Transcranial direct current stimulation in the treatment of essential tremor: An open-label study

Introduction: Pharmacotherapy and thalamic stimulation are the most accepted methods used for the treatment of essential tremor (ET). Transcranial direct current stimulation (tDCS) is a noninvasive method for brain stimulation, especially to treat pain, cerebrovascular disease, and depression. tDCS applied to the cerebellar region has been shown to exhibit a modulating effect on the excitability of Purkinje cells and to cause primary motor cortex inhibition through the regulation of synaptic dentato-thalamo-cortical excitability. There is only 1 trial that studied the effect of tDCS on ET with 8 patients, and the results were not satisfactory. Case Series: Six ET patients were administered the Essential Tremor Rating Assessment Scale (TETRAS) and Activities of Daily Living (ADL). We applied tDCS to the dorsolateral prefrontal areas (anode) and to inion (inion at 2 mA for 20 min in 10 consecutive sessions with a 2-d break between the first and the second 5-d sessions). One month after the initial course of therapy, 5 more tDCS sessions were administered in an every-other-day manner. TETRAS and ADL scales were readministered. The Friedman test was used to assess differences in TETRAS scores and ADL over the whole time course. Conclusions: A significant improvement was observed in TETRAS and ADL scores at the end of 50 days (P = 0.015, 0.024). We concluded that although our sample group is small, tDCS might be an alternative therapy for patients with ET.