1/67. Apraxia differs in corticobasal degeneration and left-parietal stroke: A case study.Corticobasal degeneration (CBD) is a progressive disorder characterized by both cortical and basal ganglia dysfunction such as asymmetrical apraxia, and akinetic rigidity, involuntary movements, and cortical sensory loss. Although apraxia is a key finding for the differential diagnosis of CBD, it has not been determined whether the features of apraxia seen in subjects with CBD are similar to those features exhibited by subjects with left-hemisphere damage from stroke. Therefore, for both clinical purposes and in order to better understand the brain mechanisms that lead to apraxia in CBD, we studied praxis in a patient with CBD and compared him to patients who are apraxic from left-parietal strokes. We used three-dimensional movement analyses to compare the features of apraxic movement. This subject with CBD was a dentist whose initial complaint had been that he "forgot" how to use his tools in the mouths of his patients. Analyses were performed on the trajectories made when using a knife to actually slice bread, and when repetitively gesturing slicing made to verbal command. Movements of the left hand, wrist, elbow, and shoulder were digitized in 3-D space. Although the CBD subject was clearly apraxic, the features of his apraxia differed markedly from those of the subjects with lesions in the left parietal lobe. For movements to command, the CBD subject showed joint coordination deficits, but his wrist trajectories were produced in the appropriate spatial plane, were correctly restricted to a single plane, and, like control subjects, were linear in path shape. However, when he was actually manipulating the tool and object, all of these aspects of his trajectories became impaired. In contrast, the deficits of the apraxic subjects with left-parietal damage were most pronounced to verbal command with their movements improving slightly although remaining impaired during actual tool and object manipulation. Unlike patients with parietal strokes, patients with CBD have degeneration in several systems and perhaps deficits in these other areas may account for the differences in praxic behavior.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
2/67. Neuropathology of Joubert syndrome.Very little documentation of the neuropathologic changes in Joubert syndrome exists. This paper presents a detailed postmortem neuropathologic study of a clinically and radiographically well-documented case of Joubert syndrome. In addition to aplasia of the cerebellar vermis and fragmentation of the dentate nuclei, there was marked dysplasia of structures at the pontomesencephalic junction and caudal medulla. There was abnormal decussation of the superior cerebellar peduncles and an enlarged iter (rostral 4th ventricle) with elongated tegmental nuclei (including the locus coeruleus). neurons of the basis pontis and reticular formation appeared reduced. Extensive malformations of the medulla included hypoplasia of the inferior olivary nuclei, solitary nuclei and tracts, and the nucleus and spinal tracts of trigeminal nerve (cranial nerve V). Even more striking was dysplasia of the caudal medulla at the cervicomedullary junction, which was characterized by the absence of a posterior median sulcus, neuronal swelling and axonal spheroids in the region of malformed nuclei gracilis and cuneatus, and absence of pyramidal decussation. This study suggests that, in addition to vermal agenesis, Joubert syndrome is characterized by malformation of multiple brainstem structures. The latter could explain certain clinical features of the syndrome, including episodic hyperpnea and oculomotor apraxia.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
3/67. 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 = brain (Clic here for more details about this article) |
4/67. Portal systemic encephalopathy presenting with dressing and constructional apraxia.We report a case with portal systemic encephalopathy who presented with dressing and constructional apraxia and subtle weakness of the left hand. We initially suspected a cerebrovascular attack in the right cerebral hemisphere, but brain T1-weighted magnetic resonance (MR) imaging revealed high intensity in the basal ganglia and hyperammonemia was detected. We performed abdominal MR angiography, which visualized an intrahepatic portal systemic shunt. Cerebral blood flow, measured by xenon-enhanced computed tomography, was decreased in the bilateral, but more dominantly right-sided, parietal watershed regions. We speculate that these boundary territories might be susceptible to damage by toxic metabolites of hepatic encephalopathy.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
5/67. Combined semantic dementia and apraxia in a patient with frontotemporal lobar degeneration.In this study we report neuropsychological and brain-imaging findings in a patient with frontotemporal lobar degeneration. brain imaging using registration of (18)fluorodeoxyglucose (FDG)-PET data to three-dimensional (3-D) magnetic resonance imaging showed atrophy and highly significant hypometabolism of the left temporal lobe and both frontal lobes. Volumetric measurements of the hippocampi/amygdala showed a reduction in volume of 25% on the left compared to right within cortical areas. Neuropsychological testing revealed semantic dementia with severe anomia as well as apraxia with impairment of both recognition and production of motor acts. The implications of this case of early manifestation of frontotemporal lobar degeneration for our knowledge of dementia are discussed.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
6/67. Pseudodystonic hand posturing contralateral to a metastasis of the parietal association cortex.A 56 year-old patient, with a history of surgically removed breast cancer three years earlier, presented with incoordination of hand movements while playing piano. Neurological examination disclosed mild position sensory loss and limb-kinetic apraxia of the distal part of the right upper extremity. The most conspicuous neurological sign was a dystonic posturing of the right hand, which was only elicited when the patient outstretched her arms with the eyes closed. MRI revealed a metastatic lesion involving the left parietal cortex. The association of focal dystonic postures with lesions of the parietal association cortex indicates that dystonia may feature damage of brain cortical areas far from the basal ganglia. In addition, this provides support to the hypothesis that impairment of sensory pathways may play a role in the origin of some hyperkinetic movement disorders, such as dystonia and athetosis.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
7/67. 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 = brain (Clic here for more details about this article) |
8/67. Primary central nervous system lymphoma in the SMA presenting as rapidly progressive parkinsonism.We report on a 56-year-old man who developed a rapidly progressive parkinsonism and apraxia over 2 months due to biopsy confirmed cerebral non-Hodgkin lymphoma primarily involving the SMA and parts of the superior frontal gyrus bilaterally.- - - - - - - - - - ranking = 2.286242889406keywords = central nervous system, nervous system (Clic here for more details about this article) |
9/67. gerstmann syndrome in systemic lupus erythematosus: neuropsychological, neuroimaging and spectroscopic findings.gerstmann syndrome (GS) comprises four interlaced neuropsychological symptoms including finger agnosia, right-left confusion, agraphia, and acalculia. While GS is commonly associated with focal lesions to the region of the left angular gyrus, it has also been associated with numerous diffuse etiologies including atrophy, alcoholism, carbon monoxide poisoning, lead intoxication and anaphylactic shock. Thus, a vigorous debate has emerged as to whether GS represents a syndrome arising from general brain decline or a distinct and localizing lesion. We report a right-handed patient who developed neuropsychological dysfunction secondary to systemic lupus erythematosus (SLE). Neuropsychological evaluation found the patient to exhibit symptoms consistent with the GS tetrad, as well as general cognitive decline. magnetic resonance imaging revealed a distinct focal lesion of the left parieto-occipital white matter underlying the angular gyrus as well as diffuse atrophy. (1)H-magnetic resonance spectroscopy revealed substantial metabolic derangement in a voxel placed within the visible lesion, although substantial metabolic derangement was observed in regions remote from the focal pathology. Thus, GS in this first case in SLE would appear to comprise a focal neurological tetrad of disorders within a more general pattern of cognitive decline and metabolic derangement.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
10/67. 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 = brain (Clic here for more details about this article) |
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