Parkinson’s disease (PD) is a neurodegenerative disorder linked to the neurophysiological changes in dopaminergic neurons of basal ganglia (BG). Multiple studies have shown the integrative role of BG in sensory and motor processes and confirmed the involvement of these nuclei in cognitive domains such as processing multisensory information, habit learning, coordination, balance, posture and gait. These studies also took advantage of the frequency-specific oscillatory brain rhythms (OBRs) detected on the electroencephalogram (EEG) as potential biomarkers, signalling change in various neural networks. The periodicity and temporal nature of the OBRs are well-known phenomena that are thought to govern time-dependent processes in BG, cerebellum and the frontal cortices. EEG studies have shown that neural oscillations are not only generated in the absence of external influence but could change their synchronicity as the exogenous cues change. This bidirectional property is a vital feature of our day to day interaction with the environment which helps us change behaviour accordingly and plays an important role in inter/intra neural network communication, motor and cognitive processes. Here we examined the oscillatory changes before and after amelioration of motor and non-motor symptoms in patients with Parkinson’s disease, after pharmacotherapy and neurorehabilitation and provided evidence for the putative role of these frequency-specific OBRs as the potential biomarkers in order to quantify network-dependent cognitive and motor changes in PD, and to utilize these biomarkers to develop targeted therapy options for this patient population.
Keywords: Oscillatory Brain Rhythms, Alpha Oscillations, EEG, Parkinson’s Disease, Chemical Entrainment.