Clinical StudyIncreased risk of lead fracture and migration in dystonia compared with other movement disorders following deep brain stimulation
Introduction
Deep brain stimulation (DBS) has been shown to be very effective in the alleviation of a variety of different movement disorders and is now an accepted therapy. It is reversible and adaptable, avoiding concerns related to lesioning the brain and, because of the reduced level of morbidity involved, allows bilateral surgery to be undertaken more readily. The main disadvantages include cost, the need for regular follow-up and stimulator titration, the complications associated with implantation of foreign bodies and those problems related to the hardware itself.1 Because such device-related problems lead to significant patient morbidity and increased cost of therapy in the form of, in-patient stay, repeat surgery, and device replacement, the implications of hardware-related complications cannot be ignored.
It has been suggested that amongst movement disorder patients treated with DBS, a higher rate of hardware-related complications occurs in patients with dystonic conditions.2 Although there are several publications detailing hardware failure in DBS,[3], [4], [5] none document any comparison between patients with differing movement disorders. We have therefore looked at our cohort of patients with movement disorders treated successfully with DBS in greater detail and have found an interesting apparent association between the type of movement disorder being treated and the incidence of a specific DBS lead-related complication, namely lead fracture or slippage.
Section snippets
Patient details
Patients treated successfully with DBS, for their respective movement disorder, at our unit since 1998 were included. The study was conducted retrospectively and involved a consecutive series of patients. During the study period, a total of 133 individuals underwent procedures for implantation of 240 DBS electrodes. Of these patients, 75 were men and 58 women. The age range was 7–84 years (mean, 50.2 years). A summary of patient demographics is included in Table 1. Of those that fell into the
Results
A summary of adverse events related to the implanted DBS leads is included in Table 1. Only those patients with dystonia displayed post-operative lead fracture or migration following initially successful DBS treatment. This represented 18.4% of dystonic patients and 5.3% of all those with movement disorders treated within our group. All adverse events occurred within a single lead for each affected patient. In the patients with a slipped lead, the problem was detected at about 12 months post-op
Discussion
It has been suggested previously that hardware-related complications are higher in patients with dystonia compared to other movement disorders.2 The overall complication rate, for all forms of hardware failure, previously noted by our group is in the region of 20%. These complications include lead fractures, erosion of hardware through the skin, pulse generator malfunction and lead displacement. Dystonic patients constitute less than 30% of the workload of our unit, however, these specific
Conclusion
The difficulties and complexities of implantation of DBS systems for movement disorders do not end with the actual insertion and fixation of the electrodes and pulse generators. There are considerable risks of associated complications with the hardware that may manifest much later. Some of these risks appear to be specific to the type of movement disorder being treated. As our study has found, there is a disproportionate risk of lead fracture and/or slippage in patients with dystonia. The
Acknowledgements
This work was supported by grants from the MRC and the Norman Collison Foundation.
References (9)
- et al.
Hardware-related problems of deep brain stimulation
Mov. Disord.
(2002) Deep brain stimulation for dystonia in adults
Stereotact. Funct. Neurosurg.
(2002)- et al.
Surgical and device-related events with deep brain stimulation
Neurology
(2001) - et al.
Hardware-related complications of deep brain stimulation in 100 consecutive electrodes. Proceedings of the AANS meeting
J. Neurosurg.
(2001)