cord segment, the duramater removed and the arteries dissected. At the level of the hypophysis, the internal carotid artery gave off a rostral branch, and a short caudal branch, continuing, naturally, as the caudal cerebral artery. This artery projected laterodorsalwards and, as it overpassed the optic tract, gave off its I (the first central branch. Penetrated in the cerebral transverse fissure, emitting the diencephalic artery and next its II (second central branch. Still inside the fissure, originated occipital hemispheric branches and a pineal branch. Emerged from the cerebral transverse fissure, over the occipital pole of the cerebral hemisphere. Projected rostralwards, sagital to the cerebral longitudinal fissure, as interhemispheric artery. This artery gave off medial and convex hemispheric branches to the respective surfaces of the cerebral hemispheres, anastomosed with its contralateral homologous, forming the common ethmoidal artery. This artery entered the fissure between the olfactory peduncles, emerging ventrally and dividing into ethmoidal arteries, right and left, which progressed towards the nasal cavities, vascularizing them. The territory of the caudal cerebral artery included the most caudal area of the base of the cerebral hemisphere, its convex surface, the olfactory

  10. Interest of the supplementary analysis of inter hemisphere asymmetry in the study with S.P.M. of cerebral PET-F.D.G. of patients suffering of temporal epilepsy; Interet de l'analyse supplementaire d'asymetrie interhemispherique dans l'etude avec SPM des TEP-FDG cerebrales de patients avec epilepsie temporale

    Energy Technology Data Exchange (ETDEWEB)

    Person, C.; Wolf, D. [CRAN-INPL, universite de Nancy, 54 (France); Gillet, N.; Marie, P.Y.; Laurens, M.H.; Djaballah, W.; Karcher, G. [CHU de Nancy, service de medecine nucleaire, 54 (France); Maillard, L.; Vespignani, H. [CHU de Nancy, service de neurologie, 54 (France); Guedj, E. [Hopital de la Timone, service de medecine nucleaire, AP-HM13 - Marseille (France)

    2010-07-01

    The aim of this study was to evaluate the supplementary information provided by the asymmetry analysis in the study by S.P.M. (statistical parametric mapping) of cerebral PET-F.D.G. images got for patients suffering of a drug resistant temporal epilepsy. It appears that the supplementary analysis of inter hemisphere asymmetry allow to improve the detection rate of the involved temporal lobe and bring complementary information concerning the delimitation of the hypo metabolic temporal area. (N.C.)

  11. Evidence for developmental programming of cerebral laterality in humans.

    Directory of Open Access Journals (Sweden)

    Alexander Jones

    2011-02-01

    Full Text Available Adverse fetal environments are associated with depression, reduced cognitive ability and increased stress responsiveness in later life, but underlying mechanisms are unknown. Environmental pressures on the fetus, resulting from variations in placental function and maternal nutrition, health and stress might alter neurodevelopment, promoting the development of some brain regions over others. As asymmetry of cerebral activity, with greater right hemisphere activity, has been associated with psychopathology, we hypothesized that regional specialization during fetal life might be reflected persistently in the relative activity of the cerebral hemispheres. We tested this hypothesis in 140 healthy 8-9 year-old children, using tympanic membrane temperature to assess relative blood flow to the cerebral hemispheres at rest and following psychosocial stress (Trier Social Stress Test for Children. Their birth weight and placental weight had already been measured when their mothers took part in a previous study of pregnancy outcomes. We found that children who had a smaller weight at birth had evidence of greater blood flow to the right hemisphere than to the left hemisphere (r = -.09, P = .29 at rest; r = -.18, P = .04 following stress. This finding was strengthened if the children had a relatively low birth weight for their placental weight (r = -.17, P = .05 at rest; r = -.31, P = .0005 following stress. Our findings suggest that lateralization of cerebral activity is influenced persistently by early developmental experiences, with possible consequences for long-term neurocognitive function.

  12. Personality, Hemispheric Dominance, and Cognitive Style.

    Science.gov (United States)

    Hylton, Jaime; Hartman, Steve E.

    1997-01-01

    Shows that 154 medical students and 526 undergraduates (samples treated separately) who were judged left- or right-hemisphere dominant (by the Hemispheric Mode Indicator) were found to have very different personalities (as measured by the Myers-Briggs Type Indicator). Considers some of the practical ramifications of the psychometric overlap of…

  13. Delayed radionecrosis of the cerebral hemispheres following betatron electron beam irradiation for scalp cancer. Pathological and clinical findings in one case

    International Nuclear Information System (INIS)

    Buge, A.; Escourolle, R.; Rancurel, G.; Gray, F.; Pertuiset, B.F.

    1979-01-01

    Three years following an irradiation by the Betatron's electron beam of an epithelioma in left parieto occipital area of the scalp in a female patient aged 77, early suffering from high blood pressure, a fatal pseudo-tumoral brain necrosis occurs presenting as a rapidly increasing from of Wernicke's aphasia. The necropsy shows intense radionecrosis lesions of the brain and the bone, free of any parenchymatous malignant proliferation note-wortly for the striking density of microvascular changes as previously described in radiation therapy. The case observed some years ago, allows to definite again the limits doses of the extracranial irradiations now estimated at 1760 rets. That is the 'Nominal Standard Dose' (NSD) measured by rets and taking into account the number of seances (N) and the duration of irradiation (T) which would be to take the place of 'the total dose' (D) (rads). These dosimetric criteria themselves must be adjusted to the age and the vascular features of each patient [fr

  14. Delayed radionecrosis of the cerebral hemispheres following betatron electron beam irradiation for scalp cancer. Pathological and clinical findings in one case

    Energy Technology Data Exchange (ETDEWEB)

    Buge, A; Escourolle, R; Rancurel, G; Gray, F; Pertuiset, B F [Clinique Neurologique de la Salpetriere, 75 - Paris (France)

    1979-01-01

    Three years following an irradiation by the Betatron's electron beam of an epithelioma in left parieto occipital area of the scalp in a female patient aged 77, early suffering from high blood pressure, a fatal pseudo-tumoral brain necrosis occurs presenting as a rapidly increasing from of Wernicke's aphasia. The necropsy shows intense radionecrosis lesions of the brain and the bone, free of any parenchymatous malignant proliferation note-wortly for the striking density of microvascular changes as previously described in radiation therapy. The case observed some years ago, allows to definite again the limits doses of the extracranial irradiations now estimated at 1760 rets. That is the 'Nominal Standard Dose' (NSD) measured by rets and taking into account the number of seances (N) and the duration of irradiation (T) which would be to take the place of 'the total dose' (D) (rads). These dosimetric criteria themselves must be adjusted to the age and the vascular features of each patient.

  15. Handedness is related to neural mechanisms underlying hemispheric lateralization of face processing

    Science.gov (United States)

    Frässle, Stefan; Krach, Sören; Paulus, Frieder Michel; Jansen, Andreas

    2016-06-01

    While the right-hemispheric lateralization of the face perception network is well established, recent evidence suggests that handedness affects the cerebral lateralization of face processing at the hierarchical level of the fusiform face area (FFA). However, the neural mechanisms underlying differential hemispheric lateralization of face perception in right- and left-handers are largely unknown. Using dynamic causal modeling (DCM) for fMRI, we aimed to unravel the putative processes that mediate handedness-related differences by investigating the effective connectivity in the bilateral core face perception network. Our results reveal an enhanced recruitment of the left FFA in left-handers compared to right-handers, as evidenced by more pronounced face-specific modulatory influences on both intra- and interhemispheric connections. As structural and physiological correlates of handedness-related differences in face processing, right- and left-handers varied with regard to their gray matter volume in the left fusiform gyrus and their pupil responses to face stimuli. Overall, these results describe how handedness is related to the lateralization of the core face perception network, and point to different neural mechanisms underlying face processing in right- and left-handers. In a wider context, this demonstrates the entanglement of structurally and functionally remote brain networks, suggesting a broader underlying process regulating brain lateralization.

  16. Positron emission tomography in the newborn: extensive impairment of regional cerebral blood flow with intraventricular hemorrhage and hemorrhagic intracerebral involvement

    International Nuclear Information System (INIS)

    Volpe, J.J.; Herscovitch, P.; Perlman, J.M.; Raichle, M.E.

    1983-01-01

    Positron emission tomography (PET) now provides the capability of measuring regional cerebral blood flow with high resolution and little risk. In this study, we utilized PET in six premature infants (920 to 1,200 g) with major intraventricular hemorrhage and hemorrhagic intracerebral involvement to measure regional cerebral blood flow during the acute period (5 to 17 days of age). Cerebral blood flow was determined after intravenous injection of H 2 O, labeled with the positron-emitting isotope, 15 O. Findings were similar and dramatic in all six infants. In the area of hemorrhagic intracerebral involvement, little or no cerebral blood flow was detected. However, in addition, surprisingly, a marked two- to fourfold reduction in cerebral blood flow was observed throughout the affected hemisphere, well posterior and lateral to the intracerebral hematoma, including cerebral white matter and, to a lesser extent, frontal, temporal, and parietal cortex. In the one infant studied a second time, ie, at 3 months of age, the extent and severity of the decreased cerebral blood flows in the affected hemisphere were similar to those observed on the study during the neonatal period. At the three autopsies, the affected left hemisphere showed extensive infarction, corroborating the PET scans. These observations, the first demonstration of the use of PET in the determination of regional cerebral blood flow in the newborn, show marked impairments in regional cerebral blood flow in the hemisphere containing an apparently restricted intracerebral hematoma, indicating that the hemorrhagic intracerebral involvement is only a component of a much larger lesion, ischemic in basic nature, ie, an infarction. This large ischemic lesion explains the poor neurologic outcome in infants with intraventricular hemorrhage and hemorrhagic intracerebral involvement

  17. Recurrent cerebral thrombosis; With special reference to the neuroradiological study

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Toshihiko; Abe, Shin-e; Kubo, Hideki; Hanyu, Haruo; Takasaki, Masaru (Tokyo Medical Coll. (Japan))

    1992-10-01

    Neuroradiological techniques were used to elucidate pathophysiology of recurrent cerebral thrombosis. Twenty-two patients with cerebral thrombosis who suffered a second attack under stable conditions more than 22 days after the initial stroke were studied. Hypertension, diabetes mellitus, and hypercholesterolemia were also seen in 20, 8, and 12 patients, respectively. The patients were divided into three groups according to their symptoms: (I) symptoms differed between the first and second strokes (n=12); (II) initial symptoms were suddenly deteriorated (n=6); and (III) symptoms occurring in groups I and II were seen (n=4). In group I, contralateral hemiparesis or suprabulbar palsy was often associated with the initial hemiparesis. The time of recurrent stroke varied from 4 months to 9 years. CT and MRI showed not only lacunae in both hemispheres, but also deep white-matter ischemia of the centrum semi-ovale. In group II, hemiparesis or visual field defect was deteriorated early after the initial stroke. In addition, neuroimaging revealed that infarction in the posterior cerebral artery was progressed on the contralateral side, or that white matter lesion in the middle artery was enlarged in spite of small lesion in the left cerebral hemisphere. All patients in group III had deterioration of right hemiparesis associated with aphasia. CT, MRI, SPECT, and angiography indicated deep white-matter ischemia caused by main trunk lesions in the left hemisphere. Group III seemed to be equivalent to group II, except for laterality of the lesion. Neuroradiological assessment of the initial stroke may help to predict the mode of recurrence, although pathophysiology of cerebral thrombosis is complicated and varies from patient to patient. (N.K.).

  18. [Analysis of 58 neonatal cases with cerebral infarction].

    Science.gov (United States)

    Li, Zhi-hua; Chen, Chao

    2013-01-01

    Cerebral infarction (CI) is one of severe diseases of central nervous system in neonates, and some infants with CI could have poor prognosis in the long term. This study aimed to analyze the clinical data and prognosis of all neonatal cases with cerebral infarction in recent years and to help future clinical work. Totally 58 neonatal cases with CI admitted to NICU of the hospital from January 1999 to December 2010 were included in this study. We analyzed all clinical data and prognosis by retrospective analysis. Fifty-two term babies and six preterm babies were included. There were altogether 51 cases with asphyxia and 7 with hemorrhagic cerebral infarction. Perinatal hypoxia-ischemia was the most common high-risk factor and it accounted for 46.6%. Seizure was the most frequent initial symptom and the most common clinical manifestation (accounted for 77.6%), and it was followed by intermittent cyanosis, apnea and lethargy. Cerebral CT scan and magnetic resonance imaging were major methods to help to make the diagnosis and they also had close relation with prognosis. Diffusion weighted imaging was very helpful to diagnose infarction in early stage. Left middle cerebral artery was the most common artery to be involved. Supportive therapy and symptomatic treatment were the main methods in the acute stage of neonatal cerebral infarction. Those babies with poor prognosis mostly had large infarction involving cerebral hemisphere, thalamus and basal ganglia. Neonatal cerebral infarction was a severe brain injury affecting long tern nervous system prognosis. Perinatal hypoxia was the most common high-risk factor and seizure was the most frequent initial symptom. Diffusion weighted imaging was valuable to diagnose infarction in early stage. Most of infants with poor prognosis had large infarction involving hemisphere, thalamus and basal ganglia. Early diagnosis with brain imaging would be helpful for rehabilitation therapy and improving prognosis.

  19. Imaging of rat cerebral ischemia-reperfusion injury using99mTc-labeled duramycin

    International Nuclear Information System (INIS)

    Zhang Yuqing; Stevenson, Gail D.; Barber, Christy; Furenlid, Lars R.; Barrett, Harrison H.; Woolfenden, James M.; Zhao Ming; Liu Zhonglin

    2013-01-01

    Objectives: Prompt identification of necrosis and apoptosis in the infarct core and penumbra region is critical in acute stroke for delineating the underlying ischemic/reperfusion molecular pathologic events and defining therapeutic alternatives. The objective of this study was to investigate the capability of 99m Tc-labeled duramycin in detecting ischemia-reperfusion injury in rat brain after middle cerebral artery (MCA) occlusion. Methods: Ischemic cerebral injury was induced in ten rats by vascular insertion of a nylon suture in the left MCA for 3 hr followed by 21–24 hr reperfusion. After i.v. injection of 99m Tc-duramycin (1.0-3.5 mCi), dynamic cerebral images were acquired for 1 hr in six rats using a small-animal SPECT imager. Four other rats were imaged at 2 hr post-injection. Ex vivo images were obtained by autoradiography after sacrifice. Histologic analyses were performed to assess cerebral infarction and apoptosis. Results: SPECT images showed that 99m Tc-duramycin uptake in the left cerebral hemisphere was significantly higher than that in the right at 1 and 2 hr post-injection. The level of radioactive uptake in the ischemic brain varied based on ischemic severity. The average ratio of left cerebral hot-spot uptake to right hemisphere radioactivity, as determined by computerized ROI analysis, was 4.92 ± 0.79. Fractional washout at 1 hr was 38.2 ± 4.5% of peak activity for left cerebral hot-spot areas and 80.9 ± 2.0% for remote control areas (P 99m Tc-duramycin SPECT imaging may be useful for detecting and quantifying ongoing apoptotic neuronal cell loss induced by ischemia-reperfusion injury.

  20. Behcet's disease with cerebral vasculitis

    International Nuclear Information System (INIS)

    Scardamaglia, L.; Desmond, P.M.; Gonzales, M.F.; Bendrups, A.; Brodtmann, A.

    2001-01-01

    The case presented illustrates the diagnostic dilemma off neurological involvement in Behcet's disease and other inflammatory diseases. 'Psychiatric' symptoms were present for 2 years without abnormalities on SPECT or MRI and without CSF pleocytosis. Even at the time of fitting, no CSF abnormalities were observed. The preceding psychiatric presentations may have been due to cerebral vasculitis that was exacerbated by withdrawal of steroids. Magnetic resonance imaging is currently the most sensitive imaging modality. Lesions are usually in the brainstem, cerebellum, basal ganglia region or periventricular white matter, and the pons and the mesencephalon are commonly affected. In our patient there was no diencephalic or brainstem involvement. The inflammatory process can appear as a very large lesion, with gadolinium enhancement and significant mass effect, as in our patient. Brain magnetic resonance imaging. Postgadolinium-diethylenetriamine pentaacetic acid, axial image shows two large lesions in the right frontal lobe, with the larger, posterior lesion demonstrating vivid ring enhancement. A central nodule is isodense, with the cerebral white matter within the larger lesion. Surrounding low T 1 signal involves the hemispheric white matter without cortical extension and is consistent with vasogenic oedema. Minor mass effect is demonstrated with bowing of the anterior falx cerebri to the left. Biopsy shows prominent fibrinoid necrosis in small calibre postcapillary venules and cerebral white matter. There are surrounding acute and chronic inflammatory cells and nuclear debris, consistent with vasculitis

  1. Ipsilateral hemiparesis and contralateral lower limb paresis caused by anterior cerebral artery territory infarct.

    Science.gov (United States)

    Xu, Yongfeng; Liu, Lan

    2016-07-01

    Ipsilateral hemiparesis is rare after a supratentorial stroke, and the role of reorganization in the motor areas of unaffected hemisphere is important for the rehabilitation of the stroke patients. In this study, we present a patient who had a subclinical remote infarct in the right pons developed ipsilateral hemiparesis and contralateral lower limb paresis caused by a new infarct in the left anterior cerebral artery territory. Our case suggests that the motor areas of the unaffected hemisphere might be reorganized after stroke, which is important for the rehabilitation of stroke patients.

  2. Regional cerebral blood flow in schizophrenics. Tests using the xenon Xe 133 inhalation method

    International Nuclear Information System (INIS)

    Ariel, R.N.; Golden, C.J.; Berg, R.A.; Quaife, M.A.; Dirksen, J.W.; Forsell, T.; Wilson, J.; Graber, B.

    1983-01-01

    Measurements of intrahemispheric and bilateral regional cerebral blood flow (CBF) for gray and white matter were compared in 29 schizophrenic patients and 22 normal controls, using the xenon Xe 133 inhalation method. Results showed significantly lower CBF values for all brain regions in the schizophrenic group, and post hoc comparisons showed relatively greater reduced gray-matter CBF values in the anterior areas of the brain. There was also a left-hemisphere frontal loss similar to that reported previously, although it was in the context of a generalized loss in anterior functioning. Interhemispheric comparison within both groups showed no differences between homologous regions for gray matter, and greater white-matter CBF values in the right hemisphere than in the left hemisphere. The findings support a hypothesis of a bilateral anterior deficit in schizophrenia

  3. Long-term fate of left atrial thrombi and incidence of cerebral embolism under continuous anticoagulation therapy; MR-tomographische Evaluation der Inzidenz zerebraler Embolien bei Patienten mit Vorhofflimmern und linksatrialen Thromben

    Energy Technology Data Exchange (ETDEWEB)

    Strach, K.; Meyer, C.; Hackenbroch, M.; Schild, H.; Sommer, T. [Radiologische Universitaetsklinik Bonn (Germany); Tiemann, K. [Medizinische Universitaetsklinik und Poliklinik II, Bonn (Germany); Haase, J. [Klinik Rotes Kreuz, Frankfurt/Main (Germany); Pizulli, L. [Petruskrankenhaus, Bonn (Germany); Omran, H. [St. Marien-Hospital, Bonn (Germany)

    2005-12-15

    Purpose: Patients (pts.) with atrial fibrillation (AF) and atrial thrombi are known to have an increased risk for cerebral embolism. However, little is known about the clinical course of atrial thrombi and the incidence of cerebral embolism in those patients during anticoagulation therapy. The high sensitivity of MR imaging (MRI) including diffusion-weighted imaging (DWI) suggests that this technique could provide an improved estimate of cerebral embolism associated with the presence of left atrial thrombi. The aims of this prospective study were to evaluate (1) the prevalence of clinically silent and apparent cerebral embolism in pts. with newly diagnosed AF and atrial thrombi using MRI/DWI, (2) the long-term fate of atrial thrombi under continued anticoagulation therapy and (3) the incidence of cerebral embolism during a follow-up period of 12 months with continuous anticoagulation therapy. Materials and methods: The study group consisted of 32 pts. with (1) newly diagnosed AF and evidence of left atrial (LA) thrombi detected by TEE and (2) a new start of anticoagulation therapy [International Normalized Ratio (INR) 2.0-3.0]. 19 pts. with (1) newly diagnosed AF and no evidence of atrial thrombi and (2) an equivalent anticoagulation regimen served as the control group. In both groups (a) MRI/DWI studies of the brain (weeks 0, 4, 8, 12, 20, 28, 36, 44, and 52), (b) transesophageal echocardiographic studies (TEE) for assessment of LA-Thrombi (weeks 0 and 52) and (c) clinical neurological assessments (weeks 0, 20 and 52) were performed. Results: In the study group (AF and LA-Thrombi) 11 out of 32 pts. (34%) displayed signs of acute (n=8) or chronic (n=3) cerebral embolism in the initial MRI studies. In 4 out of 32 pts.(13%), MRI/DWI depicted new or additional cerebral emboli (n=12) during the follow-up period despite continuous anticoagulation therapy. 2 (n=2/4; 50%) of these patients had clinically apparent neurological deficits. In the control group 1 out of 19 pts

  4. Diaschisis with cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Slater, R.; Reivich, M.; Goldberg, H.; Banka, R.; Greenberg, J.

    1977-01-01

    Fifteen patients admitted to Philadelphia General Hospital with acute strokes had repeated measurements of cerebral blood flow measured by the /sup 133/X inhalation method. A progressive decline in cerebral blood flow in both hemispheres was observed during the first week after infarction in twelve of these patients. This decline could be partially explained by loss of autoregulation, but could not be correlated with level of consciousness, clinical status of PCO2. This progressive decline in flow in the non-ischemic hemisphere indicates a process more complex than a simple destruction of axonal afferants to neurons as implied by the term diaschisis. The flow changes in the non-ischemic hemisphere are likely caused by a combination of the immediate effects of decreased neuronal stimulation modified by loss of autoregulation, release of vasoactive substances, cerebral edema, and other factors.

  5. Hypothalamic digoxin and hemispheric chemical dominance--relation to the pathogenesis of senile osteoporosis, degenerative osteoarthritis, and spondylosis.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-03-01

    The isoprenoid pathway produces three key metabolites: i) digoxin (a membrane sodium-potassium ATPase inhibitor which can regulate intracellular calcium/magnesium ratios), ii) dolichol (which regulates N-glycosylation of proteins), and iii) ubiquinone (a free radical scavenger), all of which are important in bone and joint metabolism. The pathway was assessed in senile osteoporosis, spondylosis, and osteoarthritis. Digoxin could possibly play a role in the genesis of cerebral dominance because it can regulate multiple neurotransmitter systems. The pathway was also assessed in individuals of differing hemispheric dominance for comparison and to find out the role of cerebral dominance in the pathogenesis of these diseases. The plasma/serum-activity of HMG CoA reductase, magnesium, digoxin, dolichol, ubiquinone, and tryptophan/tyrosine catabolic patterns, as well as RBC Na(+)-K+ ATPase activity, were measured in the above mentioned groups. The glycoconjugate metabolism, free radical metabolism, and membrane composition were also studied. The pathway was upregulated with increased digoxin synthesis in patients with spondylosis and osteoarthritis. In this group of patients, the glycoconjugate levels and dolichol levels were increased and lysosomal stability reduced. The ubiquinone levels were low and free radicals increased in spondylosis and osteoarthritis. On the other hand, in senile osteoporosis, the isoprenoid pathway was downregulated and digoxin synthesis reduced. The glycoconjugate and dolichol levels were low and lysosomal stability increased. The ubiquinone levels were increased and free radical production increased in senile osteoporosis. The significance of these changes in the pathogenesis of osteoarthritis, spondylosis, and osteoporosis is discussed. The hyperdigoxinemic state is seen in osteoarthritis and spondylosis and in right hemispheric dominance. The hypodigoxinemic state is seen in left hemispheric dominance and senile osteoporosis. Hemispheric

  6. Bihemispheric cerebral FDG PET correlates of cognitive dysfunction as assessed by the CERAD in Alzheimer's disease.

    Science.gov (United States)

    Schönknecht, Oskar Dieter Peter; Hunt, Aoife; Toro, Pablo; Guenther, Thomas; Henze, Marcus; Haberkorn, Uwe; Schröder, Johannes

    2011-04-01

    Alzheimer's disease (AD) is characterized by a variety of cognitive deficits which can be reliably assessed by the neuropsychological test battery of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), but the cerebral changes underlying the respective cognitive deficits are only partly understood. Measures of severity of dementia in AD as well as delayed episodic memory performance in mild cognitive impairment significantly correlated with bihemispheric cerebral glucose hypometabolism. We therefore hypothesized that the CERAD cognitive battery may represent cerebral dysfunction of both hemispheres in patients with AD. In 32 patients with AD, cerebral glucose metabolism was investigated using positron-emission-tomography with 18Fluorodeoxyglucose (FDG PET) and associated with the test scores of the CERAD cognitive battery by statistical parametric mapping. Episodic memory scores significantly correlated with temporopari etal glucose metabolism of both hemispheres while delayed episodic memory significantly was correlated with the right frontotemporal cortices. Verbal fluency and naming scores significantly correlated with glucose metabolism in left temporoparietal and right frontal cortices, whereas constructional praxis predominantly correlated significantly with the bilateral precuneus. In conclusion, the results of our study demonstrate that not only memory function but also functions of language and constructional praxis in AD are associated with glucose metabolism as revealed by FDG PET in subsets of uni- and bilateral brain areas. The findings of our study for the first time demonstrate that in AD neuropsychological deficits as assessed by the CERAD refer to different cerebral sites of both hemispheres.

  7. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation

    Science.gov (United States)

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-01-01

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation. PMID:25624815

  8. Hypothalamic digoxin, hemispheric chemical dominance, and oncogenesis: evidence from multiple myeloma.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Paramesware Achutha

    2003-12-01

    This study assessed the changes in the isoprenoid pathway and its metabolites digoxin, dolichol, and ubiquinone in multiple myeloma. The isoprenoid pathway and digoxin status were also studied for comparison in individuals of differing hemispheric dominance to find out the rote of cerebral dominance in the genesis of multiple myeloma and neoplasms. The following parameters were assessed: isoprenoid pathway metabolites, tyrosine and tryptophan catabolites, glycoconjugate metabolism, RBC membrane composition, and free radical metabolism--in multiple myeloma, as well as in individuals of differing hemispheric dominance. There was elevation in plasma HMG CoA reductase activity, serum digoxin, and dolichol, and a reduction in RBC membrane Na(+)-K+ ATPase activity, serum ubiquinone, and magnesium levels. Serum tryptophan, serotonin, nicotine, strychnine, and quinolinic acid were elevated, while tyrosine, dopamine, noradrenaline, and morphine were decreased. The total serum glycosaminoglycans and glycosaminoglycan fractions, the activity of GAG degrading enzymes and glycohydrolases, carbohydrate residues of glycoproteins, and serum glycolipids were elevated. The RBC membrane glycosaminoglycans, hexose, and fucose residues of glycoproteins, cholesterol, and phospholipids were reduced. The activity of all free-radical scavenging enzymes, concentration of glutathione, iron binding capacity, and ceruloplasmin decreased significantly, while the concentration of lipid peroxidation products and nitric oxide increased. Hyperdigoxinemia-related altered intracellular Ca++/Mg++ ratios mediated oncogene activation, dolichol-induced altered glycoconjugate metabolism, and ubiquinone deficiency-related mitochondrial dysfunction can contribute to the pathogenesis of multiple myeloma. The biochemical patterns obtained in multiple myeloma are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. But all the patients with

  9. Hemispheric Asymmetries in the Activation and Monitoring of Memory Errors

    Science.gov (United States)

    Giammattei, Jeannette; Arndt, Jason

    2012-01-01

    Previous research on the lateralization of memory errors suggests that the right hemisphere's tendency to produce more memory errors than the left hemisphere reflects hemispheric differences in semantic activation. However, all prior research that has examined the lateralization of memory errors has used self-paced recognition judgments. Because…

  10. The Influence of Context on Hemispheric Recruitment during Metaphor Processing

    Science.gov (United States)

    Diaz, Michele T.; Hogstrom, Larson J.

