Familial motor neurone disease associated with non-specific organic dementia. A clinico-pathological study of a family.

Two sisters developed motor neurone disease (MND), which was associated with progressive intellectual impairment in one; they survived for 18 and 24 months, respectively. At necropsy, the features of MND were confirmed, and the demented patient had severe non-specific cerebral atrophy. No evidence of Alzheimer's disease was found. Organic dementia of non-specific type can be associated with up to 15% of the familial cases of MND and with about 2% of the sporadic cases of MND in the Western world.