ANT-DBS in epilepsy shows no effect on selected neuropsychiatric tests

Deep brain stimulation of the anterior thalamic nucleus (ANT-DBS) is an established option in treatment-resistant epilepsy and obtained FDA approval in 2018. Increased psychiatric comorbidity is well known in epilepsy. The main objective of this study was to investigate possible neuropsychiatric treatment-related changes in patients receiving ANT-DBS.

Bilateral ANT electrodes were implanted in 18 adult patients with refractory epilepsy in a randomized, double-blinded study. Immediately after implantation, patients were randomized to stimulation ON (n = 8) or OFF (n = 10) for the first 6 months (blinded phase). During the next six months (open phase), both groups received active stimulation. Neuropsychiatric assessment was conducted before implantation (T1), at the end of the blinded period (T2), and 1 year after implantation (T3).

Comparing preoperative status (T1) and 12 months (T3), postoperative outcome in all patients did not show significant differences between the two groups for any of the applied tests. Groupwise comparisons across the two first time points (the blinded period, representing the randomized controlled trial) showed no significant differences between the two groups in any of the neuropsychiatric parameters studied. Comparing test results after 6 months of stimulation in both groups (sum of ON group T1 to T2 and OFF group T2 to T3) did not show significant changes for any of the psychiatric assessments.

Our results indicate that ANT-DBS has limited effect concerning psychiatric issues. Subjective side effects were, however, reported in individual patients.