    2011-01-01

    Although the left hemisphere's prominence in language is well established, less emphasis has been placed on possible roles for the right hemisphere. Behavioral, patient, and neuroimaging research suggests that the right hemisphere may be involved in processing figurative language. Additionally, research has demonstrated that context can modify…

  11. Hypothalamic digoxin, hemispheric chemical dominance, and eating behavior.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-08-01

    The isoprenoid pathway produces an endogenous membrane Na+-K+ ATPase inhibitor, digoxin, which can regulate neurotransmitter and amino acid transport. Digoxin synthesis and neurotransmitter patterns were assessed in eating disorders. The patterns were compared in those with right hemispheric and left hemispheric dominance. The serum HMG CoA reductase activity, RBC membrane Na+-K+ ATPase activity, serum digoxin, magnesium, tryptophan catabolites (serotonin, quinolinic acid, strychnine, and nicotine), and tyrosine catabolites (morphine, dopamine, and noradrenaline) were measured in anorexia nervosa, bulimia nervosa, right hemispheric dominant, left hemispheric dominant, and bihemispheric dominant individuals. Digoxin synthesis was increased with upregulated tryptophan catabolism and downregulated tyrosine catabolism in those with anorexia nervosa and right hemispheric chemical dominance. Digoxin synthesis was reduced with downregulated tryptophan catabolism and upregulated tyrosine catabolism in those with bulimia nervosa and left hemispheric chemical dominance. The membrane Na+-K+ ATPase activity and serum magnesium were decreased in anorexia nervosa and right hemispheric chemical dominance while they were increased in bulimia nervosa and left hemispheric chemical dominance. Hypothalamic digoxin and hemispheric chemical dominance play a central role in the regulation of eating behavior. Anorexia nervosa represents the right hemispheric chemically dominant/hyperdigoxinemic state and bulimia nervosa the left hemispheric chemically dominant/hypodigoxinemic state.

  12. Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

    Science.gov (United States)

    Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

    2012-08-01

    To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

  13. Atypical category processing and hemispheric asymmetries in high-functioning children with autism: revealed through high-density EEG mapping.

    Science.gov (United States)

    Fiebelkorn, Ian C; Foxe, John J; McCourt, Mark E; Dumas, Kristina N; Molholm, Sophie

    2013-05-01

    Behavioral evidence for an impaired ability to group objects based on similar physical or semantic properties in autism spectrum disorders (ASD) has been mixed. Here, we recorded brain activity from high-functioning children with ASD as they completed a visual-target detection task. We then assessed the extent to which object-based selective attention automatically generalized from targets to non-target exemplars from the same well-known object class (e.g., dogs). Our results provide clear electrophysiological evidence that children with ASD (N=17, aged 8-13 years) process the similarity between targets (e.g., a specific dog) and same-category non-targets (SCNT) (e.g., another dog) to a lesser extent than do their typically developing (TD) peers (N=21). A closer examination of the data revealed striking hemispheric asymmetries that were specific to the ASD group. These findings align with mounting evidence in the autism literature of anatomic underconnectivity between the cerebral hemispheres. Years of research in individuals with TD have demonstrated that the left hemisphere (LH) is specialized toward processing local (or featural) stimulus properties and the right hemisphere (RH) toward processing global (or configural) stimulus properties. We therefore propose a model where a lack of communication between the hemispheres in ASD, combined with typical hemispheric specialization, is a root cause for impaired categorization and the oft-observed bias to process local over global stimulus properties. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects)

    International Nuclear Information System (INIS)

    Lechevalier, B.; Petit, M.C.; Eustache, F.; Lambert, J.; Chapon, F.; Viader, F.

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation

  15. Immunological functioning in Alzheimer's disease: differential effects of relative left versus right temporoparietal dysfunction.

    Science.gov (United States)

    Foster, Paul S; Roosa, Katelyn M; Williams, Megan R; Witt, John C; Heilman, Kenneth M; Drago, Valeria

    2013-10-15

    The cerebral hemispheres are differentially involved in regulating immunological functioning and the neuropathology associated with Alzheimer's disease (AD) is asymmetrical. Thus, subgroups of AD patients may exhibit different patterns of immunological dysfunction. We explored this possibility in a group of AD patients and found that patients with low white blood cell counts and low lymphocyte numbers exhibited better performance on tests of right temporoparietal functioning. Also, a significant positive relationship exists between lymph numbers and performance on a test of left temporoparietal functioning. Thus, some AD patients have greater immunological dysfunction based on relative left versus right temporoparietal functioning. © 2013.

  16. Hypothalamic digoxin and hemispheric chemical dominance: relation to alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-08-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin (modulate tryptophan/tyrosine transport), dolichol (important in N -glycosylation of proteins), and ubiquinone (free radical scavenger). It was considered pertinent to assess the pathway in alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration. Since endogenous digoxin can regulate neurotransmitter transport, the pathway was also assessed in individuals with differing hemispheric dominance to find out the role of hemispheric dominance in its pathogenesis. In the patient group there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites as reduced endogenous morphine synthesis from tyrosine. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these groups of patients. The same patterns were obtained in individuals with right hemispheric chemical dominance. Alcoholic cirrhosis, alcoholic addiction, and acquired hepatocerebral degeneration are associated with an upregulated isoprenoid pathway and elevated digoxin secretion from the hypothalamus. This can contribute to NMDA excitotoxicity and altered connective tissue/lipid metabolism important in its pathogenesis. Endogenous morphine deficiency plays a role in alcoholic addiction. Alcoholic cirrhosis, addiction, and acquired hepato -cerebral degeneration occur in right hemispheric chemically dominant individuals. Ninety percent of the patients with alcoholic addiction, alcoholic cirrhosis, and acquired hepatocerebral degeneration were right-handed and left hemispheric dominant by the dichotic listening test. However, their biochemical patterns were similar to those obtained in right hemispheric chemical dominance. Hemispheric chemical dominance is a different entity and has no correlation

  17. Effects of smoking on regional cerebral blood flow in cerebral vascular disease patients and normal subjects

    International Nuclear Information System (INIS)

    Kubota, Kazuo; Yamaguchi, Tatsuo; Fujiwara, Takehiko; Matsuzawa, Taiju

    1987-01-01

    The chronic effect of smoking on the regional cerebral blood flow (r-CBF) was studied by 133-Xenon inhalation method and described with the Initial Slope Index (ISI). Fifty-two patients as the control group who had no abnormality neurologically or with CT scan, 32 patients with old cerebral infarction and 20 patients with old cerebral hemorrhage were introduced to the present study, and these patients were divided into smokers and non-smokers in each group. Those whose smoking index of 200 or more [(number of cigarettes/day) x (years of smoking history) ≥ 200] were designated as smokers. ISI values were decreased significantly in smokers than non-smokers in all groups. Mean ISI value of unaffected hemisphere in smokers decreased by 16 % in the infarction group and 22 % in the hemorrhage group comparing to the non-smokers', respectively. In the control group, mean ISI value of right hemisphere decreased by 15 % and left 14 % in smokers compared to the non-smokers. The r-CBF values in 44 of the 47 smokers were found to be lower than the expected age matched values in non-smokers. Serum high density lipoprotein cholesterol value in smokers was significantly lower than that in non-smokers. We demonstrated preliminarily that the smoking chronically reduced the r-CBF. Advanced atherosclerosis associated with the smoker was suggested to affect the CBF. (author)

  18. A case of diffuse hemispheric gyral high density on CT scan following acute subdural hematoma in children

    International Nuclear Information System (INIS)

    Kannuki, Seiji; Oi, Shizuo

    1986-01-01

    A case of diffuse hemispheric gyral high density area following acute subdural hematoma was reported. A 2 - 10/12 year-old male was admitted to our hospital in comatous state after head injury by fall. Neurological examination revealed deep coma with anisocoria (R < L), absence of light reflex and positive bilateral Babinski reflex. CT scan disclosed left acute subdural hematoma with remarkable midline shift and tentorial herniation sign. Emergency decompressive craniectomy was performed. Posttraumatic hydrocephalus appeared after 10 days. So, ventriculoperitoneal shunt was done. The patient became gradually improved, but was in appalic state. 23 days after craniectomy, suddenly diffuse hemispheric gyral high density appeared on plain CT scan. In spite of this change, no clinical change was found. This high density spontaneously disappeared 10 days after appearance. Cerebral infarction-like phenomenon on postoperative CT scan of acute subdural hematoma in infants was sometimes reported. This phenomenon was sometimes accompanied with hemorrhagic infarction-like high density on CT scan. Diffuse hemispheric gyral high density was probably a kind of those hemorrhagic infarction-like phenomenon. Possible mechanism of this peculiar high density is discussed on the basis of characteristics of child's cerebral artery and pathophysiology of cerebral infarction. (author)

  19. The Joint Development of Hemispheric Lateralization for Words and Faces

    Science.gov (United States)

    Dundas, Eva M.; Plaut, David C.; Behrmann, Marlene

    2013-01-01

    Consistent with long-standing findings from behavioral studies, neuroimaging investigations have identified a region of the inferior temporal cortex that, in adults, shows greater face selectivity in the right than left hemisphere and, conversely, a region that shows greater word selectivity in the left than right hemisphere. What has not been…

  20. Cerebral and Renal Oxygen Saturation Are Not Compromised in the Presence of Retrograde Blood Flow in either the Ascending or Descending Aorta in Term or Near-Term Infants with Left-Sided Obstructive Lesions.

    Science.gov (United States)

    van der Laan, Michelle E; Mebius, Mirthe J; Roofthooft, Marcus T R; Bos, Arend F; Berger, Rolf M F; Kooi, Elisabeth M W

    2017-01-01

    In infants with left-sided obstructive lesions (LSOL), the presence of retrograde blood flow in either the ascending or descending aorta may lead to diminished cerebral and renal blood flow, respectively. Our aim was to compare cerebral and renal tissue oxygen saturation (rSO2) between infants with LSOL with antegrade and retrograde blood flow in the ascending aorta and with and without diastolic backflow in the descending aorta. Based on 2 echocardiograms, the study group was categorized according to the direction of blood flow in the ascending and descending aorta. We measured cerebral and renal rSO2 using near-infrared spectroscopy and calculated fractional tissue oxygen extraction (FTOE). Nineteen infants with LSOL, admitted to the NICU between 0 and 28 days after birth, were included. Infants with antegrade blood flow (n = 12) and infants with retrograde blood flow in the ascending aorta (n = 7) had similar cerebral rSO2 and FTOE during both echocardiograms. Only during the first echocardiogram, infants with retrograde blood flow in the ascending aorta had lower renal FTOE (0.14 vs. 0.32, p = 0.04) and tended to have higher renal rSO2 (80 vs. 65%, p = 0.09). The presence of diastolic backflow in the descending aorta was not associated with cerebral or renal rSO2 and FTOE during the first (n = 8) as well as the second echocardiogram (n = 10). Retrograde blood flow in the ascending aorta was not associated with cerebral oxygenation, while diastolic backflow in the descending aorta was not associated with renal oxygenation in infants with LSOL. © 2017 S. Karger AG, Basel.

  1. Regional cerebral blood flow in schizophrenics

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, J.; Ohta, Y.; Nakane, Y.; Mori, H.; Hirota, N.; Yonekura, M.

    1987-01-01

    The present study on schizophrenics dealt with the relationship of regional cerebral blood flow (rCBF) to age, disease duration, and treatment length with chlorpromazine hydrochloride (CPZ). Regional cerebral blood flow in 28 cerebral regions of interest was measured by iv injection of /sup 133/X in 54 schizophrenic patients and 39 healthy volunteers. Neither age nor dosage of CPZ significantly influenced rCBF. All patients, including 11 treated for a short period of time (6 months or less), were characterized by having a decreased rCBF over the whole cerebrum. Thirty-four patients treated for a long period of time (2 years or more) had a varied rCBF distribution in the left hemisphere, with the most predominant feature being the decrease in rCBF in the frontal lobe (i.e., hypofrontality); however, there was no linear correlation between rCBF and disease duration. A decreased rCBE in the right occipital region was seen in patients with paranoid schizophrenia, suggesting that manifestations of symptoms may depend on disturbed regions. These results suggest that cerebral dysfunction in schizophrenic patients may not be restricted to the frontal lobe, but cover the whole cerebrum, and that nonuniform dysfunction in various regions of the cerebrum, including the frontal lobe, may be involved in manifestations of symptoms.

  2. Regional cerebral blood flow in schizophrenics

    International Nuclear Information System (INIS)

    Uchino, Jun; Ohta, Yasuyuki; Nakane, Yoshibumi; Mori, Hiroyuki; Hirota, Noriyoshi; Yonekura, Masahiro.

    1987-01-01

    The present study on schizophrenics dealt with the relationship of regional cerebral blood flow (rCBF) to age, disease duration, and treatment length with chlorpromazine hydrochloride (CPZ). Regional cerebral blood flow in 28 cerebral regions of interest was measured by iv injection of X-133 in 54 schizophrenic patients and 39 healthy volunteers. Neither age nor dosage of CPZ significantly influenced rCBF. All patients, including 11 treated for a short period of time (6 months or less), were characterized by having a decreased rCBF over the whole cerebrum. Thirty-four patients treated for a long period of time (2 years or more) had a varied rCBF distribution in the left hemisphere, with the most predominant feature being the decrease in rCBF in the frontal lobe (i.e., ''hypofrontality''); however, there was no linear correlation between rCBF and disease duration. A decreased rCBE in the right occipital region was seen in patients with paranoid schizophrenia, suggesting that manifestations of symptoms may depend on disturbed regions. These results suggest that cerebral dysfunction in schizophrenic patients may not be restricted to the frontal lobe, but cover the whole cerebrum, and that nonuniform dysfunction in various regions of the cerebrum, including the frontal lobe, may be involved in manifestations of symptoms. (Namekawa, K.)

  3. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation

    OpenAIRE

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-01-01

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel coun...

  4. Hypothalamic digoxin, hemispheric chemical dominance and sarcoidosis.

    Science.gov (United States)

    Ravi Kumar, A; Kurup, Parameswara Achutha

    2004-06-01

    The isoprenoid pathway produces three key metabolites: endogenous digoxin (membrane sodium-potassium ATPase inhibitor, immunomodulator and regulator of neurotransmitter/amino acid transport), dolichol (regulates N-glycosylation of proteins) and ubiquinone (free radical scavenger). The role of the isoprenoid pathway in the pathogenesis of sarcoidosis in relation to hemispheric dominance was studied. The isoprenoid pathway-related cascade was assessed in patients with systemic sarcoidosis with pulmonary involvement. The pathway was also assessed in patients with right hemispheric, left hemispheric and bihemispheric dominance for comparison to find out the role of hemispheric dominance in the pathogenesis of sarcoidosis. In patients with sarcoidosis there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in the cholesterol:phospholipid ratio and a reduction in the glycoconjugate level of red blood cell (RBC) membrane in this group of patients. The same biochemical patterns were obtained in individuals with right hemispheric dominance. In individuals with left hemispheric dominance the patterns were reversed. Endogenous digoxin, by activating the calcineurin signal transduction pathway of T cells, can contribute to immune activation in sarcoidosis. An altered glycoconjugate metabolism can lead to the generation of endogenous self-glycoprotein antigens in the lung as well as other tissues. Increased free radical generation can also lead to immune activation. The role of a dysfunctional isoprenoid pathway and endogenous digoxin in the pathogenesis of sarcoidosis in relation to right hemispheric chemical dominance is discussed. All the patients with sarcoidosis were right-handed/left hemispheric dominant according to the dichotic listening test, but their biochemical patterns

  5. Modulating transcallosal and intra-hemispheric brain connectivity with tDCS: Implications for interventions in Aphasia.

    Science.gov (United States)

    Zheng, Xin; Dai, Weiying; Alsop, David C; Schlaug, Gottfried

    2016-07-25

    Transcranial direct current stimulation (tDCS) can enhance or diminish cortical excitability levels depending on the polarity of the stimulation. One application of non-invasive brain-stimulation has been to modulate a possible inter-hemispheric disinhibition after a stroke. This disinhibition model has been developed mainly for the upper extremity motor system, but it is not known whether the language/speech-motor system shows a similar inter-hemispheric interaction. We aimed to examine physiological evidence of inter- and intra-hemispheric connectivity changes induced by tDCS of the right inferior frontal gyrus (IFG) using arterial-spin labeling (ASL) MRI. Using an MR-compatible DC-Stimulator, we applied anodal stimulation to the right IFG region of nine healthy adults while undergoing non-invasive cerebral blood flow imaging with arterial-spin labeling (ASL) before, during, and after the stimulation. All ASL images were then normalized and timecourses were extracted in regions of interest (ROIs), which were the left and right IFG regions, and the right supramarginal gyrus (SMG) in the inferior parietal lobule. Two additional ROIs (the right occipital lobe and the left fronto-orbital region) were taken as control regions. Using regional correlation coefficients as a surrogate marker of connectivity, we could show that inter-hemispheric connectivity (right IFG with left IFG) decreased significantly (p < 0.05; r-scores from 0.67 to 0.53) between baseline and post-stimulation, while the intra-hemispheric connectivity (right IFG with right SMG) increased significantly (p < 0.05;r-scores from 0.74 to 0.81). A 2 × 2 ANOVA found a significant main effect of HEMISPHERE (F(8) = 6.83, p < 0.01) and a significant HEMISPHERE-by-TIME interaction (F(8) = 4.24, p < 0.05) in connectivity changes. The correlation scores did not change significantly in the control region pairs (right IFG with right occipital and right IFG with left fronto-orbital) over

  6. Regional cerebral blood flow in schizophrenia

    International Nuclear Information System (INIS)

    Kanoh, Masayuki

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured at rest using the 133 Xe inhalation technique in 40 DSM-III-diagnosed schizophrenics (22 males, 18 females: mean age 35.0 years, range 20-49 years) and 31 age-and sex-matched normal controls (16 males, 15 females: mean age 34.3 years, range 21-49 years). The absolute value (AV) and the percent value (PV) of the rCBF in schizophrenics were compared with those in controls. Correlations between rCBF and the Brief Psychiatric Rating Scale (BPRS) scores or the performance of Wisconsin Card Sorting Test (WCST) were examined in schizophrenics. Schizophrenics showed significantly lower AVs in all brain regions examined and a significantly lower PV in the left superior frontal region than controls. The hyperfrontal rCBF distribution which was found in both hemispheres in controls, was absent in the left hemisphere in schizophrenics. In schizophrenics, superior frontal blood flows were significantly negatively correlated with the negative symptom scores of the BPRS but not with the total scores and the positive symptom scores of the BPRS. In schizophrenics, inferior frontal blood flows were significantly correlated with the number of sorting categories achieved. These results indicate that rCBF in schizophrenia is reduced in the whole brain and especially in the left superior frontal region. These findings suggest a frontal lobe dysfunction in schizophrenia. (author)

  7. White-matter microstructure and language lateralization in left-handers: a whole-brain MRI analysis.

    Science.gov (United States)

    Perlaki, Gabor; Horvath, Reka; Orsi, Gergely; Aradi, Mihaly; Auer, Tibor; Varga, Eszter; Kantor, Gyongyi; Altbäcker, Anna; John, Flora; Doczi, Tamas; Komoly, Samuel; Kovacs, Norbert; Schwarcz, Attila; Janszky, Jozsef

    2013-08-01

    Most people are left-hemisphere dominant for language. However the neuroanatomy of language lateralization is not fully understood. By combining functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), we studied whether language lateralization is associated with cerebral white-matter (WM) microstructure. Sixteen healthy, left-handed women aged 20-25 were included in the study. Left-handers were targeted in order to increase the chances of involving subjects with atypical language lateralization. Language lateralization was determined by fMRI using a verbal fluency paradigm. Tract-based spatial statistics analysis of DTI data was applied to test for WM microstructural correlates of language lateralization across the whole brain. Fractional anisotropy and mean diffusivity were used as indicators of WM microstructural organization. Right-hemispheric language dominance was associated with reduced microstructural integrity of the left superior longitudinal fasciculus and left-sided parietal lobe WM. In left-handed women, reduced integrity of the left-sided language related tracts may be closely linked to the development of right hemispheric language dominance. Our results may offer new insights into language lateralization and structure-function relationships in human language system. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Hemispheric resource limitations in comprehending ambiguous pictures.

    Science.gov (United States)

    White, H; Minor, S W

    1990-03-01

    Ambiguous pictures (Roschach inkblots) were lateralized for 100 msec vs. 200 msec to the right and left hemispheres (RH and LH) of 32 normal right-handed males who determined which of two previously presented words (an accurate or inaccurate one) better described the inkblot. Over the first 32 trials, subjects receiving each stimulus exposure duration were less accurate when the hemisphere receiving the stimulus also controlled the hand used to register a keypress response (RH-left hand and LH-right hand trials) than when hemispheric resources were shared, i.e., when one hemisphere controlled stimulus processing and the other controlled response programming. These differences were eliminated when the 32 trials were repeated.

  9. Study of cerebral vascular diseases with radioisotopes in cerebral atherosclerotical subjects and/for subjects with sequelae of cerebral stroke, before and after use of the association piracetam-dihydroergotoxine

    International Nuclear Information System (INIS)

    Lara, P.F.; Ferreira, A.; Paulillo, L.F.; Cukierman, M.

    1985-01-01

    Twently subjects with cerebral sclerosis and/or sequelas of cerebral stroke were studied, before and after use of piracetam-dihydroergotoxine. We performed the complete hemispheric cerebral blood flow and cerebral scintigraphy, beyond clinical and neurological examination. Scintigraphies were unchanged. Cerebral circulation times, or both hemispheres, diminished. This occurred, probably, in relation with metabolic effects of both pharmaceutical drugs. The alpha sympatolytic and modulatory effects of dihydroergotoxine should be considered. (author) [pt

  10. Right hemisphere control of visuospatial attention in near space.

    Science.gov (United States)

    Longo, Matthew R; Trippier, Sarah; Vagnoni, Eleonora; Lourenco, Stella F

    2015-04-01

    Traditionally, the right cerebral hemisphere has been considered to be specialized for spatial attention and orienting. A large body of research has demonstrated dissociable representations of the near space immediately surrounding the body and the more distance far space. In this study, we investigated whether right hemisphere activations commonly reported for tasks involving spatial attention (such as the line bisection and landmark tasks) are specific to stimuli presented in near space. In separate blocks of trials, participants judged either whether a vertical transector was to the left or right of the centre of a line (landmark task) or whether the line was red or blue (colour task). Stimuli were seen from four distances (30, 60, 90, 120 cm). We used EEG to measure an ERP component (the 'line-bisection effect') specific to the direction of spatial attention (i.e., landmark minus colour). Consistent with previous results, spatial attention produced a right-lateralized negativity over occipito-parietal channels. The magnitude of this negativity was inversely related to viewing distance, being largest in near space and reduced in far space. These results suggest that the right occipito-temporal cortex may be specialized not just for the orientation of spatial attention generally, but specifically for orienting attention in the near space immediately surrounding the body. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Change in drawing placement: A measure of change in mood state reflective of hemispheric lateralization of emotion.

    Science.gov (United States)

    Butler, Tracy R; O'Mara, Erin M; Wilson, Josephine F

    2018-04-26

    The Valence Hypothesis of cerebral lateralization of emotion suggests greater right hemisphere activation during negative mood and greater left hemisphere activation during positive mood. This can manifest as visual field attentional bias. Here, study participants completed an assessment of current mood state (PANAS) and made a drawing (Drawing 1). To induce positive or negative mood, participants played a game; then, the winner read a script depicting a positive interpersonal interaction and the loser read a script depicting a negative interpersonal interaction. Participants then drew a second picture (Drawing 2) and completed the PANAS. We hypothesized that the game outcome would change current mood state and hemispheric activation, which would be reflected in drawing placement. The placement of Drawing 2 moved right for winners and left for losers. Winners experienced a greater increase in positive affect from Time 1 to Time 2 than losers and had decreased negative affect from Time 1. Losers had decreased positive affect from Time 1 and had a greater increase in negative affect from Time 1 to Time 2 than winners. Our results suggest that change in current mood state may be objectively observed by evaluating hemispatial bias reflective of brain hemispheric activation with drawings. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Specialization of the left supramarginal gyrus for hand-independent praxis representation is not related to hand dominance

    Science.gov (United States)

    Króliczak, Gregory; Piper, Brian J.; Frey, Scott H.

    2016-01-01

    Data from focal brain injury and functional neuroimaging studies implicate a distributed network of parieto-fronto-temporal areas in the human left cerebral hemisphere as playing distinct roles in the representation of meaningful actions (praxis). Because these data come primarily from right-handed individuals, the relationship between left cerebral specialization for praxis representation and hand dominance remains unclear. We used functional magnetic resonance imaging (fMRI) to evaluate the hypothesis that strongly left-handed (right hemisphere motor dominant) adults also exhibit this left cerebral specialization. Participants planned familiar actions for subsequent performance with the left or right hand in response to transitive (e.g., “pounding”) or intransitive (e.g. “waving”) action words. In linguistic control trials, cues denoted non-physical actions (e.g., “believing”). Action planning was associated with significant, exclusively left-lateralized and extensive increases of activity in the supramarginal gyrus (SMg), and more focal modulations in the left caudal middle temporal gyrus (cMTg). This activity was hand- and gesture-independent, i.e., unaffected by the hand involved in subsequent action performance, and the type of gesture (i.e., transitive or intransitive). Compared directly with right-handers, left-handers exhibited greater involvement of the right angular gyrus (ANg) and dorsal premotor cortex (dPMC), which is indicative of a less asymmetric functional architecture for praxis representation. We therefore conclude that the organization of mechanisms involved in planning familiar actions is influenced by one’s motor dominance. However, independent of hand dominance, the left SMg and cMTg are specialized for ideomotor transformations—the integration of conceptual knowledge and motor representations into meaningful actions. These findings support the view that higher-order praxis representation and lower-level motor dominance rely

  13. Brain State-dependent Functional Hemispheric Specialization in Men but not in Women

    OpenAIRE

    Mohr, Christine; Michel, Christoph M.; Lantz, Goran; Ortigue, Stephanie; Viaud-Delmon, Isabelle; Landis, Theodor

    2017-01-01

    Hemispheric specialization is reliably demonstrated in patients with unilateral lesions or disconnected hemispheres, but is inconsistent in healthy populations. The reason for this paradox is unclear. We propose that functional hemispheric specialization in healthy participants depends upon functional brain states at stimulus arrival (FBS). Brain activity was recorded from 123 surface electrodes while 22 participants (11 women) performed lateralized lexical decisions (left hemisphere processi...

