Thalamic neuromodulation for epilepsy: A clinical perspective

Abstract

Thalamic neuromodulation can be an effective therapeutic option for select patients with medically refractory epilepsy. However, successful outcome depends on several factors, beginning with appropriate patient and thalamic target selection. Among thalamic targets, the anterior (ANT) and centromedian (CeM) nuclei have the greatest clinical evidence for efficacy. However, the place of thalamic neuromodulation in the treatment armamentarium for intractable seizures is at the tail end of a long list of options. It's relative efficacy, if any, in relation to other treatment modalities however, can be inferred. As we will discuss, considerable work remains to be done in optimal targeting of thalamic nuclei, appropriate to the epilepsy syndrome and seizure type of the individual patient, which may change our current understanding of the place of thalamic neuromodulation on a range of treatment modality efficacies. Currently, it appears that ANT DBS is most efficacious for limbic epilepsies whereas CM, for generalized, multifocal (especially frontotemporal) epilepsies. Based on controlled studies, the efficacy of ANT and CeM DBS is roughly in line with other neuromodulatory therapies (i.e. RNS, VNS) when assessed within the cohort of patients for which the therapy is indicated. Much improvement is needed to render thalamic DBS more efficacious, and use of optimal targeting strategies, especially direct targeting, can positively affect outcomes. Thalamic neuromodulation is still in its infancy; however, clinical advances in this therapy are being realized.

Keywords: Deep brain stimulation; Epilepsy; Outcome; Review; Thalamus.