Brain Stimulation May Cut Seizures in Hard-to-Treat Epilepsy

What was studied

This paper was a systematic review with pooled analysis of studies on deep brain stimulation (DBS) in the thalamus for adults with drug-resistant epilepsy. The authors searched PubMed, EMBASE, and Cochrane for studies published from 2000 to 2025. They included studies with at least 4 adults, at least 6 months of follow-up, and reported seizure frequency reduction after DBS.

Nineteen studies with 651 patients were included. The review looked at three thalamic targets: the anterior nucleus of the thalamus (ANT, 551 patients), the centromedian nucleus (CM, 89 patients), and the medial pulvinar nucleus (PuM, 11 patients). The authors also performed subgroup comparisons by epilepsy classification and seizure onset zone within each target.

What they found

Across the included studies, weighted mean seizure frequency reduction was 48.7% for ANT DBS, 71.4% for CM DBS, and 62.0% for PuM DBS. The share of patients with at least a 50% drop in seizures was 48.7% for ANT, 76.2% for CM, and 60.0% for PuM.

For ANT DBS, seizure reduction increased over time, from about 33% to 41% at 1 year to about 56% to 69% by 5 years. Temporal lobe origin was associated with better ANT outcomes. CM DBS had the best results in generalized epilepsy syndromes, including Lennox-Gastaut syndrome. PuM DBS showed promising results for posterior quadrant and temporal-plus epilepsy.

Adverse events differed by target. ANT studies reported depression and memory impairment, CM studies reported postoperative drowsiness, and PuM studies reported hemorrhagic complications. No stimulation-related deaths were reported.

Limits of the evidence

This review combined results from separate studies, so it cannot show from these pooled data alone that one DBS target is definitively better than another. There were no head-to-head trials directly comparing ANT, CM, and PuM.

The evidence base was much larger for ANT than for CM or PuM because most patients were in ANT studies. PuM results were based on only 11 patients in 2 studies, so those findings need prospective validation. Study designs, patient groups, follow-up times, and outcome reporting likely differed across studies, which can affect pooled results.

The abstract does not give enough detail to know how consistent the results were across all studies or how often adverse events happened overall.

For families and caregivers

For families, this review suggests that thalamic DBS may reduce seizures for some adults whose epilepsy has not responded to medicines, and that results may vary by epilepsy type and where seizures begin.

The review reports Class I evidence supporting ANT DBS in focal epilepsies, particularly temporal lobe origin. CM DBS showed strong preliminary efficacy for generalized epilepsies, and PuM DBS had promising but very limited early data that still need validation. This does not mean DBS will help every person, but it may be one option to discuss with an epilepsy specialist when standard treatments have not worked.

What to watch next

Larger randomized and prospective studies, especially head-to-head comparisons of DBS targets, are needed before individualized target selection recommendations can be made.

Terms in this summary

drug-resistant epilepsy

Epilepsy that does not come under good control after trying appropriate seizure medicines.

deep brain stimulation

A treatment that uses implanted electrodes to send electrical signals to specific brain areas.

thalamus

A deep brain structure that helps relay and organize signals in the brain.

anterior nucleus of the thalamus (ANT)

One part of the thalamus that is a DBS target with Class I evidence in focal epilepsies, especially temporal lobe origin.

centromedian nucleus (CM)

Another part of the thalamus that has shown preliminary efficacy as a DBS target, especially in generalized epilepsy syndromes.

medial pulvinar nucleus (PuM)

A less-studied thalamic DBS target that requires prospective validation.

responder rate

The percentage of patients who had at least a 50% reduction in seizure frequency.

generalized epilepsy

Epilepsy in which seizures involve both sides of the brain from the start.