[A case of motor neuron disease with dementia and apraxia of the upper limbs].

We report a 61-year-old, right-handed woman with motor neuron disease, dementia, and apraxia of the upper limbs. The patient developed clumsiness of the right hand and dysarthria two years and a half prior to admission. Neurological examination showed limb-kinetic apraxia and ideomotor apraxia, predominantly on the right side, in addition to dementia and anarthria. There was mild muscle wasting in the neck and hands. A muscle biopsy from the biceps muscle of arm as well as needle EMG revealed neurogenic changes compatible with motor neuron disease. Brain MRI indicated pyramidal tract degeneration. Three-dimensional brain perfusion imaging generated from SPECT demonstrated an asymmetric decrease in cerebral blood flow in the fronto-temporo-parietal regions, predominantly on the left side. This case suggests that asymmetric limb apraxia can be associated with motor neuron disease.