Personalized transcranial alternating current stimulation (tACS) and physical therapy to treat motor and cognitive symptoms in Parkinson's disease: A randomized cross-over trial

Abstract

Abnormal cortical oscillations are markers of Parkinson's Disease (PD). Transcranial alternating current stimulation (tACS) can modulate brain oscillations and possibly impact on behaviour. Mapping of cortical activity (prevalent oscillatory frequency and topographic scalp distribution) may provide a personalized neurotherapeutic target and guide non-invasive brain stimulation. This is a cross-over, double blinded, randomized trial. Electroencephalogram (EEG) from participants with PD referred to Specialist Clinic, University Hospital, were recorded. TACS frequency and electrode position were individually defined based on statistical comparison of EEG power spectra maps with normative data from our laboratory. Stimulation frequency was set according to the EEG band displaying higher power spectra (with beta excess on EEG map, tACS was set at 4 Hz; with theta excess, tACS was set at 30 Hz). Participants were randomized to tACS or random noise stimulation (RNS), 5 days/week for 2-weeks followed by ad hoc physical therapy. EEG, motor (Unified Parkinson's Disease Rating Scale-motor: UPDRS III), neuropsychological (frontal, executive and memory tests) performance and mood were measured before (T 0 ), after (T 1 ) and 4-weeks after treatment (T 2 ). A linear model with random effects and Wilcoxon test were used to detect differences. Main results include a reduction of beta rhythm in theta-tACS vs. RNS group at T 1 over right sensorimotor area ( p = .014) and left parietal area ( p = .010) and at T 2 over right sensorimotor area ( p = .004) and left frontal area ( p = .039). Bradykinesia items improved at T 1 ( p = .002) and T 2 ( p = .047) compared to T 0 in the tACS group. In the tACS group the Montréal Cognitive Assessment (MoCA) improved at T 2 compared with T 1 ( p = .049). Individualized tACS in PD improves motor and cognitive performance. These changes are associated with a reduction of excessive fast EEG oscillations.

Effects of interactive video-game–based exercise on balance in older adults with mild-to-moderate Parkinson’s disease

“…Outcomes measured at the end of 6 and 12 weeks were compared between the groups. The crossover design decreased the variability between groups, because the same patients served as the controls and experimental subjects during different time periods as previously described [ 26 ].

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Non-invasive Transcranial Electrical Stimulation in Movement Disorders

“…Huntington's disease (cognitive dysfunction) (Eddy et al, 2017) Transcranial alternating current stimulation 1. Parkinson's disease (motor and cognitive) (Brittain et al, 2013;Krause et al, 2013;Del Felice et al, 2019) 2. Enhanced physiological tremor (Mehta et al, 2014;Ahmad et al, 2018) 3.…”

“…An improvement in motor and cognitive performance in PD was noted with individualized tACS and physiotherapy, where the frequency of tACS was set according to the higher-power spectra band in the electroencephalograph (EEG; 4 Hz tACS if beta excess on EEG map; 30 Hz tACS if theta excess, 5 days/week for 2 weeks) (Del Felice et al, 2019). Brittain et al (2013) have studied the role of tACS in suppressing rest tremor in 12 PD patients by applying a phase cancellation technique.…”

Individual Targeting Increases Control Over Inter-Individual Variability in Simulated Transcranial Electric Fields

“…Furthermore, individually targeted tES has only been described occasionally, for example in a small sample of stroke patients [22]. Other groups defined the stimulation montage based on the topographical EEG voltage distribution in patients with Parkinson's disease [43]. This approach was previously termed naive reciprocity, as it neglects volume conduction effects for the inverse definition of the stimulation montage [36].…”