Centromedian Nucleus Of Thalamus Research Articles

Deep brain stimulation of anterior nucleus and centromedian nucleus of thalamus in treatment for drug-resistant epilepsy.

Drug-resistant epilepsy (DRE) remains poorly-controlled in c.33% of patients, and up to 50% of patients suffering from DRE are deemed not to be suitable candidates for resective surgery. For these patients, deep brain stimulation (DBS) may constitute the last resort in the treatment of DRE. We undertook a systematic review of the current literature on DBS efficacy and the safety of two thalamic nuclei-anterior nucleus of the thalamus (ANT) and the centromedian nucleus of the thalamus in the management of patients with DRE. A search using two electronic databases, the Medical Literature, Analysis, and Retrieval System on-line (MEDLINE) and the Cochrane Central Register of Controlled Trials (CEN-TRAL) was conducted. We found 30 articles related to ANT DBS and 13 articles related to CMN DBS which were further analysed. Based on the clinical research articles, we found a mean seizure frequency reduction for both thalamic nuclei. For ANT DBS, the mean seizure frequency reduction ranged from 48% to 75%, and for CMN DBS from 46.7% to 91%. The responder rate (defined as at least 50% reduction in seizure frequency) was reported to be 53.2-75% for patients after ANT DBS and 50-90% for patients after CMN DBS. ANT and CMN DBS appear to be safe and efficacious treatments, particularly in patients with refractory partial seizures and primary generalised seizures. ANT DBS reduces most effectively seizures originating in the temporal and frontal lobes. CMN DBS reduces mostly primary generalised tonic-clonic and atypical absences and atonic seizures. Seizures related to Lennox-Gastaut syndrome respond very favourably to CMN DBS.

449 Stereoencephalography of Centromedian Thalamus Reveals Distinct Patterns of Thalamocortical Synchrony Across Seizure Onset Zones

INTRODUCTION: Thalamic nuclei are increasingly used targets for study and therapeutic modulation in drug-resistant epilepsy (DRE). Centromedian nucleus of thalamus (CMN) is relatively understudied despite known widespread connectivity and previous reports suggesting a role in both generalized and multifocal epilepsies. METHODS: The clinical and electrographic data of 13 consecutive patients who had at least one sEEG electrode sampling CMN were included. Electrographic seizures were visually analyzed for thalamic activity changes at seizure onset (SO), maintenance (SM), and end (SE) periods. Recordings were quantitatively assessed using a measure of sEEG signal interdependency (non-linear regression coefficient, h2) to compare thalamocortical synchrony at SO and SE periods. All analyses were performed using AnyWave software. RESULTS: Eighty focal-onset seizures (median 4, range 1-19 per patient) were captured and included in analysis. SOZs were mesial temporal (33%), neocortical temporal (23%), frontal (29%), and non-frontal extratemporal (15%). Median seizure length was 78 (IQR 25-133) seconds. In 74% of seizures, a change in thalamic activity was visually perceptible during the seizure with a median latency of 5 (IQR 2-9) seconds. A low voltage fast activity pattern predominantly in the alpha band was most commonly seen during SO. When thalamic activity changed during SM, a rhythmic spike-wave pattern was most often seen. Rhythmic waves predominantly in the delta band were the most common pattern of activity at SE. Average thalamocortical h2 values in the SE period were significantly higher than the SO period (Kruskal-Wallis p < 0.0001). Mesial temporal, temporal, and frontal seizures demonstrated significant increases in thalamocortical synchronization while non-frontal extratemporal seizures did not. CONCLUSIONS: Consistent dynamic ictal patterns can be visualized within CMN thalamus using sEEG recordings. Bidirectional signal synchronization peaks during the SE period and may be involved in seizure termination.