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Sample records for agnosia

  1. Auditory agnosia.

    Science.gov (United States)

    Slevc, L Robert; Shell, Alison R

    2015-01-01

    Auditory agnosia refers to impairments in sound perception and identification despite intact hearing, cognitive functioning, and language abilities (reading, writing, and speaking). Auditory agnosia can be general, affecting all types of sound perception, or can be (relatively) specific to a particular domain. Verbal auditory agnosia (also known as (pure) word deafness) refers to deficits specific to speech processing, environmental sound agnosia refers to difficulties confined to non-speech environmental sounds, and amusia refers to deficits confined to music. These deficits can be apperceptive, affecting basic perceptual processes, or associative, affecting the relation of a perceived auditory object to its meaning. This chapter discusses what is known about the behavioral symptoms and lesion correlates of these different types of auditory agnosia (focusing especially on verbal auditory agnosia), evidence for the role of a rapid temporal processing deficit in some aspects of auditory agnosia, and the few attempts to treat the perceptual deficits associated with auditory agnosia. A clear picture of auditory agnosia has been slow to emerge, hampered by the considerable heterogeneity in behavioral deficits, associated brain damage, and variable assessments across cases. Despite this lack of clarity, these striking deficits in complex sound processing continue to inform our understanding of auditory perception and cognition. PMID:25726291

  2. Visual agnosia.

    Science.gov (United States)

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes. PMID:26358494

  3. Pantomime agnosia.

    OpenAIRE

    Rothi, L J; Mack, L.; Heilman, K M

    1986-01-01

    Visual agnosia is impaired visual recognition not explained by defective visual acuity, visual fields, attention, or general mental ability. Two nonapraxic patients with lesions in the left occipital lobe could imitate pantomimes they could not recognise. Although both patients had a hemianopia, sparing of gesture imitation shows that no visual defect accounts for their inability to recognise pantomimes. Both patients were amnestic and alexic but had no general impairment of cognitive ability...

  4. Mirror agnosia.

    OpenAIRE

    Ramachandran, V. S.; Altschuler, E. L.; Hillyer, S

    1997-01-01

    Normal people rarely confuse the mirror image of an object with a real object so long as they realize they are looking into a mirror. We report a new neurological sign, 'mirror agnosia', following right parietal lesions in which this ability is severely compromised. We studied four right hemisphere stroke patients who had left visual field 'neglect'. i.e. they were indifferent to objects in their left visual field even though they were not blind. We then placed a vertical parasagittal mirror ...

  5. [Visual Texture Agnosia in Humans].

    Science.gov (United States)

    Suzuki, Kyoko

    2015-06-01

    Visual object recognition requires the processing of both geometric and surface properties. Patients with occipital lesions may have visual agnosia, which is impairment in the recognition and identification of visually presented objects primarily through their geometric features. An analogous condition involving the failure to recognize an object by its texture may exist, which can be called visual texture agnosia. Here we present two cases with visual texture agnosia. Case 1 had left homonymous hemianopia and right upper quadrantanopia, along with achromatopsia, prosopagnosia, and texture agnosia, because of damage to his left ventromedial occipitotemporal cortex and right lateral occipito-temporo-parietal cortex due to multiple cerebral embolisms. Although he showed difficulty matching and naming textures of real materials, he could readily name visually presented objects by their contours. Case 2 had right lower quadrantanopia, along with impairment in stereopsis and recognition of texture in 2D images, because of subcortical hemorrhage in the left occipitotemporal region. He failed to recognize shapes based on texture information, whereas shape recognition based on contours was well preserved. Our findings, along with those of three reported cases with texture agnosia, indicate that there are separate channels for processing texture, color, and geometric features, and that the regions around the left collateral sulcus are crucial for texture processing. PMID:26062585

  6. Dyspraxia and Agnosia in Schizophrenia

    OpenAIRE

    Liddle, P. F.; Haque, S; Morris, D. L.; Barnes, T R E

    1993-01-01

    A battery of tests for dyspraxia and agnosia was administered to 51 chronic schizophrenic patients to test the hypothesis that these cortical neurological signs are associated with psychomotor poverty syndrome (poverty of speech, flat affect, decreased spontaneous movement), disorganization syndrome (various disorders of the form of thought, inappropriate affect), abnormal involuntary movements, cognitive impairment, and duration of illness. The findings supported all elements of the hypothes...

  7. Dyspraxia and agnosia in schizophrenia.

    Science.gov (United States)

    Liddle, P F; Haque, S; Morris, D L; Barnes, T R

    1993-01-01

    A battery of tests for dyspraxia and agnosia was administered to 51 chronic schizophrenic patients to test the hypothesis that these cortical neurological signs are associated with psychomotor poverty syndrome (poverty of speech, flat affect, decreased spontaneous movement), disorganization syndrome (various disorders of the form of thought, inappropriate affect), abnormal involuntary movements, cognitive impairment, and duration of illness. The findings supported all elements of the hypothesis, and in particular, demonstrated a strong correlation of cortical signs with psychomotor poverty and with cognitive impairment. PMID:24487931

  8. Dyspraxia and Agnosia in Schizophrenia

    Directory of Open Access Journals (Sweden)

    P. F. Liddle

    1993-01-01

    Full Text Available A battery of tests for dyspraxia and agnosia was administered to 51 chronic schizophrenic patients to test the hypothesis that these cortical neurological signs are associated with psychomotor poverty syndrome (poverty of speech, flat affect, decreased spontaneous movement, disorganization syndrome (various disorders of the form of thought, inappropriate affect, abnormal involuntary movements, cognitive impairment, and duration of illness. The findings supported all elements of the hypothesis, and in particular, demonstrated a strong correlation of cortical signs with psychomotor poverty and with cognitive impairment.

  9. Neurodegeneration and mirror image agnosia

    Directory of Open Access Journals (Sweden)

    Sadanandavalli Retnaswami Chandra

    2014-01-01

    Full Text Available Background: Normal Percept with abnormal meaning (Agnosias has been described from nineteenth century onwards. Later literature became abundant with information on the spectrum of Prosopagnosias. However, selective difficulty in identifying reflected self images with relatively better cognitive functions leads to problems in differentiating it from non-organic psychosis. Aim: In the present study, we investigated patients with dementia who showed difficulty in identifying reflected self images while they were being tested for problems in gnosis with reference to identification of reflected objects, animals, relatives, and themselves and correlate with neuropsychological and radiological parameters. Patients and Methods: Five such patients were identified and tested with a 45 cm × 45 cm mirror kept at 30-cm distance straight ahead of them. Results: Mirror image agnosia is seen in patients with moderate stage posterior dementias who showed neuropsychological and radiological evidence of right parietal dysfunction. Conclusion: Interpretation of reflected self images perception in real time probably involves distinct data-linking circuits in the right parietal lobe, which may get disrupted early in the course of the disease.

  10. Associative Visual Agnosia: A Case Study

    OpenAIRE

    A. Charnallet; S. Carbonnel; David, D; O. Moreaud

    2008-01-01

    We report a case of massive associative visual agnosia. In the light of current theories of identification and semantic knowledge organization, a deficit involving both levels of structural description system and visual semantics must be assumed to explain the case. We suggest, in line with a previous case study [1], an alternative account in the framework of (non abstractive) episodic models of memory [4].

  11. Perception of biological motion in visual agnosia

    OpenAIRE

    Elisabeth Huberle; Paul Rupek; Markus Lappe

    2012-01-01

    Over the past twenty-five years, visual processing has been discussed in the context of the dual stream hypothesis consisting of a ventral (‘what') and a dorsal ('where') visual information processing pathway. Patients with brain damage of the ventral pathway typically present with signs of visual agnosia, the inability to identify and discriminate objects by visual exploration, but show normal perception of motion perception. A dissociation between the perception of biological motion and non...

  12. Agnosia for streets and defective root finding

    International Nuclear Information System (INIS)

    Topographical disorientation is identified as a condition in which patients are unable to find their way in familiar surroundings, such as their home neighborhood or the admitting hospital after the onset of illness. I proposed to classify topographical disorientation into two categories: agnosia for streets (landmark agnosia) and defective root finding (heading disorientation). Patients with agnosia for streets are unable to identify familiar buildings and landscapes. They can, however, morphologically perceive them and remember their way around familiar areas. The lesions are located in the right posterior part of the parahippocampus gyrus, anterior half of the lingual gyrus and adjacent fusiform gyrus. Clinical findings and functional imaging studies suggest that these regions play a crucial role in the interaction between the visual information of streets and memories of them, which are thought to be retained in the right anterior part of the temporal lobe. In particular, the posterior part of the parahippocampus gyrus is critical for the acquisition of novel information. On the other hand, patients with defective root finding can identify familiar streets, but cannot remember their own location or positional relation between two points within a comparatively wide range not surveyable at one time. The lesions are located in the right retrosplenial cortex (Areas 29, 30), posterior cingulate cortex (Areas 23, 31) and precuneus. Clinical findings and functional imaging studies suggest that these regions are involved in the orientation function for navigating in wide spaces. In particular, the retrosplenial cortex is critical for encoding novel information. (author)

  13. Perception of biological motion in visual agnosia

    Directory of Open Access Journals (Sweden)

    Elisabeth Huberle

    2012-08-01

    Full Text Available Over the past twenty-five years, visual processing has been discussed in the context of the dual stream hypothesis consisting of a ventral (‘what' and a dorsal ('where' visual information processing pathway. Patients with brain damage of the ventral pathway typically present with signs of visual agnosia, the inability to identify and discriminate objects by visual exploration, but show normal perception of motion perception. A dissociation between the perception of biological motion and non-biological motion has been suggested: Perception of biological motion might be impaired when 'non-biological' motion perception is intact and vice versa. The impact of object recognition on the perception of biological motion remains unclear. We thus investigated this question in a patient with severe visual agnosia, who showed normal perception of non-biological motion. The data suggested that the patient's perception of biological motion remained largely intact. However, when tested with objects constructed of coherently moving dots (‘Shape-from-Motion’, recognition was severely impaired. The results are discussed in the context of possible mechanisms of biological motion perception.

  14. Integrative agnosia following progressive multifocal leukoencephalopathy.

    Science.gov (United States)

    Butter, C M; Trobe, J D

    1994-03-01

    A 43 year-old man with presumed progressive multifocal leukoencephalopathy developed difficulty recognizing objects and faces in the presence of adequate visual acuity and visual fields. His copying and matching of line drawings was intact, suggesting that his agnosia was associative. However, he had difficulty perceiving overlapping forms and drawings of single objects as integrated wholes. Unlike control subjects, he made fewer errors identifying silhouettes compared to line drawings with internal details. These alterations, together with his feature-by-feature descriptions of objects and copying, suggest that his agnosia was due to a disturbance in integrating local form features, as described by Riddoch and Humphreys (1987). This interpretation is supported by the findings that his tactile recognition and semantic and structural knowledge of the objects he could not identify visually were intact. Furthermore, his deficient performance in categorical matching of photographs to objects was dependent upon the perceptual complexity of the photographs. Similar deficits in early form processing described by other investigators are discussed. PMID:8004984

  15. Implicit integration in a case of integrative visual agnosia

    OpenAIRE

    AVIEZER, Hillel; Landau, Ayelet N.; Robertson, Lynn C.; Peterson, Mary A.; Soroker, Nachum; Sacher, Yaron; Bonneh, Yoram; Bentin, Shlomo

    2007-01-01

    We present a case (SE) with integrative visual agnosia following ischemic stroke affecting the right dorsal and the left ventral pathways of the visual system. Despite his inability to identify global hierarchical letters (Navon, 1977), and his dense object agnosia, SE showed normal global-to-local interference when responding to local letters in Navon hierarchical stimuli and significant picture-word identity priming in a semantic decision task for words. Since priming was absent if these fe...

  16. Ettlinger revisited: the relation between agnosia and sensory impairment.

    OpenAIRE

    De Haan, E H; Heywood, C A; Young, A. W.; Edelstyn, N; Newcombe, F

    1995-01-01

    The concept of agnosia as a higher order functional impairment, which can occur in the absence of low level visual perceptual deficits, continues to provoke debate. This controversy is complicated by the fact that, on close examination, agnosic patients do tend to have some perceptual difficulties. Thus the issue centres around the question as to whether these deficits play a causal part in the aetiology of agnosia or whether they are functionally independent, with both impairments resulting ...

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

    Science.gov (United States)

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

    1995-03-01

    Interest in progressive focal cerebral syndromes associated with classical degenerative diseases has increased in recent years. Descriptions of posterior cortical atrophy with progressive visual agnosia are relatively rare. We present 5 patients (2 women) ranging in age between 57 and 72 years old. In all cases symptoms began and progressed with no known etiology. All cases were sporadic. The main clinical signs are difficulty in recognizing objects, colors, persons or places; topographical disorientation and visual memory alterations; alexia, simultagnosia, loss of ocular fixing and optic ataxia. Some patients presented other disturbances of praxis or memory and 2 progressed to global dementia. Language function was preserved and behavioral disturbances did not develop. The amplitude of the P100 visual evoked potential was low but latency was normal in 4 patients and prolonged in 1. Brain images showed atrophy and hypoperfusion in the parieto-occipital area. The neuropathology status of these patients is unknown. PMID:7756009

  18. "Mirror agnosia" in a patient with right occipitotemporal infarct

    OpenAIRE

    Menon Bijoy; Shanbhogue K; Mutharasu C; Gopinathan S; Balasubramanian S.; Chandramohan,; Kingsly Jebasingh; Jawahar M

    2006-01-01

    We report the clinical profile and investigation of K, a patient suffering from agnosia for the concept of "mirrors". Normal people rarely confuse a mirror image for the real image. Our patient ′K′ has intact attention, memory and language with a left visual neglect with left hemianopia. When shown an object on his left with a mirror kept sagitally on his right, K grabs for the reflection and even gropes behind the mirror for it. Yet, when shown the mirror alone, he is able to t...

  19. Agnosia for mirror stimuli: a new case report with a small parietal lesion.

    Science.gov (United States)

    Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Lebas, Axel; Gerardin, Emmanuel; Hannequin, Didier

    2014-11-01

    Only seven cases of agnosia for mirror stimuli have been reported, always with an extensive lesion. We report a new case of an agnosia for mirror stimuli due to a circumscribed lesion. An extensive battery of neuropsychological tests and a new experimental procedure to assess visual object mirror and orientation discrimination were assessed 10 days after the onset of clinical symptoms, and 5 years later. The performances of our patient were compared with those of four healthy control subjects matched for age. This test revealed an agnosia for mirror stimuli. Brain imaging showed a small right occipitoparietal hematoma, encompassing the extrastriate cortex adjoining the inferior parietal lobe. This new case suggests that: (i) agnosia for mirror stimuli can persist for 5 years after onset and (ii) the posterior part of the right intraparietal sulcus could be critical in the cognitive process of mirror stimuli discrimination. PMID:25037846

  20. Agnosia for Mirror Stimuli: A New Case Report with a Small Parietal Lesion

    OpenAIRE

    Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Lebas, Axel; Gerardin, Emmanuel; Hannequin, Didier

    2014-01-01

    Only seven cases of agnosia for mirror stimuli have been reported, always with an extensive lesion. We report a new case of an agnosia for mirror stimuli due to a circumscribed lesion. An extensive battery of neuropsychological tests and a new experimental procedure to assess visual object mirror and orientation discrimination were assessed 10 days after the onset of clinical symptoms, and 5 years later. The performances of our patient were compared with those of four healthy control subjects...

  1. Structural and functional changes across the visual cortex of a patient with visual form agnosia

    OpenAIRE

    Bridge, H; Thomas, OM; Minini, L.; Cavina-Pratesi, C.; Milner, AD; Parker, AJ

    2013-01-01

    Loss of shape recognition in visual form agnosia occurs without equivalent losses in the use of vision to guide actions, providing support for the hypothesis of two visual systems (for “perception” and “action”). The human individual DF received a toxic exposure to carbon monoxide some years ago, which resulted a persisting visual form agnosia that has been extensively characterized at the behavioral level. We conducted a detailed high-resolution MRI study of DF’s cortex, combining structural...

  2. Visual object agnosia is associated with a breakdown of object-selective responses in the lateral occipital cortex

    OpenAIRE

    Ptak, Radek; Lazeyras, François; Di Pietro Peralta-Bachman, Marie; Schnider, Armin; Simon, Stéphane

    2014-01-01

    Patients with visual object agnosia fail to recognize the identity of visually presented objects despite preserved semantic knowledge. Object agnosia may result from damage to visual cortex lying close to or overlapping with the lateral occipital complex (LOC), a brain region that exhibits selectivity to the shape of visually presented objects. Despite this anatomical overlap the relationship between shape processing in the LOC and shape representations in object agnosia is unknown. We studie...

  3. "Mirror agnosia" in a patient with right occipitotemporal infarct

    Directory of Open Access Journals (Sweden)

    Menon Bijoy

    2006-01-01

    Full Text Available We report the clinical profile and investigation of K, a patient suffering from agnosia for the concept of "mirrors". Normal people rarely confuse a mirror image for the real image. Our patient ′K′ has intact attention, memory and language with a left visual neglect with left hemianopia. When shown an object on his left with a mirror kept sagitally on his right, K grabs for the reflection and even gropes behind the mirror for it. Yet, when shown the mirror alone, he is able to tell that it is a mirror. Thus the concept of a ′mirror′ is lost in the experimental paradigm. An explanation for mirror ′agnosia′ is provided and recent controversies in the analysis of visuospatial functions in humans is highlighted.

  4. ''I Could See, and Yet, Mon, I Could Na' See'': William Macewen, the Agnosias, and Brain Surgery

    Science.gov (United States)

    Macmillan, Malcolm

    2004-01-01

    Two little noticed cases in which William Macewen used symptoms of visual agnosia to plan brain surgery on the angular gyrus are reviewed and evaluated. Following a head injury, Macewen's first patient had an immediate and severe visual object agnosia that lasted for about 2 weeks. After that he gradually became homicidal and depressed and it was…

  5. When apperceptive agnosia is explained by a deficit of primary visual processing.

    Science.gov (United States)

    Serino, Andrea; Cecere, Roberto; Dundon, Neil; Bertini, Caterina; Sanchez-Castaneda, Cristina; Làdavas, Elisabetta

    2014-03-01

    Visual agnosia is a deficit in shape perception, affecting figure, object, face and letter recognition. Agnosia is usually attributed to lesions to high-order modules of the visual system, which combine visual cues to represent the shape of objects. However, most of previously reported agnosia cases presented visual field (VF) defects and poor primary visual processing. The present case-study aims to verify whether form agnosia could be explained by a deficit in basic visual functions, rather that by a deficit in high-order shape recognition. Patient SDV suffered a bilateral lesion of the occipital cortex due to anoxia. When tested, he could navigate, interact with others, and was autonomous in daily life activities. However, he could not recognize objects from drawings and figures, read or recognize familiar faces. He was able to recognize objects by touch and people from their voice. Assessments of visual functions showed blindness at the centre of the VF, up to almost 5°, bilaterally, with better stimulus detection in the periphery. Colour and motion perception was preserved. Psychophysical experiments showed that SDV's visual recognition deficits were not explained by poor spatial acuity or by the crowding effect. Rather a severe deficit in line orientation processing might be a key mechanism explaining SDV's agnosia. Line orientation processing is a basic function of primary visual cortex neurons, necessary for detecting "edges" of visual stimuli to build up a "primal sketch" for object recognition. We propose, therefore, that some forms of visual agnosia may be explained by deficits in basic visual functions due to widespread lesions of the primary visual areas, affecting primary levels of visual processing. PMID:24607265

  6. Independent Representation of Parts and the Relations between Them: Evidence from Integrative Agnosia

    Science.gov (United States)

    Behrmann, Marlene; Peterson, Mary A.; Moscovitch, Morris; Suzuki, Satoru

    2006-01-01

    Whether objects are represented as a collection of parts whose relations are coded independently remains a topic of ongoing discussion among theorists in the domain of shape perception. S. M., an individual with integrative agnosia, and neurologically intact ("normal") individuals learned initially to identify 4 target objects constructed of 2…

  7. Visual Agnosia for Line Drawings and Silhouettes without Apparent Impairment of Real-Object Recognition: A Case Report

    OpenAIRE

    Kotaro Hiraoka; Kyoko Suzuki; Kazumi Hirayama; Etsuro Mori

    2009-01-01

    We report on a patient with visual agnosia for line drawings and silhouette pictures following cerebral infarction in the region of the right posterior cerebral artery. The patient retained the ability to recognize real objects and their photographs, and could precisely copy line drawings of objects that she could not name. This case report highlights the importance of clinicians and researchers paying special attention to avoid overlooking agnosia in such cases. The factors that lead to prob...

  8. Impaired Integration of Emotional Faces and Affective Body Context in a Rare Case of Developmental Visual Agnosia

    OpenAIRE

    AVIEZER, Hillel; Hassin, Ran. R.; Bentin, Shlomo

    2011-01-01

    In the current study we examined the recognition of facial expressions embedded in emotionally expressive bodies in case LG, an individual with a rare form of developmental visual agnosia who suffers from severe prosopagnosia. Neuropsychological testing demonstrated that LG‘s agnosia is characterized by profoundly impaired visual integration. Unlike individuals with typical developmental prosopagnosia who display specific difficulties with face identity (but typically not expression) recognit...

  9. [Simultanagnosia and scene agnosia induced by right posterior cerebral artery infarction: a case report].

    Science.gov (United States)

    Kobayashi, Yasutaka; Muramatsu, Tomoko; Sato, Mamiko; Hayashi, Hiromi; Miura, Toyoaki

    2015-01-01

    A 68-year-old man was admitted to our hospital for rehabilitation of topographical disorientation. Brain magnetic resonance imaging revealed infarction in the right medial side of the occipital lobe. On neuropsychological testing, he scored low for the visual information-processing task; however, his overall cognitive function was retained. He could identify parts of the picture while describing the context picture of the Visual Perception Test for Agnosia but could not explain the contents of the entire picture, representing so-called simultanagnosia. Further, he could morphologically perceive both familiar and new scenes, but could not identify them, representing so-called scene agnosia. We report this case because simultanagnosia associated with a right occipital lobe lesion is rare. PMID:26369377

  10. A case of tactile agnosia with a lesion restricted to the post-central gyrus

    Directory of Open Access Journals (Sweden)

    Estanol Bruno

    2008-01-01

    Full Text Available Tactile agnosia has been described after lesions of the primary sensory cortex but the exact location and extension of those lesions is not clear. We report the clinical features and imaging findings in a patient with an acute ischemic stroke restricted to the primary sensory area (S1. A 73-year-old man had a sudden onset of a left alien hand, without left hemiparesis. Neurological examination showed intact primary sensory functions, but impaired recognition of shape, size (macrogeometrical and texture (microgeometrical of objects; damage confined to the post-central gyrus, sparing the posterior parietal cortex was demonstrated on MRI. An embolic occlusion of the anterior parietal artery was suspected as mechanism of stroke. Tactile agnosia with impaired microgeometrical and macrogeometrical features′ recognition can result from a single lesion in the primary sensory cortex (S1 in the right parietal hemisphere, sparing other regions of the cerebral cortex which presumably participate in tactile object recognition.

  11. Visual associative agnosia: a clinico-anatomical study of a single case.

    OpenAIRE

    McCarthy, R A; Warrington, E K

    1986-01-01

    A single case study of a patient with visual associative agnosia is described. The patient had well preserved language, spatial, visual, and perceptual abilities but nevertheless was impaired in recognising visually presented common objects. It is argued that his deficit cannot be accounted for in terms of a disconnection syndrome. Behavioural and anatomical (MRI scan) evidence for focal unilateral dysfunction is presented. It is concluded that the left hemisphere plays a crucial role in reco...

  12. Separate visual pathways for perception of actions and objects: evidence from a case of apperceptive agnosia

    OpenAIRE

    Ferreira, C. T.; Ceccaldi, M.; Giusiano, B; Poncet, M.

    1998-01-01

    Recognition of different kinds of visual stimuli was studied in a patient who acquired apperceptive visual agnosia after a bilateral occipitotemporal lesion which partially spared the primary visual cortex. Impairment in recognising static objects perceived visually sharply contrasts with the relatively well preserved ability to recognise objects from gestures illustrating their use, and to recognise actions shown in line drawings. It is suggested that the occipitoparieto...

