1/29. Pure apraxic agraphia with abnormal writing stroke sequences: report of a Japanese patient with a left superior parietal haemorrhage.A 67 year old Japanese male patient had pure agraphia after a haemorrhage in the left superior parietal lobule. He developed difficulty in letter formation but showed no linguistic errors, consistent with the criteria of apraxic agraphia. He manifested a selective disorder of sequencing writing strokes, although he was able to orally state the correct sequences. The patient's complete recovery after 1 month, without new learning, showed that he had manifested a selective disorder of writing stroke sequences. These findings indicate that the final stage of the execution of writing according to acquired sequential memory shown as a stroke sequence can be selectively disturbed, and should be considered to be distinct from the ability of character imagery and the knowledge of the writing stroke sequence itself. This case also indicates that the left superior parietal lobule plays an important part in the execution of writing.- - - - - - - - - - ranking = 1keywords = memory (Clic here for more details about this article) |
2/29. Dyspraxia in a patient with corticobasal degeneration: the role of visual and tactile inputs to action.OBJECTIVES: To investigate the roles of visual and tactile information in a dyspraxic patient with corticobasal degeneration (CBD) who showed dramatic facilitation in miming the use of a tool or object when he was given a tool to manipulate; and to study the nature of the praxic and neuropsychological deficits in CBD. methods: The subject had clinically diagnosed CBD, and exhibited alien limb behaviour and striking ideomotor dyspraxia. General neuropsychological evaluation focused on constructional and visuospatial abilities, calculation, verbal fluency, episodic and semantic memory, plus spelling and writing because impairments in this domain were presenting complaints. Four experiments assessed the roles of visual and tactile information in the facilitation of motor performance by tools. Experiment 1 evaluated the patient's performance of six limb transitive actions under six conditions: (1) after he described the relevant tool from memory, (2) after he was shown a line drawing of the tool, (3) after he was shown a real exemplar of the tool, (4) after he watched the experimenter perform the action, (5) while he was holding the tool, and (6) immediately after he had performed the action with the tool but with the tool removed from his grasp. Experiment 2 evaluated the use of the same six tools when the patient had tactile but no visual information (while he was blindfolded). Experiments 3 and 4 assessed performance of actions appropriate to the same six tools when the patient had either neutral or inappropriate tactile feedback-that is, while he was holding a non-tool object or a different tool. RESULTS: Miming of tool use was not facilitated by visual input; moreover, lack of visual information in the blindfolded condition did not reduce performance. The principal positive finding was a dramatic facilitation of the patient's ability to demonstrate object use when he was holding either the appropriate tool or a neutral object. Tools inappropriate to the requested action produced involuntary performance of the stimulus relevant action. CONCLUSIONS: Tactile stimulation was paramount in the facilitation of motor performance in tool use by this patient with CBD. This outcome suggests that tactile information should be included in models which hypothesise modality specific inputs to the action production system. Significant impairments in spelling and letter production that have not previously been reported in CBD have also been documented.- - - - - - - - - - ranking = 2keywords = memory (Clic here for more details about this article) |
3/29. Posterior cortical atrophy variants of Alzheimer's disease.Posterior cortical atrophy (PCA) was first described by Benson in 1988 and, since then, has been regarded as a variant of Alzheimer's disease. We present 2 patients with symptoms suggestive of PCA and 2 patients with apraxia as the initial manifestation. Primary motor and sensory modalities were intact. Mild memory impairment was present early in the course of the disease and gradually worsened. Parieto-occipital atrophy was evident on brain MRI. HMPAO-SPECT demonstrated parieto-occipital hypoperfusion significantly different from the temporoparietal hypoperfusion usually described in senile dementia of the Alzheimer type. These findings suggest that HMPAO-SPECT can help in diagnosing atypical variants of Alzheimer's disease. We suggest that PCA represents two clinically related behavioral phenotypes: PCA with predominantly apraxia manifestations and PCA with predominantly visuospatial disturbances. Copyrightz1999S.KargerAG,Basel- - - - - - - - - - ranking = 1keywords = memory (Clic here for more details about this article) |
