Nucleus raphe dorsalis in parkinsonism-dementia complex of Guam.

Recently, morphometric analysis has shown that the nucleus raphe dorsalis, which is presumed to project diffuse serotonergic fibers to the telencephalon, is affected in Alzheimer's disease. A similar study was conducted in this report in two patients with parkinsonism-dementia complex of Guam and a Guamanian control. It demonstrated a significant reduction in the number of large neurons, and the presence of abundant Alzheimer's neurofibrillary tangles in this nucleus.