ALZHEIMERS-DISEASE WITH ASYMMETRIC ATROPHY OF THE CEREBRAL HEMISPHERES - MORPHOMETRIC ANALYSIS OF 4 CASES

To examine the clinicopathological correlations in rare Alzheimer's di sease patients with asymmetric cerebral atrophy and to compare their p attern of cortical involvement by senile lesions with that observed in other cases with atypical Alzheimer's disease, we performed an extens ive neuropathological analysis of the cerebral cortex in four such cas es. Three patients presented with severe language impairment but relat ively good preservation of praxis and gnosis even after several years of clinical evolution. Cerebral autopsies of these cases revealed a pr edominant left hemisphere atrophy. Conversely, in one case with marked right hemisphere atrophy, all of the cognitive functions were involve d early in the course of dementia. Neurofibrillary tangles and senile plaques were preferentially localized in the prefrontal, temporal and posterior parietal cortex in both hemispheres, whereas the hippocampal formation displayed lower lesion densities than neocortical areas. Si gnificantly higher neurofibrillary tangle and senile plaque densities were found in the more atrophic side in most of the areas studied. The ratio of neurofibrillary tangle and senile plaque densities between t he two hemispheres was not correlated with the number of these lesions in the cerebral cortex. These results indicate that the degenerative process in demented cases with interhemispheric asymmetric cerebral at rophy is characterized by a widespread involvement of the neocortex by senile lesions and lacks clear regional topography of neurofibrillary tangle and senile plaque distribution. Moreover, the relative sparing of the hippocampus, comparable to that found in cases with focal prog ressive dementia, suggests that the dementing process may involve diff erent cortical structures in cases with asymmetric cerebral atrophy th an in typical Alzheimer's disease cases.