Measurement of severity in advanced Alzheimer's disease.

Abstract

In late stages of dementia of the Alzheimer type (DAT), most scales measuring only cognitive or functional deficits lose their sensitivity to detect further disease progression. By combining ratings of cognitive (speech, eye contact) and functional deficits (dressing, eating, ambulation) with occurrence of pathological symptoms (sleep-wake cycle disturbance, muscle rigidity/contractures), a scale was developed (BANS-S) which does not lose its sensitivity until the patient reaches a vegetative state. BANS-S was tested on three Special Care Dementia Units. Data from 74 patients with the clinical diagnosis of DAT indicated that BANS-S has good reliability and reproducibility. BANS-S scores correlated with scores of Mini-Mental State Examination, Katz ADL, Test for Severe Impairment, and Language Assessment. In 25 patients with the diagnosis of DAT confirmed by autopsy, BANS-S scores determined within 3 months of death correlated with density of neurofibrillary tangles in CA2 and CA3 areas of the hippocampus. BANS-S may be a useful tool for the evaluation of different treatment strategies in severe DAT and for the correlation of clinical and pathological findings.