Dislocated Pacemaker Electrode Simulating Focal Epileptic State in a Patient with Subdural Hematoma-Case Report and Review of the Literature

Background: Due to demographic changes, the number of patients with traumatic brain injury carrying a cardiac resynchronization therapy device is increasing. One of the common complications of subdural hematoma (SDH) is epilepsy, whereas one of the most frequent early complications after cardiac resynchronization therapy device implantation is lead dislocation. The latter might then cause unintended skeletal muscle stimulation that might be misinterpreted in seizure-prone patients.

Case description: An 86-year-old female patient with an initially conservatively treated SDH on the right side presented with a tonic muscle contraction in her left arm 2 weeks after the trauma not responding to antiepileptic therapy. A computed tomography scan revealed residual hematoma on the right side with regular, time-dependent resorption. The muscle contraction was misdiagnosed as a focal epileptic state leading to evacuation of the chronic SDH. Additionally, routine postoperative chest radiographs were performed. Postoperatively, the tonic muscle contraction in her arm persisted. Chest radiographs revealed a dislocation of the left ventricular electrode, which appeared retracted into the left subclavian vein, next to the plexus brachialis. After deactivating the electrode, the alleged focal state ceased.

Conclusions: In case of refractory treatment of epilepsy, dislocation of pacemaker electrodes is a, most certainly, rare but possible differential diagnosis. Confirmation of electrode position and function is easily and quickly feasible and will help prevent futile seizure-directed therapy.