Rapidly progressing dementia with filopodia-like cytoskeletal neuritic anomalies, but without Alzheimer changes.

An unusual case of dementia is reported. The patient was a woman who died at the age of 69 years and 6 months after a two years history of organic dementia. Possibly the disease was familial. Examination of the brain at autopsy revealed no atrophy. In routine histology the brain seemed to be normal. However, when the sections were stained with highly sensitive techniques such as an antibody to phosphorylated Tau (PHF-1), widespread neuritic pathology was discovered. Probably both, axons and dendrites were involved. Only few perikarya were reactive with the antibody. In some of them, morphologic alterations were reminiscent of Pick's disease.