  13. Configural Gestalts remain nothing more than the sum of their parts in visual agnosia

    OpenAIRE

    de-Wit, Lee H.; Kubilius, Jonas; Op de Beeck, Hans P.; Wagemans, Johan

    2013-01-01

    We report converging evidence that higher stages of the visual system are critically required for the whole to become more than the sum of its parts by studying patient DF with visual agnosia using a configural superiority paradigm. We demonstrate a clear dissociation between this patient and normal controls such that she could more easily report information about parts, demonstrating a striking reversal of the normal configural superiority effect. Furthermore, by comparing DF’s perform...

  14. Intact automatic avoidance of obstacles in patients with visual form agnosia.

    OpenAIRE

    Rice, N. J.; McIntosh, R. D.; Schindler, I.; Mon-Williams, M.; Démonet, J.-F.; Milner, A D

    2006-01-01

    In everyday life our reaching behaviour has to be guided not only by the location and properties of the target object, but also by the presence of potential obstacles in the workspace. Recent evidence from neglect and optic ataxia patients has suggested that this automatic obstacle avoidance is mediated by the dorsal, rather than the ventral, stream of visual processing. We tested this idea in two studies involving patients with visual form agnosia resulting from bilateral ventral-stream dama...

  15. Patient DF's visual brain in action : visual feedforward control in patient with visual form agnosia.

    OpenAIRE

    Whitwell, R.L.; Milner, A D; Cavina-Pratesi, C.; Barat, M.; Goodale, M. A.

    2015-01-01

    Patient DF, who developed visual form agnosia following ventral-stream damage, is unable to discriminate the width of objects, performing at chance, for example, when asked to open her thumb and forefinger a matching amount. Remarkably, however, DF adjusts her hand aperture to accommodate the width of objects when reaching out to pick them up (grip scaling). While this spared ability to grasp objects is presumed to be mediated by visuomotor modules in her relatively intact dorsal stream, it i...

  16. Autism and visual agnosia in a child with right occipital lobectomy

    OpenAIRE

    Jambaque, I; Mottron, L; Ponsot, G; Chiron, C.

    1998-01-01

    OBJECTIVES—Autistic disorder is a developmental handicap with an unknown neurological basis. Current neuropsychological models for autism suggest an abnormal construction of visual perceptual representation or a deficit in executive functions. These models predict cerebral lesions in the temporo-occipital or frontal regions of autistic patients. The present study aimed at studying the presence of symptoms of autism and visual agnosia in a 13 year old girl who had a right tem...

  17. Pleasurable Emotional Response to Music: A Case of Neurodegenerative Generalized Auditory Agnosia

    OpenAIRE

    Matthews, Brandy R.; Chang, Chiung-Chih; May, Mary; Engstrom, John; Bruce L. Miller

    2009-01-01

    Recent functional neuroimaging studies implicate the network of mesolimbic structures known to be active in reward processing as the neural substrate of pleasure associated with listening to music. Psychoacoustic and lesion studies suggest that there is a widely distributed cortical network involved in processing discreet musical variables. Here we present the case of a young man with auditory agnosia as the consequence of cortical neurodegeneration who continues to experience pleasure when e...

  18. Emergence delirium with transient associative agnosia and expressive aphasia reversed by flumazenil in a pediatric patient.

    Science.gov (United States)

    Drobish, Julie K; Kelz, Max B; DiPuppo, Patricia M; Cook-Sather, Scott D

    2015-06-01

    Multiple factors may contribute to the development of emergence delirium in a child. We present the case of a healthy 12-year-old girl who received preoperative midazolam with the desired anxiolytic effect, underwent a brief general anesthetic, and then exhibited postoperative delirium, consisting of a transient associative agnosia and expressive aphasia. Administration of flumazenil led to immediate and lasting resolution of her symptoms. We hypothesize that γ-aminobutyric acid type A receptor-mediated effects, most likely related to an atypical offset of midazolam, are an important subset of emergence delirium that is amenable to pharmacologic therapy with flumazenil. PMID:26035220

  19. Radical “Visual Capture” Observed in a Patient with Severe Visual Agnosia

    OpenAIRE

    Akiko Takaiwa; Hirokazu Yoshimura; Hirofumi Abe; Satoshi Terai

    2003-01-01

    We report the case of a 79-year-old female with visual agnosia due to brain infarction in the left posterior cerebral artery. She could recognize objects used in daily life rather well by touch (the number of objects correctly identified was 16 out of 20 presented objects), but she could not recognize them as well by vision (6 out of 20). In this case, it was expected that she would recognize them well when permitted to use touch and vision simultaneously. Our patient, however, performed poor...

  20. The Role of Sensory-Motor Information in Object Recognition: Evidence from Category-Specific Visual Agnosia

    Science.gov (United States)

    Wolk, D.A.; Coslett, H.B.; Glosser, G.

    2005-01-01

    The role of sensory-motor representations in object recognition was investigated in experiments involving AD, a patient with mild visual agnosia who was impaired in the recognition of visually presented living as compared to non-living entities. AD named visually presented items for which sensory-motor information was available significantly more…

  1. Visual object agnosia is associated with a breakdown of object-selective responses in the lateral occipital cortex.

    Science.gov (United States)

    Ptak, Radek; Lazeyras, François; Di Pietro, Marie; Schnider, Armin; Simon, Stéphane R

    2014-07-01

    Patients with visual object agnosia fail to recognize the identity of visually presented objects despite preserved semantic knowledge. Object agnosia may result from damage to visual cortex lying close to or overlapping with the lateral occipital complex (LOC), a brain region that exhibits selectivity to the shape of visually presented objects. Despite this anatomical overlap the relationship between shape processing in the LOC and shape representations in object agnosia is unknown. We studied a patient with object agnosia following isolated damage to the left occipito-temporal cortex overlapping with the LOC. The patient showed intact processing of object structure, yet often made identification errors that were mainly based on the global visual similarity between objects. Using functional Magnetic Resonance Imaging (fMRI) we found that the damaged as well as the contralateral, structurally intact right LOC failed to show any object-selective fMRI activity, though the latter retained selectivity for faces. Thus, unilateral damage to the left LOC led to a bilateral breakdown of neural responses to a specific stimulus class (objects and artefacts) while preserving the response to a different stimulus class (faces). These findings indicate that representations of structure necessary for the identification of objects crucially rely on bilateral, distributed coding of shape features. PMID:24863251

  2. Affective agnosia: Expansion of the alexithymia construct and a new opportunity to integrate and extend Freud's legacy.

    Science.gov (United States)

    Lane, Richard D; Weihs, Karen L; Herring, Anne; Hishaw, Alex; Smith, Ryan

    2015-08-01

    We describe a new type of agnosia consisting of an impairment in the ability to mentally represent or know what one is feeling. Freud the neurologist coined the term "agnosia" in 1891 before creating psychoanalysis in 1895 but the term has not been previously applied to the domain of affective processing. We propose that the concept of "affective agnosia" advances the theory, measurement and treatment of what is now called "alexithymia," meaning "lack of words for emotion." We trace the origin of the alexithymia construct and discuss the strengths and limitations of extant research. We review evidence that the ability to represent and put emotions into words is a developmental achievement that strongly influences one's ability to experience, recognize, understand and use one's own emotional responses. We describe the neural substrates of emotional awareness and affective agnosia and compare and contrast these with related conditions. We then describe how this expansion of the conceptualization and measurement of affective processing deficits has important implications for basic emotion research and clinical practice. PMID:26054794

  3. Middle components of the auditory evoked response in bilateral temporal lobe lesions. Report on a patient with auditory agnosia

    DEFF Research Database (Denmark)

    Parving, A; Salomon, G; Elberling, Claus;

    1980-01-01

    An investigation of the middle components of the auditory evoked response (10--50 msec post-stimulus) in a patient with auditory agnosia is reported. Bilateral temporal lobe infarctions were proved by means of brain scintigraphy, CAT scanning, and regional cerebral blood flow measurements. The mi...

  4. A case of carbon monoxide poisoning by explosion of coal mine presenting as visual agnosia: re-evaluation after 40 years

    Energy Technology Data Exchange (ETDEWEB)

    Takaiwa, A.; Yamashita, K.; Nomura, T.; Shida, K.; Taniwaki, T. [Kyushu University, Fukuoka (Japan). Department of Neurology, Graduate School of Medical Science

    2005-11-15

    We re-evaluated a case of carbon monoxide poisoning presenting as visual agnosia who had been injured by explosion of Miike-Mikawa coal mine 40 years ago. In an early stage, his main neuropsychological symptoms were visual agnosia, severe anterograde amnesia, alexia, agraphia, constructional apraxia, left hemispatial neglect and psychic paralysis of gaze, in addition to pyramidal and extra pyramidal signs. At the time of re-evaluation after 40 years, he still showed visual agnosia associated with agraphia and constructional apraxia. Concerning visual agnosia, recognition of the real object was preserved, while recognition of object photographs and picture was impaired. Thus, this case was considered to have picture agnosia as he could not recognize the object by pictorial cues on the second dimensional space. MRI examination revealed low signal intensity lesions and cortical atrophy in the bilateral parieto-occipital lobes on T1-weighted images. Therefore, the bilateral parieto-occipital lesions are likely to be responsible for his picture agnosia.

  5. Verbal auditory agnosia with focal EEG abnormality: an unusual case of a child presenting to an ENT surgeon with "deafness".

    Science.gov (United States)

    Kale, U; el-Naggar, M; Hawthorne, M

    1995-05-01

    Verbal auditory agnosia implies the failure to recognize sounds in a patient who is nevertheless not deaf. We present a child referred to the ENT outpatients for suspected hearing loss investigation. At one point she had grommets inserted on the basis of a flat tympanogram but with no effect. All hearing tests, including electrocochleography and distraction tests, revealed normal hearing thresholds. At the age of three years and three months, and on direct questioning of the parents, we discovered that the child responded remarkably well to music. Paediatric neurologists made the diagnosis of verbal auditory agnosia. The condition is very similar to another acquired language disorder called Landau-Kleffner syndrome. It is unusual for such a case to present primarily to an ENT surgeon. PMID:7798001

  6. The Right Place at the Right Time: Priming Facial Expressions with Emotional Face Components in Developmental Visual Agnosia

    OpenAIRE

    Aviezer, Hillel; Hassin, Ran R.; Perry, Anat; Dudarev, Veronica; Bentin, Shlomo

    2012-01-01

    The current study examined the nature of deficits in emotion recognition from facial expressions in case LG, an individual with a rare form of developmental visual agnosia (DVA). LG presents with profoundly impaired recognition of facial expressions, yet the underlying nature of his deficit remains unknown. During typical face processing, normal sighted individuals extract information about expressed emotions from face regions with activity diagnostic for specific emotion categories. Given LG...

  7. Making Memories: The Development of Long-Term Visual Knowledge in Children with Visual Agnosia

    Directory of Open Access Journals (Sweden)

    Tiziana Metitieri

    2013-01-01

    Full Text Available There are few reports about the effects of perinatal acquired brain lesions on the development of visual perception. These studies demonstrate nonseverely impaired visual-spatial abilities and preserved visual memory. Longitudinal data analyzing the effects of compromised perceptions on long-term visual knowledge in agnosics are limited to lesions having occurred in adulthood. The study of children with focal lesions of the visual pathways provides a unique opportunity to assess the development of visual memory when perceptual input is degraded. We assessed visual recognition and visual memory in three children with lesions to the visual cortex having occurred in early infancy. We then explored the time course of visual memory impairment in two of them at 2 years and 3.7 years from the initial assessment. All children exhibited apperceptive visual agnosia and visual memory impairment. We observed a longitudinal improvement of visual memory modulated by the structural properties of objects. Our findings indicate that processing of degraded perceptions from birth results in impoverished memories. The dynamic interaction between perception and memory during development might modulate the long-term construction of visual representations, resulting in less severe impairment.

  8. Functional dissociation between action and perception of object shape in developmental visual object agnosia.

    Science.gov (United States)

    Freud, Erez; Ganel, Tzvi; Avidan, Galia; Gilaie-Dotan, Sharon

    2016-03-01

    According to the two visual systems model, the cortical visual system is segregated into a ventral pathway mediating object recognition, and a dorsal pathway mediating visuomotor control. In the present study we examined whether the visual control of action could develop normally even when visual perceptual abilities are compromised from early childhood onward. Using his fingers, LG, an individual with a rare developmental visual object agnosia, manually estimated (perceptual condition) the width of blocks that varied in width and length (but not in overall size), or simply picked them up across their width (grasping condition). LG's perceptual sensitivity to target width was profoundly impaired in the manual estimation task compared to matched controls. In contrast, the sensitivity to object shape during grasping, as measured by maximum grip aperture (MGA), the time to reach the MGA, the reaction time and the total movement time were all normal in LG. Further analysis, however, revealed that LG's sensitivity to object shape during grasping emerged at a later time stage during the movement compared to controls. Taken together, these results demonstrate a dissociation between action and perception of object shape, and also point to a distinction between different stages of the grasping movement, namely planning versus online control. Moreover, the present study implies that visuomotor abilities can develop normally even when perceptual abilities developed in a profoundly impaired fashion. PMID:26827163

  9. Congenital amusia in speakers of a tone language: association with lexical tone agnosia.

    Science.gov (United States)

    Nan, Yun; Sun, Yanan; Peretz, Isabelle

    2010-09-01

    Congenital amusia is a neurogenetic disorder that affects the processing of musical pitch in speakers of non-tonal languages like English and French. We assessed whether this musical disorder exists among speakers of Mandarin Chinese who use pitch to alter the meaning of words. Using the Montreal Battery of Evaluation of Amusia, we tested 117 healthy young Mandarin speakers with no self-declared musical problems and 22 individuals who reported musical difficulties and scored two standard deviations below the mean obtained by the Mandarin speakers without amusia. These 22 amusic individuals showed a similar pattern of musical impairment as did amusic speakers of non-tonal languages, by exhibiting a more pronounced deficit in melody than in rhythm processing. Furthermore, nearly half the tested amusics had impairments in the discrimination and identification of Mandarin lexical tones. Six showed marked impairments, displaying what could be called lexical tone agnosia, but had normal tone production. Our results show that speakers of tone languages such as Mandarin may experience musical pitch disorder despite early exposure to speech-relevant pitch contrasts. The observed association between the musical disorder and lexical tone difficulty indicates that the pitch disorder as defining congenital amusia is not specific to music or culture but is rather general in nature. PMID:20685803

  10. Radical “Visual Capture” Observed in a Patient with Severe Visual Agnosia

    Directory of Open Access Journals (Sweden)

    Akiko Takaiwa

    2003-01-01

    Full Text Available We report the case of a 79-year-old female with visual agnosia due to brain infarction in the left posterior cerebral artery. She could recognize objects used in daily life rather well by touch (the number of objects correctly identified was 16 out of 20 presented objects, but she could not recognize them as well by vision (6 out of 20. In this case, it was expected that she would recognize them well when permitted to use touch and vision simultaneously. Our patient, however, performed poorly, producing 5 correct answers out of 20 in the Vision-and-Touch condition. It would be natural to think that visual capture functions when vision and touch provide contradictory information on concrete positions and shapes. However, in the present case, it functioned in spite of the visual deficit in recognizing objects. This should be called radical visual capture. By presenting detailed descriptions of her symptoms and neuropsychological and neuroradiological data, we clarify the characteristics of this type of capture.

  11. Patient DF's visual brain in action: Visual feedforward control in visual form agnosia.

    Science.gov (United States)

    Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Barat, Masihullah; Goodale, Melvyn A

    2015-05-01

    Patient DF, who developed visual form agnosia following ventral-stream damage, is unable to discriminate the width of objects, performing at chance, for example, when asked to open her thumb and forefinger a matching amount. Remarkably, however, DF adjusts her hand aperture to accommodate the width of objects when reaching out to pick them up (grip scaling). While this spared ability to grasp objects is presumed to be mediated by visuomotor modules in her relatively intact dorsal stream, it is possible that it may rely abnormally on online visual or haptic feedback. We report here that DF's grip scaling remained intact when her vision was completely suppressed during grasp movements, and it still dissociated sharply from her poor perceptual estimates of target size. We then tested whether providing trial-by-trial haptic feedback after making such perceptual estimates might improve DF's performance, but found that they remained significantly impaired. In a final experiment, we re-examined whether DF's grip scaling depends on receiving veridical haptic feedback during grasping. In one condition, the haptic feedback was identical to the visual targets. In a second condition, the haptic feedback was of a constant intermediate width while the visual target varied trial by trial. Despite this incongruent feedback, DF still scaled her grip aperture to the visual widths of the target blocks, showing only normal adaptation to the false haptically-experienced width. Taken together, these results strengthen the view that DF's spared grasping relies on a normal mode of dorsal-stream functioning, based chiefly on visual feedforward processing. PMID:25199609

  12. Positron emission tomographic localization of left-sided unilateral spatial agnosia

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) was used to clarify the localization and the underlying mechanisms of left-sided unilateral spatial agnosia (LUSA). Eleven right-handed patients with cerebral infarction in the territory of the right middle cerebral artery who had LUSA were included in this study. Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were measured with PET using 15O steady state method. Sixteen right-handed patients with cerebral infarction who did not exhibit LUSA served as a control group. The mean local values of CBF and CMRO2 in the control group were 37.4 ml/100 ml tissue/min and 2.66 ml/100 ml tissue/min, respectively. By contrast, those values of CBF and CMRO2 in the patients with LUSA were 21.7 ml/100 ml tissue/min and 1.43 ml/100 ml tissue/min, respectively. Both CBF and CMRO2 in the right posterior parietal region were significantly lower in the patients with LUSA as compared with the control group (p 2 between 1.8 and 2.2 ml/100 ml tissue/min. These ranges of CBF and CMRO2 in the right parietal region were considered to include the threshold level producing LUSA. The CMRO2 values were more stabilized in the course of cerebral infarction as compared with the CBF values which may be variable on account of luxury perfusion syndrome. The right posterior parietal CMRO2 values less than 2.0 ml/100 ml tissue/min was considered to be critical in causing LUSA. The above results may suggest that severe damages of CBF and metabolism in the posterior part of the right parietal lobe play an important role in the occurrence of LUSA. (J.P.N.)

  13. Training-Induced Recovery of Low-Level Vision Followed by Mid-Level Perceptual Improvements in Developmental Object and Face Agnosia

    Science.gov (United States)

    Lev, Maria; Gilaie-Dotan, Sharon; Gotthilf-Nezri, Dana; Yehezkel, Oren; Brooks, Joseph L.; Perry, Anat; Bentin, Shlomo; Bonneh, Yoram; Polat, Uri

    2015-01-01

    Long-term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid-level deficits such as contour integration and motion coherence, to high-level face and object agnosia. Yet it is unclear whether training during adulthood, at a post-developmental…

  14. Selective Impairment of Living Things and Musical Instruments on a Verbal "Semantic Knowledge Questionnaire" in a Case of Apperceptive Visual Agnosia

    Science.gov (United States)

    Masullo, Carlo; Piccininni, Chiara; Quaranta, Davide; Vita, Maria Gabriella; Gaudino, Simona; Gainotti, Guido

    2012-01-01

    Semantic memory was investigated in a patient (MR) affected by a severe apperceptive visual agnosia, due to an ischemic cerebral lesion, bilaterally affecting the infero-mesial parts of the temporo-occipital cortices. The study was made by means of a Semantic Knowledge Questionnaire (Laiacona, Barbarotto, Trivelli, & Capitani, 1993), which takes…

  15. Auditory agnosia due to long-term severe hydrocephalus caused by spina bifida - specific auditory pathway versus nonspecific auditory pathway.

    Science.gov (United States)

    Zhang, Qing; Kaga, Kimitaka; Hayashi, Akimasa

    2011-07-01

    A 27-year-old female showed auditory agnosia after long-term severe hydrocephalus due to congenital spina bifida. After years of hydrocephalus, she gradually suffered from hearing loss in her right ear at 19 years of age, followed by her left ear. During the time when she retained some ability to hear, she experienced severe difficulty in distinguishing verbal, environmental, and musical instrumental sounds. However, her auditory brainstem response and distortion product otoacoustic emissions were largely intact in the left ear. Her bilateral auditory cortices were preserved, as shown by neuroimaging, whereas her auditory radiations were severely damaged owing to progressive hydrocephalus. Although she had a complete bilateral hearing loss, she felt great pleasure when exposed to music. After years of self-training to read lips, she regained fluent ability to communicate. Clinical manifestations of this patient indicate that auditory agnosia can occur after long-term hydrocephalus due to spina bifida; the secondary auditory pathway may play a role in both auditory perception and hearing rehabilitation. PMID:21413843

  16. Modeling eye movements in visual agnosia with a saliency map approach: bottom-up guidance or top-down strategy?

    Science.gov (United States)

    Foulsham, Tom; Barton, Jason J S; Kingstone, Alan; Dewhurst, Richard; Underwood, Geoffrey

    2011-08-01

    Two recent papers (Foulsham, Barton, Kingstone, Dewhurst, & Underwood, 2009; Mannan, Kennard, & Husain, 2009) report that neuropsychological patients with a profound object recognition problem (visual agnosic subjects) show differences from healthy observers in the way their eye movements are controlled when looking at images. The interpretation of these papers is that eye movements can be modeled as the selection of points on a saliency map, and that agnosic subjects show an increased reliance on visual saliency, i.e., brightness and contrast in low-level stimulus features. Here we review this approach and present new data from our own experiments with an agnosic patient that quantifies the relationship between saliency and fixation location. In addition, we consider whether the perceptual difficulties of individual patients might be modeled by selectively weighting the different features involved in a saliency map. Our data indicate that saliency is not always a good predictor of fixation in agnosia: even for our agnosic subject, as for normal observers, the saliency-fixation relationship varied as a function of the task. This means that top-down processes still have a significant effect on the earliest stages of scanning in the setting of visual agnosia, indicating severe limitations for the saliency map model. Top-down, active strategies-which are the hallmark of our human visual system-play a vital role in eye movement control, whether we know what we are looking at or not. PMID:21316191

  17. Pure associative tactile agnosia for the left hand: clinical and anatomo-functional correlations.

    Science.gov (United States)

    Veronelli, Laura; Ginex, Valeria; Dinacci, Daria; Cappa, Stefano F; Corbo, Massimo

    2014-09-01

    Associative tactile agnosia (TA) is defined as the inability to associate information about object sensory properties derived through tactile modality with previously acquired knowledge about object identity. The impairment is often described after a lesion involving the parietal cortex (Caselli, 1997; Platz, 1996). We report the case of SA, a right-handed 61-year-old man affected by first ever right hemispheric hemorrhagic stroke. The neurological examination was normal, excluding major somaesthetic and motor impairment; a brain magnetic resonance imaging (MRI) confirmed the presence of a right subacute hemorrhagic lesion limited to the post-central and supra-marginal gyri. A comprehensive neuropsychological evaluation detected a selective inability to name objects when handled with the left hand in the absence of other cognitive deficits. A series of experiments were conducted in order to assess each stage of tactile recognition processing using the same stimulus sets: materials, 3D geometrical shapes, real objects and letters. SA and seven matched controls underwent the same experimental tasks during four sessions in consecutive days. Tactile discrimination, recognition, pantomime, drawing after haptic exploration out of vision and tactile-visual matching abilities were assessed. In addition, we looked for the presence of a supra-modal impairment of spatial perception and of specific difficulties in programming exploratory movements during recognition. Tactile discrimination was intact for all the stimuli tested. In contrast, SA was able neither to recognize nor to pantomime real objects manipulated with the left hand out of vision, while he identified them with the right hand without hesitations. Tactile-visual matching was intact. Furthermore, SA was able to grossly reproduce the global shape in drawings but failed to extract details of objects after left-hand manipulation, and he could not identify objects after looking at his own drawings. This case

  18. Training-induced recovery of low-level vision followed by mid-level perceptual improvements in developmental object and face agnosia

    OpenAIRE

    Lev, Maria; Gilaie-Dotan, Sharon; Gotthilf-Nezri, Dana; Yehezkel, Oren; Brooks, Joseph L.; Perry, Anat; Bentin, Shlomo; Bonneh, Yoram; Polat, Uri

    2015-01-01

    Long-term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid-level deficits such as contour integration and motion coherence, to high-level face and object agnosia. Yet it is unclear whether training during adulthood, at a post-developmental stage of the adult visual system, can overcome such developmental impairments. Here, we visually trained LG, a developmental object and face agnosic ind...

  19. Real-time vision, tactile cues, and visual form agnosia in pantomimed grasping: removing haptic feedback induces a switch from natural to pantomime-like grasps

    OpenAIRE

    Robert Leslie Whitwell; Tzvika Ganel

    2015-01-01

    Investigators study the kinematics of grasping movements (prehension) under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. When patient DF, who suffers from visual form agnosia, performs natural grasps, her in-flight hand aperture is scaled to the widths of targets ('grip scaling') that she cannot discriminate amongst. In contrast, when DF's pantomime grasps are based on a memory of a previewed object, her grip scaling is very poor. Her failure o...

