Posterior cortical atrophy in Alzheimer's disease: analysis of a new case and re-evaluation of a historical report

Autor: J. H. Dougherty, N. Archin, Patrick R. Hof, John H. Morrison, Constantin Bouras, A. P. Osmand, C. Wells
Rok vydání: 1993
Předmět:
Zdroj: Acta Neuropathologica. 86:215-223
ISSN: 1432-0533
0001-6322
DOI: 10.1007/bf00304135
Popis: Disturbances of visual function are not uncommon in Alzheimer's disease and several cases with complex impairment of visuospatial abilities have been described. For instance, posterior cortical atrophy has been demonstrated in cases displaying Balint's syn-drome as the first symptom of the dementing illness. Such cases showed very high lesion counts in the occipital cortex, as well as in visual association regions in the posterior parietal and posterior cingulate cortex, whereas the prefrontal cortex was consistently less severely involved than usually observed in Alzheimer's disease. This suggests that the distribution of the lesions had been shifted to specific elements of the visual system. In the present study; we report the quantitative analysis of a new case of Alzheimer's disease with possible Balint's syndrome and re-evaluate a case originally described in 1945. The distribution of lesions in these two cases parallels previous observations of Alzheimer's disease cases with early visual impairment. Both cases displayed very high densities of neurofibrillary tangles and senile plaques in the primary visual cortex, secondary visual cortex, visual association areas of the dorsal occipital and posterior parietal lobe and in the posterior cingulate cortex, whereas the prefrontal and inferior temporal regions were comparatively less affected. These cases may define clinical subgroups of Alzheimer's disease and suggest that the breakdown of corticocortical projections that is known to occur in dementia may involve select components of specific functional systems in certain cases. In particular, path-ways that subserve motion detection and visuospatial analysis appear to be dramatically affected in these cases presenting with Balint's syndrome. Thus, Alzheimer's disease may be a more heterogeneous disorder than previously thought, and refined neuropsychological testing as well as detailed neuropathological evaluation may be of value to detect possible clinical variants of this dementing conditon.
Databáze: OpenAIRE