Seizure outcome during bilateral, continuous, thalamic centromedian nuclei deep brain stimulation in patients with generalized epilepsy: a prospective, open-label study

•The thalamic intralaminar centromedian nucleus (CM) is part of the ascending reticular formation and likely related to attentional processes.•Due to its widespread cortical connectivity, the CM has been investigated as a target to treat refractory generalized epilepsy.•This prospective, open label study included a large, homogeneous cohort and provided evidence on the efficacy of CM-DBS in patients with refractory epilepsy.•CM-DBS was also associated with attention improvement in this cohort. We report on the seizure frequency and attention outcome during thalamic centromedian stimulation (CM-DBS) in patients with refractory generalized epilepsy (GE). Twenty consecutive patients with GE who were submitted to CM-DBS and had at least one year of follow-up were prospectively studied. The CM was targeted bilaterally. Stimulation intensity was ramped up (bipolar, continuous, 130 Hz; 300μsec) until 4.5 V or until side effects developed. Contacts` position was determined on postoperative volumetric MRI scans. Attention was qualitatively evaluated using the SNAP-IV (Swanson, Nolan, and Pelham) questionnaire. Patients were considered responders during CM-DBS if an at least 50% seizure frequency reduction was obtained compared to baseline. Median age was 15.5 years (13 males). Median follow-up time was 2.55 years. EEG disclosed generalized spike-and wave discharges in all patients. MRI was normal in 10 patients, showed diffuse atrophy in 6 patients, and showed abnormalities in 4 patients (3 patients had bilateral cortical development abnormalities and one had unilateral hemispheric atrophy). Patients presented with daily multiple seizure types (8 to 66 per day; median: 37), including tonic, atonic, myoclonic, atypical absence and generalized tonic-clonic seizures. Mean DBS intensity was 4.3 V. An insertional effect was noted in 14 patients. CM-DBS was able to significantly reduce the frequency of tonic (p