Frontotemporal lobar degeneration with motor neuron disease showing severe and circumscribed atrophy of anterior temporal lobes.

Abstract Frontotemporal lobar degeneration (FTLD) is characterized by a variety of behavioral and psychiatric symptoms based on the dysfunction of frontal and/or temporal lobes. A 63-year-old Japanese man without a family history of neurological diseases developed progressive symptoms of frontotemporal dementia, followed by motor neuron disease (MND). Brain magnetic resonance images demonstrated severe atrophy in the anterior temporal lobes from early clinical stage. The symptoms got rapidly worsened and the patient died of respiratory failure 1 year 8 months after the disease onset. A postmortem study revealed severe and circumscribed atrophy in the anterior temporal lobes, and histological examination disclosed marked neuronal loss with many neuronal cytoplasmic inclusions which were immunoreactive for ubiquitin antibodies and phosphorylated TAR DNA-binding protein of 43 kDa (TDP-43) antibodies in hippocampal dentate granule cells and amygdalae, as well as a few neuronal cytoplasmic inclusions without dystrophic neurites in the temporal neocortex. This case report showed typical features of FTLD–MND in clinical course and TDP-43 pathology with unusual severity and distribution of cerebral atrophy, suggesting a unique manifestation of FTLD–MND.