Neuromodulation of the Centromedian Thalamic Nuclei in the Treatment of Generalized Seizures and the Improvement of the Quality of Life in Patients with Lennox–Gastaut Syndrome

Abstract

Summary:Purpose: Our aim was to evaluate the efficacy of ESCM (electrical stimulation of the centromedian thalamic nucleus) in treatment of generalized seizures of the LennoxGastaut syndrome (LGS) and improvement of patient disability.Methods: Thirteen patients with LGS were studied. They had severe generalized tonic-clonic seizures (GTC) and atypical absences (AA). All patients had at least a 6-month baseline before bilateral electrode implantation to the centromedian (CM) nuclei of the thalamus to undergo therapeutic ESCM. Once implanted, electrodes were temporally externalized through a retromastoid point for electrophysiologic confirmation of their placement. After target confirmation, stimulation parameters were set. Patients came for follow-up assessment of seizures and neurophysiologic tests every 3 months during an 18-month period of time; AED therapy was not modified.Results: The surgical procedure as well as electrical stimulation was well tolerated by all patients. No side effects occurred with the therapeutic stimulation parameters used, and patients were not aware of device activation. Two patients were explanted because of repeated and multiple skin erosions that could not be controlled by plastic surgery procedures. Overall seizure reduction was 80%. The three patients with poorest outcomes for seizure control did not improve their ability scale score. In contrast, the two patients rendered seizure free are living a normal life at present. The remaining eight patients experienced progressive improvement, from being totally disabled to becoming independent in five cases and partially dependent in two. Patients with adequate electrode placement had a seizure reduction >87%. To consider that an electrode is correctly placed, both stereotactic placement and neurophysiologic responses are taken into account.Conclusions: ESCM provides a nonlesional, neuromodulatory method with improvement in seizure outcome and in the abilities of patients with severe LGS.

Deep brain stimulation for the treatment of drug-refractory epilepsy in a patient with a hypothalamic hamartoma

“…The experience reported by Kahane et al 17 demonstrated seizure induction with frequency parameters ranging between 1 and 50 Hz. Velasco et al 36 reported on scalp-EEG synchronization followed by a recruiting response with a stimulation of 6-10 Hz to the centromedian thalamic nucleus, and spike wave complex discharges and typical absence with stimulation at 3 Hz. These results were reported with both uni-and bilateral stimulation.…”

“…The effect of neuromodulation on deep brain nuclei 4,10,12,20,[36][37][38]43 exerts seizure control by anterograde or antidromic stimulation or inhibition of the cortex, 21 but no conclusive data on the ideal parameters for stimulation are known. The experience reported by Kahane et al 17 demonstrated seizure induction with frequency parameters ranging between 1 and 50 Hz.…”

Possible new avenues in epilepsy treatment: the stimulation techniques deep brain stimulation, vagal nerve stimulation, transcranial magnetic stimulation

“…Other studies have indicated no reduction in seizure frequency [20,32]. Stimulation of the centromedian nucleus of the thalamus has also been investigated as a treatment of Lennox-Gastaut syndrome [27]. Overall, a seizure reduction of about 80% was achieved and 2 out of 13 patients became seizure-free.…”

Deep Brain Stimulation for Epilepsy

“…47 A recent open-label trial in 13 patients with LennoxGastaut syndrome reported overall seizure reduction of 80%, with significant improvement in quality of life. 48 Although CMT DBS may be effective in controlling frequency of generalized seizures, results in patients with complex partial seizures are unclear. 49 -52 In contrast to the results of these open-label studies, a trial of CMT DBS in seven patients using a double-blind, cross-over design, revealed no significant difference in seizure frequency, 53 and a recent report indicated no short-term benefit in two patients, one of whom was subsequently implanted with electrodes in the ANT.…”