Background: Several centers have reported efficacious cluster headache suppression with deep brain stimulation (DBS) of the hypothalamic region using a variety of targets. While the connectivity of some of these targets has individually been studied, commonalities across these targets, especially with respect to network-level connectivity, have not previously been explored.
Methods: We examined the anatomic connectivity of the four distinct DBS targets reported in the literature using probabilistic diffusion tensor tractography in normal subjects.
Results: Despite being described as hypothalamic, the DBS targets localized in the midbrain tegmentum posterior to the hypothalamus. Common tracts across DBS targets and subjects included projections to the ipsilateral hypothalamus, reticular formation, and cerebellum.
Discussion: Although DBS target coordinates are not located within the hypothalamus, a strong connection between DBS targets and the hypothalamus likely exists. Moreover, a common projection to the medial ipsilateral cerebellum was identified. Understanding the common connectivity of DBS-targeted regions may elucidate anatomic pathways that are involved in modulating cluster headache attacks and facilitate more precise patient-specific targeting of DBS.
Keywords: Cluster headache; cerebellum; deep brain stimulation; hypothalamus; probabilistic tractography.