Spinal cord neurofibrillary pathology in Alzheimer disease and Guam parkinsonism-dementia complex

We examined spinal cords of neurodegenerative disease patients and controls living on the Island of Guam and in the continental United States. These p atients had pathologically confirmed parkinsonism dementia-complex (PDC) wi th or without amyotrophic lateral sclerosis (ALS), or Alzheimer disease (AD ), respectively. Nearly all of the spinal cords examined from both groups o f patients contained neurofibrillary tangles (NFT). The immunohistochemical profile of these NFTs indicates that they are composed of hyperphosphoryla ted tau protein like their counterparts in the brains of these patients. We stern blot analysis confirmed this by revealing that sarcosyl insoluble tau in spinal cord extracts from patients with NFTs exhibited the presence of all 6 tau isoforms similar to that from AD and ALS/PDC cortical gray matter .