rTMS effects on levodopa induced dyskinesias in Parkinson's disease patients: Searching for effective cortical targets

Issue title: Brain Stimulation and Brain Repair – rTMS

Article type: Research Article

Authors: Koch, Giacomo^;

Affiliations: Laboratorio di Neurologia Clinica e Comportamentale, Fondazione Santa Lucia IRCCS, Rome, Italy | Stroke Unit, Dipartimento di Neuroscienze, Policlinico Tor Vergata, Rome, Italy

Note: [] Corresponding author: Giacomo Koch, Laboratorio di Neurologia Clinica e Comportamentale Fondazione Santa Lucia, IRCCS Via Ardeatina 306 00179 Roma, Italy. Tel./Fax: +39 0651501388; E-mail: [email protected]

Abstract: Long-term therapy with levodopa and dopamine agonists in Parkinson's disease (PD) patients is complicated by the development of fluctuations in motor response, such as levo-dopa induced dyskinesia (LID). Repetitive Transcranial Magnetic Stimulation (rTMS) has been recently put forward as a possible therapeutic tool able to LID in PD. Trains of 1 Hz rTMS applied either over the supplementary motor area (SMA) or the primary motor cortex (M1) were able to induce a transient reduction in the severity of LID, confirming that an over-activity of these areas plays a crucial role in the pathophysiology of LID. However, repeated sessions of rTMS were not effective in inducing persistent beneficial clinical effects. Functional or metabolic changes have been reported in the cerebellum in studies in PD patients treated with procedures known to alleviate LID, such as deep brain stimulation. Therefore, the effects of rTMS applied over the lateral cerebellum has been recently tested in patients with LID. A two-week course of bilateral cerebellar rTMS induced persistent clinical beneficial effects, reducing peak-dose LID for up to four weeks after the end of the daily stimulation period. These findings demonstrate that rTMS is a potential tool in individuating the best cortical targets and the optimal parameters of stimulation able to improve LID in dyskinetic PD patients.

DOI: 10.3233/RNN-2010-0556

Journal: Restorative Neurology and Neuroscience, vol. 28, no. 4, pp. 561-568, 2010