Repetitive transcranial magnetic stimulation decreases the number of seizures in patients with focal neocortical epilepsy.
OBJECTIVE
To evaluate the number of seizures and interictal epileptiform discharges (IEDs) in patients with focal neocortical epilepsy before, during and after rTMS.


METHODS
Twelve patients (seven men and five women, mean age 29.3+/-15.8 years) were studied. An open-label study with baseline (4 weeks), intervention (2 weeks) and follow-up (8 weeks) periods was carried out. Repetitive transcranial magnetic stimulation (rTMS) with 900 pulses, intensity of 120% motor resting threshold and 0.5Hz frequency was used. A 120 channel EEG was recorded; an electrical source analysis of IEDs with Variable Resolution Electromagnetic Tomography (VARETA) was performed. The number of seizures per week and IEDs per minute were measured and compared in the three periods.


RESULTS
During the basal period the mean seizure frequency was 2.25 per week; in the intervention period it decreased to 0.66 per week (F=2.825; p=0.0036) which corresponds to a 71% reduction. In the follow-up period the mean frequency was 1.14 seizures per week, that is, a 50% reduction in the number of seizures. In the visual EEG analysis, the baseline IED frequency was 11.9+/-8.3events/min; it decreased to 9.3+/-7.9 during 2 weeks of rTMS with a further reduction to 8.2+/-6.6 in the follow-up period. These differences however were not significant (p=0.190).


CONCLUSIONS
We conclude that 2 weeks of rTMS at 0.5Hz with a figure-of-eight coil placed over the epileptic focus, determined with VARETA, decreases the number of seizures in patients with focal epilepsy, without reduction in IEDs.
Santiago-Rodríguez
Efraín
E
Unidad de Investigación en Neurodesarrollo "Dr. Augusto Fernández Guardiola", Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico. santiago@inb.unam.mx
Cárdenas-Morales
Lizbeth
L
Harmony
Thalía
T
Fernández-Bouzas
Antonio
A
Porras-Kattz
Eneida
E
Hernández
Adriana
A
D000293:Adolescent; D000328:Adult; D004558:Electric Stimulation; D004569:Electroencephalography / Q000379:methods; D020938:Epilepsy, Partial, Motor / Q000150:complications; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012640:Seizures / Q000209:etiology / Q000473:pathology / Q000628:therapy*; D013812:Therapeutics; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult