Transcutaneous electrical nerve stimulation (TENS) improves the rest-activity rhythm in midstage Alzheimer's disease

Nightly restlessness in patients with Alzheimer's disease (AD) is probably due to a disorder of circadian rhythms. Transcutaneous electrical nerve stimulation (TENS) was previously reported to increase the strength of coupling of the circadian rest-activity rhythm to Zeitgebers in early stage Alzheimer's disease (AD) patients. It was investigated in the present study whether TENS could also improve the rest-activity rhythm of patients in a midstage. Sixteen patients who met the NINCDS-ADRDA criteria for probable AD, and the stage 6 criteria of the Global Deterioration Scale were treated with TENS or placebo. Rest-activity rhythm was assessed using actigraphy. Compared to the control group, stimulated patients showed an improvement in the rest-activity rhythm of similar magnitude as observed previously in patients in an early stage. II is concluded that TENS increased the coupling between the rest-activity rhythm and supposedly stable Zeitgebers in an advanced stage of AD. (C) 1999 Elsevier Science B.V. All rights reserved.