1/150. MR and CT imaging in the Dyke-Davidoff-Masson syndrome. Report of three cases and contribution to pathogenesis and differential diagnosis.Cerebral hemiatrophy or Dyke-Davidoff-Masson syndrome is a condition characterized by seizures, facial asymmetry, contralateral hemiplegia or hemiparesis, and mental retardation. These findings are due to cerebral injury that may occur early in life or in utero. The radiological features are unilateral loss of cerebral volume and associated compensatory bone alterations in the calvarium, like thickening, hyperpneumatization of the paranasal sinuses and mastoid cells and elevation of the petrous ridge. The authors describe three cases. Classical findings of the syndrome are present in variable degrees according to the extent of the brain injury. Pathogenesis is commented.- - - - - - - - - - ranking = 1keywords = ridge (Clic here for more details about this article) |
2/150. MRI, quantitative MRI, SPECT, and neuropsychological findings following carbon monoxide poisoning.Carbon monoxide (CO) poisoning has been shown to result in neuropathologic changes and cognitive impairments due to anoxia and other related biochemical mechanisms. The present study investigated brain-behaviour relationships between neuropsychological outcome and SPECT, MRI, and Quantitative magnetic resonance imaging (QMRI) in 21 patients with CO poisoning. Ninety-three per cent of the patients exhibited a variety of cognitive impairments, including impaired attention, memory, executive function, and mental processing speed. Ninety-five per cent of the patients experienced affective changes including depression and anxiety. The results from the imaging studies revealed that 38% of the patients had abnormal clinical MRI scans, 67% had abnormal SPECT scans, and 67% had QMRI findings including hippocampal atrophy and/or diffuse cortical atrophy evidenced by an enlarged ventricle-to-brain ratio (VBR). Hippocampal atrophy was also found on QMRI. SPECT and QMRI appear to be sensitive tools which can be used to identify the neuropathological changes and cerebral perfusion defects which occur following CO poisoning. Cerebral perfusion defects include frontal and temporal lobe hypoperfusion. Significant relationships existed between the various imaging techniques and neuropsychological impairments. The data from this study indicate that a multi-faceted approach to clinical evaluation of the neuropathological and neurobehavioural changes following CO poisoning may provide comprehensive information regarding the neuroanatomical and neurobehavioural effects of CO poisoning.- - - - - - - - - - ranking = 0.072412746314155keywords = process (Clic here for more details about this article) |
3/150. multimodal imaging of residual function and compensatory resource allocation in cortical atrophy: a case study of parietal lobe function in a patient with Huntington's disease.In a case of Huntington's disease (HD) with dementia and pronounced parieto-frontal atrophy, the functional state of the affected regions was investigated using functional magnetic resonance imaging (fMRI) and fluorodeoxyglucose-positron emission tomography (FDG-PET). It was observed that although parietal areas showed extensive atrophy and reduced resting glucose metabolism, the patient performed with similar accuracy but with longer response time in a visuospatial task compared with healthy control subjects. At the same time, the blood oxygen level-dependent (BOLD) fMRI signal in these areas, which are involved in visuospatial processing, showed a similar task-dependent modulation as in control subjects. The signal amplitude (signal percent change) of the task-dependent activation was even higher for the HD patient than in the control group. This residual functionality of parietal areas involved in visuospatial processing could account for the patient's performance in the task concerned, which contrasted with his poor performance in other cognitive tasks. The increased percent-signal change suggests that a higher neuronal effort was necessary to reach a similar degree of accuracy as in control subjects, fitting well with the longer reaction time. We propose that fMRI should be considered as a tool for the assessment of functionality of morphologically abnormal cortex and for the investigation of compensatory resource allocation in neurodegenerative disorders.- - - - - - - - - - ranking = 0.14482549262831keywords = process (Clic here for more details about this article) |
