Measurement of Severity in Advanced Alzheimer's Disease

Abstract

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.