[Cerebral degeneration in Down's syndrome]

Clinical and neuropathological findings of a 63-year-old male and a 25-year-old female with Down's syndrome are presented. Neuropathological examination of the older patient revealed intense features of Alzheimer's disease or senile dementia, including congophilic angiopathy and extensive mineral deposits in the globus pallidus and in the white matter of the cerebellum. In the hippocampus of the younger patient, plaque-like bodies and a few neurofibrillary tangles were found. From a survey of the cases hitherto reported in the literature it appears that among patients over 50 years of age it is common to encounter pathological features typical of Alzheimer's disease or senile dementia, that plaque-like bodies may occur in the second decade, neurofibrillary tangles in the third decade and a congophilic angiopathy in the fourth decade. The congophilic angiopathy is a frequent finding. Due to their high frequency, calcium or calciumlike deposits are regarded as important histopathological substrates of Down's syndrome. The clinical symptomatology of the long-surviving patients with Down's syndrome is that of a non-characteristic brain aging process and differs from that of the typical Alzheimer's disease. Organic dementia is not regularly found. Altogether, the anatomical findings in adult patients with Down's syndrome indicate a premature aging of the brain, which becomes more significant and widespread with increasing age.