Senile plaques and tangles in dialysis dementia.

The brains of 7 patients treated with hemodialysis were studied. Four of these patients had the dialysis encephalopathy syndrome (DES). Senile plaques and or neurofibrillary tangles were found in 5 of the 7 cases, 3 with and 2 without DES. One case of each group had plaques to an extent compatible with that in Alzheimer's disease, though of a different distribution. Neurofibrillary tangles were generally sparse. Plaques and tangles, both containing paired helical filaments, are the principal changes in Alzheimer's disease. Aluminum has been implicated as a possible etiologic agent behind the paired helical filaments in Alzheimer's disease, where raised cerebral aluminum contents have been demonstrated. Aluminum is known to be increased in the central nervous system also in DES, most likely as a consequence of procedures in connection with the hemodialysis. The finding of neurofibrillary tangles and senile plaques in hemodialyzed patients, some of which have developed DES, may therefore support the theories concerning aluminum as an etiological agent for cerebral changes in Alzheimer's disease.