Trigeminal paresthesia secondary to responsive neurostimulation (RNS) lead migration

BACKGROUND: The responsive neurostimulation system (RNS) is used in patients with drug-resistant epilepsy who are not candidates for surgical resection of a seizure focus. As a relatively new therapy option, the adverse effects of long-term implantation are still being clarified. We present a series of two patients who presented with similar symptoms which were attributable to migration of the intracranially implanted subdural leads. CASE DESCRIPTION: Two patients who had subdural RNS lead implantation presented with symptoms of paroxysmal unilateral facial pain which were thought to be related to the stimulation of the trigeminal nerve secondary to RNS lead migration. Adjustment of the stimulation parameters improved the symptoms in both patients. CONCLUSION: Chronically implanted subdural RNS leads can migrate over time stimulating nerves in the intracranial space. Strategies to avoid and overcome the complication are discussed.