Medial Pulvinar Stimulation in Temporal Lobe Epilepsy: A Literature Review and a Hypothesis Based on Neuroanatomical Findings

Abstract

While bilateral stimulation of the anterior thalamic nuclei remains the only approved deep brain stimulation (DBS) option for focal epilepsy, two additional thalamic targets have been proposed. Earlier work indicated the potential of centromedian thalamic nucleus stimulation with recent findings highlighting the medial pulvinar nucleus. The latter has been shown to exhibit electrophysiological and imaging alterations in patients with partial status epilepticus and temporal lobe epilepsy. On this basis, recent studies have begun assessing the feasibility and efficacy of pulvinar stimulation, with encouraging results on the reduction of seizure frequency and severity. Building on existing neuroanatomical knowledge, indicating that the medial pulvinar is connected to the temporal lobe via the temporopulvinar bundle of Arnold, we hypothesize that this is one of the routes through which medial pulvinar stimulation affects temporal lobe structures. We suggest that further anatomic, imaging, and electrophysiologic studies are warranted to deepen our understanding of the subject and guide future clinical applications.

Mapping hippocampal and thalamic atrophy in epilepsy: A 7‐T magnetic resonance imaging study

“…Recent work on intracranial recordings of temporal lobe epilepsy demonstrated increased connectivity between the anterior nucleus and the pulvinar nucleus during seizures, suggesting that both thalamic nuclei are active nodes in the epileptogenic network 48 . Furthermore, although the anterior nucleus of the thalamus remains a popular target for DBS stimulation, the centromedian and pulvinar nucleus have both been demonstrated as successful targets, although not in a randomized control trial 21,49 . Although preliminary, our findings could have implications for the DBS treatment of L‐TLE and R‐TLE, as a pulvinar/centromedian stimulation approach could be more appropriate for R‐TLE, whereas anterior nucleus stimulation could be more appropriate for L‐TLE.…”

“…48 Furthermore, although the anterior nucleus of the thalamus remains a popular target for DBS stimulation, the centromedian and pulvinar nucleus have both been demonstrated as successful targets, although not in a randomized control trial. 21,49 Although preliminary, our findings could have implications for the DBS treatment of L-TLE and R-TLE, as a pulvinar/centromedian stimulation approach could be more appropriate for R-TLE, whereas anterior nucleus stimulation could be more appropriate for L-TLE.…”

Magnetic resonance imaging fingerprints of status epilepticus: A case–control study

“…For instance, a study using structural MRI with tractography evaluated thalamic connectivity in healthy volunteers and patients with mesial temporal lobe epilepsy, revealing high‐density connections between the medial part of the pulvinar and the hippocampus 32 . More so, based on the strong connectivity between neocortical regions and pulvinar, recently conducted research advocates for using pulvinar as a potential therapeutic target in patients with refractory epilepsy 33 …”

The replication principle revisited: a shared functional organization between pulvinar-cortical and cortico-cortical connectivity and its structural and molecular imaging correlates

“…This includes deep brain stimulation of the pulvinar, an emerging area of interest in functional neurosurgery for epilepsy, which could benefit from a deeper understanding of pulvinar connectivity and its implications for treatment outcomes (Kalamatianos et al 2023;Vakilna et al 2023;Wong et al 2023). Specifically, the medial (as opposed to the lateral) pulvinar is the desired target due to its connectivity to the medial temporal lobe.…”