Impedance trend from a symptomatic perielectrode cystic cavity following deep brain stimulation: illustrative case.

Background: Deep brain stimulation (DBS) is a well-established neurosurgical intervention for a growing number of neurological and psychiatric diseases. Patients who are affected by Parkinson's disease may benefit from DBS of either the subthalamic nucleus or the globus pallidus internus. Patients who undergo DBS often notice a significant reduction in their clinical symptoms; however, the procedure is not without risks. Multicenter studies have reported postoperative complications such as hardware infection, intracranial hemorrhage, and perielectrode edema.

Observations: The authors report a case of a perielectrode cyst managed conservatively. Tracking the impedance trend was a novel approach to monitor for changes within the cyst and to herald a clinical change in the patient. Perielectrode cystic formation can be a transient process that resolves spontaneously or with conservative, nonoperative management, and all diagnostic information is valuable in making clinical decisions.

Lessons: Impedance values have provided an appropriate estimation of this patient's clinical picture. The authors suggest treatment of edema and a cyst after DBS lead implantation through conservative management and observation, avoiding the removal of hardware if a patient's clinical picture is either stable or improving and forgoing additional clinical imaging if the impedance values are trending in an appropriate direction.