Response: Deep brain stimulation targets in epilepsy: Systematic review and meta‐analysis of anterior and centromedian thalamic nuclei and hippocampus

To the Editors: We read the letter by AlKraimeen et al.1 in detail. We agree on the drawbacks imposed by performing a metaanalysis in a heterogenous subset of studies, as was described in our limitations and bias assessment sections in detail. Studies with multiple longitudinal reports did not allow for a reliable identification of unique patients. Additionally, longitudinal studies were included in the analysis to reflect on the possibility of improved seizure response after prolonged deep brain stimulation (DBS) for epilepsy. Performing the metaanalysis of the DBS of the anterior thalamic nucleus after excluding the two followup studies by Fisher et al.2 did not significantly affect the percentage of seizure reduction on a group level (60.8% vs. 59.4%). Thus, we chose to report all included studies. The use of DBS for epilepsy has gained US Food and Drug Administration approval after the study of Fisher et al.2 and their longitudinal followup provides additional evidence in support of the treatment. Further research is required to assess the efficacy of neuromodulation in different types of seizures, and the efficacy of stimulation in less studied targets.