Validation of a brief screening scale evaluating praxic abilities for use in memory clinics. Evaluation in 419 controls, 127 mild cognitive impairment and 320 demented patients

The aim of this study was to build a brief clinical scale evaluating praxic abilities of the upper limbs for use in memory clinics and to produce norms. The scale includes three subtests: symbolic gestures (five gestures), pantomimes (five gestures) and imitation of meaningless gestures (eight gestures). Data were collected in a sample of 419 normal subjects. Sensitivity and specificity were established from their comparison to data collected from 320 demented patients. A group of 127 patients with mild cognitive impairment was also studied. Cut-off scores were proposed based on the fifth percentile observed in three classes of age and three levels of education. The specificity was high. Sensitivity was higher for imitation of meaningless gestures than for pantomimes and the least for symbolic gestures. The group of patients with mild cognitive impairment was half-way between demented patients and normal subjects. The proposed scale meets its initial aims of brevity and high specificity. It can easily be used in memory clinics and identifies apraxia in dementia patients. It therefore usefully contributes to clinical diagnosis.