Transcranial magnetic stimulation may cut seizures in refractory partial epilepsy

NEW YORK (Reuters Health) – Low-frequency repetitive transcranial magnetic stimulation (rTMS) appears to reduce seizures in patients with refractory partial epilepsy, according to a small study from China.

The noninvasive technique, which alters cortical excitability, has shown limited effectiveness for seizures in earlier sham-controlled trials.

Dr. Yuping Wang and colleagues from Capital Medical University, Beijing, China evaluated the therapeutic effect of low-frequency rTMS in a randomized, single-blind controlled trial of 60 patients with refractory partial epilepsy.

Thirty-one patients received rTMS at a stimulation intensity of 90% of their resting motor threshold (high-intensity), and 29 patients received rTMS at a stimulation intensity of 20% of their resting motor threshold (low-intensity).

All patients in the September 5 Epilepsia report were treated for two weeks with three daily sessions of 500 stimuli at 0.5 Hz, separated by a 600 s interval.

Patients in the high-intensity group had an 80.6% greater reduction in seizure frequency than did patients in the low-intensity group in the first week after treatment (p<0.001), and this difference persisted over the next seven weeks.

The average seizure frequency decreased from 8.9/week at baseline to 1.8/week after rTMS in the high-intensity group, but patients in the low-intensity group did not experience a significant change in seizure frequency.

In the high-intensity group, median time to first seizure was more than six weeks, and the probability of remaining seizure-free was 35.5% (11/31) at the end of follow-up. None of the patients in the low-intensity group remained seizure-free, and their median time to first seizure was one week.

The number of interictal epileptiform discharges declined significantly in the high-intensity group, but not in the low-intensity group.

Symptom Checklist-90 scores generally improved in the high-intensity group, but did not change in the low-intensity group.

Adverse events included mild or moderate headache and tinnitus, and they occurred more often in the high-intensity group than in the low-intensity group.

The researchers conclude “that low-frequency and high intensity rTMS has suppressive effects on seizures and epileptic discharges. Additionally, our results indicate that rTMS treatment can improve the psychological conditions of the patients.”

The U.S. FDA has issued guidelines for using rTMS to treat major depressive disorder, but not seizures.

Dr. Wang did not respond to a request for comments.

SOURCE: http://bit.ly/Ug1bpo

Epilepsia 2012.