  14. Relations between neuropsychological findings and lateral asymmetries of cerebral blood flow measured by SPECT in dementia of Alzheimer type

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Nahoko; Soma, Yoshiaki; Ootsuki, Mika [Takeda General Hospital, Aizu-Wakamatsu, Fukushima (Japan)

    1993-10-01

    We studied 16 right-handed patients clinically diagnosed as dementia of Alzheimer type (6 men, 10 women; aged 63-85, mean 72.8 years). The average duration of symptoms was 2.7 years. Dementia ranged from mild to moderately severe. None had clinical or laboratory evidence of cerebrovascular disease (Hachinski ischemic scores for all patients were 4 or below 4). All received the Wechsler Adult Intelligence Scale (WAIS), Mini-mental State Test (MMS) and Western Aphasia Battery (WAB, First Japanese edition, 1986). Regional cerebral blood flow (rCBF) was evaluated by single photon emission CT (SPECT) with {sup 123}I-N-isopropyl-p-iodoamphetamine ({sup 123}I-IMP), using the Matsuda`s quantitative method. Regional tracer uptake was measured in regions of interests (ROIs) over right and left frontal, temporal, parietal and occipital cortical regions; basal ganglia; and cerebellar hemispheres. The subjects were divided into three groups on the basis of lateral asymmetries in the temporal and parietal cortexes of rCBF (leftleft, n=3; left=right, n=8). We decided that lateral asymmetry was present when rCBF for each ROI between left and right sides differs by more than 10%. General score (MMS, T-IQ) was not correlated with asymmetry of cerebral blood flow. Verbal IQ in patients with predominant hypoperfusion of left temporal and parietal lobe was significantly lower than other group, while performance IQ and WAB constructive scores were lower in those with right hemispheric hypoperfusion (p<0.05). We concluded that cerebral blood flow asymmetry by SPECT was related significantly to the deficit of language and constructive function in patients with dementia of Alzheimer type. Decreased rCBF in the left temporoparietal lobe was associated with language dysfunction, and that in the right hemisphere, with constructive dysfunction. (author).

  15. Relations between neuropsychological findings and lateral asymmetries of cerebral blood flow measured by SPECT in dementia of Alzheimer type

    International Nuclear Information System (INIS)

    Yoshimura, Nahoko; Soma, Yoshiaki; Ootsuki, Mika

    1993-01-01

    We studied 16 right-handed patients clinically diagnosed as dementia of Alzheimer type (6 men, 10 women; aged 63-85, mean 72.8 years). The average duration of symptoms was 2.7 years. Dementia ranged from mild to moderately severe. None had clinical or laboratory evidence of cerebrovascular disease (Hachinski ischemic scores for all patients were 4 or below 4). All received the Wechsler Adult Intelligence Scale (WAIS), Mini-mental State Test (MMS) and Western Aphasia Battery (WAB, First Japanese edition, 1986). Regional cerebral blood flow (rCBF) was evaluated by single photon emission CT (SPECT) with 123 I-N-isopropyl-p-iodoamphetamine ( 123 I-IMP), using the Matsuda's quantitative method. Regional tracer uptake was measured in regions of interests (ROIs) over right and left frontal, temporal, parietal and occipital cortical regions; basal ganglia; and cerebellar hemispheres. The subjects were divided into three groups on the basis of lateral asymmetries in the temporal and parietal cortexes of rCBF (left< right, n=5; right< left, n=3; left=right, n=8). We decided that lateral asymmetry was present when rCBF for each ROI between left and right sides differs by more than 10%. General score (MMS, T-IQ) was not correlated with asymmetry of cerebral blood flow. Verbal IQ in patients with predominant hypoperfusion of left temporal and parietal lobe was significantly lower than other group, while performance IQ and WAB constructive scores were lower in those with right hemispheric hypoperfusion (p<0.05). We concluded that cerebral blood flow asymmetry by SPECT was related significantly to the deficit of language and constructive function in patients with dementia of Alzheimer type. Decreased rCBF in the left temporoparietal lobe was associated with language dysfunction, and that in the right hemisphere, with constructive dysfunction. (author)

  16. Benzodiazepine receptor imaging with iomazenil SPECT in aphasic patients with cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Koshi, Yasuhiko; Kitamura, Shin; Ohyama, Masashi [Nippon Medical School, Tokyo (Japan)] (and others)

    1999-08-01

    To investigate the relationship between prognosis of aphasia and neuronal damage in the cerebral cortex, we evaluated the distribution of central-type benzodiazepine receptor (BZR) binding in post-stroke aphasics with [{sup 123}I]iomazenil and SPECT. We performed iomazenil SPECT in six aphasic patients (aged from 45 to 75 years; all right-handed) with unilateral left cerebral infarction. Three patients showed signs of Broca's aphasia and the other three Wernicke's aphasia. Cerebral blood flow (CBF) imaging was performed with [{sup 123}I]iodoamphetamine (IMP). The regions of interest (ROIs) on both images were set in the cerebral cortex, cerebellar cortex and language relevant area in both hemispheres. Three patients were classified in the mild prognosis group and the other three in the moderate prognosis group. The left language-relevant area was more closely concerned with the difference in aphasic symptoms than the right one in both BZR and CBF distribution, but the ipsilateral to the contralateral ratio (I/C ratio) in the language-relevant areas in the BZR distribution was significantly lower in the moderate prognosis group than in the mild prognosis group, although no difference was seen for these values between the two groups in the CBF distribution. These results suggest that BZR imaging, which makes possible an increase in neuronal cell viability in the cerebral cortex, is useful not only for clarifying the aphasic symptoms but also for evaluating the prognosis of aphasia in patients with cerebral infarction. (author)

  17. Benzodiazepine receptor imaging with iomazenil SPECT in aphasic patients with cerebral infarction

    International Nuclear Information System (INIS)

    Koshi, Yasuhiko; Kitamura, Shin; Ohyama, Masashi

    1999-01-01

    To investigate the relationship between prognosis of aphasia and neuronal damage in the cerebral cortex, we evaluated the distribution of central-type benzodiazepine receptor (BZR) binding in post-stroke aphasics with [ 123 I]iomazenil and SPECT. We performed iomazenil SPECT in six aphasic patients (aged from 45 to 75 years; all right-handed) with unilateral left cerebral infarction. Three patients showed signs of Broca's aphasia and the other three Wernicke's aphasia. Cerebral blood flow (CBF) imaging was performed with [ 123 I]iodoamphetamine (IMP). The regions of interest (ROIs) on both images were set in the cerebral cortex, cerebellar cortex and language relevant area in both hemispheres. Three patients were classified in the mild prognosis group and the other three in the moderate prognosis group. The left language-relevant area was more closely concerned with the difference in aphasic symptoms than the right one in both BZR and CBF distribution, but the ipsilateral to the contralateral ratio (I/C ratio) in the language-relevant areas in the BZR distribution was significantly lower in the moderate prognosis group than in the mild prognosis group, although no difference was seen for these values between the two groups in the CBF distribution. These results suggest that BZR imaging, which makes possible an increase in neuronal cell viability in the cerebral cortex, is useful not only for clarifying the aphasic symptoms but also for evaluating the prognosis of aphasia in patients with cerebral infarction. (author)

  18. Delusional misidentifications and duplications: right brain lesions, left brain delusions.

    Science.gov (United States)

    Devinsky, Orrin

    2009-01-06

    When the delusional misidentification syndromes reduplicative paramnesia and Capgras syndromes result from neurologic disease, lesions are usually bifrontal and/or right hemispheric. The related disorders of confabulation and anosognosis share overlapping mechanisms and anatomic pathology. A dual mechanism is postulated for the delusional misidentification syndromes: negative effects from right hemisphere and frontal lobe dysfunction as well as positive effects from release (i.e., overactivity) of preserved left hemisphere areas. Negative effects of right hemisphere injury impair self-monitoring, ego boundaries, and attaching emotional valence and familiarity to stimuli. The unchecked left hemisphere unleashes a creative narrator from the monitoring of self, memory, and reality by the frontal and right hemisphere areas, leading to excessive and false explanations. Further, the left hemisphere's cognitive style of categorization, often into dual categories, leads it to invent a duplicate or impostor to resolve conflicting information. Delusions result from right hemisphere lesions. But it is the left hemisphere that is deluded.

  19. Imaging network level language recovery after left PCA stroke.

    Science.gov (United States)

    Sebastian, Rajani; Long, Charltien; Purcell, Jeremy J; Faria, Andreia V; Lindquist, Martin; Jarso, Samson; Race, David; Davis, Cameron; Posner, Joseph; Wright, Amy; Hillis, Argye E

    2016-05-11

    The neural mechanisms that support aphasia recovery are not yet fully understood. Our goal was to evaluate longitudinal changes in naming recovery in participants with posterior cerebral artery (PCA) stroke using a case-by-case analysis. Using task based and resting state functional magnetic resonance imaging (fMRI) and detailed language testing, we longitudinally studied the recovery of the naming network in four participants with PCA stroke with naming deficits at the acute (0 week), sub acute (3-5 weeks), and chronic time point (5-7 months) post stroke. Behavioral and imaging analyses (task related and resting state functional connectivity) were carried out to elucidate longitudinal changes in naming recovery. Behavioral and imaging analysis revealed that an improvement in naming accuracy from the acute to the chronic stage was reflected by increased connectivity within and between left and right hemisphere "language" regions. One participant who had persistent moderate naming deficit showed weak and decreasing connectivity longitudinally within and between left and right hemisphere language regions. These findings emphasize a network view of aphasia recovery, and show that the degree of inter- and intra- hemispheric balance between the language-specific regions is necessary for optimal recovery of naming, at least in participants with PCA stroke.

  20. Treatment of Pusher Syndrome in a patient after extensive cerebral infarction caused by cerebral embolism - case report

    Directory of Open Access Journals (Sweden)

    Piotr Porzych

    2017-08-01

    Full Text Available Pusher Syndrome is defined as a disorder of perception of body orientation in the frontal plane. It is mainly observed in patients after stroke in consequence to damage to the right or left hemisphere of the brain. Characteristic clinical symptoms in people affected by this syndrome are leaning towards the paralyzed side of the body and building massive resistance during passive correction. The consequence of such behavior are falls in the direction of the affected side. The paper presents the case of a patient who, after extensive right hemisphere cerebral hemorrhage, was admitted to the Chair and Department of Rehabilitation Medicine of the Dr Antoni Jurasz University Hospital No.1 in Bydgoszcz to improve. During treatment the patient was used the neurorehabilitation based on the Bobath concept.

  1. EFFECT OF ACUPUNCTURE ON CEREBRAL IMAGES IN AUTISM CHILDREN

    Institute of Scientific and Technical Information of China (English)

    袁青; 马瑞玲; 张继武; 靳瑞

    2004-01-01

    Objective: To observe the effect of acupuncture on images in autism children. Methods: A total of 27 cases of autism children were subjected into this study. By using a SPECT, the cerebral images were collected before and after acupuncture treatment and analyzed according to the recommended methods in for assessing the state of blood flow, radioactivity quantity distribution and radioactivity count in bilateral hemispheres. "JIN's three-needling" was employed. The acupuncture treatment was given once every other day, with 4 months being a therapeutic course and an interval of one month between two courses. Results: After acupuncture treatment, of the 22 cases, 20 had remarkable improvement and 2 had improvement in cerebral blood flow, with the total effective rate of improving cerebral blood flow being 90.8%. Before the treatment there were significant differences between the left and right cerebrum (P0.05). After treatment, the radioactivity count in the whole brain decreased significantly in comparison with that of pretreatment (P<0.01). It indicates the improvement of cerebral blood flow and cellular metabolism after the treatment. Conclusion:Acupumcture con significantly improve cerebral blood flow in autism children.

  2. Writing and drawing with both hands as indicators of hemispheric dominance.

    Science.gov (United States)

    Labak, Irena; Snajder, Darija; Srzentić, Mirna Kostović; Bensić, Mirta; Nist, Marina; Ilakovac, Vesna; Heffer, Marija

    2011-01-01

    Brain lateralization is a common term used to describe dominance of one brain hemisphere over another for a specific function. The right hand dominance in writing, controlled by the left hemisphere, is preceded by development of communicative gesticulation and followed by development of speech in the same hemisphere. We assumed that some people are not aware of their own capability of using the other hand for tasks involving fine motor sequential movements. To prove this hypothesis, the participants were asked to perform one trained task (writing) and one less-trained task (drawing) with a dominant and a non-dominant hand. The final sample was comprised of 1189 children from 14 elementary schools and 8 high schools in the Osijek area, of which 685 elementary school children were attending 1st to 4th grade and 504 high school children were attending 3rd and 4th grade. The participants were asked to write two words, draw a specific object (a vase with flowers) and fill out a questionnaire with 10 questions concerning the classification of handedness and cerebral hemisphere dominance. The self-reported cerebral lateralization assessed in the questionnaire was compared with the drawing and the writing performance. The self-reported and objectively measured hand dominance deviated in the cases of the ambidextrous who consider themselves right-handers. Given the fact that the number of ambidextrous persons was greater in elementary schools than in high schools, we concluded how training of the right hand decreases the ability of using both hands equally for either of the tested functions - writing and drawing.

  3. Cerebral blood flow measurement in cerebrovascular occlusive diseases

    International Nuclear Information System (INIS)

    Yanagihara, T.; Wahner, H.W.

    1984-01-01

    In order to evaluate cerebral blood flow (CBF) patterns among individual patients with increased statistical confidence, CBF measurements were carried out using the 133Xe-inhalation method and external head detectors. F1 values representing gray matter flow from 3 to 6 head detectors were averaged to form 16 different regions for each cerebral hemisphere. Normative values were obtained from 46 healthy volunteers, and data from individual regions were analyzed for absolute blood flow rates (ml/100g/min), for concordance between right and left hemispheres and as percent of mean hemispheric flow. CBF measurements were then carried out among 37 patients with cerebrovascular occlusive diseases, and results were compared with normative values. A high incidence of abnormal flows were detected among symptomatic patients with intracranial arterial stenosis or occlusion and those with extracranial internal carotid artery occlusion. By using the above method for data analysis, it was possible to delineate hypoperfused areas among these patients. Even though the 133Xe-inhalation method has inherent limitations, this is a practical and safe method for measurement of CBF which can provide reliable information useful for management of patients with cerebrovascular occlusive diseases, particularly when the results are presented with statistical confidence

  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. Right-Brained Kids in Left-Brained Schools

    Science.gov (United States)

    Hunter, Madeline

    1976-01-01

    Students who learn well through left hemisphere brain input (oral and written) have minimal practice in using the right hemisphere, while those who are more proficient in right hemisphere (visual) input processing are handicapped by having to use primarily their left brains. (MB)

  6. Complementary functions of the two brain hemispheres: comparisons with earlier conceptions and implications for individual and society.

    Science.gov (United States)

    Zeier, H

    1989-07-01

    The concept of different functions for the left and right cerebral hemispheres coincides in an astonishing way with earlier philosophical and psychological work which divided the human mind into two complementary functions without having a neurophysiological explanation. Representative are the ideas of Fichte, Hegel and Jung. The latter postulated the two subsystems Ego and Self and associated the conscious functions of the Ego with the intellect, the capacity for rational thought, and the Self with the mind, which also includes the emotional feelings. For the harmonic development and self-realization of man the functions of both systems in complementary interaction are required. Therefore, the current overaccentuation of the intellect and of progress directed technical-scientific thinking should be corrected by making better use of the much neglected functions of the right hemisphere.

  7. Atypical hemispheric dominance for attention: functional MRI topography.

    Science.gov (United States)

    Flöel, Agnes; Jansen, Andreas; Deppe, Michael; Kanowski, Martin; Konrad, Carsten; Sommer, Jens; Knecht, Stefan

    2005-09-01

    The right hemisphere is predominantly involved in tasks associated with spatial attention. However, left hemispheric dominance for spatial attention can be found in healthy individuals, and both spatial attention and language can be lateralized to the same hemisphere. Little is known about the underlying regional distribution of neural activation in these 'atypical' individuals. Previously a large number of healthy subjects were screened for hemispheric dominance of visuospatial attention and language, using functional Doppler ultrasonography. From this group, subjects were chosen who were 'atypical' for hemispheric dominance of visuospatial attention and language, and their pattern of brain activation was studied with functional magnetic resonance imaging during a task probing spatial attention. Right-handed subjects with the 'typical' pattern of brain organization served as control subjects. It was found that subjects with an inverted lateralization of language and spatial attention (language right, attention left) recruited left-hemispheric areas in the attention task, homotopic to those recruited by control subjects in the right hemisphere. Subjects with lateralization of both language and attention to the right hemisphere activated an attentional network in the right hemisphere that was comparable to control subjects. The present findings suggest that not the hemispheric side, but the intrahemispheric pattern of activation is the distinct feature for the neural processes underlying language and attention.

  8. Correlation of severity of aphasia with cerebral blood flow

    International Nuclear Information System (INIS)

    Tagawa, Koichi; Sugimoto, Keiko; Sone, Noriaki; Yamaguchi, Takenori; Naritomi, Hiroaki; Sawada, Tohru

    1982-01-01

    In 46 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured by 133 Xe inhalation method, and relationship between severity of aphasia and degree of rCBF reduction was investigated. Measurements of rCBF were performed after 2 months of ictus in all patients. At the time of rCBF measurements, the severity of aphasia was mild in 13, moderate in 16 and severe in the other 17 patients. Control rCBF values were obtained from 16 subjects who had neither neurological deficits nor abnormal findings on CT scan. In control group, mean hemispheric rCBF values (mCBF), which were calculated from initial slope index, were 49.1 +- 3.8 and 49.4 +- 3.9 respectively in the right and left hemisphere. In all aphasic patients but two who had mild aphasia, mCBF in the left hemisphere showed lower values as compared to that in the right hemisphere. The mCBF in the left hemisphere was 46.5 +- 5.3 in the mild group, 41.3 +- 5.8 in the moderate group and 34.3 +- 5.0 in the severe group. The values in the moderate and severe groups were significantly reduced as compared to the control or those in the mild group. The mCBF in the severe group was also significantly lower than those in the moderate group. The mCBF in the right hemisphere was 48.4 +- 6.3 in the mild group, 45.6 +- 6.1 in the moderate group and 38.6 +- 4.9 in the severe group. The values in the severe group were significantly reduced as compared to those in the other groups as well as the control. The present study suggests that measurements of rCBF by 133 Xe inhalation method are valid for the evaluation of severity of aphasia in stroke patients. (author)

  9. Regional cerebral blood flow changes in schizophrenia and endogenous depression by single photon emission computed tomography (SPECT) using N-isopropyl-p-( sup 123 I)iodoamphetamine (IMP)

    Energy Technology Data Exchange (ETDEWEB)

    Kanaya, Toshinori (Hiroshima Univ. (Japan). School of Medicine)

    1989-06-01

    Regional cerebral blood flows (rCBF) were measured in patients with schizophrenia and endogenous depression by single photon emission computed tomography (SPECT) using N-isopropyl-p-({sup 123}I)iodoamphetamine (IMP). The subjects were 20 patients with shizophrenia, 32 patients with endogenous depression and 20 normal controls. The patients with depression were divided into 3 groups; unmedicated, medicated patients in depressive state, and medicated patients in remited state. The rCBF were calculated by the corticocerebellar ratio (CCR), which was expressed as a ratio of activity per pixel in cortical regions of interest to the activity per pixel in the cerebellum. The results were as follows. In patients with schizophrenia the marked decrease in rCBF in bilateral frontal regions and the lower rCBF in the left than in the right hemisphere were observed. There was no significant correlation between the mean rCBF and BPRS (Brief Psychiatric Rating Scale) in patients with shizophrenia. In patients with depression the decrease in rCBF in overall cerebral regions and the lower rCBF in the left than in the right hemisphere were observed in both groups in depressive state. These changes were normalized in remited state, though there was no significant difference in rCBF between on medication and off medication. There was significantly negative correlation between the mean rCBF and Hamilton Depression Rating Scale in patients with depression. These results support the previously reported 'hypofrontality' and the left hemispheric dysfunction in shizophrenia. In depressive patients the overall cerebral dysfunction was revealed more remarkablly in the left than in the right hemisphere, which was normalized following the improvement of depressive symptoms. Furthermore, it was suggested that the applications of IMP-SPECT could be useful for the diagnosis and research for the cerebral function in mental illness. (author) 59 refs.

  10. Regional cerebral blood flow changes in schizophrenia and endogenous depression by single photon emission computed tomography (SPECT) using N-isopropyl-p-[123I]iodoamphetamine (IMP)

    International Nuclear Information System (INIS)

    Kanaya, Toshinori

    1989-01-01

    Regional cerebral blood flows (rCBF) were measured in patients with schizophrenia and endogenous depression by single photon emission computed tomography (SPECT) using N-isopropyl-p-[ 123 I]iodoamphetamine (IMP). The subjects were 20 patients with shizophrenia, 32 patients with endogenous depression and 20 normal controls. The patients with depression were divided into 3 groups; unmedicated, medicated patients in depressive state, and medicated patients in remited state. The rCBF were calculated by the corticocerebellar ratio (CCR), which was expressed as a ratio of activity per pixel in cortical regions of interest to the activity per pixel in the cerebellum. The results were as follows. In patients with schizophrenia the marked decrease in rCBF in bilateral frontal regions and the lower rCBF in the left than in the right hemisphere were observed. There was no significant correlation between the mean rCBF and BPRS (Brief Psychiatric Rating Scale) in patients with shizophrenia. In patients with depression the decrease in rCBF in overall cerebral regions and the lower rCBF in the left than in the right hemisphere were observed in both groups in depressive state. These changes were normalized in remited state, though there was no significant difference in rCBF between on medication and off medication. There was significantly negative correlation between the mean rCBF and Hamilton Depression Rating Scale in patients with depression. These results support the previously reported 'hypofrontality' and the left hemispheric dysfunction in shizophrenia. In depressive patients the overall cerebral dysfunction was revealed more remarkablly in the left than in the right hemisphere, which was normalized following the improvement of depressive symptoms. Furthermore, it was suggested that the applications of IMP-SPECT could be useful for the diagnosis and research for the cerebral function in mental illness. (author) 59 refs

  11. Analyses of disruption of cerebral white matter integrity in schizophrenia with MR diffusion tensor fiber tracking method

    International Nuclear Information System (INIS)

    Yamamoto, Utako; Kobayashi, Tetsuo; Kito, Shinsuke; Koga, Yoshihiko

    2010-01-01

    We have analyzed cerebral white matter using magnetic resonance diffusion tensor imaging (MR-DTI) to measure the diffusion anisotropy of water molecules. The goal of this study is the quantitative evaluation of schizophrenia. Diffusion tensor images are acquired for patients with schizophrenia and healthy comparison subjects, group-matched for age, sex, and handedness. Fiber tracking is performed on the superior longitudinal fasciculus for the comparison between the patient and comparison groups. We have analysed and compared the cross-sectional area on the starting coronal plane and the mean and standard deviation of the fractional anisotropy and the apparent diffusion coefficient along fibers in the right and left hemispheres. In the right hemisphere, the cross-sectional areas in patient group are significantly smaller than those in the comparison group. Furthermore, in the comparison group, the cross-sectional areas in the right hemisphere are significantly larger than those in the left hemisphere, whereas there is no significant difference in the patient group. These results suggest that we may evaluate the disruption in white matter integrity in schizophrenic patients quantitatively by comparing the cross-sectional area of the superior longitudinal fasciculus in the right and left hemispheres. (author)

  12. Game Utilization as a Media to Train the Balance of Left and Right Brain

    Directory of Open Access Journals (Sweden)

    Evan Wijaya

    2017-10-01

    Full Text Available Human have two brain hemispheres, left hemisphere and right hemisphere. Left hemisphere is used for processing language, words, numbers, equations, etc. Right hemisphere is used for processing creativity, imagination, music, color, etc. Every human should have balance between left and right hemisphere. One method that could be used for balancing brain hemispheres is to use left and right hands for using tools, writing, or typing. “Typing Rhythm” is a game for PC platform, the purpose of this game is for brain balancing exercise by typing lyric of a song while the song is played.

  13. Methods of dichotic listening as a research methodology for hemispheric interaction.

    Directory of Open Access Journals (Sweden)

    Kovyazina M.S.

    2014-07-01

    Full Text Available Experimental data was obtained from a dichotic listening test by patients with unilateral brain lesions and corpus callosum pathology (agenesis, cysts, degenerative changes, etc. Efficiency index analysis shows that interhemispheric interaction in the audioverbal sphere depends to a greater extent on the right hemisphere state. The dichotic listening technique is not an informative means of studying hemispheric interaction, since it does not allow a clear distinction between hemispheric symptoms and symptoms of pathology of the corpus callosum. Thus, violations of hemispheric relations caused by disorders of the corpus callosum and cerebral hemispheres change worth more right hemisphere activity.

  14. Hypothalamic digoxin, hemispheric chemical dominance, and sleep.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-04-01

    The isoprenoid path way produces endogenous digoxin, a substance that can regulate neurotransmitter and amino acid transport. Digoxin synthesis and neurotransmitter patterns were assessed in individuals with chronic insomnia. The patterns were compared in those with right hemispheric and left hemispheric dominance. The activity of HMG GoA reductase and serum levels of digoxin, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in individuals with chronic insomnia and in individuals with differing hemispheric dominance. Digoxin synthesis was increased with upregulated tryptophan catabolism (increased levels of serotonin, strychnine, and nicotine), and downregulated tyrosine catabolism (decreased levels of dopamine, noradrenaline, and morphine) in those with chronic insomnia and right hemispheric chemical dominance. Digoxin synthesis was reduced with downregulated tryptophan catabolism (decreased levels of serotonin, strychnine, and nicotine) and upregulated tyrosine catabolism (increased levels of dopamine, noradrenaline, and morphine) in those with normal sleep patterns and left hemispheric chemical dominance. Hypothalamic digoxin plays a central role in the regulation of sleep behavior. Hemispheric chemical dominance in relation to digoxin status is also crucial.

