"Weekly sessions of noninvasive repetitive transcranial magnetic stimulation provided sufficient longterm pain relief in  percent of patients with central poststroke pain and delivered longterm relief for patients who continued for one year according to a study presented at the International Neuromodulation Society th World Congress by Masahito Kobayashi MD PhD of the Department of Neurosurgery Saitama Medical University  Department of Neurology Institute of Brain and Blood Vessels Mihara Memorial Hospital in Saitama Japan. Of  patients in the openlabel series  patients achieved satisfactorytoexcellent pain relief. Pain relief was sustained in six patients who continued treatment for one year. All patients received repetitive transcranial magnetic stimulation rTMS to their primary motor cortex once a week for at least  weeks.  Satisfactory relief was considered a    percent reduction in pain scores  patients and excellent relief pain reduction of  percent or more  patients. Overall  patients who had severe strokecaused dysesthesias such as uncomfortable numbness or prickling experienced less relief than patients without severe dysesthesias suggesting possible neural circuit damage was inhibiting response to treatment.  The study participants had all been treated medically after a blood clot or bleed in one side of the brain unilateral ischemic or hemorrhagic stroke. Several weeks into their recovery they had begun to experience severe hand or leg pain as a consequence of brain damage from the stroke. Such central poststroke pain can be extremely disabling and difficult to treat impacting general functioning mood and overall quality of life. Since the s Japan has been an active center of research into the study of electrical motor cortex stimulation EMCS to treat poststroke pain using surgically implanted devices. The study reported at the INS th World Congress builds on observations that electrical motor cortex stimulations effectiveness in relieving central poststroke pain can be predicted by rTMS suggesting the techniques share similar painrelief mechanisms.  However Kobayashi and colleagues point out in their peerreviewed online publication of this study Repetitive Transcranial Magnetic Stimulation Once a Week Induces Sustainable LongTerm Relief of Central Poststroke Pain Neuromodulation Technology at the Neural Interface httponlinelibrary.wiley.comdoi.ner.abstract April   https that there has still been controversy about the efficacy of rTMS in poststroke pain. Kobayashi said in comparison to EMCS his impression is rTMS efficacy seemed almost the same without requiring surgery. In  a review https suggested that there is probable efficacy a level A recommendation for shortterm rTMS treatment of neuropathic pain including central poststroke pain but did not speak to longterm efficacy.  Since pain relief from rTMS increases a few days after treatment weekly treatment sessions were selected to try to sustain pain relief at treatment intervals that could be maintained on an outpatient basis.  Kobayashi believes neurologists would especially have an interest in this method which is also attractive due to its low sideeffect profile. None of the  patients reported any serious side effects from weekly sessions of  trains of second Hz rTMS at  percent of the active motor threshold. Two patients reported transient slight scalp discomfort after rTMS. In addition to the potential of rTMS in pain relief there has been growing research into noninvasive stimulation to augment progress in physical rehabilitation soon after stroke. It is believed that the stimulation aids in plasticity the ability of the brain to gradually form new neural connections to take on functions previously performed by damaged areas. A first phase of the study assessed whether rTMS had a treatment effect on pain. In it the research team randomly assigned six patients to receive either sham or active rTMS one week and the other treatment the next measuring pain scores before and after each session. Once that phase had shown that rTMS did reduce the patients pain an openlabel treatment phase began. In this second phase the  patients underwent  weekly rTMS sessions. The patients pain scores were measured just before each weekly session.  Data were collected for eight years ending in . Kobayashi said that some patients really hoped to continue rTMS after the study because their pain worsened after rTMS treatment sessions were over and almost all the patients said that after the study ended their pain increased to the level before rTMS.  He added that the remaining question to answer is whether the level of the patients severe uncontrollable pain would continue to decrease if rTMS continued for several years.  https Kobayashi M. Fujimaki T. Mihara B. and Ohira T.  Repetitive Transcranial Magnetic Stimulation Once a Week Induces Sustainable LongTerm Relief of Central Poststroke Pain. Neuromodulation Technology at the Neural Interface. doi .ner.  https Lefaucheur JP AndrObadia N Antal A Ayache SS Baeken C Benninger DH Cantello RM Cincotta M de Carvalho M De Ridder D Devanne H Di Lazzaro V Filipovic SR Hummel FC Jskelinen SK Kimiskidis VK Koch G Langguth B Nyffeler T Oliviero A Padberg F Poulet E Rossi S Rossini PM Rothwell JC SchnfeldtLecuona C Siebner HR Slotema CW Stagg CJ VallsSole J Ziemann U Paulus W GarciaLarrea L. Evidencebased guidelines on the therapeutic use of repetitive transcranial magnetic stimulation rTMS. Clin Neurophysiol.  Nov. doi .j.clinph.... Epub  Jun . Review. PubMed PMID .  About the International Neuromodulation SocietyThe International Neuromodulation Society INS is a nonprofit medical society that unites clinicians scientists and engineers to share scientific knowledge about all aspects of neuromodulation in order to encourage best medical practice. Founded in  and based in San Francisco CA the INS presents uptodate information about the full breadth of neuromodulation therapies through an interactive website at http chapter scientific meetings the MEDLINEindexed journal Neuromodulation Technology at the Neural Interface httponlinelibrary.wiley.comjournal.ISSN and its biennial world congress."