[Autopsy case of frontotemporal lobar degeneration with motor neuron disease associated with numerous diffuse...

We report an autopsy case of dementia associated with amyotrophic lateral sclerosis (ALS) in a 73-year-old female. She developed memory impairment at the age of 68 years. Atrophy of her hand muscles was noted at the age of 71 years. She was not aware of her memory impairment or muscle weakness, and was loquacious and euphoric. She was clinically diagnosed as having Alzheimer disease (AD) complicated by ALS with dementia/frontotemporal lobar degeneration with motor neuron disease (ALS-D/FTLD-MND). A neuropathological study confirmed the presence of features of sporadic ALS. Furthermore, severe neuronal loss involving the subiculum and the rostral portion of the medial side of the temporal pole cortex was detected, and TAR DNA-binding protein-43-positive-neuronal cytoplasmic inclusions were identified in the granule cells of the dentate gyrus. These findings were compatible with the pathological features of ALS-D/FTLD-MND. Although many pretangles, neuropil threads and senile plaques were revealed in the degenerated areas, there were few neurofibrillary tangles and typical plaques (Braak stage III, C). Further discussion is required to determine whether AD with ALS-D/FTLD-MND is different from typical AD. This case might be helpful for diagnosing similar cases in the future.