[A case of motor neuron disease with progressive aphasia and dementia].

We report a 71-year-old woman showing rapidly progressive non-fluent aphasia and dementia accompanied by motor neuron disease (MND). There was no family history of dementia or motor neuron disease. There was 10 months history of dysarthria and dysphagia. On examination, she showed profound difficulty in articulation. Her comprehension was impaired in that she was unable to obey three-stage command. Her written language was also impaired with phonological spelling errors, syntactic errors, and perseveration. Neuroradiological investigations showed atrophic changes and hypoperfusion of left temporal and bilateral parietal region revealed by MRI and SPECT, respectively. Her subsequent decline was rapid. It might be likely that aphasia is much more common in dementia with bulbar MND than is currently recognized because bulbar palsy might mask the language disorder.