  15. Investigation of cerebral metabolism by positron CT in Japanese following musical stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Wakasugi, Naotoshi (Nihon Univ., Tokyo (Japan). School of Medicine)

    1994-02-01

    Cerebral metabolic responses to Japanese and Western instrumental music were examined using [sup 11]C-glucose and positron CT. Eight right-handed subjects were studied in both Japanese and Western music-stimulated states. Biaural musical stimulation with a Japanese instrument, the 'shakuhachi', produced diffuse metabolic changes in the left temporal lobe in all subjects. Biaural musical stimulation with a Western instrument, the 'violin', produced metabolic changes in the right temporal lobe in 3 subjects, changes in the left in 4, and changes on both sides in one. It was considered previously that all musical stimulation led to hypermetabolism in the right hemisphere of human beings. However, the present results indicated that Japanese music produced activation of the left hemisphere in Japanese. On the other hand, Western music produced right hemispheric hypermetabolism in Japanese with no emotion. The laterality of the hemisphere stimulated by Western music was apparently incidentally changed according to the state of mind the Japanese subjects. (author).

  16. [Autopsy case of Lissauer's general paresis with rapidly progressive left hemiparesis].

    Science.gov (United States)

    Kato, Hiroko; Yoshida, Mari; Ando, Tetsuo; Sugiura, Makoto; Hashizume, Yoshio

    2009-06-01

    A 48-years-old man presented with slowly progressive bradykinesia, personality change and rapidly progressive left hemiparesis. On admission, he presented dementia, poor judgment, left hemiparesis. MRI revealed a widespread high intensity area in right hemisphere and MRA was almost normal. Serological tests of serum and CSF demonstrated high titers of antibodies to Treponema pallidum. He was treated for syphilis with daily penicillin injections without improvement. He died of sepsis eight months after admission. At autopsy, the brain weighed 1,100 g and the right cerebral hemisphere was atrophic, especially in frontal base, temporal, parietal, angular, and posterior regions covered by thickened, fibrotic leptomeninges. Microscopically, chronic meningoencephalitis was observed. Severe neuronal loss with gliosis was seen in the right cerebral cortices. Scattered rod-shaped microglia and inflammatory cell infiltration were visible in the cerebral parenchyma. The dorsal column of the spinal cord was not involved and meningovascular syphilis was unclear. The distribution of the encephalitic lesions was well correlated with the clinical and neuroradiological findings. This was a rare autopsy case presenting Lissauer's general paresis, clinically manifesting as rapidly progressive stroke-like episode.

  17. Exchanging Catheters Over a Single Transseptal Sheath During Left Atrial Ablation is Associated with a Higher Risk for Silent Cerebral Events

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    Thomas Deneke, MD

    2014-09-01

    Conclusions: Exchanging catheters over a single transseptal access to perform left atrial ablation is associated with a significantly higher incidence of SCE compared to an ablation technique using different transseptal accesses for therapeutic and diagnostic catheters.

  18. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation: A functional MRI study.

    Science.gov (United States)

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-08-25

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation.

  19. Factors Influencing Right Hemisphere Engagement During Metaphor Comprehension

    Science.gov (United States)

    Diaz, Michele T.; Eppes, Anna

    2018-01-01

    Although the left hemisphere is critical for language, clinical, behavioral, and neuroimaging research suggest that the right hemisphere also contributes to language comprehension. In particular, research has suggested that figurative language may be one type of language that preferentially engages right hemisphere regions. However, there is disagreement about whether these regions within the right hemisphere are sensitive to figurative language per se or to other factors that co-vary with figurativeness. In this article, we will review the neuroimaging literature on figurative language processing, focusing on metaphors, within the context of several theoretical perspectives that have been proposed about hemispheric function in language. Then we will examine three factors that may influence right hemisphere engagement: novelty, task difficulty, and context. We propose that factors that increase integration demands drive right hemisphere involvement in language processing, and that such recruitment is not limited to figurative language. PMID:29643825

  20. Cardiac asystole associated with seizures of right hemispheric onset

    Directory of Open Access Journals (Sweden)

    Jennifer Chu

    2014-01-01

    Full Text Available Ictal asystole is frequently underrecognized despite being a potentially lethal condition. We report two cases of ictal asystole with right hemispheric onset. These cases are unique since previous literature reports that seizures associated with bradyarrhythmias typically arise from left hemispheric foci. These cases further underscore the importance of clinical vigilance and the need of an enhanced diagnostic biomarker.

  1. Learning-related brain hemispheric dominance in sleeping songbirds

    NARCIS (Netherlands)

    Moorman, Sanne; Gobes, Sharon M H; van de Kamp, Ferdinand C; Zandbergen, Matthijs A; Bolhuis, Johan J

    2015-01-01

    There are striking behavioural and neural parallels between the acquisition of speech in humans and song learning in songbirds. In humans, language-related brain activation is mostly lateralised to the left hemisphere. During language acquisition in humans, brain hemispheric lateralisation develops

  2. Cerebral lesions and event-related potential P300 using positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Sakai, Yasujiro; Okamoto, Kazuma; Tanaka, Makoto; Kondoh, Susumu; Hirai, Shunsaku

    1993-01-01

    To determine what lesions are involved in prolonging event-related potential P300 latency, regional cerebral blood flow (rCBF) and metabolism were investigated by positron emission tomography (PET) in a total of 40 patients with neurologic diseases (12 with chronic cerebrovascular disorder, 9 with spino-cerebellar degeneration, 4 with Alzheimer's type dementia, 4 with amyotrophic lateral sclerosis, and 11 with miscellaneous diseases). There was inverse correlation between rCBF and P300 latency in terms of any of the whole, left, and right hemispheres: P300 latency was associated with decreased rCBF. This was more noticeable in the cerebral cortex than white matter and in the right than left hemisphere, although there was no significant difference between them. In none of the regions, however, was there significant correlation between cerebral oxygen consumption and P300 latency. When the right and left frontal, temporal, parietal and occipital cortexes, thalamus, putamen, and caudatum were examined as regions of interest, there was significantly inverse correlation between rCBF and P300 latency in all regions except for the occipital cortex. This was more noticeable on the right than the left side, although no significant difference was observed. Cerebral oxygen consumption in these lesions did not correlate with P300 latency. In the study on bilateral rCBF difference, decreased rCBF confined to the right parietal lobe, bilateral thalamus and bilateral temporal lobes was found to be associated with a significantly prolonged P300 latency. Thus, rCBF in these regions seemed to be particularly responsible for P300 latency. (N.K.)

  3. Cerebral lesions and event-related potential P300 using positron emission tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Yasujiro; Okamoto, Kazuma; Tanaka, Makoto; Kondoh, Susumu; Hirai, Shunsaku (Gunma Univ., Maebashi (Japan). School of Medicine)

    1993-06-01

    To determine what lesions are involved in prolonging event-related potential P300 latency, regional cerebral blood flow (rCBF) and metabolism were investigated by positron emission tomography (PET) in a total of 40 patients with neurologic diseases (12 with chronic cerebrovascular disorder, 9 with spino-cerebellar degeneration, 4 with Alzheimer's type dementia, 4 with amyotrophic lateral sclerosis, and 11 with miscellaneous diseases). There was inverse correlation between rCBF and P300 latency in terms of any of the whole, left, and right hemispheres: P300 latency was associated with decreased rCBF. This was more noticeable in the cerebral cortex than white matter and in the right than left hemisphere, although there was no significant difference between them. In none of the regions, however, was there significant correlation between cerebral oxygen consumption and P300 latency. When the right and left frontal, temporal, parietal and occipital cortexes, thalamus, putamen, and caudatum were examined as regions of interest, there was significantly inverse correlation between rCBF and P300 latency in all regions except for the occipital cortex. This was more noticeable on the right than the left side, although no significant difference was observed. Cerebral oxygen consumption in these lesions did not correlate with P300 latency. In the study on bilateral rCBF difference, decreased rCBF confined to the right parietal lobe, bilateral thalamus and bilateral temporal lobes was found to be associated with a significantly prolonged P300 latency. Thus, rCBF in these regions seemed to be particularly responsible for P300 latency. (N.K.).

  4. Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention.

    Science.gov (United States)

    O'Hare, Aminda J; Atchley, Ruth Ann; Young, Keith M

    2017-11-16

    Two dominant theories on lateralized processing of emotional information exist in the literature. One theory posits that unpleasant emotions are processed by right frontal regions, while pleasant emotions are processed by left frontal regions. The other theory posits that the right hemisphere is more specialized for the processing of emotional information overall, particularly in posterior regions. Assessing the different roles of the cerebral hemispheres in processing emotional information can be difficult without the use of neuroimaging methodologies, which are not accessible or affordable to all scientists. Divided visual field presentation of stimuli can allow for the investigation of lateralized processing of information without the use of neuroimaging technology. This study compared central versus divided visual field presentations of emotional images to assess differences in motivated attention between the two hemispheres. The late positive potential (LPP) was recorded using electroencephalography (EEG) and event-related potentials (ERPs) methodologies to assess motivated attention. Future work will pair this paradigm with a more active behavioral task to explore the behavioral impacts on the attentional differences found.

  5. Hemispheric speech lateralisation in the developing brain is related to motor praxis ability

    Directory of Open Access Journals (Sweden)

    Jessica C. Hodgson

    2016-12-01

    Full Text Available Commonly displayed functional asymmetries such as hand dominance and hemispheric speech lateralisation are well researched in adults. However there is debate about when such functions become lateralised in the typically developing brain. This study examined whether patterns of speech laterality and hand dominance were related and whether they varied with age in typically developing children. 148 children aged 3–10 years performed an electronic pegboard task to determine hand dominance; a subset of 38 of these children also underwent functional Transcranial Doppler (fTCD imaging to derive a lateralisation index (LI for hemispheric activation during speech production using an animation description paradigm. There was no main effect of age in the speech laterality scores, however, younger children showed a greater difference in performance between their hands on the motor task. Furthermore, this between-hand performance difference significantly interacted with direction of speech laterality, with a smaller between-hand difference relating to increased left hemisphere activation. This data shows that both handedness and speech lateralisation appear relatively determined by age 3, but that atypical cerebral lateralisation is linked to greater performance differences in hand skill, irrespective of age. Results are discussed in terms of the common neural systems underpinning handedness and speech lateralisation.

  6. Gender and hemispheric differences in temporal lobe epilepsy: a VBM study.

    Science.gov (United States)

    Santana, Maria Teresa Castilho Garcia; Jackowski, Andrea Parolin; Britto, Fernanda Dos Santos; Sandim, Gabriel Barbosa; Caboclo, Luís Otávio Sales Ferreira; Centeno, Ricardo Silva; Carrete, Henrique; Yacubian, Elza Márcia Targas

    2014-04-01

    Gender differences are recognized in the functional and anatomical organization of the human brain. Differences between genders are probably expressed early in life, when differential rates of cerebral maturation occur. Sexual dimorphism has been described in temporal lobe epilepsy with mesial temporal sclerosis (TLE-MTS). Several voxel-based morphometry (VBM) studies have shown that TLE-MTS extends beyond mesial temporal structures, and that there are differences in the extent of anatomical damage between hemispheres, although none have approached gender differences. Our aim was to investigate gender differences and anatomical abnormalities in TLE-MTS. VBM5 was employed to analyze gender and hemispheric differences in 120 patients with TLE-MTS and 50 controls. VBM abnormalities were more widespread in left-TLE; while in women changes were mostly seen in temporal areas, frontal regions were more affected in men. Our study confirmed that gender and laterality are important factors determining the nature and severity of brain damage in TLE-MTS. Differential rates of maturation between gender and hemispheres may explain the distinct areas of anatomical damage in men and women. Copyright © 2013 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  7. Cirurgia do arco aórtico com perfusão cerebral bilateral pelo isolamento do tronco braquiocefálico e da artéria carótida esquerda Aortic arch surgery with bilateral cerebral perfusion by isolation of brachiocephalic trunk and left carotid artery

    Directory of Open Access Journals (Sweden)

    Valdo José Carreira

    2008-03-01

    Full Text Available OBJETIVO: Estudar os resultados da técnica descrita por Carreira et al. com utilização de perfusão cerebral seletiva bilateral (PCSAB pelo isolamento do tronco braquiocefálico e artéria carótida esquerda. MÉTODOS: Quinze pacientes foram operados consecutivamente entre de junho de 2005 e setembro de 2007. Os dados foram analisados por programa informatizado Epi Info e significância estatística com p0,05. CONCLUSÃO: A técnica de PCSAB é reprodutível e apresenta resultados semelhantes aos da literatura mundial. A excelente evolução neurológica e o fácil controle de sangramentos nas linhas de sutura podem ter contribuído com os resultados obtidos.OBJECTIVE: To evaluate the results of a technique described by Carreira et al. using bilateral antegrade selective cerebral perfusion by isolating the brachiocephalic trunk and the left carotid artery. METHODS: Fifteen patients were operated between June 2005 and September 2007. Data analysis were performed using Epi Info and statistical significance was set at p0.05. CONCLUSION: The technique of bilateral selective cerebral perfusion described by Carreira et al. can be performed by others and presents similar results to the international literature. The excellent neurological outcome and easy bleeding control on surgical sutures lines are the major advantages of this new procedure.

  8. Voxel-based statistical analysis of cerebral blood flow using Tc-99m ECD brain SPECT in patients with traumatic brain injury: group and individual analyses.

    Science.gov (United States)

    Shin, Yong Beom; Kim, Seong-Jang; Kim, In-Ju; Kim, Yong-Ki; Kim, Dong-Soo; Park, Jae Heung; Yeom, Seok-Ran

    2006-06-01

    Statistical parametric mapping (SPM) was applied to brain perfusion single photon emission computed tomography (SPECT) images in patients with traumatic brain injury (TBI) to investigate regional cerebral abnormalities compared to age-matched normal controls. Thirteen patients with TBI underwent brain perfusion SPECT were included in this study (10 males, three females, mean age 39.8 +/- 18.2, range 21 - 74). SPM2 software implemented in MATLAB 5.3 was used for spatial pre-processing and analysis and to determine the quantitative differences between TBI patients and age-matched normal controls. Three large voxel clusters of significantly decreased cerebral blood perfusion were found in patients with TBI. The largest clusters were area including medial frontal gyrus (voxel number 3642, peak Z-value = 4.31, 4.27, p = 0.000) in both hemispheres. The second largest clusters were areas including cingulated gyrus and anterior cingulate gyrus of left hemisphere (voxel number 381, peak Z-value = 3.67, 3.62, p = 0.000). Other clusters were parahippocampal gyrus (voxel number 173, peak Z-value = 3.40, p = 0.000) and hippocampus (voxel number 173, peak Z-value = 3.23, p = 0.001) in the left hemisphere. The false discovery rate (FDR) was less than 0.04. From this study, group and individual analyses of SPM2 could clearly identify the perfusion abnormalities of brain SPECT in patients with TBI. Group analysis of SPM2 showed hypoperfusion pattern in the areas including medial frontal gyrus of both hemispheres, cingulate gyrus, anterior cingulate gyrus, parahippocampal gyrus and hippocampus in the left hemisphere compared to age-matched normal controls. Also, left parahippocampal gyrus and left hippocampus were additional hypoperfusion areas. However, these findings deserve further investigation on a larger number of patients to be performed to allow a better validation of objective SPM analysis in patients with TBI.

  9. Surgical outcome after decompressive craniectomy in patients with extensive cerebral infarction

    International Nuclear Information System (INIS)

    Otani, Naoki; Takasato, Yoshio; Masaoka, Hiroyuki

    2008-01-01

    Extensive cerebral hemispheric infarction is a devastating condition leading to early death in nearly 80% of cases due to the rapid rise of intracranial pressure in spite of maximum medical treatment for brain edema and swelling. Recently, decompressive craniectomy has been reevaluated to prevent the brain herniation caused by extensive hemispheric cerebral infarction. We studied the surgical results after decompressive craniectomy for extensive cerebral infarction. Between December 1997 and August 2006, 13 consecutive patients (7 males and 6 females aged from 39 to 73 with a mean age of 59 years) with massive cerebral infarction of internal carotid (IC) (11 patients) and middle cerebral artery (MCA) (2 patients) territory were treated with decompressive craniectomy and dural plasty. Five patients had a left-sided stroke with severe aphasia. The cardioembolic source of stroke was seen in 5 patients. Surgery was performed at the point of neurological deterioration, anisocoria, and effacement of perimesencephalic cistern on CT findings. The mean time between stroke onset and surgery was 39.8 hr and ranged from 13 to 102 hr. Glasgow outcome scale (GOS) on discharge was moderately disabled (MD) 1, severe disabled (SD) 5, vegetative state (VS) 1, and dead (D) 3 (mortality rate 30.8%). Severe pneumoniae were the causes of death. All survivors underwent cranioplasty and were transferred with the aim of rehabilitation. In this study, we showed that the decompressive craniectomy reduced mortality after extensive cerebral infarction. However, the functional outcome and level of independence are poor. It seems that the early decompressive craniectomy should be aggressively performed for extensive cerebral infarction before neurological deterioration such as worsening of consciousness disturbance or pupil abnormalities. Further investigations will be needed to clarify the surgical indications, timing, and functional outcomes. (author)

  10. Isquemia cerebral como manifestación inicial de un mixoma atrial izquierdo: Reporte de un caso Brain ischemia as initial sign of a left atrial myxoma: Report of one case

    Directory of Open Access Journals (Sweden)

    Luis F Osio

    2008-04-01

    Full Text Available Los tumores primarios del corazón son raros; 75% de éstos son benignos y cerca de la mitad de los benignos son mixomas que, en la mayoría de los casos, se encuentran en las cavidades izquierdas. Las manifestaciones clínicas de los mixomas dependen del sitio de localización del tumor. Sin embargo, se afirma que la isquemia cerebral es la manifestación clínica inicial en un tercio de los mixomas atriales. Se presenta el caso de un paciente de género masculino, de 65 años de edad, en quien la primera manifestación clínica de mixoma atrial fue un evento cerebral vascular isquémico.Primary heart tumors are rare; 75% of them are benign and almost half of the benign ones are mixomas that in most cases are located in the left cavities. Clinical manifestations of myxomas depend on its localization site. Nevertheless, it is accepted that brain ischemia is the initial clinical manifestation in a third of atrial myxomas. The case of a 65 years old male patient in whom the first clinical manifestation of an atrial myxoma was an ischemic cerebrovascular event, is presented.

  11. Awake right hemisphere brain surgery.

    Science.gov (United States)

    Hulou, M Maher; Cote, David J; Olubiyi, Olutayo I; Smith, Timothy R; Chiocca, E Antonio; Johnson, Mark D

    2015-12-01

    We report the indications and outcomes of awake right hemispheric brain surgery, as well as a rare patient with crossed aphasia. Awake craniotomies are often performed to protect eloquent cortex. We reviewed the medical records for 35 of 96 patients, in detail, who had awake right hemisphere brain operations. Intraoperative cortical mapping of motor and/or language function was performed in 29 of the 35 patients. A preoperative speech impairment and left hand dominance were the main indicators for awake right-sided craniotomies in patients with right hemisphere lesions. Four patients with lesion proximity to eloquent areas underwent awake craniotomies without cortical mapping. In addition, one patient had a broncho-pulmonary fistula, and another had a recent major cardiac procedure that precluded awake surgery. An eloquent cortex representation was identified in 14 patients (48.3%). Postoperatively, seven of 17 patients (41.1%) who presented with weakness, experienced improvements in their motor functions, 11 of 16 (68.7%) with seizures became seizure-free, and seven of nine (77.7%) with moderate to severe headaches and one of two with a visual field deficit improved significantly. There were also improvements in speech and language functions in all patients who presented with speech difficulties. A right sided awake craniotomy is an excellent option for left handed patients, or those with right sided cortical lesions that result in preoperative speech impairments. When combined with intraoperative cortical mapping, both speech and motor function can be well preserved. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Predicting hemispheric dominance for language production in healthy individuals using support vector machine.

    Science.gov (United States)

    Zago, Laure; Hervé, Pierre-Yves; Genuer, Robin; Laurent, Alexandre; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie; Joliot, Marc

    2017-12-01

    We used a Support Vector Machine (SVM) classifier to assess hemispheric pattern of language dominance of 47 individuals categorized as non-typical for language from their hemispheric functional laterality index (HFLI) measured on a sentence minus word-list production fMRI-BOLD contrast map. The SVM classifier was trained at discriminating between Dominant and Non-Dominant hemispheric language production activation pattern on a group of 250 participants previously identified as Typicals (HFLI strongly leftward). Then, SVM was applied to each hemispheric language activation pattern of 47 non-typical individuals. The results showed that at least one hemisphere (left or right) was found to be Dominant in every, except 3 individuals, indicating that the "dominant" type of functional organization is the most frequent in non-typicals. Specifically, left hemisphere dominance was predicted in all non-typical right-handers (RH) and in 57.4% of non-typical left-handers (LH). When both hemisphere classifications were jointly considered, four types of brain patterns were observed. The most often predicted pattern (51%) was left-dominant (Dominant left-hemisphere and Non-Dominant right-hemisphere), followed by right-dominant (23%, Dominant right-hemisphere and Non-Dominant left-hemisphere) and co-dominant (19%, 2 Dominant hemispheres) patterns. Co-non-dominant was rare (6%, 2 Non-Dominant hemispheres), but was normal variants of hemispheric specialization. In RH, only left-dominant (72%) and co-dominant patterns were detected, while for LH, all types were found, although with different occurrences. Among the 10 LH with a strong rightward HFLI, 8 had a right-dominant brain pattern. Whole-brain analysis of the right-dominant pattern group confirmed that it exhibited a functional organization strictly mirroring that of left-dominant pattern group. Hum Brain Mapp 38:5871-5889, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Maurice Ravel and right-hemisphere musical creativity: influence of disease on his last musical works?

    Science.gov (United States)

    Amaducci, L; Grassi, E; Boller, F

    2002-01-01

    The problem of finding correspondence between a particular neuronal organization and a specific function of the human brain remains a central question of neuroscience. It is sometimes thought that language and music are two sides of the same intellectual coin, but research on brain-damaged patients has shown that the loss of verbal functions (aphasia) is not necessarily accompanied by a loss of musical abilities (amusia). Amusia without aphasia has also been described. This double dissociation indicates functional autonomy in these mental processes. Yet verbal and musical impairments often occur together. The global picture that emerges from studies of music and its neural substrate is by no means clear and much depends on which subjects and which aspect of musical abilities are investigated. An illustration of these concepts is provided by the case of the French composer Maurice Ravel, who suffered from a progressive cerebral disease of uncertain aetiology, with prominent involvement of the left hemisphere. As a result, Ravel experienced aphasia and apraxia and became unable to compose. The available facts favour a clinical diagnosis of primary progressive aphasia (PPA), with the possibility of an overlap with corticobasal degeneration (CBD). In view of Ravel's clinical history, we propose that two of his final compositions, the Bolero and the Concerto for the Left Hand, include certain patterns characteristic of right-hemisphere musical abilities and may show the influence of disease on the creative process.

  14. Hypothalamic digoxin, hemispheric chemical dominance, and spirituality.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-03-01

    The isoprenoid pathway was assessed in atheistic and spiritually inclined individuals. The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance has a correlation with spiritual and atheistic tendency. HMG CoA reductase activity, serum digoxin, RBC membrane Na(+)-K+ ATPase activity, serum magnesium, and tyrosine/tryptophan catabolic patterns were assessed in spiritual/atheistic individuals and in those differing hemispheric dominance. In spiritually-inclined individuals, there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in spiritually-inclined individuals correlated with right hemispheric chemical dominance. In atheistic individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolities (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in atheistic individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to spirituality or atheism.

  15. Hypothalamic digoxin, hemispheric chemical dominance, and mesenteric artery occlusion.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Paramesware Achutha

    2003-12-01

    The role of the isoprenoid pathway in vascular thrombosis, especially mesenteric artery occlusion and its relation to hemispheric dominance, was assessed in this study. The following parameters were measured in patients with mesenteric artery occlusion and individuals with right hemispheric, left hemispheric, and bihemispheric dominance: (1) plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; (2) tryptophan/tyrosine catabolic patterns; (3) free radical metabolism; (4) glycoconjugate metabolism; and (5) membrane composition. In patients with mesenteric artery occlusion there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, low ubiquinone, and elevated free radical levels. The RBC membrane Na(+)-K+ ATPase activity and serum magnesium were decreased. There was also an increase in tryptophan catabolites and reduction in tyrosine catabolites in the serum. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these patients. The biochemical patterns obtained in mesenteric artery occlusion is similar to those obtained in left-handed/right hemispheric dominant individuals by the dichotic listening test. But all the patients with mesenteric artery occlusion were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Mesenteric artery occlusion occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function. Hemispheric chemical dominance may thus control the risk for developing vascular thrombosis in individuals.

  16. Hemispheric lateralization of topological organization in structural brain networks.

    Science.gov (United States)

    Caeyenberghs, Karen; Leemans, Alexander

    2014-09-01

    The study on structural brain asymmetries in healthy individuals plays an important role in our understanding of the factors that modulate cognitive specialization in the brain. Here, we used fiber tractography to reconstruct the left and right hemispheric networks of a large cohort of 346 healthy participants (20-86 years) and performed a graph theoretical analysis to investigate this brain laterality from a network perspective. Findings revealed that the left hemisphere is significantly more "efficient" than the right hemisphere, whereas the right hemisphere showed higher values of "betweenness centrality" and "small-worldness." In particular, left-hemispheric networks displayed increased nodal efficiency in brain regions related to language and motor actions, whereas the right hemisphere showed an increase in nodal efficiency in brain regions involved in memory and visuospatial attention. In addition, we found that hemispheric networks decrease in efficiency with age. Finally, we observed significant gender differences in measures of global connectivity. By analyzing the structural hemispheric brain networks, we have provided new insights into understanding the neuroanatomical basis of lateralized brain functions. Copyright © 2014 Wiley Periodicals, Inc.

  17. Right-hemispheric processing of non-linguistic word features

    DEFF Research Database (Denmark)

    Baumgaertner, Annette; Hartwigsen, Gesa; Roman Siebner, Hartwig

    2013-01-01

    -hemispheric homologues of classic left-hemispheric language areas may partly be due to processing nonlinguistic perceptual features of verbal stimuli. We used functional MRI (fMRI) to clarify the role of the right hemisphere in the perception of nonlinguistic word features in healthy individuals. Participants made...... perceptual, semantic, or phonological decisions on the same set of auditorily and visually presented word stimuli. Perceptual decisions required judgements about stimulus-inherent changes in font size (visual modality) or fundamental frequency contour (auditory modality). The semantic judgement required......, the right inferior frontal gyrus (IFG), an area previously suggested to support language recovery after left-hemispheric stroke, displayed modality-independent activation during perceptual processing of word stimuli. Our findings indicate that activation of the right hemisphere during language tasks may...

