Dual-task performances can be improved in patients with dementia: a randomized controlled trial.

BACKGROUND Deficits in attention-related cognitive performance measured as dual-task performance represent early markers of dementia and are associated with motor deficits and increased risk of falling. The purpose of this study was to examine the effect of a specific dual-task training in patients with mild to moderate dementia. METHODS Sixty-one geriatric patients with confirmed dementia took part in a 12-week randomized, controlled trial. Subjects in the intervention group (IG) underwent dual-task-based exercise training. The control group (CG) performed unspecific low-intensity exercise. Motor performance (gait speed, cadence, stride length, stride time, single support) and cognitive performance (serial 2 forward calculation [S2], serial 3 backward calculation [S3]) were examined as single and dual tasks. Decrease in performance during dual tasks compared to single task expressed as motor, cognitive, and combined motor/cognitive dual-task cost (DTC) was calculated before and after intervention. Primary outcome was defined as DTC for gait speed under complex S3 conditions. RESULTS Specific training significantly improved dual-task performance under complex S3 conditions compared to the CG (reduction of DTC: gait speed 21.7% IG, 2.6% CG, p < 0.001; other gait variables: 8.7% to 41.1% IG, -0.9% to 8.1% CG, p <or= 0.001 to 0.056; combined motor/cognitive: 20.6% IG, 2.2% CG, p = 0.026). No significant effects were found under less challenging dual-task S2 conditions or for cognitive dual-task S3 performance. CONCLUSIONS The specific exercise program was effective to improve dual-task performance in patients with dementia. CLASSIFICATION OF EVIDENCE This study provides Class II evidence that specific dual-task training improves dual-task performance during walking under complex S3 conditions in geriatric patients with mild to moderate dementia.