  20. Hurt but still alive: Residual activity in the parahippocampal cortex conditions the recognition of familiar places in a patient with topographic agnosia

    OpenAIRE

    van Assche, Mitsouko; Kebets, Valeria; Lopez, Ursula; SAJ, Arnaud; Goldstein, Rachel; Bernasconi, Françoise; Vuilleumier, Patrik; Assal, Frédéric

    2016-01-01

    The parahippocampal cortex (PHC) participates in both perception and memory. However, the way perceptual and memory processes cooperate when we navigate in our everyday life environment remains poorly understood. We studied a stroke patient presenting a brain lesion in the right PHC, which resulted in a mild and quantifiable topographic agnosia, and allowed us to investigate the role of this structure in overt place recognition. Photographs of personally familiar and unfamiliar places were di...

  1. Reprint of: Visual processing of words in a patient with visual form agnosia: A behavioural and fMRI study.

    Science.gov (United States)

    Cavina-Pratesi, Cristiana; Large, Mary-Ellen; Milner, A David

    2015-11-01

    Patient D.F. has a profound and enduring visual form agnosia due to a carbon monoxide poisoning episode suffered in 1988. Her inability to distinguish simple geometric shapes or single alphanumeric characters can be attributed to a bilateral loss of cortical area LO, a loss that has been well established through structural and functional fMRI. Yet despite this severe perceptual deficit, D.F. is able to "guess" remarkably well the identity of whole words. This paradoxical finding, which we were able to replicate more than 20 years following her initial testing, raises the question as to whether D.F. has retained specialized brain circuitry for word recognition that is able to function to some degree without the benefit of inputs from area LO. We used fMRI to investigate this, and found regions in the left fusiform gyrus, left inferior frontal gyrus, and left middle temporal cortex that responded selectively to words. A group of healthy control subjects showed similar activations. The left fusiform activations appear to coincide with the area commonly named the visual word form area (VWFA) in studies of healthy individuals, and appear to be quite separate from the fusiform face area (FFA). We hypothesize that there is a route to this area that lies outside area LO, and which remains relatively unscathed in D.F. PMID:26475097

  2. Visual processing of words in a patient with visual form agnosia: a behavioural and fMRI study.

    Science.gov (United States)

    Cavina-Pratesi, Cristiana; Large, Mary-Ellen; Milner, A David

    2015-03-01

    Patient D.F. has a profound and enduring visual form agnosia due to a carbon monoxide poisoning episode suffered in 1988. Her inability to distinguish simple geometric shapes or single alphanumeric characters can be attributed to a bilateral loss of cortical area LO, a loss that has been well established through structural and functional fMRI. Yet despite this severe perceptual deficit, D.F. is able to "guess" remarkably well the identity of whole words. This paradoxical finding, which we were able to replicate more than 20 years following her initial testing, raises the question as to whether D.F. has retained specialized brain circuitry for word recognition that is able to function to some degree without the benefit of inputs from area LO. We used fMRI to investigate this, and found regions in the left fusiform gyrus, left inferior frontal gyrus, and left middle temporal cortex that responded selectively to words. A group of healthy control subjects showed similar activations. The left fusiform activations appear to coincide with the area commonly named the visual word form area (VWFA) in studies of healthy individuals, and appear to be quite separate from the fusiform face area (FFA). We hypothesize that there is a route to this area that lies outside area LO, and which remains relatively unscathed in D.F. PMID:25461705

  3. Hurt but still alive: Residual activity in the parahippocampal cortex conditions the recognition of familiar places in a patient with topographic agnosia.

    Science.gov (United States)

    van Assche, Mitsouko; Kebets, Valeria; Lopez, Ursula; Saj, Arnaud; Goldstein, Rachel; Bernasconi, Françoise; Vuilleumier, Patrik; Assal, Frédéric

    2016-01-01

    The parahippocampal cortex (PHC) participates in both perception and memory. However, the way perceptual and memory processes cooperate when we navigate in our everyday life environment remains poorly understood. We studied a stroke patient presenting a brain lesion in the right PHC, which resulted in a mild and quantifiable topographic agnosia, and allowed us to investigate the role of this structure in overt place recognition. Photographs of personally familiar and unfamiliar places were displayed during functional magnetic resonance imaging (fMRI). Familiar places were either recognized or unrecognized by the patient and 6 age- and education-matched controls in a visual post-scan recognition test. In fMRI, recognized places were associated with a network comprising the fusiform gyrus in the intact side, but also the right anterior PHC, which included the lesion site. Moreover, this right PHC showed increased connectivity with the left homologous PHC in the intact hemisphere. By contrasting recognized with unrecognized familiar places, we replicate the finding of the joint involvement of the retrosplenial cortex, occipito-temporal areas, and posterior parietal cortex in place recognition. This study shows that the ability for left and right anterior PHC to communicate despite the neurological damage conditioned place recognition success in this patient. It further highlights a hemispheric asymmetry in this process, by showing the fundamental role of the right PHC in topographic agnosia. PMID:26909331

  4. Complicações neurológicas no decurso de tratamento pelo ACTH: A propósito de um caso de agnosia visual

    Directory of Open Access Journals (Sweden)

    O. Freitas Julião

    1953-12-01

    Full Text Available Os autores relatam a observação de um menino de 8 anos de idade, portador de síndrome nefrótica tratada pelo ACTH e que apresentou uma série de graves distúrbios neurológicos conseqüentes a uma crise hipertensiva (a pressão arterial elevou-se a 220-130 mm Hg, ocorrida por ocasião desse tratamento. Manifestando-se inicialmente por cefaléia intensa, depois por crise convulsiva generalizada, à qual se seguiu estado comatoso e posteriormente síndrome confusional, a encefalopatía hipertensiva condicionou, como seqüelas neurológicas mais importantes, distúrbios visuais. Êstes, que se apresentaram, a princípio, sob a forma de amaurose total, assumiram depois o aspecto de distúrbios da percepção, tipo agnóstico, persistentes ainda hoje. A agnosia visual refere-se aos objetos, pessoas, figuras simbólicas e côres.

  5. Hurt but still alive: Residual activity in the parahippocampal cortex conditions the recognition of familiar places in a patient with topographic agnosia

    Directory of Open Access Journals (Sweden)

    Mitsouko van Assche

    2016-01-01

    Photographs of personally familiar and unfamiliar places were displayed during functional magnetic resonance imaging (fMRI. Familiar places were either recognized or unrecognized by the patient and 6 age- and education-matched controls in a visual post-scan recognition test. In fMRI, recognized places were associated with a network comprising the fusiform gyrus in the intact side, but also the right anterior PHC, which included the lesion site. Moreover, this right PHC showed increased connectivity with the left homologous PHC in the intact hemisphere. By contrasting recognized with unrecognized familiar places, we replicate the finding of the joint involvement of the retrosplenial cortex, occipito-temporal areas, and posterior parietal cortex in place recognition. This study shows that the ability for left and right anterior PHC to communicate despite the neurological damage conditioned place recognition success in this patient. It further highlights a hemispheric asymmetry in this process, by showing the fundamental role of the right PHC in topographic agnosia.

  6. Alteraciones en el reconocimiento de gestos por daño a nivel del praxicon de entrada de acciones. (Agnosia de las pantomimas

    Directory of Open Access Journals (Sweden)

    Daniel G. Politis

    2002-01-01

    Full Text Available Clásicamente el estudio de la apraxia estuvo limitado a los problemas en la ejecución gestual (Geschwind, 1965; Liepmann, 1908 [c.f. De Renzi, 1990]; Luria, 1977. Si bien se presentaron varias hipótesis sobre la capacidad de reconocer gestos y su alteración por lesiones cerebrales, González Rothi, Ochipa y Heilman (1991,1997 en su modelo cognitivo de las apraxias de los miembros incluyen la capacidad de reconocer gestos y proponen que la misma es mediada por un sub-componente específico, el praxicón de entrada de acciones. La alteración de este produce un cuadro caracterizado por un déficit en el reconocimiento de gestos que denominaron Agnosia de las Pantomimas. En este trabajo se presenta el estudio de un paciente con dificultades en el reconocimiento de gestos y sin dificultades en la producción gesrual lo que constituye una disociación, que reafirma la hipótesis planteada por González Rothi y colaboradores (1991, 1997 y se discute el valor de estos hallazgos en relación con el modelo antes mencionado.

  7. Real-time vision, tactile cues, and visual form agnosia in pantomimed grasping: removing haptic feedback induces a switch from natural to pantomime-like grasps

    Directory of Open Access Journals (Sweden)

    Robert Leslie Whitwell

    2015-05-01

    Full Text Available Investigators study the kinematics of grasping movements (prehension under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. When patient DF, who suffers from visual form agnosia, performs natural grasps, her in-flight hand aperture is scaled to the widths of targets ('grip scaling' that she cannot discriminate amongst. In contrast, when DF's pantomime grasps are based on a memory of a previewed object, her grip scaling is very poor. Her failure on this task has been interpreted as additional support for the dissociation between the use of object vision for action and object vision for perception. Curiously, however, when DF directs her pantomimed grasps towards a displaced imagined copy of a visible object where her fingers make contact with the surface of the table, her grip scaling does not appear to be particularly poor. In the first of two experiments, we revisit this previous work and show that her grip scaling in this real-time pantomime grasping task does not differ from controls, suggesting that terminal tactile feedback from a proxy of the target can maintain DF's grip scaling. In a second experiment with healthy participants, we tested a recent variant of a grasping task in which no tactile feedback is available (i.e. no haptic feedback by comparing the kinematics of target-directed grasps with and without haptic feedback to those of real-time pantomime grasps without haptic feedback. Compared to natural grasps, removing haptic feedback increased RT, slowed the velocity of the reach, reduced grip aperture, sharpened the slopes relating grip aperture to target width, and reduced the final grip aperture. All of these effects were also observed in the pantomime grasping task. Taken together, these results provide compelling support for the view that removing haptic feedback induces a switch from real-time visual control to one that depends more on visual perception and cognitive supervision.

  8. Real-time vision, tactile cues, and visual form agnosia: removing haptic feedback from a "natural" grasping task induces pantomime-like grasps.

    Science.gov (United States)

    Whitwell, Robert L; Ganel, Tzvi; Byrne, Caitlin M; Goodale, Melvyn A

    2015-01-01

    Investigators study the kinematics of grasping movements (prehension) under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. "Natural" prehensile acts are directed at the goal object and are executed using real-time vision. Typically, they also entail the use of tactile, proprioceptive, and kinesthetic sources of haptic feedback about the object ("haptics-based object information") once contact with the object has been made. Natural and simulated (pantomimed) forms of prehension are thought to recruit different cortical structures: patient DF, who has visual form agnosia following bilateral damage to her temporal-occipital cortex, loses her ability to scale her grasp aperture to the size of targets ("grip scaling") when her prehensile movements are based on a memory of a target previewed 2 s before the cue to respond or when her grasps are directed towards a visible virtual target but she is denied haptics-based information about the target. In the first of two experiments, we show that when DF performs real-time pantomimed grasps towards a 7.5 cm displaced imagined copy of a visible object such that her fingers make contact with the surface of the table, her grip scaling is in fact quite normal. This finding suggests that real-time vision and terminal tactile feedback are sufficient to preserve DF's grip scaling slopes. In the second experiment, we examined an "unnatural" grasping task variant in which a tangible target (along with any proxy such as the surface of the table) is denied (i.e., no terminal tactile feedback). To do this, we used a mirror-apparatus to present virtual targets with and without a spatially coincident copy for the participants to grasp. We compared the grasp kinematics from trials with and without terminal tactile feedback to a real-time-pantomimed grasping task (one without tactile feedback) in which participants visualized a copy of the visible target as instructed in our laboratory in the

  9. Pattern discrimination in a human subject suffering visual agnosia

    OpenAIRE

    Bromley, J. M.; Humphreys, G.W.; Javadnia, A.; Riddoch, M. J.; Ruddock, K H

    1986-01-01

    Since suffering a stroke some four years ago, H.J.A. has exhibited lack of visual pattern recognition, and CT scans show areas of neuronal damage localized bilaterally in the posterior cerebral cortex (Humphreys & Riddoch, 1984)

  10. Visual Agnosia and Posterior Cerebral Artery Infarcts: An Anatomical-Clinical Study

    OpenAIRE

    Martinaud, Olivier; Pouliquen, Dorothée; Gérardin, Emmanuel; Loubeyre, Maud; Hirsbein, David; Hannequin, Didier; Cohen, Laurent

    2012-01-01

    Background To evaluate systematically the cognitive deficits following posterior cerebral artery (PCA) strokes, especially agnosic visual disorders, and to study anatomical-clinical correlations. Methods and Findings We investigated 31 patients at the chronic stage (mean duration of 29.1 months post infarct) with standardized cognitive tests. New experimental tests were used to assess visual impairments for words, faces, houses, and objects. Forty-one healthy subjects participated as controls...

  11. Agnosia for global patterns: when the cross-talk between grouping and visual selective attention fails

    OpenAIRE

    C. Piccini; R. Lauro Grotto; M. Del Viva; D. C. Burr

    2003-01-01

    We present a single case study of a 72-year-old mild AD patient, MC, with a highly specific deficit in deriving the global pattern of visual stimuli, in the absence of visuospatial neglect.MCshows a specific difficulty in segregating overlapping figures, in object decision, and in all neuropsychological tasks requiring perception of a global structure from local cues, such as the Street Completion Test and the perception of illusory contours and of the global level of hierarchical stimu...

  12. Concurrent visuomotor behaviour improves form discrimination in a patient with visual form agnosia.

    OpenAIRE

    Schenk, T.; Milner, A D

    2006-01-01

    It is now well established that the visual brain is divided into two visual streams, the ventral and the dorsal stream. Milner and Goodale have suggested that the ventral stream is dedicated for processing vision for perception and the dorsal stream vision for action [A.D. Milner & M.A. Goodale (1995) The Visual Brain in Action, Oxford University Press, Oxford]. However, it is possible that ongoing processes in the visuomotor stream will nevertheless have an effect on perceptual processes. Th...

  13. The Product-Agnosia Effect: How More Visual Impressions Affect Product Distinctiveness in Comparative Choice

    OpenAIRE

    Jayson Shi Jia; Baba Shiv; Sanjay Rao

    2014-01-01

    Consumer choice is often based on the relative visual appeal of competing products. Lay intuition, common marketing practice, and extant literature all suggest that more visual impressions help consumers distinguish products. This research shows that the opposite can occur. Rather than highlighting differences, seeing more pictures of products being compared can obfuscate perceptions, reduce distinctiveness and attractiveness of products, and increase choice uncertainty. Six experiments demon...

  14. Making Memories: The Development of Long-Term Visual Knowledge in Children with Visual Agnosia

    OpenAIRE

    Tiziana Metitieri; Carmen Barba; Simona Pellacani; Maria Pia Viggiano; Renzo Guerrini

    2013-01-01

    There are few reports about the effects of perinatal acquired brain lesions on the development of visual perception. These studies demonstrate nonseverely impaired visual-spatial abilities and preserved visual memory. Longitudinal data analyzing the effects of compromised perceptions on long-term visual knowledge in agnosics are limited to lesions having occurred in adulthood. The study of children with focal lesions of the visual pathways provides a unique opportunity to assess the developme...

  15. Visual agnosia and posterior cerebral artery infarcts: an anatomical-clinical study.

    Directory of Open Access Journals (Sweden)

    Olivier Martinaud

    Full Text Available BACKGROUND: To evaluate systematically the cognitive deficits following posterior cerebral artery (PCA strokes, especially agnosic visual disorders, and to study anatomical-clinical correlations. METHODS AND FINDINGS: We investigated 31 patients at the chronic stage (mean duration of 29.1 months post infarct with standardized cognitive tests. New experimental tests were used to assess visual impairments for words, faces, houses, and objects. Forty-one healthy subjects participated as controls. Brain lesions were normalized, combined, and related to occipitotemporal areas responsive to specific visual categories, including words (VWFA, faces (FFA and OFA, houses (PPA and common objects (LOC. Lesions were located in the left hemisphere in 15 patients, in the right in 13, and bilaterally in 3. Visual field defects were found in 23 patients. Twenty patients had a visual disorder in at least one of the experimental tests (9 with faces, 10 with houses, 7 with phones, 3 with words. Six patients had a deficit just for a single category of stimulus. The regions of maximum overlap of brain lesions associated with a deficit for a given category of stimuli were contiguous to the peaks of the corresponding functional areas as identified in normal subjects. However, the strength of anatomical-clinical correlations was greater for words than for faces or houses, probably due to the stronger lateralization of the VWFA, as compared to the FFA or the PPA. CONCLUSIONS: Agnosic visual disorders following PCA infarcts are more frequent than previously reported. Dedicated batteries of tests, such as those developed here, are required to identify such deficits, which may escape clinical notice. The spatial relationships of lesions and of regions activated in normal subjects predict the nature of the deficits, although individual variability and bilaterally represented systems may blur those correlations.

  16. Pure word deafness with auditory object agnosia after bilateral lesion of the superior temporal sulcus.

    Science.gov (United States)

    Gutschalk, Alexander; Uppenkamp, Stefan; Riedel, Bernhard; Bartsch, Andreas; Brandt, Tobias; Vogt-Schaden, Marlies

    2015-12-01

    Based on results from functional imaging, cortex along the superior temporal sulcus (STS) has been suggested to subserve phoneme and pre-lexical speech perception. For vowel classification, both superior temporal plane (STP) and STS areas have been suggested relevant. Lesion of bilateral STS may conversely be expected to cause pure word deafness and possibly also impaired vowel classification. Here we studied a patient with bilateral STS lesions caused by ischemic strokes and relatively intact medial STPs to characterize the behavioral consequences of STS loss. The patient showed severe deficits in auditory speech perception, whereas his speech production was fluent and communication by written speech was grossly intact. Auditory-evoked fields in the STP were within normal limits on both sides, suggesting that major parts of the auditory cortex were functionally intact. Further studies showed that the patient had normal hearing thresholds and only mild disability in tests for telencephalic hearing disorder. Prominent deficits were discovered in an auditory-object classification task, where the patient performed four standard deviations below the control group. In marked contrast, performance in a vowel-classification task was intact. Auditory evoked fields showed enhanced responses for vowels compared to matched non-vowels within normal limits. Our results are consistent with the notion that cortex along STS is important for auditory speech perception, although it does not appear to be entirely speech specific. Formant analysis and single vowel classification, however, appear to be already implemented in auditory cortex on the STP. PMID:26343343

  17. Separate processing of texture and form in the ventral stream : evidence from fMRI and visual agnosia.

    OpenAIRE

    Cavina-Pratesi, C.; Kentridge, R. W.; Heywood, C A; Milner, A D

    2010-01-01

    Real-life visual object recognition requires the processing of more than just geometric (shape, size, and orientation) properties. Surface properties such as color and texture are equally important, particularly for providing information about the material properties of objects. Recent neuroimaging research suggests that geometric and surface properties are dealt with separately, within the lateral occipital cortex (LOC) and the collateral sulcus (CoS), respectively. Here we compared objects ...

  18. Which visual functions depend on intermediate visual regions? Insights from a case of developmental visual form agnosia.

    Science.gov (United States)

    Gilaie-Dotan, Sharon

    2016-03-01

    A key question in visual neuroscience is the causal link between specific brain areas and perceptual functions; which regions are necessary for which visual functions? While the contribution of primary visual cortex and high-level visual regions to visual perception has been extensively investigated, the contribution of intermediate visual areas (e.g. V2/V3) to visual processes remains unclear. Here I review more than 20 visual functions (early, mid, and high-level) of LG, a developmental visual agnosic and prosopagnosic young adult, whose intermediate visual regions function in a significantly abnormal fashion as revealed through extensive fMRI and ERP investigations. While expectedly, some of LG's visual functions are significantly impaired, some of his visual functions are surprisingly normal (e.g. stereopsis, color, reading, biological motion). During the period of eight-year testing described here, LG trained on a perceptual learning paradigm that was successful in improving some but not all of his visual functions. Following LG's visual performance and taking into account additional findings in the field, I propose a framework for how different visual areas contribute to different visual functions, with an emphasis on intermediate visual regions. Thus, although rewiring and plasticity in the brain can occur during development to overcome and compensate for hindering developmental factors, LG's case seems to indicate that some visual functions are much less dependent on strict hierarchical flow than others, and can develop normally in spite of abnormal mid-level visual areas, thereby probably less dependent on intermediate visual regions. PMID:26209358

  19. Delayed action does not always require the ventral stream: a study on a patient with visual form agnosia.

    Science.gov (United States)

    Hesse, Constanze; Schenk, Thomas

    2014-05-01

    It has been suggested that while movements directed at visible targets are processed within the dorsal stream, movements executed after delay rely on the visual representations of the ventral stream (Milner & Goodale, 2006). This interpretation is supported by the observation that a patient with ventral stream damage (D.F.) has trouble performing accurate movements after a delay, but performs normally when the target is visible during movement programming. We tested D.F.'s visuomotor performance in a letter-posting task whilst varying the amount of visual feedback available. Additionally, we also varied whether D.F. received tactile feedback at the end of each trial (posting through a letter box vs posting on a screen) and whether environmental cues were available during the delay period (removing the target only vs suppressing vision completely with shutter glasses). We found that in the absence of environmental cues patient D.F. was unaffected by the introduction of delay and performed as accurately as healthy controls. However, when environmental cues and vision of the moving hand were available during and after the delay period, D.F.'s visuomotor performance was impaired. Thus, while healthy controls benefit from the availability of environmental landmarks and/or visual feedback of the moving hand, such cues seem less beneficial to D.F. Taken together our findings suggest that ventral stream damage does not always impact the ability to make delayed movements but compromises the ability to use environmental landmarks and visual feedback efficiently. PMID:24657477

  20. Real-time vision, tactile cues, and visual form agnosia: removing haptic feedback from a “natural” grasping task induces pantomime-like grasps

    OpenAIRE

    Whitwell, Robert L.; Ganel, Tzvi; Byrne, Caitlin M.; Goodale, Melvyn A.

    2015-01-01

    Investigators study the kinematics of grasping movements (prehension) under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. “Natural” prehensile acts are directed at the goal object and are executed using real-time vision. Typically, they also entail the use of tactile, proprioceptive, and kinesthetic sources of haptic feedback about the object (“haptics-based object information”) once contact with the object has been made. Natural and simulated (...

  1. Nevropsihološka diagnostika sposobnosti prepoznavanja in celostnega združevanja informacij - možnosti za ocenjevanje, trening in kognitivno nevrorehabilitacijo: Neuropsychological assessment of recognition ability and complex integration of information - possibilities for assessment, training and cognitive rehabilitation:

    OpenAIRE

    Starovasnik, Barbara

    2012-01-01

    Agnosias develop when the meaning is striped from a percept, and there are problems associated with the cortical processing of stimuli which are not related to or can be explained by deficits in the sensory organ. Traditionally, a distinction between apperceptive and associative forms of agnosia has been made, and due to some modality specifics several types of agnosia have been identified (visual, auditory, tactile). Anosognosia refers to patients suffering from various neurological impairme...

  2. Görme Agnozisi İle Seyreden Bir Oksipital İnfrakt Olgusu

    OpenAIRE

    TUNALI, G.

    2010-01-01

    SUMMARY A CASE WITH VISUAL AGNOSIA DUE TO OCCIPITAL INFARCT In this paper, a case who had visual agnosia, alexia and complex visual halusinations was presented. CT scan showed left occipi¬tal infarct which also involved posterior temporal lobe. The propable mechanism of visual agnosia was discussed in wiev of the literature. ÖZET Bu yazıda görme agnozisi, aleksi ve kompleks görme halüsinasyonları olan bir vaka sunuldu. Bu vakada BT sol tarafta posterior temporal loba da yayılan...

  3. Pure alexia and right hemiachromatopsia in posterior dementia.

    OpenAIRE

    Freedman, L; Costa, L.

    1992-01-01

    A 66 year old, right handed woman presented with pure alexia and right hemiachromatopsia (PARH) in the context of a posterior dementia. PARH was accompanied by prosopagnosia, 2-D object agnosia, and environmental agnosia. Visual fields were normal to confrontation testing. The pathological anatomy of PARH involves circumscribed damage to the lingual and fusiform gyri and paraventricular white matter of the left occipital cortex, two contiguous cortical regions functionally specialised for pro...

