Intraneuronal polyglucosan bodies and peculiar inclusions in the midbrain-tegmentum of the aged.

A small number of intraneuronal polyglucosan bodies, the so-called Lafora bodies, is occasionally found in the tegmental areas of the midbrain in aged cases with no metabolic or degenerative diseases. The occasional appearance of peculiar bodies, which Kato et al. (1982) reported in a case of presenile dementia, is also observed during the examination of the inclusions. The ultrastructure of the bodies reveals an amorphous, electron-dense central core and a peripheral zone of radially oriented 100 A wide filaments.