The Effect of 20 Hz versus 1 Hz Repetitive Transcranial Magnetic Stimulation on Motor Dysfunction in Parkinson’s Disease: Which Is More Beneficial?

Abstract

BACKGROUND: There is evidence that both high and low frequency rTMS may have therapeutic effects on motor performance of Parkinson's disease. OBJECTIVE: The aim of the study was to conduct the first direct comparison of the two approaches. METHODS: 52 PD patients were randomly classified into two groups. The first group received 20Hz and the 2 nd group received 1Hz rTMS with a total of 2000 pulses over M1of each hemisphere for ten days. Effects were assessed with the Unified Parkinson's Disease Rating Scale part III (UPDRS), Instrumental Activity of Daily Living (IADL), and a self-assessment score (SA) before, after the last session, and one month later. Cortical excitability was measured before and after the end of sessions. RESULTS: There was a significant improvement on all rating scales after either 1 Hz or 20 Hz rTMS, although but the effect was greaterpersisted for longer at after 20 Hz (treatment X time interaction for UPDRS and IADL (P = 0.075 and 0.04 respectively). Neither treatment affected motor thresholds, but 20 Hz rTMS increased MEP amplitude and the duration of transcallosal inhibition. In an exploratory analysis, Eeach group was subdivided into akinetic-rigid and tremor dominant subgroups and the effects of 1 Hz and 20 Hz treatment recalculated. There is was weak evidence that patients with an akinetic-rigid presentation may respond better than those with predominant tremor. CONCLUSION: Both 20 Hz and 1 Hz rTMS improve motor function in PD, but 20 Hz rTMS is more effective and patients with an akinetic-rigid respond better than predominant tremor.

Transcranial Magnetic Stimulation Promotes Gait Training in Parkinson Disease

“…This reflects a more widespread improvement in bradykinesia, rigidity, and axial symptoms such as posture, gait, and balance. Our findings concur with a recent study that reported 1Hz and 20Hz rTMS improve motor symptoms in PD 37 . We extend previous research by finding that the effects of rTMS‐TT on PD motor symptoms last up to 3 months postintervention 8 .…”

“…Our findings concur with a recent study that reported 1Hz and 20Hz rTMS improve motor symptoms in PD. 37 We extend previous research by finding that the effects of rTMS-TT on PD motor symptoms last up to 3 months postintervention. 8 The interaction between rTMS and treadmill training might induce plastic changes in motor processing within the basal ganglia-thalamocortical circuits 38 and/or restore the efficacy of dopamine transmission, 39 leading to a long-term improvement in motor symptoms.…”

“…One possible explanation would be that 1Hz rTMS also increased baseline activity to gate the induction of subsequent LTP induced in treadmill training. Although this postulation disagrees with the conventional view that high‐frequency rTMS increases excitability and low‐frequency rTMS decreases it, the effects of low‐frequency rTMS on cortical excitability in PD has not been confirmed in previous studies 37,45,46 . Furthermore, the decreased activation of intracortical inhibition pathways in PD may influence the aftereffect of 1Hz rTMS such that an excitatory effect may outweigh the inhibitory effects 47 .…”

“…Although this postulation disagrees with the conventional view that high-frequency rTMS increases excitability and lowfrequency rTMS decreases it, the effects of low-frequency rTMS on cortical excitability in PD has not been confirmed in previous studies. 37,45,46 Furthermore, the decreased activation of intracortical inhibition pathways in PD may influence the aftereffect of 1Hz rTMS such that an excitatory effect may outweigh the inhibitory effects. 47 Another possible explanation would be that both 25Hz and 1Hz rTMS act to increase cortical inhibitory mechanisms and downregulated the corticomotor hyperexcitability in PD.…”

Short-Term Immobilization Promotes a Rapid Loss of Motor Evoked Potentials and Strength That Is Not Rescued by rTMS Treatment

“…Indeed, high-frequency 20 Hz rTMS has been shown to confer significant increases in excitability in the motor pathway to the hand through increasing motor evoked potential (MEP) amplitudes in both healthy populations (Maeda et al, 2000a,b;Gangitano et al, 2002) and individuals with Parkinson's disease (Khedr et al, 2019). Motor excitability appears to be maximally enhanced following 20 Hz rTMS relative to lower frequency rTMS of 10 and 1 Hz (e.g., Jennum et al, 1995;Maeda et al, 2000a).…”