  4. Visual Barriers to Prevent Ambulatory ALzheimer's Patients from Exiting through an Emergency Door.

    Science.gov (United States)

    Namazi, Kevan H.; And Others

    1989-01-01

    Conducted study on Alzheimer's unit to test seven different visual barrier conditions for reducing patient exits. Findings indicated that exiting was eliminated under two conditions. Results suggest visual agnosia, the inability to interpret what the eye sees, may be used as tool in managing wandering behavior of Alzheimer's patients. (Author/NB)

  5. Establishing Visual Category Boundaries between Objects: A PET Study

    Science.gov (United States)

    Saumier, Daniel; Chertkow, Howard; Arguin, Martin; Whatmough, Cristine

    2005-01-01

    Individuals with Alzheimer's disease (AD) often have problems in recognizing common objects. This visual agnosia may stem from difficulties in establishing appropriate visual boundaries between visually similar objects. In support of this hypothesis, Saumier, Arguin, Chertkow, and Renfrew (2001) showed that AD subjects have difficulties in…

  6. A Study to Determine the Existence and Characteristics of Distinctively Different Subpopulations Subsumed within the Reading Disabled Population.

    Science.gov (United States)

    Steinberg, Laurie S.

    Forty-five third-grade and fourth-grade boys identified by their schools as being both normal in intelligence and severely disabled in reading were given a battery of tests of language, visual perception, silent reading comprehension, and finger agnosia. Three consistent groups of subjects emerged from cluster analyses of the results. One group…

  7. Kluver-Bucy syndrome developed after convulsion: A case report

    OpenAIRE

    Okur, Mesut; Yılmaz, Cahide; Epçaçan, Serdar; Üstyol, Lokman; KAYA, Avni; Çaksen, Hüseyin

    2013-01-01

    Abstract. Kluver-Bucy syndrome is characterized by increased appetite, hypersexuality, hypermetamorphosis, memory disorders, visual agnosia, stagnancy, aphasia, bulimia, polyuria, and polydipsia. A 14 year old girl had generalized tonic-clonic convulsions at admission, and an incomplete Kluver-Bucy syndrome with hypersexuality, recent memory disturbance, hypermetamorphosis, speech disturbance, hyperactivity, agitation, aggressiveness, and hallucinations, developed the following day. Here in, ...

  8. Regional cerebral blood flow in primary degenerative dementia

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was examined, using SPECT by Xe-133 inhalation, in patients with primary degenerative dementia who were subgrouped according to predominant symptoms with respect to amnesia, apraxia, agnosia, aphasia, and personality changes. Also the effect of sex and age at dementia onset on the rCBF patterns was assessed. (author). 26 refs.; 1 fig.; 7 tabs

  9. Blissymbols and Manual Signs: A Multimodal Approach to Intervention in a Case of Multiple Disability.

    Science.gov (United States)

    Hooper, Janice; And Others

    1987-01-01

    A multimodal intervention program designed for a nine-year-old with severe communication problems (secondary to cerebral palsy, receptive dysphasia, and auditory agnosia) combined manual signs and graphic symbols to help her communicate. The intensive, highly structured program had significant positive results. (Author/CB)

  10. [Visual disturbances following right cerebral lesion: a case report].

    Science.gov (United States)

    Sato, M; Yasui, N; Suzuki, A; Kobayashi, T

    1984-07-01

    A 49-year-old right handed male, who showed three types of visual disturbance, e. g. hemianopsia, obscuration phenomena and unilateral visuospatial agnosia at different times, was reported. At first, he had hemiparesis, hemisensory disturbance and homonymous hemianopsia on the left side because of multiple stenoses of posterior branches of the right middle cerebral artery. His motor and visual field disturbances improved for several days after onset, but there appeared transient obscuration phenomena on the left visual field. CT scan revealed an abnormal low density area in the right temporo-parietal region. At about 4.5 years after the first attack, he again had hemiparesis and homonymous hemianopsia on the left side. Cerebral angiography showed an occlusion of the right middle cerebral artery. Since his paresis was progressive, STA-MCA anastomoses was performed. Hemiparesis was improved, but homonymous hemianopsia remained. Moreover, at about one year after the second attack, left visuospatial agnosia participated in his hemianopsia. Cerebral angiography showed an additional occlusion in the crural segment of the right posterior cerebral artery. CT scan showed a lesion in the right basal ganglia and temporo-parietal lobe. In most cases, unilateral visuospatial agnosia occurs with hemianopsia. But, in this case, these symptoms occurred at different times. This may indicate the differentiation between unilateral visuospatial agnosia and hemianopsia. PMID:6487433

  11. Vision after 53 years of blindness

    Czech Academy of Sciences Publication Activity Database

    Šikl, Radovan; Šimeček, Michal; Porubanová-Norquist, M.; Bezdíček, O.; Kremláček, J.; Stodůlka, P.; Fine, I.; Ostrovsky, Y.

    2013-01-01

    Roč. 4, č. 8 (2013), s. 498-507. ISSN 2041-6695 R&D Projects: GA ČR(CZ) GAP407/12/2528 Institutional support: RVO:68081740 Keywords : sight recovery * blindness * visual deprivation * object agnosia * prosopagnosia Subject RIV: AN - Psychology http://i-perception.perceptionweb.com/fulltext/i04/i0611.pdf

  12. Cortical deafness in multiple sclerosis

    OpenAIRE

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

    1981-01-01

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

  13. Mirrored and rotated stimuli are not the same: A neuropsychological and lesion mapping study.

    Science.gov (United States)

    Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Champmartin, Cécile; Pouliquen, Dorothée; Cruypeninck, Yohann; Hannequin, Didier; Gérardin, Emmanuel

    2016-05-01

    Agnosia for mirrored stimuli is a rare clinical deficit. Only eight patients have been reported in the literature so far and little is known about the neural substrates of this agnosia. Using a previously developed experimental test designed to assess this agnosia, namely the Mirror and Orientation Agnosia Test (MOAT), as well as voxel-lesion symptom mapping (VLSM), we tested the hypothesis that focal brain-injured patients with right parietal damage would be impaired in the discrimination between the canonical view of a visual object and its mirrored and rotated images. Thirty-four consecutively recruited patients with a stroke involving the right or left parietal lobe have been included: twenty patients (59%) had a deficit on at least one of the six conditions of the MOAT, fourteen patients (41%) had a deficit on the mirror condition, twelve patients (35%) had a deficit on at least one the four rotated conditions and one had a truly selective agnosia for mirrored stimuli. A lesion analysis showed that discrimination of mirrored stimuli was correlated to the mesial part of the posterior superior temporal gyrus and the lateral part of the inferior parietal lobule, while discrimination of rotated stimuli was correlated to the lateral part of the posterior superior temporal gyrus and the mesial part of the inferior parietal lobule, with only a small overlap between the two. These data suggest that the right visual 'dorsal' pathway is essential for accurate perception of mirrored and rotated stimuli, with a selective cognitive process and anatomical network underlying our ability to discriminate between mirrored images, different from the process of discriminating between rotated images. PMID:27035699

  14. Categorical Perception of Lexical Tones in Mandarin-speaking Congenital Amusics

    Directory of Open Access Journals (Sweden)

    Wan Ting Huang

    2015-06-01

    Full Text Available Previous research suggests that within Mandarin-speaking congenital amusics, only a subgroup has behavioral lexical tone perception impairments (tone agnosia, whereas the rest of amusics do not. The purpose of the current study was to investigate the categorical nature of lexical tone perception in Mandarin-speaking amusics with and without behavioral lexical tone deficits. Three groups of listeners (controls, pure amusics and amusics with tone agnosia participated in tone identification and discrimination tasks. Indexes of the categorical perception of a physical continuum of fundamental frequencies ranging from a rising to level tone were measured. Specifically, the stimulus durations were manipulated at 100 and 200 ms. For both stimulus durations, all groups exhibited similar categorical boundaries. The pure amusics showed sharp identification slopes and significantly peaked discrimination functions similar to those of normal controls. However, such essential characteristics for the categorical perception of lexical tones were not observed in amusics with tone agnosia. An enlarged step-size from 20 Hz to 35 Hz was not able to produce any discrimination peaks in tone agnosics either. The current study revealed that only amusics with tone agnosia showed a lack of categorical tone perception, while the pure amusics demonstrated typical categorical perception of lexical tones, indicating that the deficit of pitch processing in music does not necessarily result in the deficit in the categorical perception of lexical tones. The different performance between congenital amusics with and without tone agnosia provides a new perspective on the proposition of the relationship between music and speech perception.

  15. [Mind and brain "Kasane-egaki (Oomori, S.)"].

    Science.gov (United States)

    Kashima, Haruo

    2014-01-01

    A mind-brain problem might be explainable by the concept "Kasane-egaki (Oomori, 1994)". Kasane-egaki of the mind and brain is crucial and meaningful in medical treatment. For Kasane-egaki, it is important to note that the mind (psychiatric symptoms) must be translated into an expression which could be connected with the brain function, and vice versa As a case of Kasane-egaki, a patient with left frontal infarction showing mild obsessive-compulsive-like symptoms is introduced. However, there are two situations in which Kasane-egaki of the mind and brain cannot be applied: visual agnosia and auditory hallucination of schizophrenia The author discusses visual experiences of patients with associative visual agnosia, and the relation between auditory hallucination of schizophrenia and activation of the temporal lobe from the viewpoint of language function. PMID:24864566

  16. Optic aphasia, optic apraxia, and loss of dreaming.

    Science.gov (United States)

    Peña-Casanova, J; Roig-Rovira, T; Bermudez, A; Tolosa-Sarro, E

    1985-09-01

    A 47-year-old man with a left temporo-occipital infarct in the area of the posterior cerebral artery is presented. The neuropsychological examination did not reveal aphasia or gross mental deficits. The patient presented with alexia without agraphia, color agnosia, but few visual perceptual deficits. The main impairment was in confrontation naming; he was incapable of naming objects and pictures, not from lack of recognition (excluding visual agnosia) but from lack of access to the appropriate word (optic aphasia). The patient also exhibited a deficit in the evocation of gesture from the visual presentation of an object (optic apraxia) and a difficulty in "conjuring up" visual images of objects (impaired visual imagery) and loss of dreams. The fundamental deficit of this patient is tentatively explained in terms of visuoverbal and visuogestural disconnection and a deficit of mental imagery. PMID:2413956

  17. Critical appraisal of the long-term impact of memantine in treatment of moderate to severe Alzheimer’s disease

    OpenAIRE

    Umamon Puangthong; Ging-Yuek Robin Hsiung

    2009-01-01

    Umamon Puangthong, Ging-Yuek Robin HsiungDivision of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, CanadaAbstract: Alzheimer’s disease is the most common cause of dementia in older adults. The clinical features include progressive memory decline as well as cognitive deficits with executive dysfunction, language, visual perceptual difficulties, apraxia and agnosia. During the moderate to severe stage of the disease, there is a major decline in memo...

  18. Neuronale Korrelate zerebral bedingter visueller Wahrnehmungsstörungen

    OpenAIRE

    Praß, Maren

    2013-01-01

    Two aspects of visual processing are investigated in this work. First, the impact of unilateral occipito-temporal cortical lesions on object categorization, and second, the influence of top-down manipulation on object categorization in healthy subjects. Major visual object recognition deficits (object agnosia) are rare, and occur mainly after bilateral damage to ventral visual cortices. Most patients suffering from unilateral ventral lesions are clinically non-agnostic. We studied the effect ...

  19. A Rare Symptom of Electrical Injury: Prosopagnosia

    OpenAIRE

    Kamışlı, Özden; Kamışlı, Suat; Kaplan, Yüksel; Aydın, Sibel; Özcan, Cemal

    2013-01-01

    Although electrical injury is rare, it is important due to the high rate of morbidity and mortality. Electrical injury may cause many systemical and neurological symptoms. Disorders of higher cortical functions due to electrical shock are very rare. Prosopagnosia is a selective agnosia that occurs due to the dysfunction of cortical networks. Cerebral injury, congenital and hereditary disorders are the reasons of prosopagnosia. Involvement of bilateral inferior and medial visual association co...

  20. The fusiform face area is not sufficient for face recognition : evidence from a patient with dense prosopagnosia and no occipital face area.

    OpenAIRE

    Steeves, J. K. E.; Culham, J. C.; Duchaine, B. C.; Cavina Pratesi, C.; Valyear, K. F.; Schindler, I.; Humphrey, G. K.; Milner, A D; Goodale, M. A.

    2006-01-01

    We tested functional activation for faces in patient D.F., who following acquired brain damage has a profound deficit in object recognition based on form (visual form agnosia) and also prosopagnosia that is undocumented to date. Functional imaging demonstrated that like our control observers, D.F. shows significantly more activation when passively viewing face compared to scene images in an area that is consistent with the fusiform face area (FFA) (p < 0.01). Control observers also show occip...

  1. Normal form from biological motion despite impaired ventral stream function

    OpenAIRE

    Gilaie-Dotan, S.; Bentin, S.; Harel, M; Rees, G.; Saygin, A.P.

    2011-01-01

    We explored the extent to which biological motion perception depends on ventral stream integration by studying LG, an unusual case of developmental visual agnosia. LG has significant ventral stream processing deficits but no discernable structural cortical abnormality. LG's intermediate visual areas and object-sensitive regions exhibit abnormal activation during visual object perception, in contrast to area V5/MT+ which responds normally to visual motion (Gilaie-Dotan, Perry, Bonneh, Malach, ...

  2. Object-based attentional facilitation and inhibition are neuropsychologically dissociated.

    OpenAIRE

    Smith, D T; Ball, K.; Swalwell, R.; Schenk, T.

    2016-01-01

    Salient peripheral cues produce a transient shift of attention which is superseded by a sustained inhibitory effect. Cueing part of an object produces an inhibitory cueing effect (ICE) that spreads throughout the object. In dynamic scenes the ICE stays with objects as they move. We examined object-centred attentional facilitation and inhibition in a patient with visual form agnosia. There was no evidence of object-centred attentional facilitation. In contrast, object-centred ICE was observed ...

  3. Critical appraisal of the long-term impact of memantine in treatment of moderate to severe Alzheimer’s disease

    OpenAIRE

    Puangthong, Umamon; Hsiung, Ging-Yuek Robin

    2009-01-01

    Alzheimer’s disease is the most common cause of dementia in older adults. The clinical features include progressive memory decline as well as cognitive deficits with executive dysfunction, language, visual perceptual difficulties, apraxia and agnosia. During the moderate to severe stage of the disease, there is a major decline in memory and function, while neuropsychiatric disturbances often emerge and patients become difficult to manage. These distressing symptoms increase caregiver burden a...

  4. Detection of visuoperceptual deficits in preclinical and mild Alzheimer’s disease

    OpenAIRE

    Alegret, Montse; Boada-Rovira, Mercè; Vinyes-Junqué, Georgina; Valero, Sergi; Espinosa, Ana; Hernández, Isabel; Modinos, Gemma; Rosende-Roca, Maitee; Mauleón, Ana; Becker, James T.; Tárraga, Lluís

    2009-01-01

    Exhaustive neuropsychological assessment of mild cognitive impairment (MCI) subjects frequently identifies cognitive deficits other than memory. However, visuoperception has rarely been investigated in MCI. The 15-Objects Test (15-OT), a visual discrimination task based on the Poppelreuter Test, consists of 15 overlapping objects. Poppelreuter-type tests are frequently used to detect visual agnosia. However, more complex tests, such as the 15-OT, are required to detect visuoperceptual signs i...

  5. Stereoscopic Vision in the Absence of the Lateral Occipital Cortex

    OpenAIRE

    Read, JC; Phillipson, GP; Serrano-Pedraza, I; Milner, AD; Parker, AJ

    2010-01-01

    Both dorsal and ventral cortical visual streams contain neurons sensitive to binocular disparities, but the two streams may underlie different aspects of stereoscopic vision. Here we investigate stereopsis in the neurological patient D.F., whose ventral stream, specifically lateral occipital cortex, has been damaged bilaterally, causing profound visual form agnosia. Despite her severe damage to cortical visual areas, we report that DF's stereo vision is strikingly unimpaired. She is better th...

  6. Post-ictal Klüver-Bucy syndrome after temporal lobectomy.

    OpenAIRE

    Anson, J A; Kuhlman, D T

    1993-01-01

    In both animals and humans, Klüver-Bucy syndrome is produced by bilateral temporal lobectomy. It is characterised by hypersexuality, visual agnosia, strong oral tendencies, dietary changes, and hypermetamorphosis. Recurrent, postictal Klüver-Bucy syndrome occurred transiently after seizures in a female who had undergone unilateral temporal lobectomy. The pathophysiological mechanism may have been postictal dysfunction of the remaining temporal lobe, producing a transient functional bilateral ...

  7. Visuomotor system uses target features unavailable to conscious awareness

    OpenAIRE

    Binsted, Gordon; Brownell, Kyle; Vorontsova, Zofia; Heath, Matthew; Saucier, Deborah

    2007-01-01

    After lesions to primary visual cortex, patients lack conscious awareness of visual stimuli. Interestingly, however, some retain the ability to make accurate judgments about the visual world (i.e., so-called blindsight). Similarly, damage to inferior occipitotemporal regions of cortex (e.g., lateral occipital cortex) can result in an inability to perceive object properties while retaining the ability to act on them (i.e., visual form agnosia). In the present work, we demonstrate that the abil...

  8. The Two Visual Systems Hypothesis: New Challenges and Insights from Visual form Agnosic Patient DF

    OpenAIRE

    Whitwell, Robert L.; Milner, A. David; Goodale, Melvyn A.

    2014-01-01

    Patient DF, who developed visual form agnosia following carbon monoxide poisoning, is still able to use vision to adjust the configuration of her grasping hand to the geometry of a goal object. This striking dissociation between perception and action in DF provided a key piece of evidence for the formulation of Goodale and Milner’s Two Visual Systems Hypothesis (TVSH). According to the TVSH, the ventral stream plays a critical role in constructing our visual percepts, whereas the dorsal strea...

  9. DF's visual brain in action : the role of tactile cues.

    OpenAIRE

    Whitwell, R.L.; Milner, A D; Cavina-Pratesi, C.; Byrne, C. M.; Goodale, M. A.

    2014-01-01

    Patient DF, an extensively-tested woman with visual form agnosia from ventral-stream damage, is able to scale her grip aperture to match a goal object's geometry when reaching out to pick it up, despite being unable to explicitly distinguish amongst objects on the basis of their different geometries. Using evidence from a range of sources, including functional MRI, we have proposed that she does this through a functionally intact visuomotor system housed within the dorsal stream of the poster...

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

    OpenAIRE

    Simona Gardini; Letizia Concari; Salvatrice Pagliara; Caterina Ghetti; Annalena Venneri; Paolo Caffarra

    2011-01-01

    This study investigated the cognitive profile and the cerebral perfusion pattern in a highly educated 70 year old gentleman with posterior cortical atrophy (PCA). Visuo-perceptual abilities, spatial memory, spatial representation and navigation, visuo-spatial mental imagery, semantic and episodic-autobiographical memory were assessed. Regional cerebral blood flow (rCBF) was imaged with SPECT. Cognitive testing showed visual-perceptual impairment, apperceptive visual and landmark agnosia, topo...

  11. Preserved local but disrupted contextual figure-ground influences in an individual with abnormal function of intermediate visual areas

    OpenAIRE

    Brooks, Joseph L.; Gilaie-Dotan, Sharon; Rees, Geraint; Bentin, Shlomo; Driver, Jon

    2012-01-01

    Visual perception depends not only on local stimulus features but also on their relationship to the surrounding stimulus context, as evident in both local and contextual influences on figure-ground segmentation. Intermediate visual areas may play a role in such contextual influences, as we tested here by examining LG, a rare case of developmental visual agnosia. LG has no evident abnormality of brain structure and functional neuroimaging showed relatively normal V1 function, but his intermedi...

  12. Holistic processing impairment can be restricted to faces in acquired prosopagnosia : evidence from the global/local Navon effect

    OpenAIRE

    Busigny, Thomas; Rossion, Bruno

    2011-01-01

    Previous studies have shown that acquired prosopagnosia is characterized by impairment at holistic/configural processing. However, this view is essentially supported by studies performed with patients whose face recognition difficulties are part of a more general visual (integrative) agnosia. Here, we tested the patient PS, a case of acquired prosopagnosia whose face-specific recognition difficulties have been related to the inability to process individual faces holistically (absence of inver...

  13. Achromatopsia in the aura of migraine.

    OpenAIRE

    Lawden, M C; Cleland, P. G.

    1993-01-01

    A 49 year old woman reported an attack of transient neurological dysfunction associated with unilateral headache. A prominent feature of the aura was a period of complete achromatopsia, so that the visual scene was experienced in monochrome. The episode developed to include features of prosopagnosia and spatial agnosia before resolving completely. Other episodes of transient neurological dysfunction followed at regular intervals until prophylactic antimigrainous therapy was initiated. Four ve...

  14. Neurolinguistic analysis of the language abilities of a patient with a "double disconnection syndrome": a case of subangular alexia in the presence of mixed transcortical aphasia.

    OpenAIRE

    Pirozzolo, F J; Kerr, K L; Obrzut, J E; Morley, G K; Haxby, J V; Lundgren, S.

    1981-01-01

    In contrast to the classic form of alexia without agraphia, subangular alexia results from a single lesion located deep in the white matter of the left parietal lobe. In the present report, a patient with subangular alexia and features of mixed transcortical aphasia is described. Neurolinguistic findings include: alexia without agraphia, paucity of spontaneous speech, moderate auditory comprehension difficulty, excellent repetition, echopraxia, colour agnosia, and naming disorder. Neurolingui...

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

    OpenAIRE

    2013-01-01

    Dementia presenting with prominent higher order visual symptoms may be observed in a range of neurodegenerative conditions and is often challenging to diagnose. We describe a case of progressive dementia presenting with prominent visual cortical symptoms. A 55-year-old, right-handed, woman with early onset of visual impairment not associated with anterior visual pathology, presenting with dyslexia, visual agnosia, Balint's syndrome, and spatial disorientation. Ophthalmologists should consider...

  16. Selective impairment of facial recognition due to a haematoma restricted to the right fusiform and lateral occipital region

    OpenAIRE

    Wada, Y.; Yamamoto, T.

    2001-01-01

    A 67 year old right handed Japanese man developed prosopagnosia caused by a haemorrhage. His only deficit was the inability to perceive and discriminate unfamiliar faces, and to recognise familiar faces. He did not show deficits in visual or visuospatial perception of non-facial stimuli, alexia, visual agnosia, or topographical disorientation. Brain MRI showed a haematoma limited to the right fusiform and the lateral occipital region. Single photon emission computed tomography con...

  17. Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct

    OpenAIRE

    Bhattacharyya, S.; Cai, X.(Central China Normal University, Wuhan, China); Klein, J P

    2014-01-01

    The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with ...

  18. Cortical Lewy body dementia: clinical features and classification.

    OpenAIRE

    Gibb, W R; Luthert, P. J.; Janota, I; Lantos, P. L.

    1989-01-01

    Seven patients, aged 65-72 years, are described with dementia and cortical Lewy bodies. In one patient a Parkinsonian syndrome was followed by dementia and motor neuron disease. In the remaining six patients dementia was accompanied by dysphasia, dyspraxia and agnosia. One developed a Parkinsonian syndrome before the dementia, in three cases a Parkinsonian syndrome occurred later, and in two cases not at all. All patients showed Lewy bodies and cell loss in the substantia nigra, locus coerule...

  19. Acute parietal lobe infarction presenting as Gerstmann’s syndrome and cognitive decline mimicking senile dementia

    OpenAIRE

    Chen, Tien-Yu; Chen, Chun-Yen; Yen, Che-Hung; Kuo, Shin-Chang; Yeh, Yi-Wei; Chang, Serena; Huang, San-Yuan

    2013-01-01

    Gerstmann’s syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly man with a history of several cardiovascular diseases was initially brought to the psychiatric outpatient department by his family because of worsening of recent memory, executive function, and mixed anxious-depressive mood. Gerstmann’s syndrome without obvious motor function impairment and dementia-like features could be observed at first. Emergent brain computed tomograph...