4/29. Expressive language disorder after infarction of left lentiform nucleus.A 53 year old bilingual woman presented with apraxia of speech and writing in English and German after ischaemic infarction of the left posterior lentiform nucleus. Detailed language assessment revealed impairments of articulation, verbal fluency, auditory repetition, interpretation of complex semantic relationships, formulation of definitions and verbal short-term memory. The case illustrates the role of the basal ganglia in speech planning, word retrieval and verbal short-term memory.- - - - - - - - - - ranking = 2keywords = memory (Clic here for more details about this article) |
5/29. Transient crossed aphasia and persistent amnesia after right thalamic haemorrhage.A 45-year-old right-handed woman suffered transient aphasia and persistent amnesia after a right thalamic haemorrhage. This patient appeared to have crossed aphasia, although it disappeared within 8 weeks. It is noteworthy that the patient had a unilateral right thalamic lesion but exhibited both verbal and non-verbal memory impairment. Computed tomography and magnetic resonance imaging revealed cerebral haemorrhage in the right thalamus involving the ventral anterior nucleus, medioventral nucleus, mamillothalamic tract, internal medullary lamina, and mediodorsal nucleus. An amytal test was performed and suggested that the right hemisphere was dominant for language functions and the left hemisphere was dominant for visuospatial functions. Single photon emission CT revealed a low perfusion area only in the right thalamus. These findings suggest that the right hemisphere might be dominant for both verbal and non-verbal memory function in this patient, although visuospatial function was lateralized in the left hemisphere.- - - - - - - - - - ranking = 2keywords = memory (Clic here for more details about this article) |
6/29. Dissociated active and passive tactile shape recognition: a case study of pure tactile apraxia.Disorders of tactile object recognition (TOR) may result from primary motor or sensory deficits or higher cognitive impairment of tactile shape representations or semantic memory. Studies with healthy participants suggest the existence of exploratory motor procedures directly linked to the extraction of specific properties of objects. A pure deficit of these procedures without concomitant gnostic disorders has never been described in a brain-damaged patient. Here, we present a patient with a right hemispheric infarction who, in spite of intact sensorimotor functions, had impaired TOR with the left hand. Recognition of 2D shapes and objects was severely deficient under the condition of spontaneous exploration. Tactile exploration of shapes was disorganized and exploratory procedures, such as the contour-following strategy, which is necessary to identify the precise shape of an object, were severely disturbed. However, recognition of 2D shapes under manually or verbally guided exploration and the recognition of shapes traced on the skin were intact, indicating a dissociation in shape recognition between active and passive touch. Functional MRI during sensory stimulation of the left hand showed preserved activation of the spared primary sensory cortex in the right hemisphere. We interpret the deficit of our patient as a pure tactile apraxia without tactile agnosia, i.e. a specific inability to use tactile feedback to generate the exploratory procedures necessary for tactile shape recognition.- - - - - - - - - - ranking = 1keywords = memory (Clic here for more details about this article) |
7/29. rehabilitation of Balint's syndrome: a single case report.Very little research has been done in the area of rehabilitation of the visual perceptual deficits observed after Balint's syndrome. This syndrome is characterized by difficulties with visual scanning, dysmetria secondary to visual perceptual deficits, and an inability to perceive more than 1 object at a time. This article describes the effects of a neuropsychological treatment protocol on a 23-year-old patient who suffered a fat embolism involving the territory of the posterior cerebral arteries. A neuropsychological evaluation carried out 12 months after the brain embolism disclosed Balint's syndrome, alexia without agraphia, visual agnosia, prosopagnosia, and memory impairments. The rehabilitation protocol included both visuoperceptual retraining and a functional program designed to provide rehabilitation in contexts that were meaningful to the patient. After 1 year of treatment, a second neuropsychological evaluation was carried out. Significant improvement was demonstrated in terms of both objective testing and the return of an integrated and productive lifestyle.- - - - - - - - - - ranking = 1keywords = memory (Clic here for more details about this article) |
