Abstracts

This abstract is a recipient of the Nurse and Advanced Practice Provider Travel Award

Rationale: With 3 targets (anterior nucleus [AN], centromedian nucleus [CMN], pulvinar) and 2 devices (deep brain stimulation [DBS] and responsive neurostimulation [RNS] that are currently being used for thalamic stimulation, the selection process is often complex and confusing.

Methods: We describe our approach to thalamic stimulation in 4 consecutive, refractory, non-resectable epilepsy patients (Tables 1, 2).

Results: Patient A has non-lesional focal epilepsy with focal seizures of non-lateralized, bitemporal onset with slight left temporal precedence and rapid spread to the right temporal region, based on SEEG. She underwent corticothalamic stimulation with RNS with a left anterior temporal strip and bilateral ANT depth electrodes (right ANT not connected) because of lateralized onset and rapid contralateral spread while also entertaining the possibility of future resective surgery. Over 25 months of follow-up, she had 50% improvement in seizure frequency (3-4/week to 1-2/week)._x000D_ _x000D_ Patient B has Lennox-Gastaut syndrome (LGS) with tonic, atonic, myoclonic and focal seizures, and prior history of intellectual disability, corpus callosotomy, right frontal resection and hypothalamic hamartoma resection. She underwent DBS implant (given LGS) with left AN and right CMN electrodes (due to absence of right AN from prior tumor resection). Over 39 months of follow-up, there has been 50% improvement in overall seizure frequency (4/day to 2/day); her repetitive behavior improved significantly with improvement in seizure control._x000D_ _x000D_ Patient C has a history of left cerebellar resection (for medulloblastoma), left frontal resection (for radiation-induced meningioma) and focal epilepsy. SEEG showed independent left temporal and right temporal/orbito-frontal ictal onsets. She underwent DBS with bilateral AN electrodes (given bitemporal seizures). Over 16 months of follow-up, she has been seizure free (3-4/month prior to implant). Postoperatively, she had worsening depression, which is currently being treated._x000D_ _x000D_ Patient D has juvenile myoclonic epilepsy with myoclonic, absence and GTC seizures, along with frequent nonepileptic seizures. She underwent bilateral CMN implant (given generalized seizures) with an RNS (to differentiate between epileptic and nonepileptic seizures using the stored ECoGs). Over 13  months of follow-up, the absence seizures have resolved (3-4/week prior to implant), GTC seizures are less frequent (1/week from 2/week), daily myoclonic seizures (as before), and frequent nonepileptic seizures (as noted by the lack of RNS ECoG signature).

Conclusions: Thalamic stimulation is promising in refractory non-resectable epilepsy. It seems focal seizures respond better to AN stimulation whereas absence seizures respond better to CMN stimulation. Use of a device capable of storing ECoG can be useful in differentiating epileptic vs nonepileptic seizures in patients who experience both. Although favorable outcomes can be achieved regardless of the device implanted, patient factors and the potential for future resection might dictate device selection.  

Funding: No funding was received for this abstract.