  18. Protective effect of Kombucha tea on brain damage induced by transient cerebral ischemia and reperfusion in rat

    Directory of Open Access Journals (Sweden)

    Najmeh Kabiri

    2016-09-01

    Full Text Available The aim of study was to investigate the potential neuroprotective effects of Kombucha on cerebral damage induced by ischemia in rats (n=99. Cerebral infarct volume in the ischemic rats received Kombucha solution showed no significance alteration. However, the permeability of blood-brain barrier significantly decreased in both ischemic rats received 15 mg/kg Kombucha tea and Sham group. In addition, brain water content in the ischemic groups treated with Kombucha solution was significantly higher than the Sham group, although right hemispheres in all of the treated groups illustrated higher brain water content than the left ones. Brain anti-oxidant capacity elevated in the ischemic rats treated with Kombucha and in the Sham group. Brain and plasma malondialdehyde concentrations significantly decreased in both of the ischemic groups injected with Kombucha. The findings suggest that Kombucha tea could be useful for the prevention of cerebral damage.

  19. Leftward spatial bias in children's drawing placement: hemispheric activation versus directional hypotheses.

    Science.gov (United States)

    Picard, Delphine; Zarhbouch, Benaissa

    2014-01-01

    A leftward spatial bias in drawing placement was demonstrated by Heller (1991) using the draw-a-person test with right-handed American children. No such bias was observed in left-handed children who are assumed to be less lateralised than their right-handed peers. According to Heller the leftward spatial bias is primarily a reflection of the right hemisphere specialisation for spatial processing. However, an alternative explanation in terms of directional trends may be put forward. In the present study we first confirm Heller's findings of a handedness effect on drawing placement using the draw-a-tree task with a large sample of right- and left-handed French children aged 5-15 years (Exp. 1). We then provide evidence that a similar leftward bias occurs in right-handed Moroccan children aged 7-11 years with opposite script directionality and opposite preferred drawing movement directions (i.e., right-to-left directional trends) to the those of right-handed French children (Exp. 2). Taken together these findings suggest that directionality trends arising from learned cultural habits and motor preferences play little role in determining spatial bias in the centring of a single object drawn on a page. Rather there may be a cerebral origin for drawing single objects slightly on the left side of the graphic space.

  20. Hemispheric Asymmetries in Meaning Selection: Evidence from the Disambiguation of Homophonic vs. Heterophonic Homographs

    Science.gov (United States)

    Peleg, Orna; Markus, Andrey; Eviatar, Zohar

    2012-01-01

    Research investigating hemispheric asymmetries in meaning selection using homophonic homographs (e.g., "bank"), suggests that the left hemisphere (LH) quickly selects contextually relevant meanings, whereas the right hemisphere (RH) maintains a broader spectrum of meanings including those that are contextually irrelevant (e.g., Faust & Chiarello,…

  1. Regional cerebral blood flow of the patients with schizophrenia. A study using 99mTc-ECD SPECT at rest and activation

    International Nuclear Information System (INIS)

    Hu Ping; Wu Kening; Zeng Shiquan; Lin Zengtao; Yu Jinlong

    1996-01-01

    Regional cerebral blood flow (rCBF) changes of the patients with schizophrenia were observed. 99m Tc-ECD SPECT was performed on 22 patients with schizophrenia and 10 healthy volunteers at rest and activation with a cognitive task: a modified Wisconsin Card Sorting Test. At rest state, only 4 patients have abnormal rCBF pattern: left hemisphere over-perfusion relative to the right. A significant relative activation deficit in the left inferior prefrontal region was revealed in the patients during activation. The patients with schizophrenia may have frontal lobe dysfunction

  2. Cerebral Laterality and Verbal Processes

    Science.gov (United States)

    Sherman, Jay L.; And Others

    1976-01-01

    Research suggests that we process information by way of two distinct and functionally separate coding systems. Their location, somewhat dependent on cerebral laterality, varies in right- and left-handed persons. Tests this dual coding model. (Editor/RK)

  3. Apraxia in left-handers.

    Science.gov (United States)

    Goldenberg, Georg

    2013-08-01

    In typical right-handed patients both apraxia and aphasia are caused by damage to the left hemisphere, which also controls the dominant right hand. In left-handed subjects the lateralities of language and of control of the dominant hand can dissociate. This permits disentangling the association of apraxia with aphasia from that with handedness. Pantomime of tool use, actual tool use and imitation of meaningless hand and finger postures were examined in 50 consecutive left-handed subjects with unilateral hemisphere lesions. There were three aphasic patients with pervasive apraxia caused by left-sided lesions. As the dominant hand is controlled by the right hemisphere, they constitute dissociations of apraxia from handedness. Conversely there were also three patients with pervasive apraxia caused by right brain lesions without aphasia. They constitute dissociations of apraxia from aphasia. Across the whole group of patients dissociations from handedness and from aphasia were observed for all manifestations of apraxia, but their frequency depended on the type of apraxia. Defective pantomime and defective tool use occurred rarely without aphasia, whereas defective imitation of hand, but not finger, postures was more frequent after right than left brain damage. The higher incidence of defective imitation of hand postures in right brain damage was mainly due to patients who had also hemi-neglect. This interaction alerts to the possibility that the association of right hemisphere damage with apraxia has to do with spatial aptitudes of the right hemisphere rather than with its control of the dominant left hand. Comparison with data from right-handed patients showed no differences between the severity of apraxia for imitation of hand or finger postures, but impairment on pantomime of tool use was milder in apraxic left-handers than in apraxic right-handers. This alleviation of the severity of apraxia corresponded with a similar alleviation of the severity of aphasia as

  4. Reduced contralateral hemispheric flow measured by SPECT in cerebellar lesions

    DEFF Research Database (Denmark)

    Sönmezoğlu, K; Sperling, B; Henriksen, T

    1993-01-01

    Four patients with clinical signs of cerebellar stroke were studied twice by SPECT using 99mTc-HMPAO as a tracer for cerebral blood flow (CBF). When first scanned 6 to 22 days after onset, all had a region of very low CBF in the symptomatic cerebellar hemisphere, and a mild to moderate CBF reduct...

  5. Diffuse damage to central nervous system in progressive rheumatoid arthritis complicated by cerebral hermorrhage after radioisotope cisternography

    International Nuclear Information System (INIS)

    Tarnowska-Dziduszko, E.; Lazarowicz, J.

    1980-01-01

    Presented case reveals unusual reaction of central nervous system in the course of progressive rheumatoid arthritis and cerebral hemorrhage as a rare complication after radioisotope investigation of cerebro-spinal fluid spaces. Female, 58 years old which was treated for 22 years for progressive rheumatoid arthritis developed during last 3 years of life a psychoorganic syndrome with temporal epilepsy and slight left sided hemiparesis. After radioisotope cisternography appeared decerebration followed by death. On autopsy the hemorrhagic foci were found in left cerebral hemisphere and in the brain stem. Histological finding was generalized severe damage to interstitial vessels diagnosed as fibrinotic, necrotizing degeneration of capillary and arteriolar wall, significant proliferation of microglia in the white matter and brain stem. Chronic inflammatory infiltrates were present in leptomeninges. Pathogenesis of findings in connection with progressive rheumatoid arthritis and complications due to cisternography is discussed. (author)

  6. Measuring right-hemisphere dysfunction in children: validity of two new computer tests

    NARCIS (Netherlands)

    Sips, H.J.W.A.; C.E. Catsman-Berrevoets (Coriene); H.R. van Dongen (Huug); van der Werff, P.J.J.; Brooke, L.J.

    1994-01-01

    textabstractThe validity of two new computer‐mediated tests for the detection of right‐cerebral hemisphere lesions in children–the Right‐hemisphere Dysfunction Test and the Visual Perception Test–was evaluated. Normative data were drawn from a group of 91 children (aged five to 14 years) and 14

  7. Ischemic Left Ventricular Perforation Covered by a Thrombus in a Patient Presenting with Cerebral Ischemia: Importance of Time-Sensitive Performance and Adequate Interpretation of Bedside Transthoracic Echography

    Directory of Open Access Journals (Sweden)

    A. J. Fischer

    2016-01-01

    Full Text Available If myocardial infarction remains silent, only clinical signs of complications may unveil its presence. Life-threatening complications include myocardial rupture, thrombus formation, or arterial embolization. In the presented case, a 76-year-old patient was admitted with left-sided hemiparesis. In duplex sonography, a critical stenosis of the right internal carotid artery was identified and initially but retrospectively incorrectly judged as the potential cause for ischemia. During operative thromboendarterectomy, arterial embolism of the right leg occurred coincidentally, more likely pointing towards a cardioembolic origin. Percutaneous interventions remained unsuccessful and local fibrinolysis was applied. Delayed bedside echocardiography by an experienced cardiologist demonstrated a discontinuity of the normal myocardial texture of the left ventricular apex together with an echodense, partly floating structure merely attached by a thin bridge not completely sealing the myocardial defect, accompanied by pericardial effusion. The patient was immediately transferred to emergency cardiac surgery with extirpation of the thrombus, aortocoronary bypass graft placement, and aneurysmectomy. This didactic case reveals decisive structural shortcomings in patient’s admission and triage processes and underlines, if performed timely and correctly, the value of transthoracic echocardiography as a noninvasive and cost-effective tool allowing immediate decision-making, which, in this case, led to the correct but almost fatally delayed diagnosis.

  8. Ischemic Left Ventricular Perforation Covered by a Thrombus in a Patient Presenting with Cerebral Ischemia: Importance of Time-Sensitive Performance and Adequate Interpretation of Bedside Transthoracic Echography.

    Science.gov (United States)

    Fischer, A J; Lebiedz, P; Wiaderek, M; Lichtenberg, M; Böse, D; Martens, S; Breuckmann, F

    2016-01-01

    If myocardial infarction remains silent, only clinical signs of complications may unveil its presence. Life-threatening complications include myocardial rupture, thrombus formation, or arterial embolization. In the presented case, a 76-year-old patient was admitted with left-sided hemiparesis. In duplex sonography, a critical stenosis of the right internal carotid artery was identified and initially but retrospectively incorrectly judged as the potential cause for ischemia. During operative thromboendarterectomy, arterial embolism of the right leg occurred coincidentally, more likely pointing towards a cardioembolic origin. Percutaneous interventions remained unsuccessful and local fibrinolysis was applied. Delayed bedside echocardiography by an experienced cardiologist demonstrated a discontinuity of the normal myocardial texture of the left ventricular apex together with an echodense, partly floating structure merely attached by a thin bridge not completely sealing the myocardial defect, accompanied by pericardial effusion. The patient was immediately transferred to emergency cardiac surgery with extirpation of the thrombus, aortocoronary bypass graft placement, and aneurysmectomy. This didactic case reveals decisive structural shortcomings in patient's admission and triage processes and underlines, if performed timely and correctly, the value of transthoracic echocardiography as a noninvasive and cost-effective tool allowing immediate decision-making, which, in this case, led to the correct but almost fatally delayed diagnosis.

  9. Changes in Cerebral Cortex of Children Treated for Medulloblastoma

    International Nuclear Information System (INIS)

    Liu, Arthur K.; Marcus, Karen J.; Fischl, Bruce; Grant, P. Ellen; Young Poussaint, Tina; Rivkin, Michael J.; Davis, Peter; Tarbell, Nancy J.; Yock, Torunn I.

    2007-01-01

    Purpose: Children with medulloblastoma undergo surgery, radiotherapy, and chemotherapy. After treatment, these children have numerous structural abnormalities. Using high-resolution magnetic resonance imaging, we measured the thickness of the cerebral cortex in a group of medulloblastoma patients and a group of normally developing children. Methods and Materials: We obtained magnetic resonance imaging scans and measured the cortical thickness in 9 children after treatment of medulloblastoma. The measurements from these children were compared with the measurements from age- and gender-matched normally developing children previously scanned. For additional comparison, the pattern of thickness change was compared with the cortical thickness maps from a larger group of 65 normally developing children. Results: In the left hemisphere, relatively thinner cortex was found in the perirolandic region and the parieto-occipital lobe. In the right hemisphere, relatively thinner cortex was found in the parietal lobe, posterior superior temporal gyrus, and lateral temporal lobe. These regions of cortical thinning overlapped with the regions of cortex that undergo normal age-related thinning. Conclusion: The spatial distribution of cortical thinning suggested that the areas of cortex that are undergoing development are more sensitive to the effects of treatment of medulloblastoma. Such quantitative methods may improve our understanding of the biologic effects that treatment has on the cerebral development and their neuropsychological implications

  10. Regional cerebral blood flow in schizophrenic patients

    International Nuclear Information System (INIS)

    Sagawa, Katsuo; Sibuya, Isoo; Oiji, Arata; Kawakatsu, Sinobu; Morinobu, Shigeru; Totsuka, Shiro; Kinoshita, Osami; Yazaki, Mitsuyasu.

    1990-01-01

    Seventy-six schizophrenic patients were examined by a Xe-133 inhalation method to determine regional cerebral blood flow. A decreased blood flow was observed in the frontal lobe, especially in the right inferior part. In a study on the relationship between disease subtypes and regional cerebral blood flow, negative symptoms were found more predominantly associated with dissolution type than delusion type. In the group of dissolution type, a decreased blood flow was observed in both the right inferior frontal lobe and the right upper hemisphere, in comparison to the group of delution type. Patients presenting with auditory hallucination had a significantly higher incidence of both negative and positive symptoms, as compared with those not presenting with it. In such patients, a significantly decreased blood flow was also seen in the left upper frontal lobe and the bilateral parietal lobe. Xe-133 inhalation method should assist in evaluating brain function in schizophrenic patients, thus leading to the likelihood of developing a new treatment modality. (N.K.)

  11. Dissociated language functions: a matter of atypical language lateralization or cerebral plasticity?

    Science.gov (United States)

    Acioly, Marcus Andre; Gharabaghi, Alireza; Zimmermann, Christoph; Erb, Michael; Heckl, Stefan; Tatagiba, Marcos

    2014-01-01

    The left hemisphere is generally considered to harbor language functions. Atypical cortical language lateralization is mainly demonstrated in left-handed and ambidextrous individuals, whereas dissociated language functions have been reported in association with brain injuries as a part of the reorganization process. We present a thoughtful discussion on the underlying mechanisms of dissociated language functions through an illustrative case of dissociated expressive language. A 31-year-old left-handed woman presented with a recurrent left frontal glioma. Preoperative language functional magnetic resonance imaging (fMRI) panel revealed right-sided dominance for two different language tasks (verbal fluency and visual naming), and the word chain task demonstrated maximal activation in the left hemisphere at the posterior margin of the tumor. The patient was operated on awake to assess language functions intraoperatively. Preoperative fMRI findings were confirmed revealing a task-specific dissociation of expressive language functions. Surgical resection was taken to the functional boundaries. Postoperatively, no language dysfunction occurred. Dissociated language functions are prone to occur in long-standing lesions. Different patterns of dissociation may be encountered due to interindividual particularities and cerebral plasticity. The presented patient is unique by demonstrating new insight into expressive language dissociation, emphasizing the role of a preoperative language fMRI panel and the capability of intraoperative language mapping for identifying special language networks. Georg Thieme Verlag KG Stuttgart · New York.

  12. Hemispheric dominance and cell phone use.

    Science.gov (United States)

    Seidman, Michael D; Siegel, Bianca; Shah, Priyanka; Bowyer, Susan M

    2013-05-01

    A thorough understanding of why we hold a cell phone to a particular ear may be of importance when studying the impact of cell phone safety. To determine if there is an obvious association between sidedness of cell phone use and auditory hemispheric dominance (AHD) or language hemispheric dominance (LHD). It is known that 70% to 95% of the population are right-handed, and of these, 96% have left-brain LHD. We have observed that most people use their cell phones in their right ear. An Internet survey was e-mailed to individuals through surveymonkey.com. The survey used a modified Edinburgh Handedness Inventory protocol. Sample questions surveyed which hand was used to write with, whether the right or left ear was used for phone conversations, as well as whether a brain tumor was present. General community. An Internet survey was randomly e-mailed to 5000 individuals selected from an otology online group, patients undergoing Wada testing and functional magnetic resonance imaging, as well as persons on the university listserv, of which 717 surveys were completed. Determination of hemispheric dominance based on preferred ear for cell phone use. A total of 717 surveys were returned. Ninety percent of the respondents were right handed, and 9% were left handed. Sixty-eight percent of the right-handed people used the cell phone in their right ear, 25% in the left ear, and 7% had no preference. Seventy-two of the left-handed respondents used their left ear, 23% used their right ear, and 5% had no preference. Cell phone use averaged 540 minutes per month over the past 9 years. An association exists between hand dominance laterality of cell phone use (73%) and our ability to predict hemispheric dominance. Most right-handed people have left-brain LHD and use their cell phone in their right ear. Similarly, most left-handed people use their cell phone in their left ear. Our study suggests that AHD may differ from LHD owing to the difference in handedness and cell phone ear use

  13. Label-free in vivo optical micro-angiography imaging of cerebral capillary blood flow within meninges and cortex in mice with the skull left intact

    Science.gov (United States)

    Jia, Yali; Wang, Ruikang K.

    2011-03-01

    Abnormal microcirculation within meninges is common in many neurological diseases. There is a need for an imaging method that is capable of visualizing functional meningeal microcirculations alone, preferably decoupled from the cortical blood flow. Optical microangiography (OMAG) is a recently developed label-free imaging method capable of producing 3D images of dynamic blood perfusion within micro-circulatory tissue beds at an imaging depth up to ~2 mm, with an unprecedented imaging sensitivity to the blood flow at ~4 μm/s. In this study, we demonstrate the utility of ultra-high sensitive OMAG in imaging the detailed blood flow distributions, at a capillary level resolution, within meninges and cortex in mice with the cranium left intact. The results indicate that OMAG can be a valuable tool for the study of meningeal circulations.

  14. Hypothalamic-mediated model for systemic lupus erythematosis: relation to hemispheric chemical dominance.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-11-01

    The isoprenoid pathway including endogenous digoxin was assessed in systemic lupus erythematosis (SLE). All the patients with SLE were right-handed/left hemispheric dominant by the dichotic listening test. This was also studied for comparison in patients with right hemispheric and left hemispheric dominance. The isoprenoid pathway was upregulated with increased digoxin synthesis in patients with SLE and in those with right hemispheric dominance. In this group of patients (i) the tryptophan catabolites were increased and the tyrosine catabolites reduced, (ii) the dolichol and glycoconjugate levels were elevated, (iii) lysosomal stability was reduced, (iv) ubiquinone levels were low and free radical levels increased, and (v) the membrane cholesterol:phospholipid ratios were increased and membrane glycoconjugates reduced. On the other hand, in patients with left hemispheric dominance the reverse patterns were obtained. The biochemical patterns obtained in SLE is similar to those obtained in left-handed/right hemispheric chemically dominant individuals. But all the patients with SLE were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. SLE occurs in right hemispheric chemically dominant individuals, and is a reflection of altered brain function. The role of the isoprenoid pathway in the pathogenesis of SLE and its relation to hemispheric dominance is discussed.

  15. Theories of inter-hemispheric interactions in aphasia: the role of tDCS in rehabilitation of post-stroke aphasia

    Directory of Open Access Journals (Sweden)

    Roy H Hamilton

    2014-04-01

    Full Text Available Mounting data from behavioral and neuroimaging studies have shown that the process of recovery from aphasia is largely driven by the reorganization of brain networks related to language. Evidence implicates a variety of potential mechanisms in this reorganization, some of which involve substantive changes in brain functional activity within and between cerebral hemispheres. These changes include intrahemispheric recruitment of perilesional left-hemisphere regions and transcallosal interhemispheric interactions between lesioned left-hemisphere language areas and homologous regions in the right hemisphere. With respect to the role of the right hemisphere, it is debated whether interhemispheric interactions are beneficial or deleterious to recovering language networks. Recent years have also seen the emergence of noninvasive brain stimulation techniques such as transcranial magnetic stimulation (TMS and transcranial direct current stimulation (tDCS as potential novel treatments for post-stroke aphasia. Because these techniques are predicated on either focal excitation or inhibition of brain areas, characterization of the functional roles of the left and right hemispheres and transcallosal interactions in aphasia recovery is of central importance to the development and refinement of stimulation-based therapies. However, most treatment studies involving noninvasive brain stimulation in aphasia have tacitly accepted the interhemispheric inhibition model, in which right hemisphere activity interferes with language recovery that is mediated by left hemisphere perisylvian regions. Based on this account, many studies in aphasia involving TMS and tDCS have adopted one of two approaches consistent with the model: left hemisphere excitation or right hemisphere inhibition. In this presentation, we will review both clinical and cognitive neuroscience evidence that elucidates different hemispheric mechanisms that influence recovery from aphasia after stroke

  16. Heterogeneity of cerebral blood flow: a fractal approach

    International Nuclear Information System (INIS)

    Kuikka, J.T.; Hartikainen, P.

    2000-01-01

    Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and single-photon emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (=coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17±0.05 (mean±SD) for the left hemisphere and 1.15±0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04±0.03 than in healthy controls. (orig.) [de

  17. Imaging manifestation of cerebral gumma: report of 3 cases

    International Nuclear Information System (INIS)

    Wen Ming; Miao Tizong; Zheng Luping; Zhang Shilin

    2003-01-01

    Objective: To evaluate the imaging manifestations of cerebral gumma. Methods: Three cases of surgically proved cerebral gumma were analyzed. All patients had history of ultra-marriage sexual life, and the laboratory tests, including the serums and/or the cerebrospinal fluid test, highly indicated the diagnosis of syphilis. Pathological results demonstrated cerebral gumma after operation. Results: On CT scan, case 1 showed a 5.0 cm x 3.5 cm hypo-density area at left temporal lobe with obvious mass effect, and post-contrast CT scan revealed a rim enhancement. MR scanning was not performed. In case 2, a mixture lesion was detected on right frontal lobe on pre-contrast CT scan, and spot-like central enhancement and mild mass effect were demonstrated on postcontrast CT scan. Pre-contrast T 1 WI showed 2 round lesions situated at right frontal lobe (1.5 cm in diameter) and right periventricular areas (1.0 cm in diameter), separately, which showed iso-signal on T 1 WI and hyper-signal on T 2 WI, and ring-like enhancement with slight compression of the right lateral ventricle. In case 3, CT plain scan demonstrated multiple hypo-dense lesions, most of the lesions located on both frontal lobe and left temporal lobe, and enhanced CT scan was not performed. MR imaging revealed many nodule and mass lesions with hypo-signal on T 1 WI and hyper-signal on T 2 WI, located on both hemispheres with nodular or circular enhancement after injection of contrast media. Conclusion: The imaging manifestations of cerebral gumma were nonspecific. Thus, the preoperational diagnosis should be made combining the clinical, laboratory, and imaging data

  18. Unilateral Hemispheric Encephalitis

    Directory of Open Access Journals (Sweden)

    Mohan Leslie Noone

    2014-10-01

    Full Text Available A 10 year old boy presented with history of mild fever and upper respiratory symptoms followed by recurrent seizures and loss of consciousness on the next day. Normal blood counts and abnormal hepatic transaminases were noted. MRI of the brain, done on the fourth day of illness, showed extensive involvement of the cortex in the right hemisphere. Lumbar CSF was normal. The EEG showed bilateral slowing with frontal sharp wave discharges and marked attenuation over the entire right hemisphere. The patient succumbed to the illness on the ninth day. A similar pattern of acute unilateral hemispheric cortical involvement is described in the hemiconvulsion-hemiplegia-epilepsy (HHE syndrome, which is typically described to occur in children below 4 years of age. This case of fulminant acute unilateral encaphilitic illness could represent the acute phase of HHE syndrome.

  19. Reading the Wrong Way with the Right Hemisphere

    Directory of Open Access Journals (Sweden)

    Ian J. Kirk

    2013-07-01

    Full Text Available Reading is a complex process, drawing on a variety of brain functions in order to link symbols to words and concepts. The three major brain areas linked to reading and phonological analysis include the left temporoparietal region, the left occipitotemporal region and the inferior frontal gyrus. Decreased activation of the left posterior language system in dyslexia is well documented but there is relatively limited attention given to the role of the right hemisphere. The current study investigated differences in right and left hemisphere activation between individuals with dyslexia and non-impaired readers in lexical decision tasks (regular words, irregular words, pseudowords during functional Magnetic Resonance Imaging (fMRI. Results revealed the expected hypo-activation in the left posterior areas in those with dyslexia but also areas of overactivation in the right hemisphere. During pseudoword decisions, for example, adults with dyslexia showed more right inferior occipital gyrus activation than controls. In general the increased activation of left-hemisphere language areas found in response to both regular and pseudowords was absent in dyslexics. Laterality indices showed that while controls showed left lateralised activation of the temporal lobe during lexical decision making, dyslexic readers showed right activation. Findings will inform theories of reading and will have implications for the design of reading interventions.

  20. Reading the wrong way with the right hemisphere.

    Science.gov (United States)

    Waldie, Karen E; Haigh, Charlotte E; Badzakova-Trajkov, Gjurgjica; Buckley, Jude; Kirk, Ian J

    2013-07-17

    Reading is a complex process, drawing on a variety of brain functions in order to link symbols to words and concepts. The three major brain areas linked to reading and phonological analysis include the left temporoparietal region, the left occipitotemporal region and the inferior frontal gyrus. Decreased activation of the left posterior language system in dyslexia is well documented but there is relatively limited attention given to the role of the right hemisphere. The current study investigated differences in right and left hemisphere activation between individuals with dyslexia and non-impaired readers in lexical decision tasks (regular words, irregular words, pseudowords) during functional Magnetic Resonance Imaging (fMRI). Results revealed the expected hypo-activation in the left posterior areas in those with dyslexia but also areas of overactivation in the right hemisphere. During pseudoword decisions, for example, adults with dyslexia showed more right inferior occipital gyrus activation than controls. In general the increased activation of left-hemisphere language areas found in response to both regular and pseudowords was absent in dyslexics. Laterality indices showed that while controls showed left lateralised activation of the temporal lobe during lexical decision making, dyslexic readers showed right activation. Findings will inform theories of reading and will have implications for the design of reading interventions.

  1. Hemispheric asymmetry and theory of mind: is there an association?

    Science.gov (United States)

    Herzig, Daniela A; Sullivan, Sarah; Evans, Jonathan; Corcoran, Rhiannon; Mohr, Christine

    2012-01-01

    In autism and schizophrenia attenuated/atypical functional hemispheric asymmetry and theory of mind impairments have been reported, suggesting common underlying neuroscientific correlates. We here investigated whether impaired theory of mind performance is associated with attenuated/atypical hemispheric asymmetry. An association may explain the co-occurrence of both dysfunctions in psychiatric populations. Healthy participants (n=129) performed a left hemisphere (lateralised lexical decision task) and right hemisphere (lateralised face decision task) dominant task as well as a visual cartoon task to assess theory of mind performance. Linear regression analyses revealed inconsistent associations between theory of mind performance and functional hemisphere asymmetry: enhanced theory of mind performance was only associated with (1) faster right hemisphere language processing, and (2) reduced right hemisphere dominance for face processing (men only). The majority of non-significant findings suggest that theory of mind and functional hemispheric asymmetry are unrelated. Instead of "overinterpreting" the two significant results, discrepancies in the previous literature relating to the problem of the theory of mind concept, the variety of tasks, and the lack of normative data are discussed. We also suggest how future studies could explore a possible link between hemispheric asymmetry and theory of mind.

