Presenile dementia with motor neuron disease in Japan. A new entity?

A 61-year-old woman suffered the gradual onset of difficulty with memory, concentration, and cognition at age 58. Progressively more severe dementia was accompanied by muscle wasting and fasciculation prominent in hand and bulbar muscles. An electromyogram and a muscle biopsy specimen demonstrated denervation patterns, and a computerized tomographic scan showed considerable cerebral atrophy. This report reviews cases of presenile dementia with motor neuron disease reported in Japan and discusses the possibility of a new clinicopathologic entity.