Transcranial Sonographic Localization of Deep Brain Stimulation Electrodes Is Safe, Reliable and Predicts Clinical Outcome

In patients with deep brain stimulation (DBS), poor postoperative outcome or unexpected clinical change require brain imaging to check the lead location. Here, we studied safety, reliability and prognostic value of transcranial sonography (TCS) for DBS lead localization applying predefined TCS criteria. After measuring thermal effects of TCS and imaging artefact sizes of DBS lead using a skull phantom, we prospectively enrolled 34 patients with DBS of globus pallidus internus, ventro-intermediate thalamic or subthalamic nucleus. TCS had no influence on lead temperature, electrical parameters of DBS device or clinical state of patients. TCS measures of lead coordinates agreed with MRI measures in anterior-posterior and medial-lateral axis. Lead dislocation requiring reinsertion was reliably detected. Only patients with optimal lead position on TCS had favorable clinical 12-month outcome (>50% improvement), whereas unfavorable outcome (<25% improvement) was associated with suboptimal lead position. TCS may therefore become a first-choice modality to monitor lead location.