CORTICAL PLASTICITY INVESTIGATED WITH TRANSCRANIAL MAGNETIC STIMULATION TECHNIQUES IN PATIENTS WITH MOVEMENT DISORDERS”

This thesis have been designed, performed or completed during the period between 2010 to 2013 in the Department of Neurology and Psychiatry, Sapienza University of Rome, Italy, (supervised by Prof. Alfredo Berardelli). The main focus of this thesis is the investigation of mechanisms of Long-Term potentiation and Long-Term depression (LTP)/(LTD)-like plasticity in primary motor cortex (M1) with repetitive transcranial magnetic stimulation (rTMS) techniques such as Theta Bursts Stimulation (TBS) in patients with different types of movement disorders including Focal Hand Dystonia (FHD) and Multiple System Atrophy (MSA). Section 1 will introduce the general knowledge and biophysical principles of Transcranial Magnetic Stimulation (TMS). Section 2 will report two studies investigating abnormalities of LTP/LTD-like plasticity in M1 in patients with FHD and MSA. The first study (Suppa A, Marsili L, Di Stasio F, Latorre A, Parvez AK, Colosimo C, Berardelli A.) is mainly focused on cortical plasticity and motor learning in patients with FHD. This study showed that patients with FHD are characterized by altered cortical plasticity in M1. In addition, in FHD patients, motor execution of simple finger movements is abnormal and characterized by reducing movement speed and altered early motor learning. The second study (Belvisi D, Suppa A, Marsili L, Di Stasio F, Parvez AK, Agostino R, Fabbrini G, Berardelli A.) focused on cortical plasticity in patients with MSA. This study showed reduced LTP/LTD-like plasticity in MSA patients reflecting abnormalities in the cortico-basal ganglia-thalamo-cortical motor circuit.