4/150. Muscular reconstruction to improve the deterioration of facial appearance and speech caused by mandibular atrophy: technique and case reports.One of the consequences of severe mandibular atrophy is the loss of attachment of the facial muscles that originate from the alveolar process and basal bone. Another is a loss of vestibular depth and reduction in the width of the attached gingiva. The result is reduced ability to chew, a changed and aged appearance, difficulties with pronunciation, and a reduced range of expressions. The traditional goal of treatment has been to improve the ability to chew. We describe a technique by which all these functions can be improved by a combination of insertion of implants and functional reconstruction of the facial muscles and position of the lips. When the muscles are repositioned, the buccal vestibule is deepened, and the incidence of gingival hyperplasia and infrabony pockets along the posts is eliminated. This treatment, which also rejuvenates the face and improves the ability to speak, should help to overcome the loss of self-confidence and self-esteem of these patients by improving their quality of life.- - - - - - - - - - ranking = 0.27574896997498keywords = alveolar, process (Clic here for more details about this article) |
5/150. Shedding of peripheral cytoplasm - a mechanism of liver cell atrophy in human amyloidosis.A liver biopsy specimen from a case of primary amyloidosis was investigated by electron microscopy. The cytoplasmic periphery of the hepatocytes showed degenerativechanges which are interpreted as indicating shedding of peripheral parts of the cytoplasm. Two main variants of this process could be discerned: 1) Protrusion and sequestration of hernia-like blebs of cytoplasm, and 2) shedding of vesicles derived from degenerated endoplasmic reticulum. In the latter case transient defects of the plasma membrane seem to be relevance. endoplasmic reticulum and cytoplasmic ground substance appeared to be shed preferentially, whereas mitochondria are retained within the cell. As a consequence the fractional volume of the mitochondria in the cytoplasm of atrophic cells is markedly increased. Shedding of peripheral cytoplasm, therefore, seems to be an effective mechanism enabeling the cell to adapt the mass and the composition of its cytoplasm to an unfavourable environment.- - - - - - - - - - ranking = 0.072412746314155keywords = process (Clic here for more details about this article) |
6/150. Unconscious letter discrimination is enhanced by association with conscious color perception in visual form agnosia.Adaptive behavior guided by unconscious visual cues occurs in patients with various kinds of brain damage as well as in normal observers, all of whom can process visual information of which they are fully unaware [1] [2] [3] [4] [5] [6] [7] [8]. Little is known on the possibility that unconscious vision is influenced by visual cues that have access to consciousness [9]. Here we report a 'blind' letter discrimination induced through a semantic interaction with conscious color processing in a patient who is agnosic for visual shapes, but has normal color vision and visual imagery. In seeing the initial letters of color names printed in different colors, it is normally easier to name the print color when it is congruent with the initial letter of the color name than when it is not [10]. The patient could discriminate the initial letters of the words 'red' and 'green' printed in the corresponding colors significantly above chance but without any conscious accompaniment, whereas he performed at chance with the reverse color-letter mapping as well as in standard tests of letter reading. We suggest that the consciously perceived colors activated a representation of the corresponding word names and their component letters, which in turn brought out a partially successful, unconscious processing of visual inputs corresponding to the activated letter representations.- - - - - - - - - - ranking = 0.21723823894247keywords = process (Clic here for more details about this article) |
7/150. Ulcerated dystrophic calcinosis cutis secondary to localised linear scleroderma.Dystrophic calcinosis is a more common form of calcinosis cutis; calcium salts are deposited secondary to local inflammation, tissue damage and degeneration. Various conditions can cause dystrophic calcinosis, including connective tissue disease, infection, inflammatory processes, chronic venous stasis, cutaneous neoplasm and trauma. We report a case of ulcerated cutaneous calcinosis associated with a localised linear scleroderma or morphea. Healing of the ulcerations took place after four months of treatment with colchicine 1 mg per day.- - - - - - - - - - ranking = 0.072412746314155keywords = process (Clic here for more details about this article) |
