Alpha tACS in Dementia With Lewy Bodies

Brain oscillations are ubiquitous in the human brain and have been implicated in cognitive and behavioral states defined in precisely tuned neural networks. In neurodegenerative disorders, neurodegeneration is accompanied by changes in oscillatory activity leading to the emerging concept of neurological and psychiatric disorders as "oscillopathies". Dementia with Lewy bodies (DLB), which is the second most frequent cause of neurodegenerative dementia, is characterized by an important alteration of brain oscillations. The restoration of oscillations by neuronal entrainment in animal models of neurodegenerative disease has shown a significant reduction in the neuropathological load of toxic proteins, with a consequent significant increase in cognitive performance. Transcranial alternating current brain stimulation (tACS), is a neurophysiological method of non-invasive modulation of the excitability of the central nervous system that is having an increasingly numerous spectrum of potential therapeutic applications. Recent studies have demonstrated the effectiveness of this method in modulating the natural frequencies of cerebral oscillation, underlying multiple cognitive processes such as verbal memory, perception and working memory. On the basis of these premises, the treatment with alpha tACS is proposed in patients with DLB. In this randomized, double-blind, sham-controlled, cross-over study, the investigators will evaluate whether a single stimulation with alpha tACS on the occipital lobes can improve symptoms in patients with DLB. Subjects will be randomized in two groups, one receiving a single treatment with alpha tACS (12 Hz) first and the other receiving sham stimulation. After one week the treatments will be exchanged. Patients will be evaluated with neuropsychological tests and neurophysiological measures of cholinergic transmission.