Effect of a single session of transcranial pulse stimulation (TPS) on resting tremor in patients with Parkinson's disease

Introduction: Tremor is a common symptom in movement disorders and is evident at rest in Parkinson's Disease (PD). In PD, tremor may be responsive to brain stimulation, ranging from Deep Brain Stimulation to Transcranial Magnetic Stimulation. Transcranial Pulse Stimulation (TPS) is a novel/painless/non-invasive technique which appears to induce biomolecular changes through shock waves. Here, as one of the first studies in the field of PD, we exploratively investigate the possibility to observe changes in tremor, induced by single-session TPS delivered on the motor cortex of PD patients. Methods: TPS was delivered in 16 patients. Of these, 9 were admitted to sham (placebo). Resting tremor was measured at baseline (T0), after TPS (T1), and after 24 h from intervention (T2). Results: At baseline, tremor was always present. After TPS, tremor reduction was noted at T1 and T2 (compared to T0 and placebo). We noted a decrease in the amplitude of resting tremor (not its frequency). Discussion: TPS is a non-invasive technique that may be a novel solution for reducing tremor in PD, lasting at least 24 h after single-sessions. No side effects were reported. We discuss evidence suggesting potential physiological changes in mechanisms of neural circuits that are affected in PD.