Abnormal resting state EEG and vigilance in neurodegenerative dementias

Background Alzheimer’s disease dementia (ADD) is the most common neurodegenerative dementing disorder explaining about 60-70% of 50 million patients worldwide (www.who.int). Dementia with Lewy Bodies (DLB) another diffuse inducing abnormalities in vigilance (visual hallucinations, cognitive fluctuations, and REM sleep behavior disorder). These may be reflected reduction amplitude (“reactivity”) resting-state EEG (rsEEG) alpha rhythms (7-9 Hz) posterior cortical areas from eye-closed to -open conditions. Indeed, this “reactivity” probes cholinergic inputs basal forebrain thalamocortical mechanisms regulating vigilance. The present study tested such a hypothesis. Method Clinical rsEEG demographic- age-matched AD (N = 48), DLB 42), healthy cognitively unimpaired (Nold, N 38) persons were enrolled. Pathological groups matched as status (i.e., grade). eLORETA freeware estimated sources on individual basis. Result There was substantial (> -10%) source activities eyes-closed eyes-open condition 93% Nold seniors, 77% ADD patients, 64% patients. In these participants, there less reactivity than group. Furthermore, occipital group (p < 0.05 corrected; Figure 1). Conclusion novel results suggest that neurophysiological oscillatory arousal visual system during changes more abnormal dementia, possibly concurring misperceptions, fluctuations reported function functional connectivity areas. many suffer pathological transition “reactive” eye-opening “unreactive” theta becoming dominant background frequency. Importantly, erroneously considered “alpha” if those not both -opening