Treatment and Physiology in Parkinson’s Disease and Dystonia: Using Transcranial Magnetic Stimulation to Uncover the Mechanisms of Action

Abstract

Transcranial magnetic stimulation (TMS) has served as an important technological breakthrough in the field of movement disorders physiology over the last three decades. TMS has grown popular due to the ease of application as well as its painless and noninvasive character. The technique has shed important insights into understanding the pathophysiology of movement disorders particularly Parkinson’s disease and dystonia. The basic applications have included the study of motor cortex excitability, functioning of excitatory and inhibitory circuits, study of interactions between sensory and motor systems, and the plasticity response of the brain. TMS has also made important contributions in understanding response to treatments such as the dopaminergic medications, botulinium toxin injections and deep brain stimulation surgery. This review summarizes the knowledge gained to date with TMS in Parkinson’s disease and dystonia and highlights the current challenges in utilization of TMS technology.

Non‐invasive brain stimulation for dystonia: therapeutic implications

“…These neuromodulatory techniques are applied non‐invasively over the scalp (Fig. ) and hence avoid the possible complications associated with DBS surgery and the side effects of systemic medications . Theoretically, both can be applied over selected cortical regions to modulate the specific cortical–subcortical network that is supposedly linked with a given subset of symptoms.…”

“…The putative pathophysiological mechanisms of dystonia have been exploited for the development of non‐invasive brain stimulation (NIBS) techniques. These would be able to induce plastic changes in one or more nodes of the altered network and possibly reverse the aforementioned abnormalities . The concept of neuromodulation holds onto the hope of translating such NIBS techniques into novel therapeutic strategies for dystonia .…”

“…These would be able to induce plastic changes in one or more nodes of the altered network and possibly reverse the aforementioned abnormalities . The concept of neuromodulation holds onto the hope of translating such NIBS techniques into novel therapeutic strategies for dystonia . Two other review articles have been previously produced about the therapeutic use of NIBS in dystonia, but both focused on patients with FHD only.…”

Physiological effects of subthalamic nucleus deep brain stimulation surgery in cervical dystonia

“…Transcranial magnetic stimulation (TMS) studies in dystonia have identified an abnormal sensorimotor integration, an excessive sensorimotor plasticity and an increased motor cortex excitability as key pathophysiological features 4. Short and long latency afferent inhibition (SAI and LAI) are effective TMS measures for examination of sensorimotor integration.…”

Repetitive Transcranial Magnetic Stimulation (rTMS) Therapy in Parkinson Disease: A Meta‐Analysis

“…Transcranial magnetic stimulation (TMS) is a painless, noninvasive, well‐tolerated technique of brain stimulation based on the theory of electromagnetic induction [5]. rTMS is the repetitious application of TMS pulses over a predefined target with ability to modulate the excitability of the brain and therefore serve a therapeutic role in control of PD symptoms.…”