Cerebellar DBS 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 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 three patients with distinct cerebellar DBS hardware orientations. Following heating estimates, and as part of an ongoing trial (NCT06122675), we then collected three functional MRI runs in one anesthetized patient with DBS turned ON, turned OFF, and cycled ON/OFF in 30s intervals. Simulations suggested acceptable heating under our scanner and sequence conditions, with peak temperature increases ranging from 0.6-1.5°C. Preliminary stimulation-induced brain activations and functional connectivity changes appeared consistent with the underlying structural anatomy.