Long-term anterior thalamus stimulation for intractable epilepsy.
BACKGROUND
Deep brain stimulation (DBS) has re-emerged as an alternative therapy for intractable epilepsy. In this study, we investigated the feasibility, efficacy and safety of long-term anterior thalamic nucleus (ATN) stimulation for intractable epilepsy.


METHODS
In this open-label pilot study of electrical stimulation of the ATN, we investigated four cases of intractable epilepsy (one man with generalized seizure, and three woman with partial seizure and secondary generalization; age range, 18-45 years), with a follow up of 2 years. Under the indication of bilateral or nonlocalized epileptic foci, each patient underwent stereotactic implantation of a quadripolar stimulating electrode in the bilateral ATN, guided by single-unit microelectrode recording. The stimulator was turned on after a sham period of 2-4 weeks. Seizure frequency was monitored and compared with the pre-implantation baseline. Twenty-one similar cases reported in the literature during the past 20 years were reviewed.


RESULTS
Insertion into and stimulation through electrodes implanted in the ATN decreased seizure frequency, with a mean reduction rate of 49.6% in the current series. Two patients had seizure reductions of > or = 60%, with complete remission achieved in one patient. These findings were consistent with those in four other investigations of intractable epilepsy, which showed an overall rate of 45-55% in seizure reduction. One of our patients suffered a small frontal hemorrhage, and a second patient had extension erosion over the scalp; however, no resultant major or permanent neurological deficits were observed.


CONCLUSIONS
Based on our study results and literature review, it appears reasonable to conclude that long-term ATN stimulation is a safe and effective treatment for seizure reduction in patients with intractable epilepsy.
Lim
Siew-Na
SN
Section of Epilepsy, Department of Neurology, Chang Gung Memorial Hospital, Taipei, Taiwan, ROC.
Lee
Shih-Tseng
ST
Tsai
Yu-Tai
YT
Chen
I-An
IA
Tu
Po-Hsun
PH
Chen
Jean-Lon
JL
Chang
Hsiu-Wen
HW
Su
Yu-Chin
YC
Wu
Tony
T
D000293:Adolescent; D000328:Adult; D004599:Electric Stimulation Therapy / Q000379:methods*; D004567:Electrodes, Implanted; D004827:Epilepsy / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D013788:Thalamus / Q000502:physiology*; D016896:Treatment Outcome