Atypical late-onset dementia characterized by limbic degeneration with coiled bodies and argyrophilic threads

This report concerns an autopsy case of late-onset dementia with atypical neuropathological features. The patient was a Japanese man who was 83 years old at the age of death. At 73 years, he developed behavioral disorders, including emotional changes, and dementia. He died at the age of 83. A neuropathological study revealed largely confined involvement of the limbic regions, characterized by degeneration consisting of neuronal loss with a spongy state and gliosis. Massive tau-positive oligodendroglial coiled bodies and argyrophilic threads were also observed mainly in these regions. Although the clinicopathological findings of the present case showed some similarities to those of a unique subtype of frontotemporal dementia, including mesolimbocortical dementia, argyrophilic grain disease, corticobasal degeneration and dementia with tangles, there seems to be no suitable category of neurodegenerative disease into which our case can be classified. Further study is needed to determine whether the present case could be classified as an atypical case of these diseases or represents a new entity.