8/29. Manual approach during hand gesture imitation.BACKGROUND: patients' tendency to draw near or into the target when copying figures, a phenomenon termed closing-in, has been previously described. That the closing-in could occur when copying hand gestures has also been noted. OBJECTIVES: To study a patient with corticobasal degeneration to quantify his manual approach behavior and to test a possible working memory hypothesis. methods: The subject of this study is a patient with severe ideomotor apraxia from probable corticobasal degeneration. fluorine 18-labeled deoxyglucose-positron emission tomographic findings revealed a hypometabolism involving the bilateral parietotemporal and the right frontal lobes. When asked to copy an examiner's (J.C.K.) hand gesture, the patient approached, touched, or grasped the examiner's hand, a behavior mostly consistent with the closing-in behavior previously proposed. To investigate the frequency and severity of closing-in, the patient was asked to copy 20 meaningless hand gestures (10 simple and 10 complex). Copying the 20 hand gestures was performed with either the left or the right hand while the patient was seated opposite the examiner (across condition) or on the same side of the examiner (lateral condition). RESULTS: Of the 80 trials, closing-in occurred in 43 (53.8%) (35 with approaching, 6 with touching, and 2 with grasping). The closing-in was more frequent and more severe when gesturing with the left than the right hand, but it did not differ between the lateral and across conditions and between simple and complex gestures. CONCLUSIONS: Corticobasal degeneration might be associated with aberrant manual approach behavior. Although our results do not support the working memory hypothesis, frontal dysfunction might have led to a loss of voluntary control of ontologically primitive propensity to move the forelimb in the direction to which one attends.- - - - - - - - - - ranking = 2keywords = memory (Clic here for more details about this article) |
9/29. language function and dysfunction in corticobasal degeneration.OBJECTIVE:S: The authors assessed language functioning in corticobasal degeneration (CBD), an area that has received little systematic study. aphasia has been reported occasionally, and the authors hypothesized that appropriate assessments would reveal at least mild language impairment, particularly affecting phonologic (sound-based) processing, even in cases without frank aphasia. methods: A series of 10 unselected patients with CBD (one with pathologic confirmation) were administered neuropsychological tests assessing the following aspects of cognitive functioning: verbal fluency, naming, reading, oral spelling, auditory-verbal short-term memory, phoneme blending and segmentation, visuospatial skills, and semantic memory. RESULTS: Phonologic and spelling impairments were prevalent, even in nonaphasic patients. The prevalence of visuospatial, constructional, and frontal impairments, demonstrated in previous research, was also replicated. A minority of patients had deficits in semantic memory, naming, and reading, but the impairments were usually mild. CONCLUSIONS: The authors found phonologic impairment to be a typical feature of CBD. There is substantial overlap between progressive nonfluent aphasia and CBD, and the linguistic impairment can be thought of as a continuum, with mild phonologic impairment at one end and severe aphasia at the other.- - - - - - - - - - ranking = 3keywords = memory (Clic here for more details about this article) |
10/29. Pantomimes are special gestures which rely on working memory.The case of a patient is reported who presented consistently with overt deficits in producing pantomimes in the absence of any other deficits in producing meaningful gestures. This pattern of spared and impaired abilities is difficult to reconcile with the current layout of cognitive models for praxis. This patient also showed clear impairment in a dual-task paradigm, a test taxing the co-ordination aspect of working memory, though performed normally in a series of other neuropsychological measures assessing language, visuo-spatial functions, reasoning function, and executive function. A specific working memory impairment associated with a deficit of pantomiming in the absence of any other disorders in the production of meaningful gestures suggested a way to modify the model to account for the data. Pantomimes are a particular category of gestures, meaningful, yet novel. We posit that by their very nature they call for the intervention of a mechanism to integrate and synthesise perceptual inputs together with information made available from the action semantics (knowledge about objects and functions) and the output lexicon (stored procedural programmes). This processing stage conceived as a temporary workspace where gesture information is actively manipulated, would generate new motor programmes to carry out pantomimes. The model of gesture production is refined to include this workspace.- - - - - - - - - - ranking = 6keywords = memory (Clic here for more details about this article) |
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