  2. [A clinical case of young, oral combined contraceptive using women, heterozygous carrier of the Factor V (Leiden) which revealed thrombosis of the left internal jugular vein and brain ischemia with cerebral infarction and ischemic stroke].

    Science.gov (United States)

    Kovachev, S; Ramshev, K; Ramsheva, Z; Ivanov, A; Ganovska, A

    2013-01-01

    Thrombophilia is associated with increased risks of venous thrombosis in women taking oral contraceptive preparations. Universal thrombophilia screening in women prior to prescribing oral contraceptive preparations is not supported by current evidence. The case is presented of a 23 year-old women with a personal history of interruption and on the same day started with oral contraceptive (0.03 microg ethynil estradiol - 0.075 microg gestodene), which due on a 18 pill/day to acute headache, increasing vomiting and speaking defects. Physical/neurologic/gynecologic examinations observed a normal status. The MRI and CT revealed thrombosis of the left internal jugular vein and brain ischemia with cerebral infarction and ischemic stroke. The acute therapy of thrombotic findings was accompanied with many tests. The thrombophilia PCR-Real time - test finds heterozygous carrier of the Factor V (Leiden). This case shows the need of large prospective studies that should be undertaken to refine the risks and establish the associations of thrombophilias with venous thrombosis among contraceptive users. The key to a prompt diagnosis is to know the risk factors. The relative value of a thrombophilia screening programme before contraceptive using needs to be established.

  3. Patterns of music agnosia associated with middle cerebral artery infarcts.

    Science.gov (United States)

    Ayotte, J; Peretz, I; Rousseau, I; Bard, C; Bojanowski, M

    2000-09-01

    The objective of the study is to evaluate if the rupture of an aneurysm located on the middle cerebral artery (MCA) results in disorders of music recognition. To this aim, 20 patients having undergone brain surgery for the clipping of a unilateral left (LBS), right (RBS) or bilateral (BBS) aneurysm(s) of the MCA and 20 neurologically intact control subjects (NC) were evaluated with a series of tests assessing most of the abilities involved in music recognition. In general, the study shows that a ruptured aneurysm on the MCA that is repaired by brain surgery is very likely to produce deficits in the auditory processing of music. The incidence of such a deficit was not only very high but also selective. The results show that the LBS group was more impaired than the NC group in all three tasks involving musical long-term memory. The study also uncovered two new cases of apperceptive agnosia for music. These two patients (N.R. and R.C.) were diagnosed as such because both exhibit a clear deficit in each of the three music memory tasks and both are impaired in all discrimination tests involving musical perception. Interestingly, the lesions overlap in the right superior temporal lobe and in the right insula, making the two new cases very similar to an earlier case report. Altogether, the results are also consistent with the view that apperceptive agnosia results from damage to right hemispheric structures while associative agnosia results from damage to the left hemisphere.

  4. Motivation, affect, and hemispheric asymmetry: power versus affiliation.

    Science.gov (United States)

    Kuhl, Julius; Kazén, Miguel

    2008-08-01

    In 4 experiments, the authors examined to what extent information related to different social needs (i.e., power vs. affiliation) is associated with hemispheric laterality. Response latencies to a lateralized dot-probe task following lateralized pictures or verbal labels that were associated with positive or negative episodes related to power, affiliation, or achievement revealed clear-cut laterality effects. These effects were a function of need content rather than of valence: Power-related stimuli were associated with right visual field (left hemisphere) superiority, whereas affiliation-related stimuli were associated with left visual field (right hemisphere) superiority. Additional results demonstrated that in contrast to power, affiliation primes were associated with better discrimination between coherent word triads (e.g., goat, pass, and green, all related to mountain) and noncoherent triads, a remote associate task known to activate areas of the right hemisphere. (c) 2008 APA, all rights reserved

  5. From the Left to the Right: How the Brain Compensates Progressive Loss of Language Function

    Science.gov (United States)

    Thiel, Alexander; Habedank, Birgit; Herholz, Karl; Kessler, Josef; Winhuisen, Lutz; Haupt, Walter F.; Heiss, Wolf-Dieter

    2006-01-01

    In normal right-handed subjects language production usually is a function of the left brain hemisphere. Patients with aphasia following brain damage to the left hemisphere have a considerable potential to compensate for the loss of this function. Sometimes, but not always, areas of the right hemisphere which are homologous to language areas of the…

  6. [Left-handedness and health].

    Science.gov (United States)

    Milenković, Sanja; Belojević, Goran; Kocijancić, Radojka

    2010-01-01

    Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome), developmental disorders (autism, dislexia and sttutering) and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about "anomalous" cerebral domination, as a consequence of hormonal disbalance.

  7. Hemispheric asymmetry in the influence of language on visual perception.

    Science.gov (United States)

    Sun, Yanliang; Cai, Yongchun; Lu, Shena

    2015-07-01

    Many studies have shown that language can affect visual perception; however, our understanding of the neural basis of linguistic influence is inadequate. This can be investigated by examining the hemispheric asymmetry of linguistic influence. The left and right hemispheres are dominant in close and distant semantic processing, respectively. In this study, we investigated whether the hemispheric asymmetry of semantic processing led to hemispheric asymmetry for concept priming on the detection of objects degraded by continuous flash suppression. We combined a priming paradigm with the divided visual field paradigm and used continuous flash suppression, which renders objects invisible. The results indicated that the hemispheric asymmetry of semantic processing led to a right lateralization in the influence of more abstract concepts on visual perception. The lateralization of brain connectomes may be the underlying neural basis of this effect. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Hemispheric Lateralization of Resting-State Functional Connectivity of the Anterior Insula: Association with Age, Gender, and a Novelty-Seeking Trait

    Science.gov (United States)

    Kann, Sarah; Zhang, Sheng; Manza, Peter; Leung, Hoi-Chung

    2016-01-01

    Abstract Resting-state functional connectivity (rsFC) is widely used to examine cerebral functional organization. The imaging literature has described lateralization of insula activations during cognitive and affective processing. Evidence appears to support a role of the right-hemispheric insula in attentional orientation to salient stimulus, interoception, and physiological arousal, and a role of the left-hemispheric insula in cognitive and affective control, as well as perspective taking. In this study, in a large data set of healthy adults, we examined lateralization of the rsFC of the anterior insula (AI) by computing a laterality index (LI) of connectivity with 54 regions from the Automated Anatomic Labeling atlas. At a corrected threshold (p lateralized in connectivity with the dorsomedial prefrontal cortex, superior frontal gyrus, inferior frontal cortex, and posterior orbital gyrus and right lateralized in connectivity with the postcentral gyrus, supramarginal gyrus, and superior parietal lobule. In gender differences, women, but not men, showed right-lateralized connectivity to the thalamus. Furthermore, in a subgroup of participants assessed by the tridimensional personality questionnaire, novelty seeking is correlated with the extent of left lateralization of AI connectivity to the pallidum and putamen in men and with the extent of right lateralization of AI connectivity to the parahippocampal gyrus in women. These findings support hemispheric functional differentiation of the AI. PMID:27604154

  9. Internal structure of the cerebral hemispheres: an introduction of fiber dissection technique Estrutura interna dos hemisférios cerebrais: introdução à técnica de dissecação de fibras

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    Igor de Castro

    2005-06-01

    Full Text Available The aim of this study is to introduce the fiber dissection technique and its importance in the comprehension of the three-dimensional intrinsic anatomy of the brain. A total of twenty brain hemispheres were dissected. Using Kingler's technique we demonstrated the intrinsic structures of the brain. The supra lateral aspect of the brain as well as the medial aspect were presented. The most important fiber systems were demonstrated. The use and comprehension of new neuroimaging techniques demand a better understanding of this fascinating anatomy. The knowledge acquired with this technique will improve our understanding of critical pathways of the central nervous system.O objetivo é mostrar a técnica de dissecação de fibras e sua importância na compreensão da anatomia tridimensional do cérebro. Um total de 20 hemisférios cerebrais foram dissecados. Usando a técnica de dissecação descrita por Kingler, pudemos demonstrar as estruturas que compõem a anatomia interna do cérebro. A anatomia da face súpero-lateral assim como da face medial foi apresentada. O uso e compreensão de novas técnicas de neuroimagem requerem um melhor conhecimento desta anatomia. O conhecimento adquirido com essa técnica contribuirá para o melhor entendimento de vias essenciais do sistema nervoso central.

  10. Hypothalamic digoxin, hemispheric chemical dominance, and peptic ulcer disease.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-10-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin-like factor (EDLF) (membrane sodium-potassium ATPase inhibitor and regulator of neurotransmitter transport), ubiquinone (free radical scavenger), and dolichol (regulator of glycoconjugate metabolism). The pathway was assessed in peptic ulcer and acid peptic disease and its relation to hemispheric dominance studied. The activity of HMG CoA reductase, serum levels of EDLF, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in acid peptic disease, right hemispheric dominant, left hemispheric dominant, and bihemispheric dominant individuals. All the patients with peptic ulcer disease were right-handed/left hemispheric dominant by the dichotic listening test. The pathway was upregulated with increased EDLF synthesis in peptic ulcer disease (PUD). There was increase in tryptophan catabolites and reduction in tyrosine catabolites in these patients. The ubiquinone levels were low and free radical production increased. Dolichol and glycoconjugate levels were increased and lysosomal stability reduced in patients with acid peptic disease (APD). There was increase in cholesterol:phospholipid ratio with decreased glyco conjugate levels in membranes of patients with PUD. Acid peptic disease represents an elevated EDLF state which can modulate gastric acid secretion and the structure of the gastric mucous barrier. It can also lead to persistence of Helicobacter pylori infection. The biochemical pattern obtained in peptic ulcer disease is similar to those obtained in left-handed/right hemispheric chemically dominant individuals. But all the patients with peptic ulcer disease were right-handed/left hemispheric dominant by the dichotic listen ing test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Peptic ulcer disease occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.

  11. A Preliminary fMRI Study of a Novel Self-Paced Written Fluency Task: Observation of Left-Hemispheric Activation, and Increased Frontal Activation in Late vs. Early Task Phases

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    Laleh eGolestanirad

    2015-03-01

    Full Text Available Neuropsychological tests of verbal fluency are very widely used to characterize impaired cognitive function. For clinical neuroscience studies and potential medical applications, measuring the brain activity that underlies such tests with functional magnetic resonance imaging (fMRI is of significant interest - but a challenging proposition because overt speech can cause signal artifacts, which tend to worsen as the duration of speech tasks becomes longer. In a novel approach, we present the group brain activity of 12 subjects who performed a self-paced written version of phonemic fluency using fMRI-compatible tablet technology that recorded responses and provided task-related feedback on a projection screen display, over long-duration task blocks (60 s. As predicted, we observed robust activation in the left anterior inferior and medial frontal gyri, consisting with previously reported results of verbal fluency tasks which established the role of these areas in strategic word retrieval. In addition, the number of words produced in the late phase (last 30 s of written phonemic fluency was significantly less (p < 0.05 than the number produced in the early phase (first 30 s. Activation during the late phase vs. the early phase was also assessed from the first 20 s and last 20 s of task performance, which eliminated the possibility that the sluggish hemodynamic response from the early phase would affect the activation estimates of the late phase. The last 20 s produced greater activation maps covering extended areas in bilateral precuneus, cuneus, middle temporal gyrus, insula, middle frontal gyrus and cingulate gyrus. Among them, greater activation was observed in the bilateral middle frontal gyrus (Brodmann area BA 9 and cingulate gyrus (BA 24, 32 likely as part of the initiation, maintenance, and shifting of attentional resources.

  12. Comparatively rare case of a child-patient's cerebral echinococcus

    International Nuclear Information System (INIS)

    Todorov, A.; Simova, E.; Traykova, N.; Stoev, D.; Danev, V.

    2012-01-01

    Full text: Echinococcosis is a parasitic condition with a wide spread in Bulgaria. The possibility of an extensive as well as various localization of the cysts is vastly accounted for. However, according to book references and data available, and medical practice, the brain is somewhat one of the loci with a rare occurrence. The authors panel has taken into consideration the case of an eight-year-old male, who was diagnosed through CT scan with a large cystic lesion in the left cerebral hemisphere with a temporal and parietal localization, as well as a partial destruction of the adjacent pyramid. The presence of an echinococcal cyst has been established through methods of surgical intervention, as well as histologic sample examination. The authors demonstrate the complete anatomical recovery of the encephalic structures of the patient through an ensuing routine CT scan

  13. Hemispheric differences in processing the literal interpretation of idioms: converging evidence from behavioral and fMRI studies.

    Science.gov (United States)

    Mashal, Nira; Faust, Miriam; Hendler, Talma; Jung-Beeman, Mark

    2008-01-01

    The present study examined the role of the left (LH) and right (RH) cerebral hemispheres in processing alternative meanings of idiomatic sentences. We conducted two experiments using ambiguous idioms with plausible literal interpretations as stimuli. In the first experiment we tested hemispheric differences in accessing either the literal or the idiomatic meaning of idioms for targets presented to either the left or the right visual field. In the second experiment, we used functional magnetic resonance imaging (fMRI) to define regional brain activation patterns in healthy adults processing either the idiomatic meaning of idioms or the literal meanings of either idioms or literal sentences. According to the Graded Salience Hypothesis (GSH, Giora, 2003), a selective RH involvement in the processing of nonsalient meanings, such as literal interpretations of idiomatic expressions, was expected. Results of the two experiments were consistent with the GSH predictions and show that literal interpretations of idioms are accessed faster than their idiomatic meanings in the RH. The fMRI data showed that processing the idiomatic interpretation of idioms and the literal interpretations of literal sentences involved LH regions whereas processing the literal interpretation of idioms was associated with increased activity in right brain regions including the right precuneus, right middle frontal gyrus (MFG), right posterior middle temporal gyrus (MTG), and right anterior superior temporal gyrus (STG). We suggest that these RH areas are involved in semantic ambiguity resolution and in processing nonsalient meanings of conventional idiomatic expressions.

  14. Compreensão leitora pós-lesão cerebral de hemisfério direito: um estudo de caso = Reading comprehension after right hemisphere brain damage: a case study

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    Jerônimo, Gislaine Machado

    2013-01-01

    Full Text Available A compreensão leitora é uma das habilidades linguísticas mais deficitárias na população brasileira (SCLIAR-CABRAL, 2009. Pesquisadores da área de Neuropsicolinguística, através de um estudo de interface, vêm buscando compreender a forma como os hemisférios cerebrais processam o texto. Mas os estudos, principalmente no que tange à integração textual, ainda são controversos, pois alguns apontam o hemisfério esquerdo e outros o hemisfério direito como responsável por essa função. No intuito de contribuir para esse debate, propomos a presente pesquisa. Trata-se de um estudo de caso com um sujeito acometido de lesão cerebral no hemisfério direito, onde verificamos os três níveis de compreensão textual propostos por Kintsch e Van Dijk (1983; Van Dijk (2010: microestrutura, macroestrutura e modelo situacional. Com esse estudo queremos ampliar nossa compreensão sobre o funcionamento da linguagem na patologia, sua relação com os hemisférios cerebrais e outros componentes cognitivos

  15. Motivation and motor control: hemispheric specialization for approach motivation reverses with handedness.

    Science.gov (United States)

    Brookshire, Geoffrey; Casasanto, Daniel

    2012-01-01

    According to decades of research on affective motivation in the human brain, approach motivational states are supported primarily by the left hemisphere and avoidance states by the right hemisphere. The underlying cause of this specialization, however, has remained unknown. Here we conducted a first test of the Sword and Shield Hypothesis (SSH), according to which the hemispheric laterality of affective motivation depends on the laterality of motor control for the dominant hand (i.e., the "sword hand," used preferentially to perform approach actions) and the nondominant hand (i.e., the "shield hand," used preferentially to perform avoidance actions). To determine whether the laterality of approach motivation varies with handedness, we measured alpha-band power (an inverse index of neural activity) in right- and left-handers during resting-state electroencephalography and analyzed hemispheric alpha-power asymmetries as a function of the participants' trait approach motivational tendencies. Stronger approach motivation was associated with more left-hemisphere activity in right-handers, but with more right-hemisphere activity in left-handers. The hemispheric correlates of approach motivation reversed between right- and left-handers, consistent with the way they typically use their dominant and nondominant hands to perform approach and avoidance actions. In both right- and left-handers, approach motivation was lateralized to the same hemisphere that controls the dominant hand. This covariation between neural systems for action and emotion provides initial support for the SSH.

  16. Vessel encoded arterial spin labeling with cerebral perfusion: preliminary study

    International Nuclear Information System (INIS)

    Wu Bing; Xiao Jiangxi; Xie Cheng; Wang Xiaoying; Jiang Xuexiang; Wong, E.C.; Wang Jing; Guo Jia; Zhang Beiru; Zhang Jue; Fang Jing

    2008-01-01

    Objective: To evaluate a noninvasive vessel encoded imaging for selective mapping of the flow territories of the left and fight internal carotid arteries and vertebral-basilar arteries. Methods: Seven volunteers [(33.5 ± 4.1) years; 3 men, 4 women] and 6 patients [(55.2 ± 3.2) years; 2 men, 4 women] were given written informed consent approved by the institutional review board before participating in the study. A pseudo-continuous tagging pulse train is modified to encode all vessels of interest. The selectivity of this method was demonstrated. Regional perfusion imaging was developed on the same arterial spin labeling sequence. Perfusion-weighted images of the selectively labeled cerebral arteries were obtained by subtraction of the labeled from control images. The CBF values of hemisphere, white matter, and gray matter of volunteers were calculated. The vessel territories on patients were compared with DSA. The low perfusion areas were compared with high signal areas on T 2 -FLAIR. Results: High SNR maps of left carotid, right carotid, and basilar territories were generated in 8 minutes of scan time. Cerebral blood flow values measured with regional perfusion imaging in the complete hemisphere (32.6 ± 4.3) ml·min -1 · 100 g -1 , white matter (10.8 ± 0.9) ml·min -1 ·100 g -1 , and gray matter (55.6±2.9) ml·min -1 · 100 g -1 were in agreement with data in the literature. Vessel encoded imaging in patients had a good agreement with DSA. The low perfusion areas were larger than high signal areas on T 2 -FLAIR. Conclusion: We present a new method capable of evaluating both quantitatively and qualitatively the individual brain- feeding arteries in vivo. (authors)

  17. Cerebral Palsy

    Science.gov (United States)

    Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

  18. Callosal tracts and patterns of hemispheric dominance: a combined fMRI and DTI study.

    Science.gov (United States)

    Häberling, Isabelle S; Badzakova-Trajkov, Gjurgjica; Corballis, Michael C

    2011-01-15

    Left-hemispheric dominance for language and right-hemispheric dominance for spatial processing are distinctive characteristics of the human brain. However, variations of these hemispheric asymmetries have been observed, with a minority showing crowding of both functions to the same hemisphere or even a mirror reversal of the typical lateralization pattern. Here, we used diffusion tensor imaging and functional magnetic imaging to investigate the role of the corpus callosum in participants with atypical hemispheric dominance. The corpus callosum was segmented according to the projection site of the underlying fibre tracts. Analyses of the microstructure of the identified callosal segments revealed that atypical hemispheric dominance for language was associated with high anisotropic diffusion through the corpus callosum as a whole. This effect was most evident in participants with crowding of both functions to the right. The enhanced anisotropic diffusion in atypical hemispheric dominance implies that in these individuals the two hemispheres are more heavily interconnected. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Long Term Neuropsychological Follow-Up in Patients With Herpes Simplex Encephalitis and Predominantly Left-Sided Lesions

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    B. Laurent

    1991-01-01

    Full Text Available Five patients with predominantly dominant cerebral hemisphere lesions due to herpes simplex encephalitis are described. Verbal amnesia was the main deficit but amnesic aphasia sometimes associated with impairment of remote memory also occurred. Semantic and episodic memory deficits were also explored in one case and the role of the right cerebral hemisphere in facilitating recovery of learning is discussed.

  20. Music-induced changes in functional cerebral asymmetries.

    Science.gov (United States)

    Hausmann, Markus; Hodgetts, Sophie; Eerola, Tuomas

    2016-04-01

    After decades of research, it remains unclear whether emotion lateralization occurs because one hemisphere is dominant for processing the emotional content of the stimuli, or whether emotional stimuli activate lateralised networks associated with the subjective emotional experience. By using emotion-induction procedures, we investigated the effect of listening to happy and sad music on three well-established lateralization tasks. In a prestudy, Mozart's piano sonata (K. 448) and Beethoven's Moonlight Sonata were rated as the most happy and sad excerpts, respectively. Participants listened to either one emotional excerpt, or sat in silence before completing an emotional chimeric faces task (Experiment 1), visual line bisection task (Experiment 2) and a dichotic listening task (Experiment 3 and 4). Listening to happy music resulted in a reduced right hemispheric bias in facial emotion recognition (Experiment 1) and visuospatial attention (Experiment 2) and increased left hemispheric bias in language lateralization (Experiments 3 and 4). Although Experiments 1-3 revealed an increased positive emotional state after listening to happy music, mediation analyses revealed that the effect on hemispheric asymmetries was not mediated by music-induced emotional changes. The direct effect of music listening on lateralization was investigated in Experiment 4 in which tempo of the happy excerpt was manipulated by controlling for other acoustic features. However, the results of Experiment 4 made it rather unlikely that tempo is the critical cue accounting for the effects. We conclude that listening to music can affect functional cerebral asymmetries in well-established emotional and cognitive laterality tasks, independent of music-induced changes in the emotion state. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Opposed hemispheric specializations for human hypersexuality and orgasm?

    Science.gov (United States)

    Suffren, Sabrina; Braun, Claude M J; Guimond, Anik; Devinsky, Orrin

    2011-05-01

    With a multiple case report analysis we demonstrate that hypersexuality more often results from right hemisphere (RH) (n=26) than left hemisphere (LH) (n=7) lesions, possibly because of LH release after the RH lesion, and that ictal orgasm more often occurs in patients with right-sided (n=23) than left-sided (n=8) seizure foci, with the symptom probably resulting from RH activation. The LH may be specialized for increasing sexual tension, whereas the RH may be specialized for release of this tension (orgasm), the former being catabolic and the latter anabolic. Several other interpretations of the findings are also discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Pure Left Neglect for Arabic Numerals

    Science.gov (United States)

    Priftis, Konstantinos; Albanese, Silvia; Meneghello, Francesca; Pitteri, Marco

    2013-01-01

    Arabic numerals are diffused and language-free representations of number magnitude. To be effectively processed, the digits composing Arabic numerals must be spatially arranged along a left-to-right axis. We studied one patient (AK) to show that left neglect, after right hemisphere damage, can selectively impair the computation of the spatial…

  3. Malaria cerebral Cerebral malaria

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    Carlos Hugo Zapata Zapata

    2003-03-01

    Full Text Available La malaria Cerebral (MC es la complicación más frecuente de la malaria por P. falciparum; aproximadamente el 90% de las personas que la han padecido se recuperan completamente sin secuelas neurológicas. Aún no se conoce con claridad su patogénesis pero se han postulado cuatro hipótesis o mecanismos posibles: 1 citoadherencia y secuestro de glóbulos rojos parasitados en la microvasculatura cerebral; 2 formación de rosetas y aglutinación de glóbulos rojos parasitados; 3 producción de citoquinas y activación de segundos mensajeros y, 4 apertura de la barrera hematoencefálica. Sin embargo, queda un interrogante sin resolver aún: ¿qué proceso se lleva a cabo para que el parásito, desde el espacio microvascular, pueda interferir transitoriamente con la función cerebral? Recientemente se ha utilizado el precursor de la proteína b-Amiloide como un marcador de daño neuronal en MC; este precursor será de gran ayuda en futuras investigaciones realizadas en nuestro medio que aporten información para comprender la patogénesis de la MC. Is the most common complication of P. falciparum malaria; nearly 90% of people who have suffered CM can recover without neurological problems. Currently there are four hypotheses that explain pathogenesis of CM: cytoadherence and sequestering of parasitized red blood cells to cerebral capillaries; rosette formation and parasitized red blood cells agglutination; production of cytokines and activation of second messengers and opening of the blood-brain barrier. However the main question remains to be answered; how the host-parasite interaction in the vascular space interferes transiently with cerebral function? Recently, the beta amyloid precursor peptide has been employed as marker of neural injury in CM. It is expected that the beta amyloid precursor peptide will help to understand the pathogenesis of CM in complicated patients of endemic areas of Colombia.

  4. Neural Dissociation in the Production of Lexical versus Classifier Signs in ASL: Distinct Patterns of Hemispheric Asymmetry

    Science.gov (United States)

    Hickok, Gregory; Pickell, Herbert; Klima, Edward; Bellugi, Ursula

    2009-01-01

    We examine the hemispheric organization for the production of two classes of ASL signs, lexical signs and classifier signs. Previous work has found strong left hemisphere dominance for the production of lexical signs, but several authors have speculated that classifier signs may involve the right hemisphere to a greater degree because they can…

  5. The Nature of Hemispheric Specialization for Linguistic and Emotional Prosodic Perception: A Meta-Analysis of the Lesion Literature

    Science.gov (United States)

    Witteman, Jurriaan; van IJzendoorn, Marinus H.; van de Velde, Daan; van Heuven, Vincent J. J. P.; Schiller, Niels O.

    2011-01-01

    It is unclear whether there is hemispheric specialization for prosodic perception and, if so, what the nature of this hemispheric asymmetry is. Using the lesion-approach, many studies have attempted to test whether there is hemispheric specialization for emotional and linguistic prosodic perception by examining the impact of left vs. right…

  6. [Amusia and aphasia of Bolero's creator--influence of the right hemisphere on music].

