How to Avoid Twiddler’s Syndrome in Deep Brain Stimulation for Dystonia?

Abstract

We report an unusual hardware complication after deep brain stimulation (DBS) for primary dystonia. A 43-year-old woman with primary refractory dystonia, characterized by dysphonia, dysphagia, and torticollis, underwent DBS of the posteroventral globus pallidus internus. Three days later, the patient had a second surgical procedure for lead internalization with the positioning of the internal pulse generators (IPG, Kinetra-Medtronic, Minneapolis, MN, USA) placed subcutaneously in the right subclavicular region. Both procedures were uneventful. Postoperative T1-weighted magnetic resonance imaging showed electrodes in place (Fig. 1). One week after the second procedure, the IPG was switched on, resulting in a slow and progressive improvement of dystonia. However, after six months, the patient experienced worsening of dysphonia with dysarthria. IPG interrogation evidenced high levels of impedance (>2000 ːΩ) indicating potential hardware malfunction. The patient was hospitalized and plain x-rays of the skull, neck, and chest were performed, showing twisting of the two lead cords with a double-helix pattern (Figs. 2 and 3).