The Neglected Half of Alzheimer Disease: Cognitive and Functional Concomitants of Severe Dementia

Abstract

OBJECTIVE: Traditional mental status and psychometric assessments bottom out in the late stages of Alzheimer disease (AD). A method adapted from cognitive testing in infants, the Ordinal Scales of Psychological Development was modified (M-OSPD) and applied to a severely demented population. The concurrent validity of this method was tested in comparison with Functional Assessment Staging (FAST). Internal consistency as a measure for reliability was also determined. DESIGN: Cross sectional study. SETTING: Subjects were generally evaluated in their residence, usually a nursing home or a private home. PATIENTS: Severely cognitively impaired subjects who fulfilled criteria for probable AD were studied. MEASUREMENTS: Evaluation consisted of clinical global, mental status, functional, and cognitive assessments including the Global Deterioration Scale (GDS) and the Mini-Mental State Examination (MMSE). RESULTS: Seventy patients were evaluated. Traditional mental status assessments (eg, the MMSE) manifested virtually uniform bottom scores in all GDS stage 7 subjects (n = 46), and GDS stage 6 subjects had MMSE scores within one standard deviation unit of zero. In contrast, the M-OSPD scale continued to show results in the last stages of the disease. The Spearman correlation coefficient between the M-OSPD total score and the 11 FAST substages represented in this sample was -0.77 (P < 0.001). CONCLUSIONS: The results indicate that patients who are functionally more impaired also show continuing increments in cognitive loss. These cognitive and functional assessments for measuring the magnitude of deterioration in AD can be applied to the estimated half-million nursing home residents presently labeled "untestable" with the goal of optimization of care and residual capacities.