  20. Prospects for de-automatization.

    Science.gov (United States)

    Kihlstrom, John F

    2011-06-01

    Research by Raz and his associates has repeatedly found that suggestions for hypnotic agnosia, administered to highly hypnotizable subjects, reduce or even eliminate Stroop interference. The present paper sought unsuccessfully to extend these findings to negative priming in the Stroop task. Nevertheless, the reduction of Stroop interference has broad theoretical implications, both for our understanding of automaticity and for the prospect of de-automatizing cognition in meditation and other altered states of consciousness. PMID:20356765

  1. Word deafness: one hundred years later.

    OpenAIRE

    Buchman, A.S.; Garron, D C; Trost-Cardamone, J E; Wichter, M D; M. Schwartz

    1986-01-01

    Since its original description the diagnosis of word deafness has been greatly expanded. Confusion has arisen with regard to the usage of the related terms pure word deafness, auditory agnosia, and cortical deafness. Three new cases of word deafness are presented including one case with CT and necropsy correlation. These cases are compared with 34 previously reported cases of various cortical auditory disorders. Our review establishes that patients with word deafness who have had formal testi...

  2. [Carbon monoxide poisoning: clinical features of the victims of the explosion accident of Mitsui-Miike Mikawa coal mine 50 years ago].

    Science.gov (United States)

    Kato, Motohiro

    2015-01-01

    Clinical features of carbon monoxide poisoning have been described in 24 victims of an intense explosion accident of the Mitsui-Miike Mikawa coal mine in Japan 50 years ago; these victims were admitted to the Kyushu University Hospital as they suffered from severe poisoning. In the early stage of poisoning, all victims showed disturbed state of consciousness, varying in duration from 5.5 hours to 3 months, and the duration of unconsciousness was closely correlated to the clinical severity in the late stage. Some of the severely poisoned patients showed a transient stage of apallic syndrome. After recovery from unconsciousness, all patients presented with severe amnestic syndrome and loss of initiative. Neurologically, the extrapyramidal signs were prominent in the early stage, which gradually improved in the late stage. Variable types of agnosia and apraxia were apparent in some of the severely and moderately poisoned patients in the late stage, with prominent Gerstmann syndrome and visual-visuospatial agnosias. Since these signs showed poor improvement, the agnosia and apraxia, as well as impaired intellectual ability, remained as a sequela of the poisoning, and were one of the major causes of deficits of the patients in their daily life activities in the late stage. PMID:25585432

  3. Influencing factors for the disappearance of hemispatial neglect in patients during acute stroke

    Institute of Scientific and Technical Information of China (English)

    Yaobin Long

    2006-01-01

    BACKGROUND: Some researches are proved that early sitting balance and body motor control performed on patients with stroke and hemiplegia is related to functional prognosis. For patients with hemispatial neglect (HSN) during acute stroke, whether HSN disappearance is related to those trainings or not should be further studied.OBJ ECTIVE: To analyze the correlation between HSN disappearance and related intervention of patients during acute stroke.DESIGN: Case analysis.SETTING: Department of Neurology, First Affiliated Hospital of Guangxi Medical University.PARTICIPANTS: A total of 21 patients with stroke were selected from the Department of Neurology, the First Affiliated Hospital of Guangxi Medical University from May 2005 to March 2006. Diagnosis criteria: ① Stroke was diagnosed by CT and MRI; ② Diagnosis was coincidence with HSN evaluation criteria; ③ All cases were consent. Exclusion criteria: Patients who had poly-focus, conscious disturbance, severe amentia and hard communication combined with aphasia were excluded. A total of 12 males and 9 females were included, and the mean age was (68±10) years. Among them, 14 patients had cerebral infarction and 7 had cerebral hemorrhage.METHODS: Disappearance and existence of HSN were analyzed with HSN evaluation criteria: body agnosia, left and right agnosia, maintenance of supine position, place of things, sitting up straight, center of line measured by eyes, and cutting 30 lines with paring method. Items mentioned below belonged to HSN disappearance: ① without body agnosia; ② without left and right agnosia; ③ be able to maintain supine position; ④ knowing place of things; ⑤ sitting up straight by one's own; ⑥ be able to measure the center of line by eyes; ⑦ be able to cut 30 lines with paring method. However, only one item belonged to HSN remnant; but only one item belonged to HSN remnant. Numbers of patients who were of body agnosia, left and right agnosia and difficult maintenance of supine

  4. [In Process Citation

    Science.gov (United States)

    Ackermann; Mathiak

    1999-11-01

    Pure word deafness (auditory verbal agnosia) is characterized by an impairment of auditory comprehension, repetition of verbal material and writing to dictation whereas spontaneous speech production and reading largely remain unaffected. Sometimes, this syndrome is preceded by complete deafness (cortical deafness) of varying duration. Perception of vowels and suprasegmental features of verbal utterances (e.g., intonation contours) seems to be less disrupted than the processing of consonants and, therefore, might mediate residual auditory functions. Often, lip reading and/or slowing of speaking rate allow within some limits to compensate for speech comprehension deficits. Apart from a few exceptions, the available reports of pure word deafness documented a bilateral temporal lesion. In these instances, as a rule, identification of nonverbal (environmental) sounds, perception of music, temporal resolution of sequential auditory cues and/or spatial localization of acoustic events were compromised as well. The observed variable constellation of auditory signs and symptoms in central hearing disorders following bilateral temporal disorders, most probably, reflects the multitude of functional maps at the level of the auditory cortices subserving, as documented in a variety of non-human species, the encoding of specific stimulus parameters each. Thus, verbal/nonverbal auditory agnosia may be considered a paradigm of distorted "auditory scene analysis" (Bregman 1990) affecting both primitive and schema-based perceptual processes. It cannot be excluded, however, that disconnection of the Wernicke-area from auditory input (Geschwind 1965) and/or an impairment of suggested "phonetic module" (Liberman 1996) contribute to the observed deficits as well. Conceivably, these latter mechanisms underly the rare cases of pure word deafness following a lesion restricted to the dominant hemisphere. Only few instances of a rather isolated disruption of the discrimination

  5. Correlations between neurological signs and brain MR images of patients in consecutive stages of subacute sclerosing panencephalitis

    International Nuclear Information System (INIS)

    Correlations between neurological symptoms and brain MRI changes during the course of SSPE in 10 patients were studied. Visual agnosia and mental regression - very frequent symptoms at the early stages of the disease were caused by nearly symmetrical, focal involvement of the occipital and frontal white matter in all cases. Pyramidal and extrapyramidal disturbances reflected rather diffuse lesions of both cerebral hemispheres in late second stage of the illness. In cases with clinical improvement the brain changes disclosed an entire stability, but not diminishing intensity. (author)

  6. Differential contribution of right and left temporo-occipital and anterior temporal lesions to face recognition disorders

    Directory of Open Access Journals (Sweden)

    Guido Gainotti

    2011-06-01

    The implications of our review are, therefore, the following: (1 to consider the components of visual agnosia often observed in prosopagnosic patients with bilateral temporo-occipital lesions as part of a semantic defect, resulting from left-sided lesions (and not from prosopagnosia proper; (2 to systematically investigate voice recognition disorders in patients with right anterior temporal lesions to determine whether the face recognition defect should be considered a form of ‘associative prosopagnosia’ or a form of the ‘multimodal people recognition disorder’.

  7. Ventral extra-striate cortical areas are required for optimal orientation averaging

    OpenAIRE

    Allen, Harriet A.; Humphreys, Glyn W.; Bridge, Holly

    2007-01-01

    We examined the ability of a previously well-studied patient with visual agnosia to compute the average orientation of elements in visual displays. In a structural MRI study, we show that the lesion is likely to involve a variety of ventral extra-striate areas, including V2, V3 and V4; however, the lesion does not extend dorsally. Subsequently we show that some ability to compute average orientation is spared, though there are limitations on the ability to scale the averaging process as a fun...

  8. Correlations between neurological signs and brain MR images of patients in consecutive stages of subacute sclerosing panencephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Kulczycki, J.; Kryst-Widzgowska, T.; Sobczyk, W.; Bochynska, A.; Pilkowska, E.; Milewska, D. [Pracownia Rezonansu Magnetycznego, Inst. Psychiatrii i Neurologii, Warsaw (Poland)

    1994-12-31

    Correlations between neurological symptoms and brain MRI changes during the course of SSPE in 10 patients were studied. Visual agnosia and mental regression - very frequent symptoms at the early stages of the disease were caused by nearly symmetrical, focal involvement of the occipital and frontal white matter in all cases. Pyramidal and extrapyramidal disturbances reflected rather diffuse lesions of both cerebral hemispheres in late second stage of the illness. In cases with clinical improvement the brain changes disclosed an entire stability, but not diminishing intensity. (author) 9 refs, 8 figs, 3 tabs

  9. Vision without knowledge.

    OpenAIRE

    Milner, A D

    1997-01-01

    A brain-damaged patient (D.F.) with visual form agnosia is described and discussed. D.F. has a profound inability to recognize objects, places and people, in large part because of her inability to make perceptual discriminations of size, shape or orientation, despite having good visual acuity. Yet she is able to perform skilled actions that depend on that very same size, shape and orientation information that is missing from her perceptual awareness. It is suggested that her intact vision can...

  10. Seeing with Profoundly Deactivated Mid-level Visual Areas: Non-hierarchical Functioning in the Human Visual Cortex

    OpenAIRE

    Gilaie-Dotan, Sharon; Perry, Anat; Bonneh, Yoram; Malach, Rafael; Bentin, Shlomo

    2008-01-01

    A fundamental concept in visual processing is that activity in high-order object-category distinctive regions (e.g., lateral occipital complex, fusiform face area, middle temporal+) is dependent on bottom-up flow of activity in earlier retinotopic areas (V2, V3, V4) whose main input originates from primary visual cortex (V1). Thus, activity in down stream areas should reflect lower-level inputs. Here we qualify this notion reporting case LG, a rare case of developmental object agnosia and pro...

  11. Imaging of Retrochiasmal and Higher Cortical Visual Disorders.

    Science.gov (United States)

    Tantiwongkosi, Bundhit; Salamon, Noriko

    2015-08-01

    Retrochiasmal visual pathways include optic tracts, lateral geniculate nuclei, optic radiations, and striate cortex (V1). Homonymous hemianopsia and field defect variants with relatively normal visual acuity suggest that the lesions involve retrochiasmal pathways. From V1, visual input is projected to higher visual association areas that are responsible for perception of objects, faces, colors, and orientation. Visual association areas are classified into ventral and dorsal pathways. Damage to the ventral stream results in visual object agnosia, prosopagnosia, and achromatopsia. Balint syndrome, visual inattention, and pure alexia are examples of dorsal stream disorders. Posterior cortical atrophy can involve ventral and dorsal streams, often preceding dementia. PMID:26208417

  12. Object based attention and visual area LO.

    OpenAIRE

    de-Wit, L.; Kentridge, R. W.; Milner, A D

    2009-01-01

    We investigated the neural basis of so-called “object-based attention” by examining patient D.F., who has visual form agnosia caused by bilateral damage to the lateral occipital (LO) area of the ventral visual stream. We tested D.F.’s object-based attention in two ways. In the first experiment, we used a spatial cueing procedure to compare the costs associated with shifting attention within versus between two separate outline figures. D.F. did not show the normal advantage of within-object ov...

  13. Neuropsicología clínica y cognoscitiva

    OpenAIRE

    Montañés, Patricia; De Brigard, Felipe

    2005-01-01

    En este libro se realiza la descripción semiológica y sistemática de los procesos que permiten al hombre «ser» (lo que se llama los procesos cognoscitivos), cosa que se perfila como uno de los desafíos más importantes del ser humano: el saber cómo percibimos, hablamos, escribimos, sumamos, aprendemos, recordamos, reconocemos y actuamos, a luz del estudio de las difunciones en cada uno de los procesos, v.gr. afasia, alexia, acalculia, agnosia, apraxia. / Contenido. Preliminares; Capítulo 1 - A...

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

    Directory of Open Access Journals (Sweden)

    Leonardo Ferreira Caixeta

    2013-10-01

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

  15. Acute parietal lobe infarction presenting as Gerstmann’s syndrome and cognitive decline mimicking senile dementia

    OpenAIRE

    Chen TY; Chen CY; Yen CH; Kuo SC; Yeh YW; Chang S; Huang SY

    2013-01-01

    Tien-Yu Chen,1 Chun-Yen Chen,1,3 Che-Hung Yen,2,3 Shin-Chang Kuo,1,3 Yi-Wei Yeh,1,3 Serena Chang,1 San-Yuan Huang1,31Department of Psychiatry, 2Department of Neurology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, 3Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of ChinaAbstract: Gerstmann’s syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly m...

  16. A Critical Review of Alzheimer's Disease Researches in the Past Decade%Alzheimer病近十年研究述评

    Institute of Scientific and Technical Information of China (English)

    高定国; 高尚仁; 郭丽

    2001-01-01

    Alzheimer病(Alzheimer'S disease-AD)也称Alzheimer型痴呆(dementia of Alzheimer’s type-DAT),是一种伴有神经病理学和神经化学特性的原发性退行性大脑认知功能疾病。主要表现为记忆力下降(不能学习或回忆)以及其它认知功能障碍:如失语(aphasia)、失动(apraxia)、失知(agnosia)

  17. [A Case of Musicophilia with Right Predominant Temporal Lobe Atrophy].

    Science.gov (United States)

    Shinagawa, Shunichiro; Nakayama, Kazuhiko

    2015-11-01

    A 68-year-old woman exhibiting musicophilia with right predominant temporal lobe atrophy happened to visit our clinic. She had no musical background, but beginning two years ago, she acquired a strong preference for especially popular music and sometimes sang at home. She did not exhibit obvious semantic aphasia or facial agnosia, and showed only mild behavioral changes including apathy. Her musicophilia can be explained as an instance of stereotypical behavior. Her right temporal lobe atrophy may have caused changes in her emotional and reward systems, resulting in her music specific behaviors. PMID:26560960

  18. Partial Kluver-Bucy syndrome secondary to tubercular meningitis.

    Science.gov (United States)

    Jha, Kunal Kishor; Singh, Satyajeet Kumar; Kumar, Prem; Arora, Charu Dutt

    2016-01-01

    Tubercular meningitis (TBM) is a devastating extra pulmonary manifestation of tuberculosis and demonstrates a high neurological morbidity. A rare complication of this condition is Kluver-Bucy syndrome (KBS), which is a neurobehavioral disorder characterised by hyper-sexuality, visual agnosia, bulimia, placidity, hyperorality and memory deficits caused by lesions to the amygdala. The amygdala lesions can be due to many causes, including traumatic brain injury, systemic conditions and infections such as tuberculosis. Here, we present a case of partial KBS in a patient undergoing treatment for TBM. PMID:27530874

  19. [Higher Brain Dysfunction in Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke-Like Episodes (MELAS)].

    Science.gov (United States)

    Ichikawa, Hiroo

    2016-02-01

    Stroke-like episodes are one of the cardinal features of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), and occur in 84-99% of the patients. The affected areas detected on neuroimaging do not have classical vascular distribution, and involve predominantly the temporal, parietal and occipital lobes. Thus, the neurological symptoms including higher brain dysfunction correlate with this topographical distribution. In association with the occipital lobe involvement, the most frequent symptom is cortical blindness. Other symptoms have been occasionally reported in case reports: visual agnosia, prosopagnosia, cortical deafness, auditory agnosia, topographical disorientation, various types of aphasia, hemispatial neglect, and so on. On the other hand, cognitive decline associated with more diffuse brain impairment rather than with focal stroke-like lesions has been postulated. This condition is also known as mitochondrial dementia. Domains of cognitive dysfunction include abstract reasoning, verbal memory, visual memory, language (naming and fluency), executive or constructive functions, attention, and visuospatial function. Cognitive functions and intellectual abilities may decline from initially minimal cognitive impairment to dementia. To date, the neuropsychological and neurologic impairment has been reported to be associated with cerebral lactic acidosis as estimated by ventricular spectroscopic lactate levels. PMID:26873235

  20. Hurt but still alive: Residual activity in the parahippocampal cortex conditions the recognition of familiar places in a patient with topographic agnosia☆

    Science.gov (United States)

    van Assche, Mitsouko; Kebets, Valeria; Lopez, Ursula; Saj, Arnaud; Goldstein, Rachel; Bernasconi, Françoise; Vuilleumier, Patrik; Assal, Frédéric

    2016-01-01

    The parahippocampal cortex (PHC) participates in both perception and memory. However, the way perceptual and memory processes cooperate when we navigate in our everyday life environment remains poorly understood. We studied a stroke patient presenting a brain lesion in the right PHC, which resulted in a mild and quantifiable topographic agnosia, and allowed us to investigate the role of this structure in overt place recognition. Photographs of personally familiar and unfamiliar places were displayed during functional magnetic resonance imaging (fMRI). Familiar places were either recognized or unrecognized by the patient and 6 age- and education-matched controls in a visual post-scan recognition test. In fMRI, recognized places were associated with a network comprising the fusiform gyrus in the intact side, but also the right anterior PHC, which included the lesion site. Moreover, this right PHC showed increased connectivity with the left homologous PHC in the intact hemisphere. By contrasting recognized with unrecognized familiar places, we replicate the finding of the joint involvement of the retrosplenial cortex, occipito-temporal areas, and posterior parietal cortex in place recognition. This study shows that the ability for left and right anterior PHC to communicate despite the neurological damage conditioned place recognition success in this patient. It further highlights a hemispheric asymmetry in this process, by showing the fundamental role of the right PHC in topographic agnosia. PMID:26909331

  1. Object-based attentional facilitation and inhibition are neuropsychologically dissociated.

    Science.gov (United States)

    Smith, Daniel T; Ball, Keira; Swalwell, Robert; Schenk, Thomas

    2016-01-01

    Salient peripheral cues produce a transient shift of attention which is superseded by a sustained inhibitory effect. Cueing part of an object produces an inhibitory cueing effect (ICE) that spreads throughout the object. In dynamic scenes the ICE stays with objects as they move. We examined object-centred attentional facilitation and inhibition in a patient with visual form agnosia. There was no evidence of object-centred attentional facilitation. In contrast, object-centred ICE was observed in 3 out of 4 tasks. These inhibitory effects were strongest where cues to objecthood were highly salient. These data are evidence of a neuropsychological dissociation between the facilitatory and inhibitory effects of attentional cueing. From a theoretical perspective the findings suggest that 'grouped arrays' are sufficient for object-based inhibition, but insufficient to generate object-centred attentional facilitation. PMID:26551577

  2. The contribution of single case studies to the neuroscience of vision.

    Science.gov (United States)

    Zihl, Josef; Heywood, Charles A

    2016-03-01

    Visual neuroscience is concerned with the neurobiological foundations of visual perception, that is, the morphological, physiological, and functional organization of the visual brain and its co-operative partners. One important approach for understanding the functional organization of the visual brain is the study of visual perception from the pathological perspective. The study of patients with focal injury to the visual brain allows conclusions about the representation of visual perceptual functions in the framework of association and dissociation of functions. Selective disorders have been reported for more "elementary" visual capabilities, for example, color and movement vision, but also for visuo-cognitive capacities, such as visual agnosia or the visual field of attention. Because these visual disorders occur rather seldom as selective and specific dysfunctions, single cases have always played, and still play, a significant role in gaining insights into the functional organization of the visual brain. PMID:27061638

  3. Cognitive problems related to vertebrobasilar circulation.

    Science.gov (United States)

    Koçer, Abdulkadir

    2015-01-01

    Neurodegenerative disorders are characterized by decreased regional cerebral blood flow. Supporting this concept, both cognitive training exercises and physical activity promote blood flow increase and correlate with healthy cognitive aging. The terminal branches of the posterior circulation supply blood to areas of the brain, such as the thalamus, hippocampus, occipital lobe, and cerebellum, involved with important intellectual functions, particularly recent memory, visual-spatial functioning, and visuomotor adaptations. Amnesia and visual agnosia may be a complication of not only posterior circulation infarctions but also vertebrobasilar insufficiency (VBI) without accompanying structural infarcts. The cognitive impairment maybe a manifestation of transient attacks and may persist beyond resolution of symptoms related to ischemia. Early recognition of cognitive deficits in the VBI patient is important because several recent reports show stent placements or medical treatment may improve cognition. PMID:26738337

  4. Dyscalculia, dysgraphia, and left-right confusion from a left posterior peri-insular infarct.

    Science.gov (United States)

    Bhattacharyya, S; Cai, X; Klein, J P

    2014-01-01

    The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation. PMID:24817791

  5. Síndrome de gerstmann de desenvolvimento associada a neoplasia cerebelar: relato de um caso e revisão da literatura

    Directory of Open Access Journals (Sweden)

    Lineu César Werneck

    1975-03-01

    Full Text Available É relatado um caso de síndrome de Gerstmann de Desenvolvimento, que apresentava acalculia, agrafía, confusão direita-esquerda, agnosia de dedos e apraxia construcional, em um menino de 7 anos. O tratamento inicial com metilfenidato determinou bons resultados no que concerne à hiperatividade, à atenção e à apraxia construcional. Durante o curso clínico, o paciente apresentou sintomatologia cerebelar, hipertensão intracraniana, tendo sido feita intervenção cirúrgica na fossa posterior, sendo excisado um meduloblastoma de cerebelo. O autor acredita que é esta a primeira descrição na literatura da concomitância da síndrome de Gerstmann de Desenvolvimento e neoplasia de fossa posterior. São feitos comentários focalizando cada um dos aspectos clínicos, fatores etiológicos e topográficos.

  6. Hyperacute cognitive stroke syndromes.

    Science.gov (United States)

    Ferro, J M

    2001-10-01

    Cognitive syndromes are common clinical manifestations of hyperacute stroke and may be the single or dominant presenting features. They are related to acute dysfunction of complex integrated distributed functional networks serving different cognitive domains. The most common cortical syndromes include nonfluent or fluent aphasia, neglect, collor agnosia, pure alexia and Balint's syndrome. Disturbances of declarative memory are common following posterior cerebral artery and thalamic strokes. Abulia can follow thalamic, caudate and capsular lesions. Intraventricular and subarachnoid haemorrhages can cause preeminent neuropsychological changes. Disorientation is present in about 40% of acute stroke patients and delirium complicates the course of 25% of acute strokes. Some hyperacute cognitive stroke syndromes are useful indicators of later disability. Cognitive syndromes may pose special difficulties to neurology residents, unless formal teaching in neuropsychology and psychiatry is included in their training programs. PMID:11697519

  7. Mindblindness: metaphor and neuroaesthetics in the works of Silas Weir Mitchell and Simon Baron-Cohen.

    Science.gov (United States)

    Swenson, Kristine

    2013-01-01

    Silas Weir Mitchell's novel, When All the Woods are Green (1894), acknowledges the medical use of mindblindness (agnosia) but also casts it as a developmental disorder, bringing it provocatively close to how current neuropsychologist, Simon Baron-Cohen and his followers use the term in relation to autism. This chapter traces the mindblindess metaphor in the works of Mitchell and Baron-Cohen to show how mindblindness informs the larger paradigms by which they theorize the brain. This analysis suggests that Baron-Cohen, and thus much current thinking about autism spectrum conditions, is influenced by Victorian-era cultural assumptions and neurosexism, a connection that calls for scrutiny of Baron-Cohen's current models of the brain and theories of autism. This chapter also demonstrates the extent to which Mitchell used fiction and advocated writing as neuroaesthetic tools and thus bridged in his work cognitive science and aesthetics--a connection that current scholars of neuroaesthetics are now theorizing. PMID:24290271

  8. Neurological, neuropsychological and neuroradiological studies of the posterior cerebral artery occlusion

    International Nuclear Information System (INIS)

    Neurological, neuropsychological and neuroradiological studies were performed on 31 cases of the posterior cerebral artery (PCA) occlusion diagnosed by cerebral angiography and/or computed tomography (CT). Neurological examinations revealed visual field defect in 28 cases, contralateral sensory disturbance and hemiparesis in 23 cases and mental syndrome of memory disturbance, disorientation or confusion in 8 cases. CT was done on 17 cases out of 23 cases with contralateral sensory disturbance and hemiparesis. Ten cases of them revealed to have thalamic lesions by CT. In 7 cases which had no evidence of thalamic lesion by CT, 3 cases were highly suspected to have thalamic involvement clinically. The neurological and neuroradiological findings revealed high incidence and its pathomechanism of thalamic lesion in the cases of PCA occlusion. Neuropsychological examinations disclosed pure alexia in 6 cases, cortical blindness in 2 cases and hemispatial agnosia in 2 cases. Four cases with pure alexia were followed their alexic symptoms. Alexic symptoms lasted long in 3 cases. In these cases, collateral flow to the territory of the occlude PCA was hardly visible. One case with a relatively good collateral filling of the occluded PCA, alexic symptoms showed gradual improvement. Two cases with cortical blindness were proven to have bilateral PCA occlusion. In these 2 cases, collateral filling was hardly visible and their symptoms were permanent. The neurological and neuroradiological findings mentioned above suggest that the prognosis of pure alexia and cortical blindness depends largely on the degree of development of collateral circulation to the occluded PCA. Hemispatial agnosia was seen in 2 cases. (author)

  9. Síndrome de gerstmann de desenvolvimento associada a neoplasia cerebelar: relato de um caso e revisão da literatura Developmental Gerstmann syndrome associated with cerebellar neoplasm: a case report with review of litterature

    Directory of Open Access Journals (Sweden)

    Lineu César Werneck

    1975-03-01

    Full Text Available É relatado um caso de síndrome de Gerstmann de Desenvolvimento, que apresentava acalculia, agrafía, confusão direita-esquerda, agnosia de dedos e apraxia construcional, em um menino de 7 anos. O tratamento inicial com metilfenidato determinou bons resultados no que concerne à hiperatividade, à atenção e à apraxia construcional. Durante o curso clínico, o paciente apresentou sintomatologia cerebelar, hipertensão intracraniana, tendo sido feita intervenção cirúrgica na fossa posterior, sendo excisado um meduloblastoma de cerebelo. O autor acredita que é esta a primeira descrição na literatura da concomitância da síndrome de Gerstmann de Desenvolvimento e neoplasia de fossa posterior. São feitos comentários focalizando cada um dos aspectos clínicos, fatores etiológicos e topográficos.A Developmental Gerstmann syndrome in a 7 years-old-boy with hyperactivity, short attention span, acalculia, agraphia, right-left confusion, finger agnosia and constructional apraxia is reported. An initial trial with methylphenidate was done with good improvement regarding hyperactivity, attention span and constructional apraxia. In the clinical course developed a cerebellar syndrome and intracranial hypertension. Surgical exploration of the cerebellum discovered a medulloblastoma. The author believes that this is the first described association of Developmental Gerstmann syndrome and cerebellar neoplasia. The clinical findings, the etiology and the topography of the Gerstmann syndrome are discussed.

