Entraining brain oscillatory activity at alpha frequencies in dementia with Lewy bodies

Abstract

AbstractBackgroundDementia with Lewy bodies (DLB) is characterized by a marked shift of electroencephalographic (EEG) power and dominant rhythm, from the alpha towards the theta frequency range. Transcranial alternate current stimulation (tACS) is a novel non‐invasive brain stimulation technique that allows entrainment of cerebral oscillations at desired frequencies. The objective of the present study was to evaluate safety and efficacy of occipital alpha tACS in DLB patients.MethodWe performed a double‐blind, randomized, sham‐controlled, cross‐over clinical trial in 12 DLB patients. Patients were randomized to receive real (60 minutes of 3 mA peak‐to‐peak stimulation at 12 Hz) or sham stimulation over the occipital cortex (Oz according to the 10‐20 international EEG system). Patients underwent clinical evaluation (clock‐drawing test, trail‐making test part A and B, the quantitative pentagon drawing test subitem), neurophysiological assessment (short‐latency afferent inhibition to evaluate cholinergic circuits) and EEG recordings, at baseline and after real/sham stimulation.ResultOccipital alpha tACS was safe and well tolerated in all patients. We observed a significant increase in clinical performance scores, in neurophysiological measures of cholinergic transmission and in occipital alpha power spectrum density after real stimulation but not sham stimulation.ConclusionOccipital tACS delivered at alpha frequencies may be a novel therapeutic approach in patients with DLB.