Search

Deep brain stimulation (DBS) has provided new treatment options for refractory epilepsy; however, treatment outcomes of DBS in refractory epilepsy patients previously treated with vagus nerve stimulation (VNS) have not been clarified. Herein, treatment outcomes of DBS of the anterior nucleus of the thalamus (ANT-DBS) in patients who had previously experienced VNS failure are reported. Seven patients who had previously experienced VNS failure underwent ANT-DBS device implantation. VNS was turned off before DBS device implantation. Monthly seizure counts starting from baseline to 12–18 months after DBS were analyzed. Five (71.3%) of the 7 patients experienced a >50% reduction of seizure counts after DBS; 1 responder reached a seizure-free status after DBS therapy. Of the 2 nonresponders, 1 subject showed improvement in seizure strength and duration, which lessened the impact of the seizures on the patient’s quality of life. This is the first study in which favorable outcomes of ANT-DBS surgery were observed in individual patients with refractory epilepsy who had not responded to prior VNS. Further studies with a larger number of subjects and longer follow-up period are needed to confirm the feasibility of ANT-DBS in patients who have previously experienced VNS failure.

Dysembryoplastic neuroepithelial tumor (DNT) is a well-known epileptogenic lesion with favorable seizure outcome after surgical resection. However, sometimes surgery may be difficult technically, and epilepsy may continue throughout the patient’s lifetime despite surgical intervention. We report a case of intractable epilepsy related to DNT that was treated with gamma knife radiosurgery (GKRS). The frequency of seizure was reduced remarkably after GKRS, and finally a seizure-free state was accomplished in two years. Neuropsychological tests also showed improvement. It is suggested that GKRS may be an effective and less invasive alternative treatment for the patients in whom surgical treatment is difficult.

To study the influence of interictal spikes on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), EEG monitoring was performed during PET scanning in 21 patients with temporal lobe epilepsy. Asymmetry indices were calculated in the polar, mesial, anterior-lateral, mid-lateral and posterior-lateral temporal region of interests of FDG-PET (PET-AI). 70.7% of spikes were recorded with their maximum at the anterior temporal region (F7, F8, FT9, FT10), 29.3% at mid-temporal (T7, T8), and none at posterior temporal region (P7, P8). Regardless of the side of epileptic focus, right-left difference of the total spikes had a significant negative correlation with right/left PET-AIs of the anterior-lateral temporal region (Spearman’s ρ = –0.565, p = 0.009), polar (ρ = –0.500, p = 0.021) and whole temporal region (ρ = –0.480, p = 0.028). FDG-PET hypometabolism may reflect not only a permanent functional deficit but also a transient regional cerebral dysfunction related to the occurrence of interictal spikes.