Cerebellar Deep Brain Stimulation during fMRI: Initial Findings and Simulation-Informed Thermal Assessment.

The cerebellum has garnered increasing interest as a promising deep brain stimulation (DBS) target for dyskinetic cerebral palsy and other conditions such as cerebellar ataxia and stroke. Functional MRI of cerebellar stimulation can facilitate a more comprehensive understanding of the mechanisms underlying symptom response; however, evidence regarding its safety and feasibility is lacking. In this report, we first assessed the risk of radiofrequency-induced heating through simulations informed by postoperative CT images from 3 patients with distinct cerebellar DBS hardware orientations. Following heating estimates, and as part of an ongoing trial (NCT06122675), we then collected 3 functional MRI runs in one anesthetized patient with DBS turned ON, turned OFF, and cycled ON/OFF in 30-second intervals. Simulations suggested acceptable heating under our scanner and sequence conditions, with peak temperature increases ranging from 0.6°C-1.5°C. Preliminary stimulation-induced brain activations and functional connectivity changes appeared consistent with the underlying structural anatomy.