Long-term efficacy of anterior nucleus of the thalamus deep brain stimulation in drug-resistant epilepsy: a 5-year multicenter study.

BACKGROUND

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT-DBS) has demonstrated potential in reducing seizure frequency (SF) in patients with drug-resistant epilepsy (DRE). This multicenter retrospective study aimed to comprehensively evaluate the long-term effects of ANT-DBS on seizure reduction and neuropsychological outcomes, as well as to identify prognostic factors associated with postoperative efficacy.

METHODS

We retrospectively analyzed data from DRE patients who underwent ANT-DBS across three epilepsy centers between July 2019 and December 2022. SF, responder rate, neuropsychological outcomes, and quality of life (QoL) were assessed using seizure diaries and standardized rating scales at baseline and annual follow-up. Univariate and multivariate regression analyses were performed to identify predictors of postoperative SF reduction.

RESULTS

A total of 40 patients were included, with a mean age at surgery of 28.6 ± 11.1 years. The average monthly SF decreased from 15 at baseline to 6.5 at the 5-year follow-up (a 56.7% reduction, p < 0.001), with a responder rate of 62.5%. Therapeutic effect was most pronounced within the first 24 months after implantation. The Liverpool Seizure Severity Scale (LSSS) scores improved from 26.7 ± 5.2 to 17.9 ± 8.6 (p < 0.001). Mood conditions (measured by the Hamilton Depression and Anxiety Rating Scales) improved from baseline to the final follow-up, while cognitive status remained stable. QoL also improved significantly, particularly in Overall QoL, Emotional Well-being, Energy/Fatigue and Social Functioning. Multivariate logistic regression identified temporal lobe seizures (OR 8.3, p = 0.022) and stimulation amplitude (OR 4.2, p = 0.034) as independent predictors of responder status following DBS implantation. Multivariate linear regression identified baseline LSSS scores (standardized β: 3.5, p = 0.016) and temporal lobe seizures (standardized β 35.4, p = 0.024) as independent predictors of SF reduction.

CONCLUSIONS

ANT-DBS significantly reduces SF in patients with DRE and shows stable long-term efficacy. The seizure onset zone, preoperative seizure severity and stimulation amplitude are critical predictors of postoperative outcomes, providing valuable information for optimal patient selection for this intervention.