    Science.gov (United States)

    Tudor, Lorraine; Sikirić, Predrag; Tudor, Katarina Ivana; Cambi-Sapunar, Liana; Radonić, Vedran; Tudor, Mario; Buca, Ante; Carija, Robert

    2008-07-01

    The experience with cortical localization (BA 44, 45, 22) of language (Broca, Wernicke and others) in the left hemisphere has been repeatedly tested over the last 150 years and is now generally accepted. A single case report with autopsy findings (Leborgne, Tan tan), has enabled to localize the seat of spoken language in the left third frontal convolution. As music and language have a lot in common and even share the same hearing system, it is logical to try to localize the cognitive centers for music too. The disabling neurological disease illness of Maurice Ravel (1875-1937), a French impressionist composer, is not the right example to localize music center as that of Broca's language center, but it demonstrates the role of the right hemisphere in music production. In the last five years of his life, Ravel suffered from an unknown disease that affected the left hemisphere causing aphasia, apraxia, alexia, agraphia and amusia. It was the reason why Ravel could not compose during the last years of his life. In contrast to Ravel, Shebalin and Britten continued writing music works of their own although aphasic after having sustained two strokes to the left hemisphere. While lacking clinical cases with selective ablative brain lesions, research into the music localization can be done using modern imaging technologies such as fMRI and PET. Exercising music (professionally) develops analytical process in the left hemisphere whereas other individuals process music in their right hemisphere. There is right ear (left hemisphere) predominance in musicians and vice versa in musical amateurs. Music lateralization towards the right hemisphere is seen in women and in inattentive listeners. It can be subject to cultural influence, so the Japanese process their traditional popular music in the left hemisphere, whereas Westerners process the same music in the right hemisphere. Music and language are processed separately; they are localized in homologous regions of the opposite

  7. Hypothalamic digoxin, hemispheric chemical dominance, and chronic bronchitis emphysema.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-09-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin (membrane sodium-potassium ATPase inhibitor, immunomodulator, and regulator of neurotransmitter/amino acid transport), dolichol (regulates N-glycosylation of proteins), and ubiquinone (free radical scavenger). This was assessed in patients with chronic bronchitis emphysema. The pathway was also assessed in patients with right hemispheric, left hemispheric, and bihemispheric dominance to find the role of hemispheric dominance in the pathogenesis of chronic bronchitis emphysema. All the 15 patients with chronic bronchitis emphysema were right-handed/left hemispheric dominant by the dichotic listening test. In patients with chronic bronchitis emphysema there was elevated digoxin synthesis, increased dolichol, and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate levels of RBC membrane in patients with chronic bronchitis emphysema. The same biochemical patterns were obtained in individuals with right hemispheric dominance. Endogenous digoxin by activating the calcineurin signal transduction pathway of T-cell can contribute to immune activation in chronic bronchitis emphysema. Increased free radical generation can also lead to immune activation. Endogenous synthesis of nicotine can contribute to the pathogenesis of the disease. Altered glycoconjugate metabolism and membranogenesis can lead to defective lysosomal stability contributing to the disease process by increased release of lysosomal proteases. The role of an endogenous digoxin and hemispheric dominance in the pathogenesis of chronic bronchitis emphysema and in the regulation of lung structure/function is discussed. The biochemical patterns obtained in chronic bronchitis emphysema is similar to those obtained in left

  8. Hypothalamic digoxin, hemispheric chemical dominance, and interstitial lung disease.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-10-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin, dolichol, and ubiquinone. This was assessed in patients with idiopathic pulmonary fibrosis and in individuals of differing hemispheric dominance to find out the role of hemispheric dominance in the pathogenesis of idiopathic pulmonary fibrosis. All 15 cases of interstitial lung disease were right-handed/left hemispheric dominant by the dichotic listening test. The isoprenoidal metabolites--digoxin, dolichol, and ubiquinone, RBC membrane Na(+)-K+ ATPase activity, serum magnesium, tyrosine/tryptophan catabolic patterns, free radical metabolism, glycoconjugate metabolism, and RBC membrane composition--were assessed in idiopathic pulmonary fibrosis as well as in individuals with differing hemispheric dominance. In patients with idiopathic pulmonary fibrosis there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in cholesterol phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in patients with idiopathic pulmonary fibrosis. Isoprenoid pathway dysfunction con tributes to the pathogenesis of idiopathic pulmonary fibrosis. The biochemical patterns obtained in interstitial lung disease are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. However, all the patients with interstitial lung disease were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Interstitial lung disease occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.

  9. Hypothalamic digoxin, hemispheric chemical dominance, and inflammatory bowel disease.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-09-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin, dolichol, and ubiquinone. It was considered pertinent to assess the pathway in inflammatory bowel disease (ulcerative colitis and regional ileitis). Since endogenous digoxin can regulate neurotransmitter transport, the pathway and the related cascade were also assessed in individuals with differing hemispheric dominance to find out the role of hemispheric dominance in its pathogenesis. All the patients with inflammatory bowel disease were right-handed/left hemispheric dominant by the dichotic listening test. The following parameters were measured in patients with inflammatory bowel disease and in individuals with differing hemispheric dominance: (1) plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; (2) tryptophan/tyrosine catabolic patterns; (3) free-radical metabolism; (4) glycoconjugate metabolism; and (5) membrane composition and RBC membrane Na+-K+ ATPase activity. Statistical analysis was done by ANOVA. In patients with inflammatory bowel disease there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these groups of patients. Inflammatory bowel disease is associated with an upregulated isoprenoid pathway and elevated digoxin secretion from the hypothalamus. This can contribute to immune activation, defective glycoprotein bowel antigen presentation, and autoimmunity and a schizophreniform psychosis important in its pathogenesis. The biochemical patterns obtained in inflammatory bowel disease is similar to those obtained in left-handed/right hemispheric dominant individuals by the dichotic listening test. But all the patients with peptic ulcer disease were right-handed/left

  10. Tomada de decisão no IGT: estudo de caso pós-AVC de hemisfério direito versus esquerdo Toma de decisión en el IGT: estudio de caso post-AVC de hemisferio derecho versus isquierdo Decision making in IGT: a case study of post-CVA of left versus right hemisphere

    Directory of Open Access Journals (Sweden)

    Caroline de Oliveira Cardoso

    2012-04-01

    decision-making process of two post-unilateral CVA adults as well as verifying the role of hemispheric laterality in the performance of Iowa Gambling Task (IGT. One adult with right hemisphere damage (RHD and another with left hemisphere damage (LHD, both following a subcortical ischemic post-CVA. The IGT was used to evaluate the decision making. Patients had appropriate performance on the IGT suggesting a general good ability to make decisions. However, only the patient with LHD presented signs of ascendant learning curve. Conclusion: These data indicate that a subcortical lesion independent of the hemisphere may not influence on the IGT performance. It is suggested that comparative studies of groups should be conducted in order to compare patients with frontal and non-frontal lesions, helping to characterize the decision-making process in population with unilateral vascular damage.

  11. Facilitation of speech repetition accuracy by theta burst stimulation of the left posterior inferior frontal gyrus.

    Science.gov (United States)

    Restle, Julia; Murakami, Takenobu; Ziemann, Ulf

    2012-07-01

    The posterior part of the inferior frontal gyrus (pIFG) in the left hemisphere is thought to form part of the putative human mirror neuron system and is assigned a key role in mapping sensory perception onto motor action. Accordingly, the pIFG is involved in motor imitation of the observed actions of others but it is not known to what extent speech repetition of auditory-presented sentences is also a function of the pIFG. Here we applied fMRI-guided facilitating intermittent theta burst transcranial magnetic stimulation (iTBS), or depressant continuous TBS (cTBS), or intermediate TBS (imTBS) over the left pIFG of healthy subjects and compared speech repetition accuracy of foreign Japanese sentences before and after TBS. We found that repetition accuracy improved after iTBS and, to a lesser extent, after imTBS, but remained unchanged after cTBS. In a control experiment, iTBS was applied over the left middle occipital gyrus (MOG), a region not involved in sensorimotor processing of auditory-presented speech. Repetition accuracy remained unchanged after iTBS of MOG. We argue that the stimulation type and stimulation site specific facilitating effect of iTBS over left pIFG on speech repetition accuracy indicates a causal role of the human left-hemispheric pIFG in the translation of phonological perception to motor articulatory output for repetition of speech. This effect may prove useful in rehabilitation strategies that combine repetitive speech training with iTBS of the left pIFG in speech disorders, such as aphasia after cerebral stroke. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Relationship between the change of language symptoms and the change of regional cerebral blood flow in the recovery process of two children with acquired aphasia.

    Science.gov (United States)

    Kozuka, Junko; Uno, Akira; Matsuda, Hiroshi; Toyoshima, Yoshiya; Hamano, Shin-Ichiro

    2017-06-01

    This study aimed to investigate the relationship between the change of language symptoms and the change of regional cerebral blood flow (rCBF) in the recovery process of two children with acquired aphasia caused by infarctions from Moyamoya disease with an onset age of 8years. We compared the results for the Standard Language Test of Aphasia (SLTA) with rCBF changes in 7 language regions in the left hemisphere and their homologous regions in the right hemisphere at 4 time points from 3weeks for up to 5years after the onset of aphasia, while controlling for the effect of age. In both cases, strong correlations were seen within a hemisphere between adjacent regions or regions that are connected by neuronal fibers, and between some language regions in the left hemisphere and their homologous regions in the right hemisphere. Conversely, there were differences between the two cases in the time course of rCBF changes during their recovery process. Consistent with previous studies, the current study suggested that both hemispheres were involved in the long-term recovery of language symptoms in children with acquired aphasia. We suggest that the differences between both cases during their recovery process might be influenced by the brain states before aphasia, by which hemisphere was affected, and by the timing of the surgical revascularization procedure. However, the changes were observed in the data obtained for rCBF with strong correlations with the changes in language performance, so it is possible that rCBF could be used as a biomarker for language symptom changes. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  13. Vocal reaction times to unilaterally presented concrete and abstract words: towards a theory of differential right hemispheric semantic processing.

    Science.gov (United States)

    Rastatter, M; Dell, C W; McGuire, R A; Loren, C

    1987-03-01

    Previous studies investigating hemispheric organization for processing concrete and abstract nouns have provided conflicting results. Using manual reaction time tasks some studies have shown that the right hemisphere is capable of analyzing concrete words but not abstract. Others, however, have inferred that the left hemisphere is the sole analyzer of both types of lexicon. The present study tested these issues further by measuring vocal reaction times of normal subjects to unilaterally presented concrete and abstract items. Results were consistent with a model of functional localization which suggests that the minor hemisphere is capable of differentially processing both types of lexicon in the presence of a dominant left hemisphere.

  14. Cerebral microangiopathies

    International Nuclear Information System (INIS)

    Linn, Jennifer

    2011-01-01

    Cerebral microangiopathies are a very heterogenous group of diseases characterized by pathological changes of the small cerebral vessels. They account for 20 - 30 % of all ischemic strokes. Degenerative microangiopathy and sporadic cerebral amyloid angiography represent the typical acquired cerebral microangiopathies, which are found in over 90 % of cases. Besides, a wide variety of rare, hereditary microangiopathy exists, as e.g. CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), Fabrys disease and MELAS syndrome (Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes). (orig.)

  15. Duplicated middle cerebral artery

    Science.gov (United States)

    Perez, Jesus; Machado, Calixto; Scherle, Claudio; Hierro, Daniel

    2009-01-01

    Duplicated middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery. The incidence DMCA is relatively law, and an association between this anomaly and cerebral aneurysms has been documented. There is a controversy whether DMCA may have perforating arteries. This is an important fact to consider in aneurysm surgery. We report the case of a 34-year-old black woman who suffered a subarachnoid hemorrhage and the angiography a left DMCA, and an aneurysm in an inferior branch of the main MCA. The DMCA and the MCA had perforating arteries. The aneurysm was clipped without complications. The observation of perforating arteries in our patient confirms that the DMCA may have perforating arteries. This is very important to be considered in cerebral aneurysms surgery. Moreover, the DMCA may potentially serve as a collateral blood supply to the MCA territory in cases of MCA occlusion. PMID:22140405

  16. Cerebral laterality for language is related to adult salivary testosterone levels but not digit ratio (2D:4D) in men: A functional transcranial Doppler ultrasound study.

    Science.gov (United States)

    Papadatou-Pastou, Marietta; Martin, Maryanne

    2017-03-01

    The adequacy of three competing theories of hormonal effects on cerebral laterality are compared using functional transcranial Doppler sonography (fTCD). Thirty-three adult males participated in the study (21 left-handers). Cerebral lateralization was measured by fTCD using an extensively validated word generation task. Adult salivary testosterone (T) and cortisol (C) concentrations were measured by luminescence immunoassay and prenatal T exposure was indirectly estimated by the somatic marker of 2nd to 4th digit length ratio (2D:4D). A significant quadratic relationship between degree of cerebral laterality for language and adult T concentrations was observed, with enhanced T levels for strong left hemisphere dominance and strong right hemisphere dominance. No systematic effects on laterality were found for cortisol or 2D:4D. Findings suggest that higher levels of T are associated with a relatively attenuated degree of interhemispheric sharing of linguistic information, providing support for the callosal and the sexual differentiation hypotheses rather than the Geschwind, Behan and Galaburda (GBG) hypothesis. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Cerebral hyperperfusion following carotid endarterectomy

    DEFF Research Database (Denmark)

    Schroeder, T; Sillesen, H; Sørensen, O

    1987-01-01

    , occurred in the low pressure ratio group, while the hemispheric asymmetry on average was unchanged in the high pressure ratio group. This relative hyperemia was most pronounced 2 to 4 days following reconstruction. The marked hyperemia, absolute as well as relative, in patients with a low ICA/CCA pressure...... ratio suggests a temporary impairment of autoregulation. Special care should be taken to avoid postoperative hypertension in such patients, who typically have preoperative hypoperfusion, to avoid the occurrence of cerebral edema or hemorrhage....

  18. Cerebral scintigraphy by 99mTc-HMPAO in sleep apnea syndromes (SAS) during the wakeful state

    International Nuclear Information System (INIS)

    Tainturier, C.; Benamor, M.; Hausser-Hauw, C.; Rakotonanahary, D.; Fleury, B.

    1997-01-01

    The SAS is associated to cerebral hemodynamic modifications and to a high frequency of cerebro-vascular accidents. The aim of this study was to verify, during wakeful state, the cerebral hemodynamic in 14 patients afflicted with SAS of various intensity (Apnea Index = 5-120/h). 555 MBq of 99m Tc-HMPAO were injected in patients maintained awake. The images were obtained 20 minutes after injection by mean of a double-head chamber equipped with fan-beam collimators. They were interpreted visually by two independent readers. Anomalies of cerebral fixation were observed in 12/14 patients. They were small sores of diffuse hypo-fixations, with a 'riddly' aspect (4 cases), sores of bi-temporal hypo-fixation with a right- or left- hemispheric predominance (6 cases), or right fronto-temporal hypo-fixations (2 cases). The cerebral fixation anomalies were reported in the SASs. Ficker et al (1997) have shown in-sleep frontal hypo-perfusions in 5/14 apneic patients, reversible under continuous positive airing pressure (CPAP). In conclusion, anomalies of cerebral fixation exist in SAS-carrying patients, even in the wakeful state. Questions about hypoperfusion, pre-lacunar syndrome, atrophy still remain. A check of this study is planned after the CPAP treatment to determine the hemodynamic or anatomic origin and the anomaly reversibility

  19. Aphasia following left thalamic hemorrhage

    International Nuclear Information System (INIS)

    Makishita, Hideo; Miyasaka, Motomaro; Tanizaki, Yoshio; Yanagisawa, Nobuo; Sugishita, Morihiro.

    1984-01-01

    We reported 7 patients with left thalamic hemorrhage in the chronic stage (from 1.5 months to 4.5 months), and described language disorders examined by Western Aphasia Battery (WAB) and measured cerebral blood flow by single photon emission CT. Examination of language by WAB revealed 4 aphasics out of 7 cases, and 3 patients had no language deficit. The patient with Wernicke's aphasia showed low density area only in the left posterior thalamus in X-ray CT, and revealed severe low blood flow area extending to left temporal lobe in emission CT. In the case with transcortical sensory aphasia, although X-ray CT showed no obvious low density area, emission CT revealed moderate low flow area in watershed area that involved the territory between posterior cerebral and middle cerebral arteries in the left temporooccipital region in addition to low blood flow at the left thalamus. In one of the two patients classified as anomic aphasia, whose score of repetition (8.4) was higher than that of comprehension (7.4), emission CT showed slight low flow area at the temporo-occipital region similarly as the case with transcortical sensory aphasia. In another case with anomic aphasia, scored 9 on both fluensy and comprehension subtests and 10 on repetition, there was wide low density area all over the left thalamus and midline shift to the right in X-ray CT, and emission CT showed severe low blood flow in the same region spreading widely toward the cerebral surface. On the other hand, in all of the 3 patients without aphasia, emission CT showed low flow region restricted to the left thalamus. (J.P.N.)

  20. Characterization and quantification of cerebral edema induced by synchrotron x-ray microbeam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Serduc, Raphael; Looij, Yohan van de; Francony, Gilles; Verdonck, Olivier; Sanden, Boudewijn van der; Farion, Regine; Segebarth, Christoph; Remy, Chantal; Lahrech, Hana [INSERM, U836, F-38043 Grenoble (France); Laissue, Jean [Institute of Pathology, University of Bern (Switzerland); Braeuer-Krisch, Elke; Siegbahn, Erik Albert; Bravin, Alberto; Prezado, Yolanda [European Synchrotron Radiation Facility, F-38043 Grenoble (France)], E-mail: serduc@esrf.fr

    2008-03-07

    Cerebral edema is one of the main acute complications arising after irradiation of brain tumors. Microbeam radiation therapy (MRT), an innovative experimental radiotherapy technique using spatially fractionated synchrotron x-rays, has been shown to spare radiosensitive tissues such as mammal brains. The aim of this study was to determine if cerebral edema occurs after MRT using diffusion-weighted MRI and microgravimetry. Prone Swiss nude mice's heads were positioned horizontally in the synchrotron x-ray beam and the upper part of the left hemisphere was irradiated in the antero-posterior direction by an array of 18 planar microbeams (25 mm wide, on-center spacing 211 mm, height 4 mm, entrance dose 312 Gy or 1000 Gy). An apparent diffusion coefficient (ADC) was measured at 7 T 1, 7, 14, 21 and 28 days after irradiation. Eventually, the cerebral water content (CWC) was determined by microgravimetry. The ADC and CWC in the irradiated (312 Gy or 1000 Gy) and in the contralateral non-irradiated hemispheres were not significantly different at all measurement times, with two exceptions: (1) a 9% ADC decrease (p < 0.05) was observed in the irradiated cortex 1 day after exposure to 312 Gy, (2) a 0.7% increase (p < 0.05) in the CWC was measured in the irradiated hemispheres 1 day after exposure to 1000 Gy. The results demonstrate the presence of a minor and transient cellular edema (ADC decrease) at 1 day after a 312 Gy exposure, without a significant CWC increase. One day after a 1000 Gy exposure, the CWC increased, while the ADC remained unchanged and may reflect the simultaneous presence of cellular and vasogenic edema. Both types of edema disappear within a week after microbeam exposure which may confirm the normal tissue sparing effect of MRT. For more information on this article, see medicalphysicsweb.org.

  1. MRI findings of acute cerebral swelling and brain edema in the acute stage

    International Nuclear Information System (INIS)

    Oki, Hideo; Ueda, Shin; Matsumoto, Keizo; Kashihara, Michiharu; Furuichi, Masashi.

    1988-01-01

    We report two cases, one of acute cerebral swelling and the other with a major stroke, whose MRI has shown very interesting findings. Case 1, a 32-year-old male, was admitted to our service because of a lowering of his consciousness immediately after a head injury. On admission, the patient was semicomatous (E 1 M 2 V 1 , with anisocoria (R > L). His plain skull X-ray was normal. A CT scan, however, demonstrated right isodensity hemispheric swelling associated with a subarachnoid hemorrhage in the right Sylvian fissure. A right carotid angiogram showed no vascular disorders. MR imaging of the spin density demonstrated a hyperintensitive thickening of the gray matter in the whole right hemisphere. Case 2, a 58-year-old female, was admitted because of a sudden onset of loss of consciousness, with right hemiparesis and dysarthria. On admission, her consciousness was semicomatous (E 1 M 3 V 1 ), and it deteriorated to a deep coma 1 hour later. A CT scan demonstrated a diffuse left hemispheric low density, with a finding of hemorrhagic infarction in the basal ganglia. MR imaging of the spin density showed a hyperintensitive thickening of the gray matter resembling that of Case 1. The findings of the spin-echo images of our two cases showed a hyperintensitive thickening of the gray matter in both. The hyperintensity and thickening of the gray matter apparently indicated a sort of hyperemia and brain edema. These findings led us to suspect that the hyperemia associated with acute cerebral swelling and ischemic brain edema of our two cases originated in the gray matter, although it has been considered that the pathogenesis of acute cerebral swelling is not known and that brain edema, especially vasogenic edema, will mostly develop in the white matter rather than in the gray matter. (author)

  2. 99mTc-HMPAO Regional Cerebral Blood Flow SPECT in Transient Ischemic Attacks

    International Nuclear Information System (INIS)

    Ahn, Myeong Im; Park, Young Ha; Lee, Sung Yong; Chung, Soo Kyo; Kim, Jong Woo; Bahk, Yong Whee

    1989-01-01

    Transient ischemic attacks (TJAs) is a syndrome resulting from brain ischemia lasting less than 24 hours. The mechanisms of TIAs may be similar to those of cerebral embolism and thrombosis, and thus TIAs may be followed by cerebral infarction. Despite the availability of CT scanning, the diagnosis and management of TIAs continue to be difficult. Recently SPECT has been advocated as a diagnostic imaging modality. We performed 99m Tc-HMPAO regional cerebral blood flow (rCRF) SPECT in 24 patients with the clinical diagnosis of TIAs to assess its ability to detect early changes of rCBF, and determine the diagnostic value. Ten men and fourteen women with an average of 51 years (range; 27-74 years) were included. All but 8 patients had normal brain CT prior to SPECT. The two patients had moderate degree of brain atrophy and the 6 patients nonspecific calcifications. Eighteen of the 24 patients had abnormal 99m Tc-HMPAO rCBF SPECT. Fifteen had unilateral involvement and the other three had bilateral involvements. Seventy-five percents of the defects were found in the left cerebral hemisphere. According to the distribution of the lesions (total number: 34 lesions), fourteen were in the parietal, eight in the temporal, and the remainders were elsewhere. 99m Tc-HMPAO rCHF SPECT is sensitive in detecting rCRF abnormalities in patients with TIAs, and represent the most accurate diagnostic tool available in the diagnosis of TIAs

  3. Comparison between visual half-field performance and cerebral blood flow changes as indicators of language dominance.

    Science.gov (United States)

    Krach, S; Chen, L M; Hartje, W

    2006-03-01

    The determination of hemispheric language dominance (HLD) can be accomplished in two ways. One approach relies on hemispheric differences in cerebral blood flow velocity (CBFV) changes during language activity, while the other approach makes use of performance differences between the left and right visual field when verbal stimuli are presented in a tachistoscopic visual field paradigm. Since both methodologically different approaches claim to assess functional HLD, it seems plausible to expect that the respective laterality indices (LI) would correspond. To test this expectation we measured language lateralisation in 58 healthy right-handed, left-handed, and ambidextrous subjects with both approaches. CBFV changes were recorded with functional transcranial Doppler sonography (fTCD). We applied a lexical decision task with bilateral visual field presentation of abstract nouns and, in addition, a task of mental word generation. In the lexical decision task, a highly significant right visual field advantage was observed for number of correct responses and reaction times, while at the same time and contrary to expectation the increase of CBFV was significantly higher in the right than left hemisphere. During mental word generation, the acceleration of CBF was significantly higher in the left hemisphere. A comparison between individual LI derived from CBF measurement during mental word generation and from visual field performances in the lexical decision task showed a moderate correspondence in classifying the subjects' HLD. However, the correlation between the corresponding individual LI was surprisingly low and not significant. The results are discussed with regard to the issue of a limited reliability of behavioural LI on the one hand and the possibility of a fundamental difference between the behavioural and the physiological indicators of laterality on the other hand.

  4. Morphometry of A1 segment of the anterior cerebral artery and its clinical importance.

    Science.gov (United States)

    Krishnamurthy, A; Nayak, S R; Bagoji, I B; D'Costa, S; Pai, M M; Jiji, P J; Kumar, C G; Rai, R

    2010-01-01

    Anterior cerebral artery, one of the terminal branches of the internal carotid artery is an important vessel taking part in the formation of circle of Willis. It supplies a large part of the medial surface of the cerebral hemisphere containing the areas of motor and somatosensory cortices of the lower limb. Aim of this study was the morphometry of A1 segment of the anterior cerebral artery. 93 formalin fixed brain specimen of either sex and of Indian origin were studied. The mean length, mean external diameter and the anomalies present in A1 segment of the vessel were studied in detail and photographed. The mean length of A1 segment of the vessel was 14.49+/-0.28 mm and 14.22+/-0.22 mm on right and left side respectively. The mean external diameter of the vessel on right and left side was 2.12+/-0.07 mm and 2.32+/-0.06 mm respectively. Narrowing, aneurysm formation, buttonhole formation and median anterior cerebral artery were the anomalies seen with an occurrence of 15.05%, 5.37%, 3.22% and 12.9%, respectively. The above anomalies did not have any sex or side predilection. Knowledge of morphometry of the vessel will be of use to neurosurgeons while performing the shunt operation, in assessing the feasibility of such operations and in the choice of patients. From this study we infer that the morphometry of anterior cerebral artery varies in different population and that the neurosurgeons operating should have a thorough knowledge of the possible variations.