  10. Effect of synapse dilution on the memory retrieval in structured attractor neural networks

    Science.gov (United States)

    Brunel, N.

    1993-08-01

    We investigate a simple model of structured attractor neural network (ANN). In this network a module codes for the category of the stored information, while another group of neurons codes for the remaining information. The probability distribution of stabilities of the patterns and the prototypes of the categories are calculated, for two different synaptic structures. The stability of the prototypes is shown to increase when the fraction of neurons coding for the category goes down. Then the effect of synapse destruction on the retrieval is studied in two opposite situations : first analytically in sparsely connected networks, then numerically in completely connected ones. In both cases the behaviour of the structured network and that of the usual homogeneous networks are compared. When lesions increase, two transitions are shown to appear in the behaviour of the structured network when one of the patterns is presented to the network. After the first transition the network recognizes the category of the pattern but not the individual pattern. After the second transition the network recognizes nothing. These effects are similar to syndromes caused by lesions in the central visual system, namely prosopagnosia and agnosia. In both types of networks (structured or homogeneous) the stability of the prototype is greater than the stability of individual patterns, however the first transition, for completely connected networks, occurs only when the network is structured.

  11. Cerebral hemorrhage without manifest motor paralysis. Reports of 5 cases

    Energy Technology Data Exchange (ETDEWEB)

    Taketani, T.; Dohi, I.; Miyazaki, T.; Handa, A. (Central Hospital of JNR, Tokyo (Japan))

    1982-01-01

    Before the introduction of computerized tomography (CT) there were some cases of intracerebral bleeding who were wrongly diagnosed as hypertensive encephalopathy or senile psychosis. We here report 5 cases who did not show any sign of motor paralysis. The clinical aspects of these cases were nausea and vomiting with dizziness (case 1), nausea and vomiting with slight headache (case 2), agnosia of left side with several kinds of disorientation (case 3), nausea and vomiting (case 4), and visual disturbance of right, lower quadrant (case 5). All of these cases showed no motor paralysis or abnormal reflex activities. By examination with CT each of them exhibited a high density area in the subcortical area of the right parietal lobe, the subcortical area of the right occipital lobe, the right temporal and parietal lobe, rather small portion of the left putamen and external capsule, and the subcortical area of left occipital lobe, respectively. Patients of cerebral hemorrhage without motor or sensory disturbances might often be taken for some psychic abnormality. We here have emphasized the importance of CT in such a group of patients. But for this technique, most of them would not be given adequate treatment and might be exposed to lifethreatening situations.

  12. A PDP model of the simultaneous perception of multiple objects

    Science.gov (United States)

    Henderson, Cynthia M.; McClelland, James L.

    2011-06-01

    Illusory conjunctions in normal and simultanagnosic subjects are two instances where the visual features of multiple objects are incorrectly 'bound' together. A connectionist model explores how multiple objects could be perceived correctly in normal subjects given sufficient time, but could give rise to illusory conjunctions with damage or time pressure. In this model, perception of two objects benefits from lateral connections between hidden layers modelling aspects of the ventral and dorsal visual pathways. As with simultanagnosia, simulations of dorsal lesions impair multi-object recognition. In contrast, a large ventral lesion has minimal effect on dorsal functioning, akin to dissociations between simple object manipulation (retained in visual form agnosia and semantic dementia) and object discrimination (impaired in these disorders) [Hodges, J.R., Bozeat, S., Lambon Ralph, M.A., Patterson, K., and Spatt, J. (2000), 'The Role of Conceptual Knowledge: Evidence from Semantic Dementia', Brain, 123, 1913-1925; Milner, A.D., and Goodale, M.A. (2006), The Visual Brain in Action (2nd ed.), New York: Oxford]. It is hoped that the functioning of this model might suggest potential processes underlying dorsal and ventral contributions to the correct perception of multiple objects.

  13. Stereoscopic vision in the absence of the lateral occipital cortex.

    Directory of Open Access Journals (Sweden)

    Jenny C A Read

    Full Text Available Both dorsal and ventral cortical visual streams contain neurons sensitive to binocular disparities, but the two streams may underlie different aspects of stereoscopic vision. Here we investigate stereopsis in the neurological patient D.F., whose ventral stream, specifically lateral occipital cortex, has been damaged bilaterally, causing profound visual form agnosia. Despite her severe damage to cortical visual areas, we report that DF's stereo vision is strikingly unimpaired. She is better than many control observers at using binocular disparity to judge whether an isolated object appears near or far, and to resolve ambiguous structure-from-motion. DF is, however, poor at using relative disparity between features at different locations across the visual field. This may stem from a difficulty in identifying the surface boundaries where relative disparity is available. We suggest that the ventral processing stream may play a critical role in enabling healthy observers to extract fine depth information from relative disparities within one surface or between surfaces located in different parts of the visual field.

  14. Connecting art and the brain: an artist’s perspective on visual indeterminacy

    Directory of Open Access Journals (Sweden)

    Robert Pepperell

    2011-08-01

    Full Text Available In this article I will discuss the intersection between art and neuroscience from the perspective of a practicing artist. I have collaborated on several scientific studies into the effects of art on the brain and behaviour, looking in particular at the phenomenon of ‘visual indeterminacy’. This is a perceptual state in which subjects fail to recognise objects from visual cues. I will look at the background to this phenomenon, and show how various artists have exploited its effect through the history of art. My own attempts to create indeterminate images will be discussed, including some of the technical problems I faced in trying to manipulate the viewer’s perceptual state through paintings. Visual indeterminacy is not widely studied in neuroscience, although references to it can be found in the literature on visual agnosia and object recognition. I will briefly review some of this work and show how my attempts to understand the science behind visual indeterminacy led me to collaborate with psychophysicists and neuroscientists. After reviewing this work, I will discuss the conclusions I have drawn from its findings and consider the problem of how best to integrate neuroscientific methods with artistic knowledge to create truly interdisciplinary approach.

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

    Science.gov (United States)

    Ortner, M; Kurz, A

    2015-07-01

    The syndrome of posterior cortical atrophy (PCA) is a rare clinical manifestation of several neurodegenerative diseases which affect the parieto-occipital cortex. The most frequent underlying pathology is Alzheimer's disease but some cases are caused by Lewy body disease, progressive subcortical gliosis, corticobasal degeneration or prion diseases. The most prominent clinical feature of PCA is complex visual disturbances including object agnosia, simultanagnosia, optical ataxia and oculomotor apraxia while basic visual functions remain intact. These deficits lead to multiple impairments in activities of daily living that require visual control. On progression of the disease amnestic, apraxic and dysexecutive symptoms occur so that a global dementia gradually emerges. At the core of the diagnostic work-up are a detailed patient history, accurate analysis of behavior and neuropsychological testing. Structural and functional brain imaging are suitable to demonstrate the localization of the disease process. Measurement of cerebrospinal fluid proteins (e.g. beta amyloid, tau, phospho-tau and 14-3-3) serves to confirm or exclude Alzheimer's disease or prion diseases. The mainstay of treatment are non-pharmacological interventions to support activities of daily living and personal independence. These treatments include cognitive training and compensatory strategies which can be prescribed as neuropsychological treatment or occupational therapy. If Alzheimer's disease or Lewy body disease is the likely cause, a treatment with cholinesterase inhibitor may be tried. Caregiver education and support are another essential part of the treatment regimen as with all forms of dementia. PMID:25791802

  16. Changes in higher mental functions in persons with late sequels of exposure to small ionizing radiation doses

    International Nuclear Information System (INIS)

    This is a report on the results of studies on the state of higher mental function in individuals with a previous history of exposure to small doses ionizing radiations. The disorders observed are assigned under several groups as follows: dyspraxia, gnostic, visual-spatial agnosia, mnestic, mental processes impairment, neurodynamic. Mnestic and acoustic-gnostical disturbances, and those of the mental processes are rather markedly expressed. Mnestic derangements play a major role in the general pattern of cognitive disorders, being characterized by both modal-specific, and modal-nonspecific features. The topical principle of the classification proposed enables to distinguish the syndrome of middle nonspecific brain structures involvement and the cortical syndromes among the higher mental function disorders, invariably encountered in combination and not isolated. The aforementioned points to the diffuse nature of the neuropsychological disorders, with involvement in the process of both nonspecific and specific structures, characterized by predomination of the frontal and temporal brain cortex sections. Impairment of the higher mental functions in young persons of active age with a past history of exposure to small doses ionizing radiations, necessitate to work out effective measures precluding occurrence and intensification of the cognitive defect. (author)

  17. Critical appraisal of the long-term impact of memantine in treatment of moderate to severe Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Umamon Puangthong

    2009-10-01

    Full Text Available Umamon Puangthong, Ging-Yuek Robin HsiungDivision of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, CanadaAbstract: Alzheimer’s disease is the most common cause of dementia in older adults. The clinical features include progressive memory decline as well as cognitive deficits with executive dysfunction, language, visual perceptual difficulties, apraxia and agnosia. During the moderate to severe stage of the disease, there is a major decline in memory and function, while neuropsychiatric disturbances often emerge and patients become difficult to manage. These distressing symptoms increase caregiver burden and add to the direct costs of care of the patients. Any improvements in patient function and behavioral symptoms can reduce caregiver burden. Memantine has been available for a number of years in Europe and in North America. In this article, we examine the pharmacological rationale for its use, and the current clinical evidence for its efficacy and long-term effectiveness in the management of cognitive and behavioral symptoms in moderate to severe stages of Alzheimer’s disease.Keywords: memantine, Alzheimer’s disease, dementia

  18. Subgroup differences in the lexical tone mismatch negativity (MMN) among Mandarin speakers with congenital amusia.

    Science.gov (United States)

    Nan, Yun; Huang, Wan-ting; Wang, Wen-jing; Liu, Chang; Dong, Qi

    2016-01-01

    The association/dissociation of pitch processing between music and language is a long lasting debate. We examined this music-language relationship by investigating to what extent pitch deficits in these two domains were dissociable. We focused on a special neurodevelopmental pitch disorder - congenital amusia, which primarily affects musical pitch processing. Recent research has also revealed lexical tone deficits in speech among amusics. Approximately one-third of Mandarin amusics exhibits behavioural difficulties in lexical tone perception, which is known as tone agnosia. Using mismatch negativities (MMNs), our current work probed lexical tone encoding at the pre-attentive level among the Mandarin amusics with (tone agnosics) and without (pure amusics) behavioural lexical tone deficits compared with age- and IQ-matched controls. Relative to the controls and the pure amusics, the tone agnosics exhibited reduced MMNs specifically in response to lexical tone changes. Their tone-consonant MMNs were intact and similar to those of the other two groups. Moreover, the tone MMN reduction over the left hemisphere was tightly linked to behavioural insensitivity to lexical tone changes. The current study thus provides the first psychophysiological evidence of subgroup differences in lexical tone processing among Mandarin amusics and links amusics' behavioural tone deficits to impaired pre-attentive tone processing. Despite the overall music pitch deficits, the subgroup differences in lexical tone processing in Mandarin-speaking amusics suggest dissociation of pitch deficits between music and speech. PMID:26638759

  19. Reducing Aβ load and tau phosphorylation: Emerging perspective for treating Alzheimer's disease.

    Science.gov (United States)

    Kalra, Jaspreet; Khan, Aamir

    2015-10-01

    Alzheimer's disease (AD) is a complex, progressive neurological disorder affecting elderly population of above 65 years of age, characterized by failure of memory, loss of acquired skills leading to apraxia, agnosia, aphasia and frequent disturbances in emotion with interpersonal and social deterioration. The extracellular senile plaques and intracellular neurofibrillary tangles composed of amyloid beta protein and highly phosphorylated tau protein, the key components involved in pathogenesis of AD are considered as the pathological hallmark of this disease. This has led to immense development in the field of treatment for AD. Recent evidences suggest that removal of protein deposits from AD brains are the newer attempts for treating AD. The major developments in this direction are the amyloid and tau based therapeutics, which could hold the key to treatment of AD in the near future. Several putative drugs have been thoroughly investigated in preclinical studies, but many of them have failed to produce results in the clinical scenario. Therefore, failures from the past can be treated as lessons for the development of efficacious drugs. In addition to this, various non- pharmacological interventions and miscellaneous drugs are also being used now for combating the AD like disease progression. Thus, present review discusses about the disease modifying therapies together with the various non-pharmacological interventions and miscellaneous drugs for treating AD. PMID:26209363

  20. Identification of a novel mutation in the presenilin 1 gene in a Chinese Alzheimer's disease family.

    Science.gov (United States)

    Deng, Bo; Lian, Yan; Wang, Xin; Zeng, Fan; Jiao, Bin; Wang, Ye-Ran; Liang, Chun-Rong; Liu, Yu-Hui; Bu, Xian-Le; Yao, Xiu-Qing; Zhu, Chi; Shen, Lu; Zhou, Hua-Dong; Zhang, Tao; Wang, Yan-Jiang

    2014-10-01

    This study has identified a gene mutation in a Chinese family with Alzheimer's disease (AD). Family members were screened by a set of medical examinations and neuropsychological tests. Their DNA was extracted from blood cells and sequenced for gene mutation in the amyloid precursor protein (APP), the presenilin 1 (PS1) and the presenilin 2 (PS2) genes. Genetic analysis showed that the AD patients in the family harbored a T to G missense mutation at the position 314 in exon 4 of the PS1 gene, resulting in a change of F105C in amino acid sequence. Clinical manifestation of these patients included memory loss, counting difficulty, personality change, disorientation, dyscalculia, agnosia, aphasia, and apraxia, which was similar to that of the familial AD (FAD) patients harboring other PS1 mutations. We intend to add a novel mutation F105C of the PS1 gene to the pool of FAD mutations. With the current available genetic data, mutations of the PS1 gene account for the majority of gene mutations in Chinese FAD. PMID:24737487

  1. Tc-99m HMPAO brain uptake patterns in patients with dementia of Alzheimer type

    International Nuclear Information System (INIS)

    Conventional gamma camera SPECT with Tc-99m HMPAO (10 MBq/kg patient weight) was carried out in 21 patients with dementia of Alzheimer type (DAT), fulfilling the criteria established by the National Institute of Neurological and Communicative Disorders and Stroke and the ADRDA criteria (nine with amnesia as the main symptom [group 1], 12 with amnesia, aphasia, and/or apraxia and agnosia [group 2], and eight age-matched control subjects. Perfusion was quantitatively studied by means of cerebrum-cerebellum activity ratios. In group 1, perfusion deficits in the mesial cortex of the temporal lobes (right, 0.70; left, 0.68) were found, and ratios were significantly lower than in the control group (right, 0.77; left, 0.76 [P < .05]). Group 2 showed low ratios throughout both temporal lobes (mesial and lateral cortex), bilaterally in the posterior parietal cortex (right, 0.69; left, 0.66 [control: right, 0.80; left, 0.81] [P < .001]), and left frontal cortex (0.75 [control, 0.79] [P < .05]). In conclusion, SPECT with Tc-99m HMPAO identifies perfusion deficits in patients with DAT, and these correlate well with the clinical findings and are significantly different from those in the control group

  2. Assessment and treatment of childhood topographical disorientation: a case study.

    Science.gov (United States)

    Brunsdon, Ruth; Nickels, Lyndsey; Coltheart, Max; Joy, Pamela

    2007-01-01

    Topographical disorientation refers to individuals who are unable to find their way around large-scale environments in a normal manner. Childhood topographical disorientation is rarely investigated or reported. Treatment of topographical disorientation is also rare with only one reported treatment study in an adult (Davis & Coltheart, 1999) and no known description of treatment in a child. This paper reports a detailed case analysis of CA, a 6-year-old child with topographical disorientation, and a description of a treatment programme focused on training orientation in the school environment. Assessment of CA revealed mild to moderate visual agnosia in conjunction with severe impairments in general spatial learning and memory, topographical new learning and memory, and a total inability to learn new topographical routes. CA was also unable to use a mental image of his environment, a simple visual plan of his environment or a simple visual map, but was able to follow verbally mediated topographical instructions. The treatment programme focused on improving CA's topographical orientation in the school environment. The programme first involved training in recognition of major school buildings and landmarks and then focused on practical training in route finding along commonly used routes in the school environment. Clear benefits from treatment were evident. The assessment and treatment methods employed provide practical and useful ideas for management of this condition in other children. PMID:17178605

  3. The hawkmoth fauna of Pakistan (Lepidoptera: Sphingidae).

    Science.gov (United States)

    Rafi, Muhammad Ather; Sultan, Amir; Kitching, Ian J; Pittaway, Anthony R; Markhasiov, Maxim; Khan, Muhammad Rafique; Naz, Falak

    2014-01-01

    This study represents the first complete modern account of the Sphingidae of Pakistan and takes the form of an annotated checklist, based on several national collections and those of a number of individuals. Of the 60 species and subspecies found, 14 are new records to the fauna of Pakistan, namely Agnosia orneus, Langia zenzeroides subsp. zenzeroides, Polyptychus trilineatus subsp. trilineatus, Dolbina inexacta, Ambulyx sericeipennis subsp. sericeipennis, Thamnoecha uniformis, Macroglossum belis, Macroglossum stellatarum, Cechetra scotti, Hippotion boerhaviae, Hyles euphorbiae subsp. euphorbiae, Rhagastis olivacea, Rethera brandti subsp. euteles and Theretra latreillii subsp. lucasii. Anambulyx elwesi subsp. kitchingi and Clanis deucalion subsp. thomaswitti are not recognised as valid subspecies and are synonymized with their respective nominotypical subspecies. An additional list is given of 30 taxa which may yet be found in Pakistan as they are present in neighbouring countries close to the border. Of the species/subspecies found, 24 are part of the Palaearctic fauna, 27 are part of the Oriental fauna and nine are Palaeo-Oriental/Palaeotropical. This reconfirms the transitional biogeographical position of the Pakistan fauna. PMID:24870331

  4. Cerebral hemorrhage without manifest motor paralysis

    International Nuclear Information System (INIS)

    Before the introduction of computerized tomography (CT) there were some cases of intracerebral bleeding who were wrongly diagnosed as hypertensive encephalopathy or senile psychosis. We here report 5 cases who did not show any sign of motor paralysis. The clinical aspects of these cases were nausea and vomiting with dizziness (case 1), nausea and vomiting with slight headache (case 2), agnosia of left side with several kinds of disorientation (case 3), nausea and vomiting (case 4), and visual disturbance of right, lower quadrant (case 5). All of these cases showed no motor paralysis or abnormal reflex activities. By examination with CT each of them exhibited a high density area in the subcortical area of the right parietal lobe, the subcortical area of the right occipital lobe, the right temporal and parietal lobe, rather small portion of the left putamen and external capsule, and the subcortical area of left occipital lobe, respectively. Patients of cerebral hemorrhage without motor or sensory disturbances might often be taken for some psychic abnormality. We here have emphasized the importance of CT in such a group of patients. But for this technique, most of them would not be given adequate treatment and might be exposed to lifethreatening situations. (author)

  5. The neuropsychology of the Klüver-Bucy syndrome in children.

    Science.gov (United States)

    Lippe, S; Gonin-Flambois, C; Jambaqué, I

    2013-01-01

    The Klüver-Bucy syndrome (KBS) is characterized by a number of peculiar behavioral symptoms. The syndrome was first observed in 1939 by Heinrich Klüver and Paul Bucy in the rhesus monkey following removal of the greater portion of the monkey's temporal lobes and rhinencephalon. The animal showed (a) visual agnosia (inability to recognize objects without general loss of visual discrimination), (b) excessive oral tendency (oral exploration of objects), (c) hypermetamorphosis (excessive visual attentiveness), (d) placidity with loss of normal fear and anger responses, (e) altered sexual behavior manifesting mainly as marked and indiscriminate hypersexuality, and (f) changes in eating behavior. In humans, KBS can be complete or incomplete. It occurs as a consequence of neurological disorders that essentially cause destruction or dysfunction of bilateral mesial temporal lobe structures (i.e., Pick disease, Alzheimer disease, cerebral trauma, cerebrovascular accidents, temporal lobe epilepsy, herpetic encephalopathy, heat stroke). As for epilepsy, complete and incomplete KBS are well documented in temporal lobe epilepsy, temporal lobectomy, and partial status epilepticus. KBS can occur at any age. Children seem to show similar symptoms to adults, although some differences in the manifestations of symptoms may be related to the fact that children have not yet learned certain behaviors. PMID:23622339

  6. The fusiform face area is not sufficient for face recognition: evidence from a patient with dense prosopagnosia and no occipital face area.

