Huntington disease associated with Alzheimer disease.

The clinicopathological study of a case of Huntington disease with early severe dementia is presented. The pathological findings were those of Huntington disease (atrophy with neuronal loss and astrocytosis in the neostriatum) and Alzheimer disease (neuronal loss with numerous senile plaques and neurofibrillary tangles in the neocortex). Ultrastructural study of neurofibrillary tangles showed that they were composed of twisted tubules similar to those found in Alzheimer disease.