Effects of spaced retrieval training (SRT) on cognitive function in Alzheimer's disease (AD) patients

Among the non-pharmacological treatments of dementia, SRT is a good candidate strategy for rehabilitating the cognition of AD patients. This study investigates the efficacy of SRT on the cognition of AD patients with very mild to mild disease. We administered 24-session SRT to 13 very mild and 6 mild AD patients. To assess the change of the neuropsychological performance after SRT, we performed the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery (CERAD-K), the logical memory test (LMT), the Benton visual retention test A (BVRT-A), and the digit span test (DST). All tests were administered both before and after SRT. Retention spans were significantly increased up to 24 min after SRT in both very mild and mild AD patients (p<0.05), and this improvement was maintained for different sets of target information. Retainable words were also significantly increased after SRT in the very mild AD patients (p=0.007). However, we observed no changes in neuropsychological performance after SRT. Although we did not observe improvements in the neuropsychological tests following SRT, our results suggest that the treatment was an effective intervention for improving the memory of very mild to mild AD patients, and could potentially improve learning and retention outside the training session.