    Science.gov (United States)

    Steeves, Jennifer K E; Culham, Jody C; Duchaine, Bradley C; Pratesi, Cristiana Cavina; Valyear, Kenneth F; Schindler, Igor; Humphrey, G Keith; Milner, A David; Goodale, Melvyn A

    2006-01-01

    We tested functional activation for faces in patient D.F., who following acquired brain damage has a profound deficit in object recognition based on form (visual form agnosia) and also prosopagnosia that is undocumented to date. Functional imaging demonstrated that like our control observers, D.F. shows significantly more activation when passively viewing face compared to scene images in an area that is consistent with the fusiform face area (FFA) (p contrast, she performed relatively normally on many face categorization tasks. D.F. can differentiate faces from non-faces given sufficient texture information and processing time, and she can do this is independent of color and illumination information. D.F. can use configural information for categorizing faces when they are presented in an upright but not a sideways orientation and given that she also cannot discriminate half-faces she may rely on a spatially symmetric feature arrangement. Faces appear to be a unique category, which she can classify even when she has no advance knowledge that she will be shown face images. Together, these imaging and behavioral data support the importance of the integrity of a complex network of regions for face identification, including more than just the FFA--in particular the OFA, a region believed to be associated with low-level processing. PMID:16125741

  7. The right cerebral hemisphere: emotion, music, visual-spatial skills, body-image, dreams, and awareness.

    Science.gov (United States)

    Joseph, R

    1988-09-01

    Based on a review of numerous studies conducted on normal, neurosurgical and brain-injured individuals, the right cerebral hemisphere appears to be dominant in the perception and identification of environmental and nonverbal sounds; the analysis of geometric and visual space (e.g., depth perception, visual closure); somesthesis, stereognosis, the maintenance of the body image; the production of dreams during REM sleep; the perception of most aspects of musical stimuli; and the comprehension and expression of prosodic, melodic, visual, facial, and verbal emotion. When the right hemisphere is damaged a variety of cognitive abnormalities may result, including hemi-inattention and neglect, prosopagnosia, constructional apraxia, visual-perceptual disturbances, and agnosia for environmental, musical, and emotional sounds. Similarly, a myriad of affective abnormalities may occur, including indifference, depression, hysteria, gross social-emotional disinhibition, florid manic excitement, childishness, euphoria, impulsivity, and abnormal sexual behavior. Patients may become delusional, engage in the production of bizzare confabulations and experience a host of somatic disturbances such as pain and body-perceptual distortions. Based on studies of normal and "split-brain" functioning, it also appears that the right hemisphere maintains a highly developed social-emotional mental system and can independently perceive, recall and act on certain memories and experiences without the aid or active reflective participation of the left. This leads to situations in which the right and left halves of the brain sometime act in an uncooperative fashion, which gives rise to inter-manual and intra-psychic conflicts. PMID:2461390

  8. Consciousness: some basic issues--A neurophilosophical perspective.

    Science.gov (United States)

    Smythies, J

    1999-06-01

    This paper concentrates on the basic properties of "consciousness" that temporal coding is postulated to relate to. A description of phenomenal consciousness based on what introspection tells us about its contents is offered. This includes a consideration of the effect of various brain lesions that result in cortical blindness, apperceptive and associative agnosia, and blindsight, together with an account of the manner in which sight is regained after cortical injuries. I then discuss two therories of perception-Direct Realism and the Representative Theory. This includes a discussion of the concept of the body-image, phantom limbs, the alleged projection of sensations, the ontological status of phenomenal space, the homunculus argument, the validity of topographic coding, the difference between the stimulus field and the visual field, and two theories of brain-mind relationship-the Identity Theory and the Bohr-Heisenberg theory of brain-mind complementarity. Finally I suggest that the binocular rivalry obtained in the case of the stroboscopic patterns that result from intermittent photic stimulation of one eye, when used in animal expeiments with unit recording, offers a good experimental method of investigating the binding problem. PMID:10447999

  9. Rehabilitation in a complex case of topographical disorientation.

    Science.gov (United States)

    Bouwmeester, Lies; van de Wege, Anja; Haaxma, Rob; Snoek, Jos W

    2015-01-01

    This paper describes the rehabilitation process of a patient with severe topographical disorientation. The study demonstrates the sustained effects of a tailor-made, meticulous rehabilitation programme based on the gradual development of compensatory strategies. The patient (RB) had a memory impairment specific to environmental landmarks. He was able to recognise objects in his environment, but was unable to identify any salient object as a landmark and was also unable to derive any directional information from a chosen landmark. As such, his topographical disorientation syndrome was complex in that he had elements of both landmark agnosia and a heading disorientation, as described by Aguirre and D'Esposito (1999). Because of this dual damage to the exocentric framework, the tools and methods used in RB's rehabilitation programme were all based on his intact egocentric frame of reference. Remarkable training effects were found for routes he used frequently. After years of training he could walk these routes without the aid of the written information he had used previously, which can be interpreted as a form of implicit learning. In the 12 years we followed this patient some transfer occurred, as the patient was ultimately able to identify his own landmarks. However, RB remains dependent on other people to construct new routes for him on the basis of these landmarks. PMID:24885419

  10. Perception, experience and body identity.

    Science.gov (United States)

    López-Ibor, Juan J; Ortiz, Tomás; López-Ibor, María I

    2011-12-01

    Physician has to know the patient in the disease and not only the disease in the patient, from the dual perspective of the body as object and the body as subject. This also affects the patient who has to cope with the reality of having a body that bursts into the subject's consciousness as a vital threat, as source of discomfort and inability and being a body (Marcel). The human body in its dual aspect has been and is a great unknown, if not a great outrage in spite of the fact that we are our body and our body is each of us. We sometimes do not feel as we are and thus a confrontation arises, sometimes more normal, others more morbid. This forces the physician to face complex ethics considerations and the scientist to accept a personal identity disorder. Dualism considers that there are two substances in us, one that distinguishes us from other beings and from the rest of the individuals of the human species, the soul, the psychic life, mind or consciousness, and another more insubstancial one, the body. The aim of the first substance is to dominate the body, to survive it after death when it is, already a corpse is meant to become putrefied, is buried, incinerated or thrown to the depth of the sea. This dualism aims to explain the origin of the evil and the attitude to defeat it and it does so efficiently. This anthropology has very ancient roots (the Upvanishads, in the orphic texts, in Plato), it is the core of Gnostic thought and the foundation of the modern science since Descartes. Some monist perspectives are a masked dualism or a mereologic fallacy, according to which, the brain is conscious, when that what is conscious is the subject, although the subject, with the brain could not be conscious. Therefore, a new perspective is proposed, chiasmatic or janicular monism, that considers the adaptive value of focusing on the reality from two perspectives, as physical universe and the world of interpersonal relationships. In the agnosias and in the phantom limb

  11. A double dissociation of the acuity and crowding limits to letter identification, and the promise of improved visual screening.

    Science.gov (United States)

    Song, Shuang; Levi, Dennis M; Pelli, Denis G

    2014-01-01

    Here, we systematically explore the size and spacing requirements for identifying a letter among other letters. We measure acuity for flanked and unflanked letters, centrally and peripherally, in normals and amblyopes. We find that acuity, overlap masking, and crowding each demand a minimum size or spacing for readable text. Just measuring flanked and unflanked acuity is enough for our proposed model to predict the observer's threshold size and spacing for letters at any eccentricity. We also find that amblyopia in adults retains the character of the childhood condition that caused it. Amblyopia is a developmental neural deficit that can occur as a result of either strabismus or anisometropia in childhood. Peripheral viewing during childhood due to strabismus results in amblyopia that is crowding limited, like peripheral vision. Optical blur of one eye during childhood due to anisometropia without strabismus results in amblyopia that is acuity limited, like blurred vision. Furthermore, we find that the spacing:acuity ratio of flanked and unflanked acuity can distinguish strabismic amblyopia from purely anisometropic amblyopia in nearly perfect agreement with lack of stereopsis. A scatter diagram of threshold spacing versus acuity, one point per patient, for several diagnostic groups, reveals the diagnostic power of flanked acuity testing. These results and two demonstrations indicate that the sensitivity of visual screening tests can be improved by using flankers that are more tightly spaced and letter like. Finally, in concert with Strappini, Pelli, Di Pace, and Martelli (submitted), we jointly report a double dissociation between acuity and crowding. Two clinical conditions-anisometropic amblyopia and apperceptive agnosia-each selectively impair either acuity A or the spacing:acuity ratio S/A, not both. Furthermore, when we specifically estimate crowding, we find a double dissociation between acuity and crowding. Models of human object recognition will need to

  12. Randomized controlled trials in frontotemporal dementia: cognitive and behavioral outcomes.

    Science.gov (United States)

    Miller, Justin B; Banks, Sarah J; Léger, Gabriel C; Cummings, Jeffrey L

    2014-01-01

    Progress has been made in understanding the genetics and molecular biology of frontotemporal dementia (FTD). Targets for intervention have been identified, therapies are being developed, and clinical trials are advancing. A major challenge for FTD research is that multiple underlying pathologies can be associated with heterogeneous phenotypes. The neuropsychological profiles associated with FTD spectrum disorders often include executive dysfunction, language impairments and behavioral disturbance. Behavioral variant FTD is characterized by an initial presentation of changes in personality, behavior and/or emotion, which are often difficult to objectively capture using traditional neuropsychological measures. The two principal language variants of FTD are Progressive Nonfluent Aphasia (PNFA) with predominant agrammatic/non-fluent impairments and Semantic Dementia (SD) with semantic impairments and visual agnosia. Selection of appropriate endpoints for clinical trials is critical to ensure that the measures are adequately sensitive to detect change, yet specific enough to isolate signal from noise, and acceptable to regulatory agencies. Given the anticipated potential for small effect sizes, measures must be able to identify small incremental changes over time. It is also imperative that the measures provide adequate coverage of the constructs or behaviors of interest. Selected outcome measures should be suitable for repeat administration, yet relatively robust to practice effects to ensure that observed changes reflect true signal variance and not residual effects due to repeated measurement or poor reliability. To facilitate widespread adoption as an endpoint, measures should be readily accessible. We provide several examples of potential global, composite, and individual cognitive measures, as well as behavioral measures promising for FTD trials. Development and application of appropriate trial outcomes is critically important to success in advancing new

  13. Line-bisectioning and obstacle avoidance: evidence for separate strategies.

    Science.gov (United States)

    Ross, Alasdair I; Schenk, Thomas; Hesse, Constanze

    2014-09-01

    Previous studies have frequently applied a combination of line-bisection tasks (in which participants indicate the middle of a line) and obstacle avoidance tasks (in which participants move their hand between two obstacles) with the aim of revealing perception-action dissociations in certain neurological disorders, such as visual form agnosia and optic ataxia. However, valid conclusions about the underlying processing pathways can only be drawn if participants apply the same strategy in both tasks (i.e. finding the middle between the obstacles). Yet, this assumption has never been tested directly. In this experiment, we investigated whether participants perform obstacle avoidance and line-bisectioning using similar strategies by manipulating the position of the obstacles and the start position of the hand relative to the obstacles. Our results indicate that the lateral hand position during obstacle avoidance does not only vary as a function of obstacle location but also strongly depends on the start position. Moreover, participants showed increased sensitivity to obstacle shifts occurring closer to the hand's start position. In contrast, during line-bisectioning the sensitivity to obstacles shifts was unaffected by the hand's start position. The findings suggest that during obstacle-avoidance the need to keep a safe distance from the obstacles is balanced with the requirement to minimise energetic demands. In contrast, the main intention during line-bisectioning is to move to the perceived midpoint as accurately as possible. The fact that very different constraints underlie trajectory planning in both tasks implies that caution has to be taken when interpreting differences in performance levels. PMID:24951918

  14. The Two Visual Systems Hypothesis: New Challenges and Insights from Visual form Agnosic Patient DF.

    Science.gov (United States)

    Whitwell, Robert L; Milner, A David; Goodale, Melvyn A

    2014-01-01

    Patient DF, who developed visual form agnosia following carbon monoxide poisoning, is still able to use vision to adjust the configuration of her grasping hand to the geometry of a goal object. This striking dissociation between perception and action in DF provided a key piece of evidence for the formulation of Goodale and Milner's Two Visual Systems Hypothesis (TVSH). According to the TVSH, the ventral stream plays a critical role in constructing our visual percepts, whereas the dorsal stream mediates the visual control of action, such as visually guided grasping. In this review, we discuss recent studies of DF that provide new insights into the functional organization of the dorsal and ventral streams. We confirm recent evidence that DF has dorsal as well as ventral brain damage - and that her dorsal-stream lesions and surrounding atrophy have increased in size since her first published brain scan. We argue that the damage to DF's dorsal stream explains her deficits in directing actions at targets in the periphery. We then focus on DF's ability to accurately adjust her in-flight hand aperture to changes in the width of goal objects (grip scaling) whose dimensions she cannot explicitly report. An examination of several studies of DF's grip scaling under natural conditions reveals a modest though significant deficit. Importantly, however, she continues to show a robust dissociation between form vision for perception and form vision-for-action. We also review recent studies that explore the role of online visual feedback and terminal haptic feedback in the programming and control of her grasping. These studies make it clear that DF is no more reliant on visual or haptic feedback than are neurologically intact individuals. In short, we argue that her ability to grasp objects depends on visual feedforward processing carried out by visuomotor networks in her dorsal stream that function in the much the same way as they do in neurologically intact individuals. PMID

  15. Remission of progressive multifocal leukoencephalopathy following highly active antiretroviral therapy in a man with AIDS

    Directory of Open Access Journals (Sweden)

    Yoganathan K

    2012-04-01

    Full Text Available Katie Yoganathan1, David Brown2, Kathir Yoganathan31Cardiff Medical School, Cardiff, Wales, UK; 2Virus Reference Department, Microbiology Services, Health Protection Agency, London, UK; 3Singleton Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, UKAbstract: A 43-year-old Caucasian homosexual man with AIDS presented with blurring of vision, change of personality, and memory loss in March 1999. He had first been admitted 2 months previously for treatment of Pneumocystis jiroveci pneumonia. A magnetic resonance imaging scan on admission showed multiple white matter lesions involving both subcortical cerebral hemispheres and cerebellar regions, with no mass effect or surrounding edema. JC virus was detected by nested polymerase chain reaction in the cerebrospinal fluid. These findings were diagnostic of progressive multifocal leukoencephalopathy (PML. His CD4 count was 34 cells/mL, and his HIV ribonucleic acid level was 800,789 copies/mL. He was treated with a combination antiretroviral therapy. He was last reviewed in October 2011. He was fully independent socially and mentally, but he still had some residual neurologic signs with right-sided homonymous hemianopia and visual agnosia. His HIV ribonucleic acid level was undetectable, and his CD4 count was 574 cells/mm3. Although the median survival of patients with PML was poor before the antiretroviral therapy era, our patient, who is now aged 55 years, is still alive 12 years after the diagnosis. The diagnosis of PML and differential diagnosis of focal neurologic signs in HIV-positive patients are discussed in this case report.Keywords: HIV, focal neurologic signs, cerebral toxoplasmosis, primary brain lymphoma, ischaemic stroke

  16. CT classification of small thalamic hemorrhages

    International Nuclear Information System (INIS)

    The thalamus is located deep in the cerebral hemispheres, and most of its nuclei have reciprocal fiber connections with specific areas over the cerebral cortex. Localized lesions in the thalamus, therefore, can cause specific neurological deficits, depending on their locations. From this point of view, we reviewed 110 cases, admitted over the past 7 years, with thalamic hemorrhages 37 (34%) of which were small hematomas less than 2 cm in diameter. These small hematomas could be divided into 4 types depending on their locations as follows: antero-lateral type, postero-lateral type, medial type, and dorsal type. Each type had the peculiar clinical features described below: 1) Postero-lateral Type (PL type, 28 cases, 76%): The original symptom was a sudden onset of moderate to severe sensori-motor deficits in most cases. The patients were mostly alert or only slightly confused. 2) Antero-lateral Type (AL type, 4 cases, 11%): The patients of this type first presented with sensori-motor disturbance and prefrontal signs. Both were generally mild and often disappeared early. 3) Medial Type (M type, 3 cases, 8%): The main symptom at onset was either a disturbance of consciousness or dementia. 4) Dorsal Type (D type, 2 cases, 5%): One patient with a right thalamic hematoma of this type showed geographical agnosia and visuo-constructive apraxia. The other patient, with a left-sided hematoma, exhibited transient clumsiness of the right hand and mild dysphasia. In our experience, the above classification of small hematomas clearly delineated the clinical symptoms and neurological signs of the different types; therefore, the symptoms and signs in larger hematoma could be explained by a combination of those of each type. (J.P.N.)

  17. Dissociation of the Reach and the Grasp in the destriate (V1) monkey Helen: a new anatomy for the dual visuomotor channel theory of reaching.

    Science.gov (United States)

    Whishaw, Ian Q; Karl, Jenni M; Humphrey, Nicholas K

    2016-08-01

    Dual visuomotor channel theory proposes that reaching depends on two neural pathways that extend from visual cortex (V1) to motor cortex via the parietal lobe. The Reach pathway directs the hand to the target's location and the Grasp pathway shapes the hand and digits for purchase. Sighted human participants integrate the Reach and the Grasp, but without vision they dissociate the movements to capitalize on tactile cues. They use a Reach with a relatively open hand to locate the target and then they use touch cues to shape the fingers to Grasp. After a V1 lesion, the rhesus monkey, Helen, learned to make near-normal visual discriminations based on size and brightness but displayed visual agnosia. She also learned to reach for food with her mouth and her hands. The present analysis of film of her reaching behavior shows that she dissociated the Reach and the Grasp, as do unsighted human participants reaching for a food target at a fixed location. Her rapid and direct Reach was made with an open hand and extended fingers to contact the food with the palm whereas her Grasp was initiated after she touched the food. She also visually fixated the target during the Reach and visually disengaged after target contact, as do sighted human participants. In contrast, Helen did integrate the Reach and the Grasp to take food from her mouth, demonstrating that she could integrate the movements using online tactile cues. The finding that extrastriate pathways can direct the hand toward extrinsic target properties (location) but not intrinsic target properties (size and shape) is discussed as a novel addition to dual visuomotor channel theory. PMID:27056084

  18. Cross-cultural studies using a modified mini mental test for healthy subjects and patients with various forms of vascular dementia.

    Science.gov (United States)

    Thajeb, Peterus; Thajeb, Teguh; Dai, Daofu

    2007-03-01

    Existing neuropsychological tests are often complex and time-consuming. We designed a modified Mini Mental Test (MMT) battery for clinical assessment of the global and regional higher cortical functions of the brain. We tested its applicability in healthy subjects with different ethnic, cultural and educational backgrounds. The usefulness of our MMT as a tool for the clinical evaluation of patients with various forms of vascular dementia was determined. The MMT comprises five subtests, including clinical evaluations of: (A) orientation (6 points); (B) attention, right-left discrimination, speech, and calculation (20); (C) immediate recall, and recent and remote memory retrieval (10); (D) praxis (10); and (E) visuospatial orientation, agnosia, hemianopsia, and visual hemineglect (14). The MMT was administered to 100 healthy subjects from two different ethnic backgrounds (Indonesian and Chinese/Taiwanese) and diverse cultural and educational backgrounds, and to 61 patients with various forms of vascular dementia. MMT scores were significantly lower in healthy subjects with a low level of education regardless of their ethnic background (p<0.001). Patients with vascular dementia had much lower MMT scores than did the comparable age-adjusted normal controls (p<0.001). Of the patients with vascular dementia, those with Binswanger's disease had the lowest MMT scores (25.5+/-28.9), followed by those with large cerebral infarcts (48.0+/-7.1), cerebral haemorrhage (49.0+/-8.5), and multiple lacunar infarctions (55.0+/-0.5) (P<0.001). With a cut-off point of 33/55 (partial score/total score), the sensitivity and positive predictive value of the MMT were 0.98 and 0.94, respectively. The MMT is a simple and useful tool for clinical assessment of the cognitive functions of healthy subjects and patients with or without vascular dementia. It can be used for individuals with different ethnic, cultural and educational backgrounds. PMID:17258132

  19. CBF tomograms with (/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

    Energy Technology Data Exchange (ETDEWEB)

    Costa, D.C.; Ell, P.J.; Burns, A.; Philpot, M.; Levy, R.

    1988-12-01

    We present preliminary data on the utility of functional brain imaging with (99mTc)-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of (99mTc)-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. (99mTc)-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions.

  20. [Phenomenological and Diagnostic Implications of Paraschemazia: A Case Report].

    Science.gov (United States)

    Mehta, Urvakhsh Meherwan; Thippeswamy, Harish; Bharath, Rose Dawn; Satishcandra, Parthasarathy

    2015-01-01

    Paraschemazia is characterized by distortions of body image, and has been observed in neurological disorders (epilepsies, migraine, and non-dominant cortical lesions), retinal damage, and hallucinogenic drug use. This complex symptom cluster of subjective and objective perceptual abnormalities forms an essential feature of Todd's Alice in Wonderland syndrome. This neuropsychiatric manifestation must be phenomenologically differentiated from hallucinations, illusions, and agnosias. Herein we report a patient with paraschemazia that occurred during the ictal phase of temporal lobe epilepsy; the patient was referred to the department of psychiatry due to symptoms of transient intense fear and abnormal perceptions. We also discuss the diagnostic difficulty and phenomenological implications associated with this rare phenomenon. A 45-year-old female presented with brief episodes (30-45 s) of sensory distortion, during which the faces and limbs of other people and her own appeared distorted (e.g. protruding eyes, elongated nose, and oval or square head). The episodes of sensory distortion were associated with intense fear and were followed by loss of consciousness for 5 min. She had been experiencing these episodes since the age of 12 years and responded poorly to several antiepileptic medications. 3-Tesla MRI performed using a complex partial seizure protocol showed altered signal intensity and volume loss in the right hippocampus, suggestive of right mesial temporal sclerosis. Neuropsychological assessment showed impaired sustained attention, working memory, and verbal and visual learning and memory, suggestive of bilateral dorsolateral prefrontal and temporal lobe deficits. She improved in response to a combination of levetiracetam and clobazam, and was seizure free at the 2-year follow-up. PMID:26111290

  1. Apraxias in neurodegenerative dementias

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    Sadanandavalli Retnaswami Chandra

    2015-01-01

    Full Text Available Background: Apraxia is a state of inability to carry out a learned motor act in the absence of motor, sensory or cerebellar defect on command processed through the Praxis circuit. Breakdown in default networking is one of the early dysfunction in cortical dementias and result in perplexity, awkwardness, omission, substitution errors, toying behavior and unrecognizable gestures in response to command with voluntary reflex dissociation where, when unobserved patient will carry out reflex movements normally. Awareness into the organicity of these phenomenas will help in early diagnosis, which will help in initiating appropriate treatment and slowing down the progression of the disease. Aims and Objectives: The aim was to look for the various kinds of apraxias in patients with dementia using appropriate simple tests. Patients and Methods: Three hundred patients satisfying Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for dementia were evaluated in detail with mandatory investigations for dementia followed by testing for ideational, ideomotor, limb-kinetic, buccopharyngeal, dressing apraxia, constructional apraxia and gait apraxias in addition to recording of rare apraxias when present. Results: Alzheimer′s disease showed maximum association with apraxias in all the phases of the disease ideational, ideomotor, dressing and constructional apraxias early and buccopharyngeal and gait apraxia late. Frontotemporal lobe dementia showed buccopharyngeal and gait apraxias late into the disease. Cortical basal ganglionic degeneration showed limb apraxias and diffuse Lewy body disease showed more agnosias and less apraxias common apraxias seen was Ideational and Ideomotor. Conclusion: Recognition of the apraxias help in establishing organicity, categorization, caregiver education, early strategies for treatment, avoiding anti-psychotics and introducing disease modifying pharmacotherapeutic agents and also prognosticating.

  2. POST-STROKE WRITING AND READING DISORDERS

    Directory of Open Access Journals (Sweden)

    Sinanović Osman

    2013-01-01

    Full Text Available The writing and reading disorders in stroke patients (alexias, agraphias and acalculias are more frequent than verified in routine exam, not only in the less developed but also in large neurological departments. Alexia is an acquired type of sensory aphasia where damage to the brain causes a patient to lose the ability to read. It is also called word blindness, text blindness orvisual aphasia. Alexia refers to an acquired inability to read caused by brain damage and must be distinguished from dyslexia, a developmental abnormality in which the individual is unable to learn to read, and from illiteracy, which reflects a poor educational back-ground. Most aphasics are also alexic, but alexia may occur in the absence of aphasia and may occasionally be the soledisability resulting from specific brain lesions. There are different classifications of alexias. Traditionally, the alexias are divided into three categories: pure alexia with agraphia, pure alexia without agraphia, and alexia associated with aphasia (“aphasic alexia”. Agraphia is defined as the disruption of previously intact writing skills by brain damage. Writing involves several elements—language processing, spelling, visual perception, visual-spatial orientation for graphic symbols, motor planning, and motor control of writing. A disturbance of any of these processes can impair writing. Agraphia may occur by itself or as association with aphasias, alexia, agnosia and apraxia. Agraphia can also result from “peripheral” involvement of the motor act of writing. Like alexia, agraphia must be distinguished from illiteracy, where writing skills were never developed. Acalculia is a clinical syndrome of acquired deficits in mathematical calculation, either mentally or with paper and pencil. This language disturbances can be classified differently, but there are three principal types of acalculia: acalculia associated with language disturbances, including number paraphasia, number

  3. [Motor amusia following a right temporal lobe hemorrhage--a case report].

