Semantic dementia with ubiquitin-positive tau-negative inclusion bodies

Three cases are reported with dementia and ubiquitin-positive but tau-negat ive inclusion bodies. All patients had a semantic dementia and the clinical details of two of these have been published as the first description of a selective semantic memory impairment. The original diagnosis had been of Pi ck's disease based on frontotemporal atrophy, but re-examination has reveal ed ubiquitin-positive but tau-negative inclusions as well as neurites in th e frontotemporal cortices and ubiquitin-positive, intracytoplasmic inclusio ns in the granule cells of the dentate fascia, These inclusions are identic al to those reported in association with amyotrophic lateral sclerosis (mot or neuron disease), but none were seen in brainstem or spinal cord motor ne urons.