Object recognition deficit in Alzheimer's disease: possible disconnection of the occipito-temporal component of the...

An early object recognition impairment was observed in a patient presenting with a slowly progressive Alzheimer's disease. At autopsy, the cerebral cortex showed increased neuritic plaque and neurofibrillary tangle counts, particularly in the occipital and temporal lobes as compared to Alzheimer's disease cases with the usual clinical presentation and distribution of the neuropathological lesions (i.e., no early visual deficits and fewer pathological profiles in the occipital cortical areas than frontal or posterior parietal areas). This observation further supports the hypothesis that long corticocortical projections are selectively damaged in Alzheimer's disease and that the resulting disconnections may underlie specific neurological symptoms.