Transcranial Pulsed Current Stimulation (tPCS) in Parkinson's Disease: A Pilot Trial.

Background: Noninvasive stimulation techniques are a promising therapy due to the ease of administration and minimal side effects. We investigated the clinical, electrophysiological and side effects of transcranial pulsed current stimulation (tPCS) in patients with Parkinson's disease (PD).

Materials and methods: Ten PD patients were called at monthly intervals in the OFF levodopa state. Patients received active tPCS for 20 minutes in the first visit and sham stimulation for 20 minutes in the second and were assessed for the levodopa response in the third. Clinical and bradykinesia scoring and gait and tremor analysis were done before and after stimulation/sham/levodopa in each visit. Scalp electroencephalography (EEG) was recorded for quantitative analysis during each visit. The interventions were compared between pre- and post-intervention.

Results: A significant improvement with levodopa as compared to active and sham tPCS was seen in clinical scores. Upper limb postural tremor severity (z-score = -2.410, p = 0.016) and the stride velocity variability during post active stimulation improved by 20.7% compared to post sham stimulation though the difference was statistically non-significant. KINARM testing showed a statistically significant difference in the reaction time (p = 0.036) when comparing pre- and post-tPCS active stimulation. EEG recording showed a transitory increase of electrical activity after tPCS, with the most significant increase seen in alpha bandpower (p = 7.95*10^-07; z score: -4.93).

Conclusions: tPCS was well tolerated in all patients. With minimal side effects, ease of administration and mild improvement in the electrophysiological parameters assessed, tPCS can be an alternative therapeutic option in patients with PD.