Session Information
Date: Wednesday, September 25, 2019
Session Title: Surgical Therapy
Session Time: 1:15pm-2:45pm
Location: Les Muses Terrace, Level 3
Objective: To report the occurrence of lead failure in a directional DBS system.
Background: Lead failure is a known complications of DBS systems. However, the use of new technologies featuring directional leads has introduced new scenarios for hardware complications. We report the occurrence of a directional lead failure in a patient with bilateral VIM DBS for Essential tremor (ET).
Method: Case Report.
Results: A 71 year-old man underwent bilateral VIM DBS implantation for disabling ET. Surgery was uncomplicated and initial programming provided excellent tremor suppression. Three months after initial programming, he developed episodic shock-like sensations in the left hand when showering. Painful paresthesias could be reproduced by touching the right shoulder with the left arm moving across the chest as if soaping. On routine device testing, program and system impedances were normal. Active settings were Left Vim 2.0 mAmp/60 µsec/186 Hz/Contacts 2-C+, Right Vim: 2.8 mAmp/70 µsec/186 Hz/ Contacts 10(ABC)- C+. Initially, amplitude reduction to 1.6 mA on the right VIM appeared to resolve abnormal symptoms, although painful paresthesias could still be triggered by pressing on the right edge of the implanted pulse generator. At a second analysis, system and program impedances were again normal at rest. However, when performed in the triggering posture, a short circuit was detected for contact 9 and subsegment 10A – as documented by abnormally low impedance (112 ohms). Deselecting segment 10A completely resolved the shocks, even when intentionally repeating the triggering posture. Excellent tremor control of the left hand was maintained.
Conclusion: This unusual hardware-related DBS complication was caused by transient short circuits triggered by a specific body posture. In this case, it was relevant to perform DBS system impedance testing in the specific trigger posture, as no abnormalities were detectable at rest. A similar malfunction in a classic annular contacts lead would have resulted in likely loss of therapeutic efficacy, while the segmented design allowed for maintaining effective stimulation in the target area. To our knowledge, this is the first case report of a lead failure in a directional lead.
To cite this abstract in AMA style:
H. Lu, A. Garland Bacerra, E. Hogg, A. Perilla, A. Mamelak, M. Tagliati. Shower Shock: Directional Lead Malfunction in a Patient with Vim DBS [abstract]. Mov Disord. 2019; 34 (suppl 2). https://www.mdsabstracts.org/abstract/shower-shock-directional-lead-malfunction-in-a-patient-with-vim-dbs/. Accessed September 22, 2023.« Back to 2019 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/shower-shock-directional-lead-malfunction-in-a-patient-with-vim-dbs/