8/150. Sentence processing in the face of semantic loss: a case study.The modularity of the sentence processor, or lack thereof, remains a much-debated issue in psycholinguistics. The authors present evidence from a semantically impaired patient (DM) that bears on this issue. As demonstrated elsewhere (S. D. Breedin, E. M. Saffran, & H. B. Coslett, 1994), DM suffered a significant loss of semantic knowledge. Here, the authors show that this impairment did not compromise DM's ability to process syntactic information. DM performed well on grammaticality judgment tasks and on sentence comprehension tasks that required the use of syntactic information for the assignment of thematic roles. The resistance of syntactic operations to semantic loss would seem to pose a challenge for models in which "the syntactic and conceptual aspects of processing are ... inextricably intertwined" (J. L. McClelland, M. St. John, & R. Taraban, 1989, p. 329).- - - - - - - - - - ranking = 0.50688922419909keywords = process (Clic here for more details about this article) |
9/150. A Japanese case of Kindler syndrome.A 25-year-old Japanese woman presented with contracture of the fingers and toes, and difficulty in opening her mouth. Her grandparents are first cousins, but none of the other members of the family are affected. Bulla formation started at birth on areas of the skin that received pressure, and in infancy and early childhood the lesions were limited only to the acral areas. She also had bilateral, incomplete syndactylies involving all web spaces (Fig. 1a). The formation of blisters ceased after the age of 15 years, but a generalized progressive poikiloderma then appeared with accompanying cutaneous atrophy of the skin of the neck, trunk, and extremities (Fig. 1b). The patient experienced mild photosensitivity of the face and neck. At age 18 years, surgical removal of the webbing of all her fingers was performed. Oral examination showed atrophy of the buccal mucosa, and an inability to fully open the mouth. The patient also suffered from poor dentition and easily bleeding gums, but had no symptoms of esophageal dysfunction. histology of separate biopsy specimens, taken from the poikilodermatous pretibial and trunk skin, showed classical features of poikiloderma, namely epidermal atrophy with flattening of the rete ridges, vacuolization of basal keratinocytes, pigmentary incontinence, and mild dermal perivascularization (Fig. 2a). Interestingly, dyskeratotic cells (Fig. 2b) and eosinophilic rounded bodies (colloid bodies) (Fig. 2c) were frequently found at the basal keratinocyte layer and in the upper dermis, respectively. Pigment was also present in the upper epidermis. To rule out the possibility of a congenital epidermolysis bullosa, ultrastructural and immunofluorescence studies were performed. Ultrastructural studies demonstrated the reduplication of the basal lamina with branching structures within the upper dermis and cleavage between the lamina densa and the cell membrane of the keratinocytes (Fig. 3a). The numbers of associated anchoring fibrils did not seem to be reduced, and colloid bodies and dyskeratotic cells were detected. Immunofluorescence studies with the antibody against type VII collagen (LH 7 : 2) were subsequently carried out. The results showed extensive broad bands with intermittently discontinuous and reticular staining at the dermo-epidermal junction (DEJ) (Fig. 3b), whereas a linear distribution is typically seen in healthy tissue (data not shown). Interestingly, direct immunofluorescence studies revealed intracellular accumulation of immunoglobulin g (IgG), IgM, IgA, and C3 in colloid bodies under the basement membrane (Fig. 3c).- - - - - - - - - - ranking = 1keywords = ridge (Clic here for more details about this article) |
10/150. D-2-hydroxyglutaric aciduria with cerebral, vascular, and muscular abnormalities in a 14-year-old boy.D-2-Hydroxyglutaric Aciduria is a rare metabolic disorder that can cause injury to the brain and other organs. This case report concerns a 14-year-old boy showing irritability and typical signs of pyloric stenosis early postnatally. From the age of 3 months he had epilepsy. He was mentally retarded, hypotonic with preserved reflexes, and dystonic. The features were dysmorphic with elongated head and high arched palate. cardiomegaly with aortic insufficiency was diagnosed. magnetic resonance imaging of the brain revealed atrophy, reduced periventricular white matter, and multiple bilateral aneurysms of the middle cerebral arteries. The boy died at the age of 14 years. autopsy confirmed the white-matter reduction of the cerebral hemispheres as well as the arterial aneurysms of the middle cerebral arteries. Lesions of a few leptomeningeal and cerebral microvessels and of the renal and pulmonary arteries were also found. There were bilateral infarcts of the kidneys and signs of cardiomyopathy with noncompensated left ventricular failure. Signs of myopathy were evident. The clinical and postmortem findings imply a disseminated mesenchymal process.- - - - - - - - - - ranking = 0.072412746314155keywords = process (Clic here for more details about this article) |
| | Next -> |