Abstracts

Rationale: Deep brain stimulation (DBS) on bilateral anterior thalamic nucleus (ATN) has been shown to reduce the frequency of seizures and improve cognition in refractory epilepsy patients. However, it is unknown over the change in electroencephalography (EEG) after the treatment. We investigated the change in EEG three months after DBS on bilateral ATN for controlling intractable epilepsy.Methods: Seven medically intractable epilepsy patients who could not be candidates for resective surgery were treated by bilateral ATN DBS. For electrical stimulation, intermittent adjustment in stimulation parameters (frequency 130 Hz, voltage 1.5-2.0 V, pulse duration 90 s, continuous stimulating mode, in one stimulated DBS electrode contact (monopolar configuration) were carried out in all patients. After implantation of the electrodes, EEG was obtained before electrical stimulation, and follow-up EEG was obtained after three months under continuous stimulation mode. The alpha powers of each electrodes before and after treatment and the frontal alpha asymmetry were tested. A pair-wise, one-tailed sLORETA analysis was also performed.Results: Six out of the seven patients showed significant reduction of seizure frequency. Mean seizure reduction rate of our patients after ATN DBS was 68.3% (33.3 ~ 100%). Alpha power was increased in all patients, especiallly in high alpha frequency. The frontal alpha asymmetry in resting states was increased in the six patients who showed seizure reduction after DBS. In sLORETA analysis, alpha and high-alpha waves were significantly increased in bilateral precentral gyrus.Conclusions: The EEGs of the patiehts who received DBS ATN surgery showed significance change three months after continuous stiumlation, and they were correlated with the previous reports describing the results of ATN DBS, such as decreased seizure frequency and improved cognition.