M P Lomarev1, D Y Kim, S Pirio Richardson, B Voller, M Hallett. 1. Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, NIH Building 10, Room 5N240, 10 Center Dr MSC 1428, Bethesda, MD 20892-1428, USA. lomarevm@ninds.nih.gov
Abstract
OBJECTIVE: Repetitive transcranial magnetic stimulation (rTMS) is a potential therapeutic tool to rehabilitate chronic stroke patients. In this study, the safety of high-frequency rTMS in stroke was investigated (Phase I). METHODS: The safety of 20 and 25 Hz rTMS over the motor cortex (MC) of the affected hemisphere, with intensities of 110-130% of the motor threshold (MT), was evaluated using surface electromyography (EMG) of hand and arm muscles. RESULTS: Brief EMG bursts, possibly representing peripheral manifestations of after discharges, and spread of excitation to proximal muscles are considered to be associated with a high risk of seizure occurrence. These events were recorded after the rTMS trains. Neither increased MC excitability nor improved pinch force dynamometry was found after rTMS. CONCLUSIONS: Stimulation parameters for rTMS, which are safe for healthy volunteers, may lead to a higher risk for seizure occurrence in chronic stroke patients. SIGNIFICANCE: rTMS at rates of 20 and 25 Hz using above threshold stimulation potentially increases the risk of seizures in patients with chronic stroke.
OBJECTIVE: Repetitive transcranial magnetic stimulation (rTMS) is a potential therapeutic tool to rehabilitate chronic strokepatients. In this study, the safety of high-frequency rTMS in stroke was investigated (Phase I). METHODS: The safety of 20 and 25 Hz rTMS over the motor cortex (MC) of the affected hemisphere, with intensities of 110-130% of the motor threshold (MT), was evaluated using surface electromyography (EMG) of hand and arm muscles. RESULTS: Brief EMG bursts, possibly representing peripheral manifestations of after discharges, and spread of excitation to proximal muscles are considered to be associated with a high risk of seizure occurrence. These events were recorded after the rTMS trains. Neither increased MC excitability nor improved pinch force dynamometry was found after rTMS. CONCLUSIONS: Stimulation parameters for rTMS, which are safe for healthy volunteers, may lead to a higher risk for seizure occurrence in chronic strokepatients. SIGNIFICANCE: rTMS at rates of 20 and 25 Hz using above threshold stimulation potentially increases the risk of seizures in patients with chronic stroke.
Authors: Giovanni Di Pino; Giovanni Pellegrino; Giovanni Assenza; Fioravante Capone; Florinda Ferreri; Domenico Formica; Federico Ranieri; Mario Tombini; Ulf Ziemann; John C Rothwell; Vincenzo Di Lazzaro Journal: Nat Rev Neurol Date: 2014-09-09 Impact factor: 42.937
Authors: David H Benninger; Mikhail Lomarev; Eric M Wassermann; Grisel Lopez; Elise Houdayer; Rebecca E Fasano; Nguyet Dang; Mark Hallett Journal: Clin Neurophysiol Date: 2009-03-14 Impact factor: 3.708
Authors: Nuray Yozbatiran; Miguel Alonso-Alonso; Jill See; Asli Demirtas-Tatlidede; Daniel Luu; Rehan R Motiwala; Alvaro Pascual-Leone; Steven C Cramer Journal: Stroke Date: 2008-10-09 Impact factor: 7.914