[Peripheral nerve stimulation in Alzheimer's disease]

The "use it or lose it' concept implies that stimulation of neurons might stop degenerative activities and initiate regenerative processes in aging and Alzheimer's disease (AD). Based on this concept, the effects of Transcutaneous Electrical Nerve Stimulation (TENS), tactile stimulation, and a combination of the two on memory and affective behaviour of AD patients were examined. The results suggest that, compared to AD patients of the control group, patients of the experimental group improved in visual short-term memory, verbal and visual long-term memory, and verbal fluency. Moreover, stimulated AD patients participated more independently in activities of daily life and their affective behaviour improved. As in those studies the therapist was present during the peripheral stimulation of the experimental group and the sham stimulation of the control group, interpersonal communication alone could not explain the treatment effects. However, a positive effect of the combination of TENS with personal interpersonal communication could not be excluded. Consequently, it was examined whether TENS, in the absence of the therapist, could also have a beneficial influence on the cognitive and behavioural functioning of AD patients. In addition, it was investigated whether TENS had a positive effect on the rest-activity rhythm of AD-patients. The results show that improvements in visual short- and long-term memory, verbal long-term memory, and verbal fluency are solely due to the peripheral stimulus itself. Furthermore, the independent and affective functioning of both the experimental and control group appeared to relatively improve by interpersonal communication. Moreover, the rest-activity rhythm of stimulated AD-patients improved. Peripheral nerve stimulation in AD might thus become a new treatment strategy to improve patients' quality of life.