Sudden loss of the deep brain stimulation effect with high impedance without macroscopic fracture: a case report and review of the published literature

Abstract

The number of deep brain stimulation (DBS) hardware complications has increased during the past decade. In cases of abnormally high lead impedance with no evidence of a macroscopic fracture, optimal treatment options have not yet been established. Here, we present the case of a 49-year-old woman with a 12-year history of Parkinson’s disease who received bilateral subthalamic nucleus DBS in March 2006. The patient showed good control of parkinsonism until December 24, 2010, when she awoke with abrupt worsening of parkinsonian symptoms. At telemetric testing, lead impedances were found at >2,000 Ω in all four leads on the left side. Fracture of a lead or an extension wire was suspected. However, radiological screening and palpation revealed no macroscopic fracture. In June 2011, the implantable pulse generator (IPG) was changed under local anesthesia without any complications. Postoperatively, her parkinsonism immediately improved to the previous level, and the lead impedance readings by telemetry were also normalized. The disconnection of the neurostimulator connector block and the hybrid circuit board of the IPG was confirmed by destructive analysis. The present report illustrates that a staged approach that starts with simple IPG replacement can be an option for some cases of acute DBS effect loss with high impedance, when radiological findings are normal, thereby sparing the intact electrodes and extension wires.

DBS Electrodes With Single Disconnected Contacts: Long-Term Observation and Implications for the Management

“…Most importantly, disconnected contacts cannot be used for DBS so that clinical efficacy has to be obtained by activation of alternative contacts. If the disconnection affects an active contact during long‐term DBS loss of therapeutic efficacy will be observed and has been previously reported including loss of therapy after IPG replacements . An important observation was that in half of the electrodes high monopolar impedances were not stable during long‐term DBS.…”

Management of Elevated Therapeutic Impedances on Deep Brain Stimulation Leads

“… 2 An increase in LII is frequently the warning sign of an open electrical circuit (e.g., connector break) and a drop is typically a sign indicating a short circuit. 2 , 3 The LII measurements available through the current IPGs have very good accuracy (less than 4% error). 4 …”

“…In some cases, extraction of the entire system is required. These proposed guidelines 3 , 10 rely on single-center experiences and have not been prospectively evaluated for clinical outcomes, side effects, or cost–benefit analysis.…”

Pediatric Deep Brain Stimulation for Dystonia: Current State and Ethical Considerations

“…Lead fractures are not easily identified in 14.3%-25% of suspected, open-circuit cases (i.e., high impedance and worsening of symptoms despite no radiological evidence of macroscopic fractures). 69 Different strategies can be used to manage these hardware issues, such as changing stimulation parameters, prolonged lead activation, and surgical revision, which comes with more risk. Few studies report improvement after such attempts are made, indicating that the management of hardware complications is still unclear.…”