  5. When One Hemisphere Takes Control: Metacontrol in Pigeons (Columba livia)

    Science.gov (United States)

    Adam, Ruth; Güntürkün, Onur

    2009-01-01

    Background Vertebrate brains are composed of two hemispheres that receive input, compute, and interact to form a unified response. How the partially different processes of both hemispheres are integrated to create a single output is largely unknown. In some cases one hemisphere takes charge of the response selection – a process known as metacontrol. Thus far, this phenomenon has only been shown in a handful of studies with primates, mostly conducted in humans. Metacontrol, however, is even more relevant for animals like birds with laterally placed eyes and complete chiasmatic decussation since visual input to the hemispheres is largely different. Methodology/Principal Findings Homing pigeons (Columba livia) were trained with a color discrimination task. Each hemisphere was trained with a different color pair and therefore had a different experience. Subsequently, the pigeons were binocularly examined with two additional stimuli that combined the positive color of one hemisphere with a negative color that had been shown to the other, omitting the availability of a coherent solution and confronting the pigeons with a conflicting situation. Some of the pigeons responded to both stimuli, indicating that none of the hemispheres dominated the overall preference. Some birds, however, responded primarily to one of the conflicting stimuli, showing that they based their choice on the left- or right-monocularly learned color pair, indicating hemispheric metacontrol. Conclusions/Significance We could demonstrate for the first time that metacontrol is a widespread phenomenon that also exists in birds, and thus in principle requires no corpus callosum. Our results are closely similar to those in humans: monocular performance was higher than binocular one and animals displayed different modes of hemispheric dominance. Thus, metacontrol is a dynamic and widely distributed process that possibly constitutes a requirement for all animals with a bipartite brain to confront the

  6. When one hemisphere takes control: metacontrol in pigeons (Columba livia.

    Directory of Open Access Journals (Sweden)

    Ruth Adam

    Full Text Available Vertebrate brains are composed of two hemispheres that receive input, compute, and interact to form a unified response. How the partially different processes of both hemispheres are integrated to create a single output is largely unknown. In some cases one hemisphere takes charge of the response selection--a process known as metacontrol. Thus far, this phenomenon has only been shown in a handful of studies with primates, mostly conducted in humans. Metacontrol, however, is even more relevant for animals like birds with laterally placed eyes and complete chiasmatic decussation since visual input to the hemispheres is largely different.Homing pigeons (Columba livia were trained with a color discrimination task. Each hemisphere was trained with a different color pair and therefore had a different experience. Subsequently, the pigeons were binocularly examined with two additional stimuli that combined the positive color of one hemisphere with a negative color that had been shown to the other, omitting the availability of a coherent solution and confronting the pigeons with a conflicting situation. Some of the pigeons responded to both stimuli, indicating that none of the hemispheres dominated the overall preference. Some birds, however, responded primarily to one of the conflicting stimuli, showing that they based their choice on the left- or right-monocularly learned color pair, indicating hemispheric metacontrol.We could demonstrate for the first time that metacontrol is a widespread phenomenon that also exists in birds, and thus in principle requires no corpus callosum. Our results are closely similar to those in humans: monocular performance was higher than binocular one and animals displayed different modes of hemispheric dominance. Thus, metacontrol is a dynamic and widely distributed process that possibly constitutes a requirement for all animals with a bipartite brain to confront the problem of choosing between two hemisphere

  7. Cerebral toxoplasmosis in a diffuse large B cell lymphoma patient

    International Nuclear Information System (INIS)

    Savsek, Lina; Opaskar, Tanja Ros

    2016-01-01

    Toxoplasmosis is an opportunistic protozoal infection that has, until now, probably been an underestimated cause of encephalitis in patients with hematological malignancies, independent of stem cell or bone marrow transplant. T and B cell depleting regimens are probably an important risk factor for reactivation of a latent toxoplasma infection in these patients. We describe a 62-year-old HIV-negative right-handed Caucasian female with systemic diffuse large B cell lymphoma who presented with sudden onset of high fever, headache, altered mental status, ataxia and findings of pancytopenia, a few days after receiving her final, 8 th cycle of rituximab, cyclophosphamide, vincristine, doxorubicin, prednisolone (R-CHOP) chemotherapy regimen. A progression of lymphoma to the central nervous system was suspected. MRI of the head revealed multiple on T2 and fluid attenuated inversion recovery (FLAIR) hyperintense parenchymal lesions with mild surrounding edema, located in both cerebral and cerebellar hemispheres that demonstrated moderate gadolinium enhancement. The polymerase chain reaction on cerebrospinal fluid (CSF PCR) was positive for Toxoplasma gondii. The patient was diagnosed with toxoplasmic encephalitis and successfully treated with sulfadiazine, pyrimethamine and folic acid. Due to the need for maintenance therapy with rituximab for lymphoma remission, the patient now continues with secondary prophylaxis of toxoplasmosis. With this case report, we wish to emphasize the need to consider cerebral toxoplasmosis in patients with hematological malignancies on immunosuppressive therapy when presenting with new neurologic deficits. In such patients, there are numerous differential diagnoses for cerebral toxoplasmosis, and the CNS lymphoma is the most difficult among all to distinguish it from. If left untreated, cerebral toxoplasmosis has a high mortality rate; therefore early recognition and treatment are of essential importance

  8. Processing of unconventional stimuli requires the recruitment of the non-specialized hemisphere

    Directory of Open Access Journals (Sweden)

    Yoed Nissan Kenett

    2015-02-01

    Full Text Available In the present study we investigate hemispheric processing of conventional and unconventional visual stimuli in the context of visual and verbal creative ability. In Experiment 1, we studied two unconventional visual recognition tasks – Mooney face and objects' silhouette recognition – and found a significant relationship between measures of verbal creativity and unconventional face recognition. In Experiment 2 we used the split visual field paradigm to investigate hemispheric processing of conventional and unconventional faces and its relation to verbal and visual characteristics of creativity. Results showed that while conventional faces were better processed by the specialized right hemisphere, unconventional faces were better processed by the non-specialized left hemisphere. In addition, only unconventional face processing by the non-specialized left hemisphere was related to verbal and visual measures of creative ability. Our findings demonstrate the role of the non-specialized hemisphere in processing unconventional stimuli and how it relates to creativity.

  9. Topographic brain mapping of emotion-related hemisphere asymmetries.

    Science.gov (United States)

    Roschmann, R; Wittling, W

    1992-03-01

    The study used topographic brain mapping of visual evoked potentials to investigate emotion-related hemisphere asymmetries. The stimulus material consisted of color photographs of human faces, grouped into two emotion-related categories: normal faces (neutral stimuli) and faces deformed by dermatological diseases (emotional stimuli). The pictures were presented tachistoscopically to 20 adult right-handed subjects. Brain activity was recorded by 30 EEG electrodes with linked ears as reference. The waveforms were averaged separately with respect to each of the two stimulus conditions. Statistical analysis by means of significance probability mapping revealed significant differences between stimulus conditions for two periods of time, indicating right hemisphere superiority in emotion-related processing. The results are discussed in terms of a 2-stage-model of emotional processing in the cerebral hemispheres.

  10. Correlation of severity of aphasia with cerebral blood flow. A study with /sup 133/Xe inhalation method

    Energy Technology Data Exchange (ETDEWEB)

    Tagawa, Koichi; Sugimoto, Keiko; Sone, Noriaki; Yamaguchi, Takenori; Naritomi, Hiroaki; Sawada, Tohru (National Cardiovascular Center, Suita, Osaka (Japan))

    1982-11-01

    In 46 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured by /sup 133/Xe inhalation method, and relationship between severity of aphasia and degree of rCBF reduction was investigated. Measurements of rCBF were performed after 2 months of ictus in all patients. At the time of rCBF measurements, the severity of aphasia was mild in 13, moderate in 16 and severe in the other 17 patients. Control rCBF values were obtained from 16 subjects who had neither neurological deficits nor abnormal findings on CT scan. In control group, mean hemispheric rCBF values (mCBF), which were calculated from initial slope index, were 49.1 +- 3.8 and 49.4 +- 3.9 respectively in the right and left hemisphere. In all aphasic patients but two who had mild aphasia, mCBF in the left hemisphere showed lower values as compared to that in the right hemisphere. The mCBF in the left hemisphere was 46.5 +- 5.3 in the mild group, 41.3 +- 5.8 in the moderate group and 34.3 +- 5.0 in the severe group. The values in the moderate and severe groups were significantly reduced as compared to the control or those in the mild group. The mCBF in the severe group was also significantly lower than those in the moderate group. The mCBF in the right hemisphere was 48.4 +- 6.3 in the mild group, 45.6 +- 6.1 in the moderate group and 38.6 +- 4.9 in the severe group. The values in the severe group were significantly reduced as compared to those in the other groups as well as the control. The present study suggests that measurements of rCBF by /sup 133/Xe inhalation method are valid for the evaluation of severity of aphasia in stroke patients.

  11. Cerebral glucose metabolic patterns in Alzheimer's disease. Effect of gender and age at dementia onset

    International Nuclear Information System (INIS)

    Small, G.W.; Kuhl, D.E.; Riege, W.H.; Fujikawa, D.G.; Ashford, J.W.; Metter, E.J.; Mazziotta, J.C.

    1989-01-01

    No previous study of Alzheimer's disease has, to our knowledge, assessed the effect of both age at dementia onset and gender on cerebral glucose metabolic patterns. To this end, we used positron emission tomography (fludeoxyglucose F 18 method) to study 24 patients with clinical diagnoses of probable Alzheimer's disease. Comparisons of the 13 patients with early-onset dementia (less than 65 years of age) with the 11 patients with late-onset dementia (greater than 65 years of age) revealed significantly lower left parietal metabolic ratios (left posterior parietal region divided by the hemispheric average) in the early-onset group. The metabolic ratio of posterior parietal cortex divided by the relatively disease-stable average of caudate and thalamus also separated patients with early-onset dementia from those with late-onset dementia, but not men from women. Further comparisons between sexes showed that, in all brain regions studied, the 9 postmenopausal women had higher nonweighted mean metabolic rates than the 15 men from the same age group, with hemispheric sex differences of 9% on the right and 7% on the left. These results demonstrate decreased parietal ratios in early-onset dementia of Alzheimer's disease, independent of a gender effect

  12. Imitation of Para-Phonological Detail Following Left Hemisphere Lesions

    Science.gov (United States)

    Kappes, Juliane; Baumgaertner, Annette; Peschke, Claudia; Goldenberg, Georg; Ziegler, Wolfram

    2010-01-01

    Imitation in speech refers to the unintentional transfer of phonologically irrelevant acoustic-phonetic information of auditory input into speech motor output. Evidence for such imitation effects has been explained within the framework of episodic theories. However, it is largely unclear, which neural structures mediate speech imitation and how…

  13. Reversible hemispheric hypoperfusion in two cases of SMART syndrome.

    Science.gov (United States)

    Wai, Karmen; Balabanski, Anna; Chia, Nicholas; Kleinig, Timothy

    2017-09-01

    Stroke-like migraine attacks after radiation therapy (SMART) syndrome manifests as prolonged episodes of cortical dysfunction, years after cranial irradiation. We present two cases demonstrating reversible hemispheric hypoperfusion. Case 1 presented with left hemispheric symptoms following previous similar episodes. CT perfusion (CTP) demonstrated reversible hemispheric hypoperfusion; subsequent investigations were consistent with SMART syndrome. Case 2 presented following the third episode of a hemispheric syndrome with near-identical CTP abnormalities. L-arginine was administered with rapid reversal of clinical and CTP abnormalities. We conclude that SMART syndrome may demonstrate significant hypoperfusion on hyperacute CTP without subsequent infarction. Impaired cerebrovascular autoregulation probably contributes to cortical dysfunction in SMART syndrome. L-arginine warrants investigation as a potential treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Hemispheric asymmetry of electroencephalography-based functional brain networks.

    Science.gov (United States)

    Jalili, Mahdi

    2014-11-12

    Electroencephalography (EEG)-based functional brain networks have been investigated frequently in health and disease. It has been shown that a number of graph theory metrics are disrupted in brain disorders. EEG-based brain networks are often studied in the whole-brain framework, where all the nodes are grouped into a single network. In this study, we studied the brain networks in two hemispheres and assessed whether there are any hemispheric-specific patterns in the properties of the networks. To this end, resting state closed-eyes EEGs from 44 healthy individuals were processed and the network structures were extracted separately for each hemisphere. We examined neurophysiologically meaningful graph theory metrics: global and local efficiency measures. The global efficiency did not show any hemispheric asymmetry, whereas the local connectivity showed rightward asymmetry for a range of intermediate density values for the constructed networks. Furthermore, the age of the participants showed significant direct correlations with the global efficiency of the left hemisphere, but only in the right hemisphere, with local connectivity. These results suggest that only local connectivity of EEG-based functional networks is associated with brain hemispheres.

  15. Perturbation of the left inferior frontal gyrus triggers adaptive plasticity in the right homologous area during speech production

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Saur, Dorothee; Price, Cathy J

    2013-01-01

    The role of the right hemisphere in aphasia recovery after left hemisphere damage remains unclear. Increased activation of the right hemisphere has been observed after left hemisphere damage. This may simply reflect a release from transcallosal inhibition that does not contribute to language...... functions. Alternatively, the right hemisphere may actively contribute to language functions by supporting disrupted processing in the left hemisphere via interhemispheric connections. To test this hypothesis, we applied off-line continuous theta burst stimulation (cTBS) over the left inferior frontal gyrus...... (IFG) in healthy volunteers, then used functional MRI to investigate acute changes in effective connectivity between the left and right hemispheres during repetition of auditory and visual words and pseudowords. In separate sessions, we applied cTBS over the left anterior IFG (aIFG) or posterior IFG (p...

  16. Hemispheric asymmetries in dorsal language pathway white-matter tracts: A magnetic resonance imaging tractography and functional magnetic resonance imaging study.

    Science.gov (United States)

    Silva, Guilherme; Citterio, Alberto

    2017-10-01

    Introduction Previous studies have shown that the arcuate fasciculus has a leftward asymmetry in right-handers that could be correlated with the language lateralisation defined by functional magnetic resonance imaging. Nonetheless, information about the asymmetry of the other fibres that constitute the dorsal language pathway is scarce. Objectives This study investigated the asymmetry of the white-matter tracts involved in the dorsal language pathway through the diffusion tensor imaging (DTI) technique, in relation to language hemispheric dominance determined by task-dependent functional magnetic resonance imaging (fMRI). Methods We selected 11 patients (10 right-handed) who had been studied with task-dependent fMRI for language areas and DTI and who had no language impairment or structural abnormalities that could compromise magnetic resonance tractography of the fibres involved in the dorsal language pathway. Laterality indices (LI) for fMRI and for the volumes of each tract were calculated. Results In fMRI, all the right-handers had left hemispheric lateralisation, and the ambidextrous subject presented right hemispheric dominance. The arcuate fasciculus LI was strongly correlated with fMRI LI ( r = 0.739, p = 0.009), presenting the same lateralisation of fMRI in seven subjects (including the right hemispheric dominant). It was not asymmetric in three cases and had opposite lateralisation in one case. The other tracts presented predominance for rightward lateralisation, especially superior longitudinal fasciculus (SLF) II/III (nine subjects), but their LI did not correlate (directly or inversely) with fMRI LI. Conclusion The fibres that constitute the dorsal language pathway have an asymmetric distribution in the cerebral hemispheres. Only the asymmetry of the arcuate fasciculus is correlated with fMRI language lateralisation.

  17. Right Hemispheric Dominance in Processing of Unconscious Negative Emotion

    Science.gov (United States)

    Sato, Wataru; Aoki, Satoshi

    2006-01-01

    Right hemispheric dominance in unconscious emotional processing has been suggested, but remains controversial. This issue was investigated using the subliminal affective priming paradigm combined with unilateral visual presentation in 40 normal subjects. In either left or right visual fields, angry facial expressions, happy facial expressions, or…

  18. Right Hemisphere Dominance for Emotion Processing in Baboons

    Science.gov (United States)

    Wallez, Catherine; Vauclair, Jacques

    2011-01-01

    Asymmetries of emotional facial expressions in humans offer reliable indexes to infer brain lateralization and mostly revealed right hemisphere dominance. Studies concerned with oro-facial asymmetries in nonhuman primates largely showed a left-sided asymmetry in chimpanzees, marmosets and macaques. The presence of asymmetrical oro-facial…

  19. Age-related shifts in hemispheric dominance for syntactic processing.

    Science.gov (United States)

    Leckey, Michelle; Federmeier, Kara D

    2017-12-01

    Recent ERP data from young adults have revealed that simple syntactic anomalies elicit different patterns of lateralization in right-handed participants depending upon their familial sinistrality profile (whether or not they have left-handed biological relatives). Right-handed participants who do not have left-handed relatives showed a strongly lateralized response pattern, with P600 responses following left-hemisphere-biased presentations and N400 responses following right-hemisphere-biased presentations. Given that the literature on aging has documented a tendency to change across adulthood from asymmetry of function to a more bilateral pattern, we tested the stability of this asymmetric response to syntactic violations by recording ERPs as 24 older adults (age 60+) with no history of familial sinistrality made grammaticality judgments on simple two-word phrases. Results showed that the asymmetric pattern observed in right-handed adults without familial sinistrality indeed changes with age, such that P600 responses come to be elicited not only with left-hemisphere-biased but also with right-hemisphere-biased presentations in older adults. These findings suggest that, as with many other cognitive functions, syntactic processing becomes more bilateral with age. © 2017 Society for Psychophysiological Research.

  20. Hemispheric lateralization of motor thresholds in relation to stuttering.

    Directory of Open Access Journals (Sweden)

    Per A Alm

    Full Text Available Stuttering is a complex speech disorder. Previous studies indicate a tendency towards elevated motor threshold for the left hemisphere, as measured using transcranial magnetic stimulation (TMS. This may reflect a monohemispheric motor system impairment. The purpose of the study was to investigate the relative side-to-side difference (asymmetry and the absolute levels of motor threshold for the hand area, using TMS in adults who stutter (n = 15 and in controls (n = 15. In accordance with the hypothesis, the groups differed significantly regarding the relative side-to-side difference of finger motor threshold (p = 0.0026, with the stuttering group showing higher motor threshold of the left hemisphere in relation to the right. Also the absolute level of the finger motor threshold for the left hemisphere differed between the groups (p = 0.049. The obtained results, together with previous investigations, provide support for the hypothesis that stuttering tends to be related to left hemisphere motor impairment, and possibly to a dysfunctional state of bilateral speech motor control.

  1. Hemispheric Lateralization of Motor Thresholds in Relation to Stuttering

    Science.gov (United States)

    Alm, Per A.; Karlsson, Ragnhild; Sundberg, Madeleine; Axelson, Hans W.

    2013-01-01

    Stuttering is a complex speech disorder. Previous studies indicate a tendency towards elevated motor threshold for the left hemisphere, as measured using transcranial magnetic stimulation (TMS). This may reflect a monohemispheric motor system impairment. The purpose of the study was to investigate the relative side-to-side difference (asymmetry) and the absolute levels of motor threshold for the hand area, using TMS in adults who stutter (n = 15) and in controls (n = 15). In accordance with the hypothesis, the groups differed significantly regarding the relative side-to-side difference of finger motor threshold (p = 0.0026), with the stuttering group showing higher motor threshold of the left hemisphere in relation to the right. Also the absolute level of the finger motor threshold for the left hemisphere differed between the groups (p = 0.049). The obtained results, together with previous investigations, provide support for the hypothesis that stuttering tends to be related to left hemisphere motor impairment, and possibly to a dysfunctional state of bilateral speech motor control. PMID:24146930

  2. Hemispheric Lateralization of Verbal and Spatial Working Memory during Adolescence

    Science.gov (United States)

    Nagel, Bonnie J.; Herting, Megan M.; Maxwell, Emily C.; Bruno, Richard; Fair, Damien

    2013-01-01

    Adult functional magnetic resonance imaging (fMRI) literature suggests that a left-right hemispheric dissociation may exist between verbal and spatial working memory (WM), respectively. However, investigation of this type has been obscured by incomparable verbal and spatial WM tasks and/or visual inspection at arbitrary thresholds as means to…

  3. What Does the Right Hemisphere Know about Phoneme Categories?

    Science.gov (United States)

    Wolmetz, Michael; Poeppel, David; Rapp, Brenda

    2011-01-01

    Innate auditory sensitivities and familiarity with the sounds of language give rise to clear influences of phonemic categories on adult perception of speech. With few exceptions, current models endorse highly left-hemisphere-lateralized mechanisms responsible for the influence of phonemic category on speech perception, based primarily on results…

  4. Hemispheric Specialization and the Growth of Human Understanding.

    Science.gov (United States)

    Kinsbourne, Marcel

    1982-01-01

    Connectionistic notions of hemispheric specialization and use are incompatible with the network organization of the human brain. Although brain organization has correspondence with phenomena at more complex levels of analysis, the correspondence is not categorical in nature, as has been claimed by the left-brain/right-brain theorists. (Author/GC)

  5. Relationship between cognitive function and regional cerebral blood flow in stroke patients using 99mTc-ECD SPECT 3DSRT

    International Nuclear Information System (INIS)

    Sasaki, Nobuyuki; Abo, Masahiro

    2006-01-01

    The purpose of this study was to investigate the associations between regional cerebral blood flow (rCBF) and cognitive function in patients having a local stroke within the thalamus or putamen. The Mini-Mental State Examination (MMSE) and the Kohs Block Design Test (KBDT) were used to evaluate cognitive function. Brain single-photon emission computed tomography (SPECT) was performed with 99m Tc-ethyl cysteinate dimer and analyzed with a 3-dimensional stereotactic region-of-interest template. Subjects were divided into subgroups according to the total MMSE score (D [Dementia: 23 points or less] and N [Normal: 24 points or more]) and according to KBDT scores (B [Bad: less than IQ 70] and G [Good: IQ 70 or more]). The rCBF was decreased in the MMSE D subgroup, especially in patients with a left putamen lesion, and in the KBDT B subgroup, especially in patients with a left thalamus lesion. When the lesion was in the right hemisphere, no significant difference in rCBF was found between the MMSE D and N subgroups or between the KBDT B and G subgroups. SPECT is useful for clinical evaluation of cerebral vascular disease, especially in patients with left hemispheric lesions. Additional data and further detailed evaluations are needed. (author)

  6. Hemispheric Asymmetries in Semantic Processing: Evidence from False Memories for Ambiguous Words

    Science.gov (United States)

    Faust, Miriam; Ben-Artzi, Elisheva; Harel, Itay

    2008-01-01

    Previous research suggests that the left hemisphere (LH) focuses on strongly related word meanings; the right hemisphere (RH) may contribute uniquely to the processing of lexical ambiguity by activating and maintaining a wide range of meanings, including subordinate meanings. The present study used the word-lists false memory paradigm [Roediger,…

  7. Hemispheric Specialization and Creative Thinking: A Meta-Analytic Review of Lateralization of Creativity

    Science.gov (United States)

    Mihov, Konstantin M.; Denzler, Markus; Forster, Jens

    2010-01-01

    In the last two decades research on the neurophysiological processes of creativity has found contradicting results. Whereas most research suggests right hemisphere dominance in creative thinking, left-hemisphere dominance has also been reported. The present research is a meta-analytic review of the literature to establish how creative thinking…

  8. Aphasic Patients Exhibit a Reversal of Hemispheric Asymmetries in Categorical Color Discrimination

    Science.gov (United States)

    Paluy, Yulia; Gilbert, Aubrey L.; Baldo, Juliana V.; Dronkers, Nina F.; Ivry, Richard B.

    2011-01-01

    Patients with left hemisphere (LH) or right hemisphere (RH) brain injury due to stroke were tested on a speeded, color discrimination task in which two factors were manipulated: (1) the categorical relationship between the target and the distracters and (2) the visual field in which the target was presented. Similar to controls, the RH patients…

  9. Questions of Brain Hemispheric Specialization and Gender Difference in Spatial Tests.

    Science.gov (United States)

    McWhinnie, Harold J.

    This paper presents a review of selected literature relevant to a general question of hemispheric specialization (right or left brain) and questions of gender differences in spatial abilities among a group of art students. Three basic questions for discussion are proposed: (1) is there a relationship between hemispheric dominance and spatial…

  10. Right Hemisphere Sensitivity to Novel Metaphoric Relations: Application of the Signal Detection Theory

    Science.gov (United States)

    Mashal, N.; Faust, M.

    2008-01-01

    The present study used the signal detection theory to test the hypothesis that the right hemisphere (RH) is more sensitive than the left hemisphere (LH) to the distant semantic relations in novel metaphoric expressions. In two divided visual field experiments, sensitivity (d') and criterion ([beta]) were calculated for responses to different types…

  11. Hemispheric specialization and creative thinking: a meta-analytic review of lateralization of creativity

    NARCIS (Netherlands)

    Mihov, K.M.; Denzler, M.; Förster, J.

    2010-01-01

    In the last two decades research on the neurophysiological processes of creativity has found contradicting results. Whereas most research suggests right hemisphere dominance in creative thinking, left-hemisphere dominance has also been reported. The present research is a meta-analytic review of the

  12. Effect of Temporal Constraints on Hemispheric Asymmetries during Spatial Frequency Processing

    Science.gov (United States)

    Peyrin, Carole; Mermillod, Martial; Chokron, Sylvie; Marendaz, Christian

    2006-01-01

    Studies on functional hemispheric asymmetries have suggested that the right vs. left hemisphere should be predominantly involved in low vs. high spatial frequency (SF) analysis, respectively. By manipulating exposure duration of filtered natural scene images, we examined whether the temporal characteristics of SF analysis (i.e., the temporal…

  13. Massive Cerebral Infarction Following Facial Fat Injection.

    Science.gov (United States)

    Shen, Xiao; Li, Qi; Zhang, Hengshu

    2016-10-01

    Autologous facial fat injection is becoming popular around the world. Semiliquid fat grafts are used for correction of deformities or aesthetic purposes. Fat transfer is a mini-invasive surgical procedure, but causes severe complications occasionally. A 30-year-old female patient presented to our hospital with sudden unconsciousness and left limb weakness 8 h after facial fat injection. Brain arteriography (CTA) and venography were performed immediately after her admission. Frontal temporoparietal decompressive craniectomy plus multiple treatments was scheduled for the patient. The patient was diagnosed with extensive cerebral infarction of the right hemisphere. CTA showed that both external and internal carotid arteries were obstructed. A sectional filling defect could be seen at the telecentric segment of the right carotid artery. No development was observed during the full course of the treatment at the carotid bifurcation, external carotid artery, or internal carotid artery. Routine cosmetic procedures of facial fat injections could cause devastating and even fatal complications to patients. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the A5 online Instructions to Authors www.springer.com/00266.

  14. Calcification within the lesion of an old cerebral infarction

    International Nuclear Information System (INIS)

    Hanyu, Haruo; Hagiwara, Akiyoshi; Yamaguchi, Katsuhiko; Imamura, Toshiharu; Iwamoto, Toshihiko; Katsunuma, Hideyo

    1987-01-01

    We described a 68-year-old woman with marked calcification in the lesion of an old cerebral infarction. Calcified deposits in an old infarcted area of the left middle cerebral artery were demonstrated by CT 9 months after she had suffered a stroke, probably because of an embolism. There have been few reports of calcification associated with cerebral infarction. (author)

  15. Left-handedness and health

    Directory of Open Access Journals (Sweden)

    Milenković Sanja

    2010-01-01

    Full Text Available Hand dominance is defined as a proneness to use one hand rather than another in performing the majority of activities and this is the most obvious example of cerebral lateralization and an exclusive human characteristic. Left-handed people comprise 6-14% of the total population, while in Serbia, this percentage is 5-10%, moving from undeveloped to developed environments, where a socio-cultural pressure is less present. There is no agreement between investigators who in fact may be considered a left-handed person, about the percentage of left-handers in the population and about the etiology of left-handedness. In the scientific literature left-handedness has been related to health disorders (spine deformities, immunological disorders, migraine, neurosis, depressive psychosis, schizophrenia, insomnia, homosexuality, diabetes mellitus, arterial hypertension, sleep apnea, enuresis nocturna and Down Syndrome, developmental disorders (autism, dislexia and sttutering and traumatism. The most reliable scientific evidences have been published about the relationship between left-handedness and spinal deformities in school children in puberty and with traumatism in general population. The controversy of other results in up-to-now investigations of health aspects of left-handedness may partly be explained by a scientific disagreement whether writing with the left hand is a sufficient criterium for left-handedness, or is it necessary to investigate other parameters for laterality assessment. Explanation of health aspects of left-handedness is dominantly based on Geschwind-Galaburda model about 'anomalous' cerebral dominati