Therapeutic effect of repetitive transcranial magnetic stimulation on motor function in Parkinson's disease patients

Abstract

Cortical excitability of the primary motor cortex is altered in patients with Parkinson's disease (PD). Therefore, modulation of cortical excitability by high frequency repetitive transcranial magnetic stimulation (rTMS) of the motor cortex might result in beneficial effects on motor functions in PD. The present study aims to evaluate the effect of rTMS of the motor cortex on motor functions in patients with PD. Thirty-six unmedicated PD patients were included consecutively in this study. The patients were assigned in a randomized pattern to one of two groups, one group receiving real-rTMS (suprathreshold 5-Hz, 2000 pulses once a day for 10 consecutive days) and the second group receiving sham-rTMS using closed envelopes. Total motor section of Unified Parkinson's Disease Rating Scale (UPDRS), walking speed, and self-assessment scale were performed for each patient before rTMS and after the first, fifth, 10th sessions, and then after 1 month. Evaluation of these measures was performed blindly without knowing the type of rTMS. anova for repeated measurements revealed a significant time effect for the total motor UPDRS, walking speed and self-assessment scale during the course of the study in the group of patients receiving real-rTMS (P = 0.0001, 0.001, and 0.002), while no significant changes were observed in the group receiving sham-rTMS except in self-assessment scale (P = 0.019). A 10-day course of real-rTMS resulted in statistically significant long-term improvement of the motor functions in comparison with the sham-rTMS. The rTMS could have a therapeutic role of for PD patients.

Transcranial magnetic stimulation and brain atrophy: a computer-based human brain model study

“…When this current is applied repetitively, repetitive transcranial magnetic stimulation (rTMS), it can modulate cortical excitability, decreasing or increasing it, depending on the parameters of stimulation. Since its inception, researchers have proposed the use of TMS and rTMS to study and treat neuropsychiatric diseases, such as major depression George et al 2000;Martin et al 2003;Holtzheimer et al 2004;Rumi et al 2005), schizophrenia (Hoffman et al 2003;Lee et al 2005), Parkinson's disease (Mally and Stone 1999;de Groot et al 2001;Khedr et al 2003;Fregni et al 2004;Lefaucheur et al 2004), dystonia (Huang et al 2004), epilepsy (Tergau et al 1999;Menkes and Gruenthal 2000;Daniele et al 2003;Fregni et al 2005) and the acute or chronic sequels derived from stroke ). However, a fundamental question that needs to be addressed before the wide-spread use of TMS in clinical practice, is how the modification of brain anatomy and tissue properties caused by certain neuropsychiatric diseases can alter the effects of TMS.…”

Transcranial Magnetic Stimulation Treatment for Motor Symptoms in Parkinson’s Disease: A Review of Two Decades of Studies

“…Nevertheless, the magnitude of effects varied significantly across studies, probably due to the heterogeneity between stimulation protocols (in terms of frequency, intensity, duration) and targeted regions. Moreover, many studies were not sham-controlled and for sham-controlled studies, different methods of sham stimulation have been used: tilted [33,37,54,56,60,62], sham [39,47,63] and inactive coils [50,66,68] have been used, as well as occipital stimulation [40,49,61], coil back surface [41] and realistic sham [51,57,58]. A very recent review [69] examined 20 RCTs of rTMS treatment for motor dysfunction in PD to evaluate the efficacy of treatment and identify protocols factors that moderate the effects of treatment.…”

“…Nine studies [32][33][34]39,45,52,54,55,63] tested the effects of only one rTMS session, while the remaining administered a higher number of sessions, ranging from 2 to 20. Most studies, especially those targeting M1, SMA and DLPFC, administered high-frequency stimulation (24 of 40 studies) [29][30][31][32][33][34][37][38][40][41][42][43][44][49][50][51][53][54][55][57][58][60][61][62], while lowfrequency stimulation was employed primarily in studies targeting other regions. The intensity of stimulation ranged from 20% of motor threshold to 120%.…”

“…Sample sizes were generally under 30 subjects, except for five studies [36,40,57,58,64]. In regard to outcome measures, the Unified Parkinson's Disease Rating Scale -Section III (UPDRS-III) was the most employed measure (33 of 40 studies) [32][33][34][36][37][38][39][40][41][42][43][44][47][48][49][50][51][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68], yet some studies employed other motor function measures such as movement and reaction time [29,30,35], Grooved Pegboard test for fine movement [31], pointing, pronation supination, Purdue Pegboard Test [45], movement frequency [46] and gait kinematics [52].…”

Non-invasive brain stimulation for Parkinson’s disease: Current concepts and outlook 2015

“…Repeated 25 Hz rTMS of M1 (Khedr, Rothwell, Shawky, Ahmed, & Hamdy, 2006) and combined M1 and DLPFC (M. P. Lomarev et al, 2006), suprathreshold 5 Hz rTMS (120% RMT, 10 sessions) of M1 (Khedr, Farweez, & Islam, 2003) and of SMA (at 110% AMT) (Hamada, Ugawa, Tsuji, & Effectiveness of rTms on Parkinson's Disease Study Group, 2008), and anodal tDCS of motor and prefrontal cortices (Benninger et al, 2010), have shown the strongest therapeutic efficacy. In contrast, iTBS of M1 and DLPFC (Benninger et al, 2011), and 0.2 Hz rTMS (110% RMT) (Okabe, Ugawa, Kanazawa, & Group, 2003) and 50 Hz rTMS (80% AMT) (Benninger et al, 2012) of M1, all failed to improve motor symptoms.…”