    Science.gov (United States)

    Takeda, K; Bandou, M; Nishimura, Y

    1990-01-01

    A 65-year-old female was admitted to our hospital because of left hemiparesis with sudden onset one week before. She was congenitally right-handed. She had been a teacher of Japanese string instrument (samisen) playing and been able to sing Japanese traditional songs well. A tape on which she had recorded her songs one year before the admission also proved her to be a good singer. Neurological examination on admission revealed almost normal findings except for minimal weakness in her left hand fingers. Right temporal lobe hemorrhage was revealed by CT scan. One month after the admission, she complained that she was unable to sing her songs and to play samisen as she used to do. Her intelligence was normal (WAIS VIQ116, PIQ108) and there were no abnormal findings as follows: aprosodia, aphasia, agraphia, memory disturbance, agnosia and ideational, ideomotor, constructional or limb-kinetic apraxia. She could point out her errors while singing. However, musical receptive function was slightly disturbed with tonal memory in Seashore test. When she was asked to sing a song without any instrumental support, she hummed a melody occasionally with wrong pitch, but rhythmically. After hearing a song she knew well, she reproduced it with slight improvement. With the vocal or the instrumental accompaniment, she could sing fairly well. She had some mistakes of pitch while playing a samisen. MRI was performed one year and a half after the brain hemorrhage. It displayed a thin linear of hematoma in the white matter of the right upper temporal and transverse gyrus. It was proved in our case that motor amusia with minimal musical receptive dysfunction could appear following a cerebral lesion and musical function might be independent of intelligence or verbal function. PMID:2184966

  4. Evaluation of diet and life style in etiopathogenesis of senile dementia: A survey study.

    Science.gov (United States)

    Chaudhuri, Kundan; Samarakoon, S M S; Chandola, H M; Kumar, Rajesh; Ravishankar, B

    2011-04-01

    Mind and body are inseparable entities and influences each other until death. Many factors such as stress, anxiety, depression, negative thoughts, unhealthy life style, unwholesome diet etc., disturb mental and physical wellbeing. Senile dementia is the mental deterioration, i.e, loss of intellectual ability associated with old age. It causes progressive deterioration of mental faculties, e.g., memory, intellect, attention, thinking, comprehension and personality, with preservation of normal level of consciousness. Two major types of senile dementia have been identified, namely that due to generalized atrophy in the cortical area of the brain (Alzheimer's type) and that due to vascular disorders mainly due to stroke. According to DSM-IV (diagnostic and statistical manual of mental disorders), the essential feature of dementia is the development of multiple cognitive deficits that include memory impairment and at least one of the following cognitive disturbances such as aphasia, apraxia, agnosia, or a disturbance in executive function. For the present study, a standardized questionnaire in the form of proforma incorporating types of foods (madhura, amla and lavana rasayukta ahara etc.) and life style (divaswapna, ratrijagarana and manasika bhavas etc) is prepared. To assess manasika bhava, Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale, Brief Psychiatry Rating Scale, and standardized gradations of anumana pariksha of manasika bhavas mentioned by Charaka at Vimana Sthana 4/8 were adopted. In this study, most of the patients had disturbed sleep, tendency to indulge in defective dietary habits and kapha vitiating diets and life style. On Hamilton Anxiety Rating Scale, patients had anxiety, tension, depression, difficulty in concentration, and memory. On Hamilton Depression Rating Scale, these patients had anxiety, depression, and hypochondriasis. On Brief Psychiatry Rating Scale, psychological factors affected include: anxiety, depression, somatic

  5. CBF tomograms with [/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

    International Nuclear Information System (INIS)

    We present preliminary data on the utility of functional brain imaging with [99mTc]-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibited patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of [99mTc]-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. [99mTc]-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions

  6. DF's visual brain in action: the role of tactile cues.

    Science.gov (United States)

    Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Byrne, Caitlin M; Goodale, Melvyn A

    2014-03-01

    Patient DF, an extensively-tested woman with visual form agnosia from ventral-stream damage, is able to scale her grip aperture to match a goal object's geometry when reaching out to pick it up, despite being unable to explicitly distinguish amongst objects on the basis of their different geometries. Using evidence from a range of sources, including functional MRI, we have proposed that she does this through a functionally intact visuomotor system housed within the dorsal stream of the posterior parietal lobe. More recently, however, Schenk (2012a). The Journal of Neuroscience, 32(6), 2013-2017; Schenk (2012b). Trends in Cognitive Sciences, 16(5), 258-259. has argued that DF performs well in visually guided grasping, not through spared and functioning visuomotor networks in the dorsal stream, but because haptic feedback about the locations of the edges of the target is available to calibrate her grasps in such tasks, whereas it is not available in standard visual perceptual tasks. We have tested this 'calibration hypothesis' directly, by presenting DF with a grasping task in which the visible width of a target varied from trial to trial while its actual width remained the same. According to the calibration hypothesis, because haptic feedback was completely uninformative, DF should be unable to calibrate her grip aperture in this task. Contrary to this prediction, we found that DF continued to scale her grip aperture to the visual width of the targets and did so well within the range of healthy controls. We also found that DF's inability to distinguish shapes perceptually is not improved by providing haptic feedback. These findings strengthen the notion that DF's spared visuomotor abilities are driven largely by visual feedforward processing of the geometric properties of the target. Crucially, these findings also indicate that simple tactile contact with an object is needed for the visuomotor dorsal stream to be engaged, and accordingly enables DF to execute

  7. Paleoneurology: neurodegenerative diseases are age-related diseases of specific brain regions recently developed by Homo sapiens.

    Science.gov (United States)

    Ghika, J

    2008-11-01

    dementia, progressive nonfluent aphasia) (11) Temporomesial-limbic-paralimbic-associative cortical dementias (Alzheimer's disease, Lewy body, progressive amnesia): processing of explicit cognition: amnesic syndrome, processing of hand, larynx and eye: disorientation, ideomotor apraxia, agnosia, visuospatial processing, transcortical aphasia. (12) Focal posterior atrophy (Benson, progressive apraxia): visuomotor processing of what and where. (13) Macular degeneration: retinal "spot" for explicit symbols. (14) "Psychiatric syndromes": metacognition, self monitoring and regulation of hierarchical processing of metacognition: hallucinations, delusions, magic and mystic logic, delusions, confabulations; drive: impulsivity, obsessive-compulsive disorders, mental automatisms; social interactions: theory of mind, autism, Asperger. (15) Mood disorders: control on emotions: anxio-depressive and bipolar disorders, moria, emotional lability. (16) Musculoskeletal: inclusion body myositis: muscles for bipedal gait and fine motility. Paget's disease: bones for bipedal gait and cranium. Understanding of the genetic mechanisms underlying the evolution of these recent human brain regions and paleoneurology my be the key to the focal, asymmetrical or systemic character of neurodegeneration, the pathologic heterogeneity/overlap of syndromic presentations associating gait, hand, language, cognition, mood and behaviour disorders. PMID:18703290

  8. [Novel advances in neuropsychology--forward to the "deconstruction" of psychiatry].

    Science.gov (United States)

    Ohigashi, Yoshitaka

    2006-01-01

    Neuropsychology has recently become a science which deals not only with instrumental disorders (e.g., aphasia, apraxia, and agnosia), but also with impairments of interpersonal relationships (e.g., emotional cognitions, social decision making, and understanding others), and many important paradigms are already provided. We could enumerate several representative instances: (1)application of the "theory of mind" to autistic or related disorders (-->"reasoning of psychological state of others"), (2) neuropsychological studies on the "social brain" concerning emotional recognition or social recognition (-->"amygdale, orbitofrontal cortex, and medial ventral frontal cortex"), (3) identifying related cerebral areas (-->"superior temporal sulcus") to detect eye or body movements of others, (4) discovering the mirror neuron and mirror systems in monkeys and humans (-->"imitation of the behavior of others in the brain"), and (5) intracerebral processes which may occur precedent to conscious intention (-->"consciousness as post-hoc phenomena"). These novel paradigms might lead us to the "deconstruction" of psychiatry. We believe that the fundamental assignments of neuropsychology should inquire into "cognitive representation", "conscious representation", and "cerebral representation" about the inner processes of human activities. As these assignments would be almost the same for the psychiatric symptoms, we do not have any necessity to fundamentally distinguish psychiatric and neuropsychologial symptoms. These two kinds of signs will be attributed finally to the same dimension. The specificity of psychiatry resides in "conscious representation" and its cerebral foundations. We reconsidered the "Theory of Neural Group Selection" proposed by Edelman and the excellent experimental results on the relationship between intention and movements reported by Libet, et al.. All these results strongly indicate the absolute necessity to reconsider conscious causality and psychogenesis

  9. Topographical, autobiographical and semantic memory in a patient with bilateral mesial temporal and retrosplenial infarction.

    Science.gov (United States)

    Hepner, Ilana J; Mohamed, Armin; Fulham, Michael J; Miller, Laurie A

    2007-04-01

    According to Consolidation Theory (Squire, 1992, Psychological Review, 99, 195; Squire & Alvarez, 1995, Current Opinion in Neurobiology, 5, 169), the mesial temporal lobes have a time-limited role in the maintenance, storage and retrieval of retrograde declarative memories, such that they are not necessary for recalling remote memories. In contrast, proponents of the Multiple Trace Theory (Fuji, Moscovitch, & Nadel, 2000, Handbook of neuropsychology, 2nd ed., p 223, Amsterdam, New York: Elsevier; Nadel & Moscovitch, 1999, Current Opinion in Neurobiology, 7, 217) posit that the mesial temporal lobe (MTL) is necessary for remembering detailed autobiographical and topographical material from all time periods. A third theory of hippocampal function, the Cognitive Map Theory (O'Keefe & Nadel, 1978, The hippocampus as a cognitive map. Oxford: Clarendon), states that the hippocampus is involved in the processing of allocentric spatial representations. The precise role of the MTL in remote memory has been difficult to elucidate, as the majority of studies present cases with widespread brain damage that often occurred many years prior to testing. We investigated retrograde autobiographical, semantic and topographical memories in a subject (SG) who had recently sustained infarctions confined to the MTL and retrosplenial region bilaterally. Inconsistent with the predictions of Cognitive Map Theory, memory for spatial maps that were learned in the past was preserved. Additional testing indicated that SG suffered from a landmark agnosia, which affected remotely and recently acquired information equally. SG was also poor at imagining which direction he would have to turn his body to move from one landmark to another. In accordance with Consolidation Theory, SG performed similarly to control subjects for remote time periods on various measures of retrograde autobiographical memory and demonstrated intact knowledge regarding famous faces and vocabulary terms that were acquired in

  10. Japanese encephalitis (JE) part II: 14 years' follow-up of survivors.

    Science.gov (United States)

    Sarkari, N B S; Thacker, A K; Barthwal, S P; Mishra, V K; Prapann, Shiv; Srivastava, Deepak; Sarkari, M

    2012-01-01

    Japanese encephalitis, the commonest Arbovirus encephalitis, has been endemic in many parts of Asia, the Pacific Islands, and India; also, there have been many epidemics. Most of the post JE cases have been associated with neurological and neuropsychiatric deficits but have not been properly classified and followed. Practically all the previous studies were in children or young adults. The aim of this study, involving only adult cases, the largest ever being reported, has been to follow the 688/1,199 survivors of JE patients out of 1,282 of acute cases admitted during four epidemics for a period of 14 years after properly classifying the sequelae. This prospective study was conducted in B.R.D. Medical College Gorakhpur (India), involving 665/688 post JE cases with neuropsychiatric deficits from four epidemics of 1978, 1980, 1988 and 1989 which were properly classified in nine groups. While the first epidemic of 1978 was being studied, more disastrous episodes flared up and the patients were subsequently added. Hence, the total duration of this prospective study was from November 1978 to December 2003. There were 14 defaulted initially from 688 followed (23/688 without sequelae and 665/688 with neuropsychiatric deficits), and later 130 were lost from time to time at various stages of follow up. Four out of 23/688 discharged without any deficit had to be readmitted for bizarre movements, assaultative behaviour and euphoria without fever and altered sensorium. All of them improved by symptomatic treatment. Progressive improvement occurred in all the parameters consisting of psychological disturbances, higher cerebral dysfunction, speech disorders (dysphonia, dysarthria, dysphasias, apraxia and agnosia), extra pyramidal, pyramidal features, and hypothalamic disturbances, cranial nerves including pupils and fundi and seizures. Maximum cases improved between 6 months (55%) to 1 year (78%). Only some features improved between 5 to 14 years. Four patients of hemiplegia

  11. Gravidez Gemelar com Morte Fetal de Um dos Gêmeos: Avaliação Neurológica dos Gemelares Sobreviventes Neurological Evaluation of the Surviving Twin When One Dies In Utero

    Directory of Open Access Journals (Sweden)

    Carolina Araújo Rodrigues Funayama

    2002-03-01

    Full Text Available Objetivo: verificar as intercorrências pré e perinatais e a evolução neurológica de crianças de gestações gemelares em que um dos fetos apresentou óbito intra-uterino. Métodos: foram avaliados 14 casos de gestações gemelares ocorridas no período de 1988 a 1994 com óbito de um dos fetos, acompanhadas no Setor de Patologia Obstétrica do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da USP. Dados do acompanhamento pré e perinatal, bem como de autópsia dos fetos mortos, foram obtidos. As crianças foram convocadas no ano de 1996 para exame neurológico, sendo avaliados dados evolutivos e sinais patológicos nas áreas motoras, sensitivas, sensoriais e funções corticais superiores, incluindo linguagem, praxias e agnosias. Resultados: do total de 14 casos, 10 retornaram para a avaliação neurológica tardia. Destas, apenas uma criança apresentou alteração no exame neurológico, cursando com paresia espástica de MIE de grau leve, tendo apresentado Apgar 0 no primeiro minuto e 5 no quinto minuto. A avaliação da placentação e idade gestacional mostrou 5 casos (35,7% com placentação monocoriônica e um caso com monoamniótica, 8 casos de pré-termo e 6 casos a termo. O óbito de um dos fetos ocorreu no segundo trimestre em 6 casos (42,8% e os demais no terceiro trimestre. Conclusões: o problema neurológico constatado em um único feto pode ser atribuído às intercorrências perinatais que este recém-nascido apresentou. Não tivemos como resultado outros RN com seqüelas provavelmente pela opção da conduta conservadora, tendo-se resolvido as gestações após a 32ª semana com diminuição das complicações do parto pré-termo extremo.Purpose: to analyze the effects of prenatal and perinatal complications and the neurological development of surviving twins when the other had died in utero. Methods: fourteen cases of twin pregnancies where one of the twins had died during the pregnancy were analyzed

  12. A 58-year-old female with blurred vision and apraxia

    Directory of Open Access Journals (Sweden)

    Zhi-hong SHI

    2014-07-01

    Full Text Available A 58-year-old right handed woman, with 12 years of formal education, had a five-year history of slowly progressive blurred vision and apraxia. Five years before the examination she gradually became blurred vision and had difficulties identifying static objects within the visual field. Then she went to an ophthalmologist and received cataract surgery. However, the symptoms were not improved after surgery. Two years later, she had difficulty doing household chores and was unable to dress herself. She developed an anxiety disorder in the absence of prominent language or memory deficits. Five years after onset, she showed global cognitive decline and abilities of daily life decline. On neurological examination she was alert. Neuropsychological testing revealed a mini-mental state examination (MMSE score of 20/30 with anomia, agraphia, alexia and partial impairment on time orientation. Biochemical investigations for disorders involving thyroid function, vitamin B12, and folate were unremarkable. A brain MRI showed diffuse cortical atrophy and hippocampus atrophy. An 18F-FDG PET scan showed bilateral hypometabolism at the frontal lobes, tempoparietooccipital adjunction, posterior cingulate cortices and precuneus, insular lobes, caudate nuclei and right thalamus. An 11C-PIB PET scan showed bilateral amyloid deposits at bilateral frontal lobes and occipital lobes, left temporal lobe and insular, basal ganglia, bilateral cingulate cortices and precuneus. No PSEN1, PSEN2 or APP mutations were identified. This early-onset patient had an unusual cognitive complaint, including visual agnosia and apraxia. The clinical features, structural and functional imaging findings of this case were compatible with the diagnosis of Posterior Cortical Atrophy (PCA. PCA is a neurodegenerative condition characterized by a progressive, often dramatic and relatively selective decline in visual processing skills and other functions subserved by parietal, occipital and

  13. Research progress of acupuncture therapy on mild cognitive impairment after stroke%针刺治疗脑卒中后轻度认知障碍的研究进展

    Institute of Scientific and Technical Information of China (English)

    杨红玲; 郑健刚; 张杰; 刘涛

    2016-01-01

    Mild cognitive impairment after stroke is a neuropsychological disorder, which is common in cerebrovascular disease and sequel of cerebrovascular disease. Cognitive impairment is a brain dysfunction caused by ischemic or hemorrhagic cerebrovascular disease, which usually manifested memory impairment, aphasia, apraxia, agnosia, alexia, visual spatial barriers. All the symptoms cause great inconvenience to the patient's daily life, social adjustment and comprehensive rehabilitation. The acupuncture therapy has a significant effect on mild cognitive impairment after stroke. Respectively use “stroke, cerebral infarction, cerebral hemorrhage, mild cognitive impairment, acupuncture”as keywords on PubMed, Cochrane, Embase, CNKI, Wan Fang DATA and VIP database from 2004 to 2014, retrieve nearly 10-year Chinese and English collections of published clinical studies. The acupuncture therapy for mild cognitive impairment after stroke in recent years was summarized to guide the clinical application, to provide new thinking with mild cognitive impairment after stroke, and pointed out the existing problems and the prospects with the future research direction and depth of acupuncture treatment of the disease.%脑卒中后轻度认知功能障碍是一种神经心理障碍,常见于脑血管病及脑血管病后遗症,表现为记忆障碍、失语、失用、失认、失读、视空间障碍等,给患者的日常生活、社会适应和全面康复造成极大的不便。针刺疗法对罹患卒中后轻度认知障碍的患者有显著疗效。分别以“卒中,脑梗死,脑出血,轻度认知障碍,针刺”为关键词,对PubMed、Cochrane、Embase、中国知网(CNKI)、万方数据库和维普数据库2004—2014年近10年收录已发表的相关临床研究报道进行中英文检索,对近年来应用针刺治疗轻度认知障碍的方法及操作加以归纳、总结。旨在指导临床应用,为治疗卒中后轻度认知障碍提供新的

  14. [A 74-year-old man with urinary incontinence, right leg weakness and multiple cranial nerve palsies].

    Science.gov (United States)

    Mochizuki, H; Satoh, S; Saikawa, M; Mori, H; Shirai, T; Kondo, T; Mizuno, Y

    1995-02-01

    We report a 74-year-old man with a lung cancer, who developed right leg weakness, neurogenic bladder, and multiple cranial nerve palsies. The patient was well until December of 1992, when he was 74-year-old, when he noted transient double vision; in February of 1993, he noted numb sensation and weakness in his right leg. Later in the same month, he developed overflow incontinence of urine and weakness in his right face. He also noted deafness in his left ear (he had a marked loss of hearing in his right ear since childhood because of otitis media). His weakness in his right leg had progressed, and he was admitted to our service on March 19, 1993. On admission, he was afebrile and BP was 130/50 mmHg. General physical examination was unremarkable. On neurologic examination, he was alert and oriented to all spheres; no dementia was noted nor were detected aphasia, apraxia, and agnosia. His optic fundi were unremarkable; ocular movement appeared normal, however, he complained of diplopia in far vision. Sensation of the face was intact. He had right facial palsy of peripheral type; he was unable to close his right eye, and Bell's phenomenon was observed on attempted eye closure. On the left side, he had facial spasm. He had marked bilateral deafness. He had no dysarthria or dysphagia. The remaining of the cranial nerves were intact. Motor wise, he was unable to stand or walk alone; weakness did not appear to account for his difficulty in gait; manual muscle testing revealed 4/5 weakness in his tibialis anterior muscle, 1/5 in the peroneus longus, 0/5 in his extensor hallucis longus and extensor digitorum longus, all on the right side. Brachioradial and quadriceps femoris reflexes were increased to 3/4; plantar response was equivocal on the right side, and flexor on the left. Sensory examination revealed loss of touch and pain sensation in the L5 and S1 distributions in his right leg: vibration and position sensations were also diminished in his right foot. He had

  15. 失眠与认知障碍的关系%Research status of relationship between insomnia and cognitive impairment

    Institute of Scientific and Technical Information of China (English)

    王椿野; 邢佳

    2016-01-01

    睡眠是人体的一种保护机制,是机体维持正常功能的生理活动,睡眠可以促使疲劳的神经细胞恢复到正常生理功能水平,保障神经系统正常的生理功能。原发性失眠属于一种心理疾患,长期的失眠会导致亚健康或多种心身疾病。目前,失眠与认识之间的研究逐渐受到重视,长期失眠患者常可见到轻度认知障碍的表现,而失眠的发生、发展又与其认知心理模式关系密切。对睡眠各方面的认知歪曲均可导致失眠,通过探讨睡眠认知歪曲的机制,目前主要形成5种理论模式,而由长期失眠导致的认知功能下降,即轻度认知障碍,主要包括记忆障碍、失语、失用、失认、执行功能、视空间功能、定向力等能力下降。认知与失眠互为因果、呈双向关系,两种认知的概念是不同的,通过探讨两者的关系,对失眠的认识会更加深入。%Sleep is a protective inhibition of the human body, which can make the fatigue of the nerve cells to restore the normal physiological function, maintain normal operation of the nervous system. Insomnia is a kind of psychological disease, long-term of insomnia is often visible in patients with mild cognitive impairment, and the occurrence of insomnia is closely related to cognitive psychology. Cognitive impairment and insomnia causal, but it is not the same as the connotation of the cognitive. To sleep in every aspects of cognitive distortions can cause insomnia, sleep at present there are five main cognitive schema theory, purpose is to explore the mechanism of insomnia. And cognitive impairment caused by insomnia, is mainly refers to people’s cognitive decline, including memory impairment, aphasia, disuse, agnosia, executive function, visual space function, disorientation, and so on. Cognition and insomnia interact as both cause and effect, each concept of cognitive is different. By discussing the relationship between

  16. Caracterização da patologia cerebral, da psicopatologia e da heredologia psiquiátrica na doutrina de Kleist

    Directory of Open Access Journals (Sweden)

    Aníbal Silveira

    1959-06-01

    Full Text Available O ano de 1959 assinala três datas especiais em uma das mais férteis carreiras científicas: completa 80 anos Karl Kleist, nascido em Mülhausen, na Alsácia, a 31 de janeiro de 1879, que comemora o jubileu de venia legendi (1909; e há um quarto de século veio à luz a Gehirnpathologie (1934, que marca a nova era da fisiopatologia cerebral. A construção doutrinária de Kleist combina e aperfeiçoa as diretrizes isoladas de Meynert, de Wernicke e de Kraepelin. Constitui nela uma constante a união da psicopatologia à patologia cerebral; e a pesquisa no domínio clínico se norteia pela patogenia, pela heredologia e pela catamnese sistemática. Na própria patogênese - tanto dos quadros clínicos como dos sintomas - há a considerar a diferente participação do tronco cerebral e da corticalidade. E aqui, a seu turno, é preciso distinguir as funções que dependem de regiões posteriores. Assim, descreveu Kleist, respectivamente, os distúrbios agramáticos e os paragramáticos, os alógicos e os paralógicos, em analogia com os afásicos e os parafásicos. Demonstrou pela primeira vez, em 1905, a existência da afasia de condução e isolou dois novos tipos de apraxia: a apraxia segmentar e a apraxia de construção. Outros quadros psicopatológicos descritos por êle também se tornaram clássicos: a carência de iniciativa, a apraxia de iniciativa, a apraxia de ação coordenada (Handlungsfolge, a cegueira espacial (Ortsblindheit, a agnosia cromática - que depende da noção abstrata de côr e nada tem a ver com o daltonismo - e ainda os quadros psiquiátricos cíngulo-orbitários. Divide a esfera da personalidade em diversos estratos de grande relevância clínico-localizatória (quadro 1. A carta localizatória - plano estrutural e funcional do cérebro - ultrapassa a qualquer empreendimento análogo, tanto pela análise penetrante quanto pela adaptação à realidade clínica (figs. 1 e 2. Sobreleva notar aí que Kleist separa

  17. Clinical features and efficacy of different treatments on 5 cases with Landau-Kleffner syndrome with poor prognosis%预后不良Landau-Kleffner综合征5例的临床特征与治疗

    Institute of Scientific and Technical Information of China (English)

    潘岗; 周水珍

    2015-01-01

    using the Engel classification scheme and the outcome of electrical status epilepticus during sleep (ESES) was classified by the decrease in spike wave index (SWI).Results All of 5 patients (2 male and 3 female) had auditory agnosia and epileptic seizure.All patients had normal background activity and epileptiform discharges,and the location of epileptiform discharge was mainly from bilateral temporal;3 patients had ESES.Four out of the 5 patients had refractory epilepsy and the other one got seizure free with antiepileptic drug.Four patients received corticosteroids for 6 months.The aphasia disappeared in 1 patient,improved in 1 patient and sustained in the other 2 patients.Three patients who had ESES did not response to corticosteroids.Among 3 patients receiving ketogenic diet,1 patient was seizure free and the ESES disappeared;in another SWI was reduced;the rest one had a significant reduction in seizure.All the patients had improvement in their aphasia and cognition,however they still had cognitive disorder of various degrees.Conclusions The patients who had multiple seizure type or special seizure type may have poor outcome.Most of these patients have refractory epilepsy or persistent ESES.Corticosteroids can improve aphasia and cognition,but the persistence of ESES can make aphasia and cognition worse.Ketogenic diet can be used as an alternative treatment for refractory epilepsy or persistent ESES in LKS.