Wire Tethering or ‘Bowstringing’ as a Long-Term Hardware-Related Complication of Deep Brain Stimulation

Abstract

Background: Widely reported long-term complications following implantation of deep brain stimulation (DBS) hardware include breakage of electrode leads, internal pulse generator (IPG) failure, skin erosions and infection. Here we report on a rarely described problem that arises from formation of scar tissue adhesions around the DBS extension wire(s). Over time, this scar tissue can become tight and pronounced, protruding noticeably beneath the skin (‘bowstringing’ in reference to its tight bow-like appearance) and leading to significant limitation of movement and discomfort. We term this ‘wire tethering’. Results:We describe 6 patients with moderate to severe wire tethering. Review of our experience suggests an association of wire tethering with the passage of two extension wires on the same side as is done when using a dual-channel IPG. Five of the patients required surgical revision of the extension wires due to the magnitude of the discomfort, limitation of movement and appearance. Removing the wires was insufficient in the most severe case, necessitating transection of the scar in several places, which was done with the extension wires in situ in 2 patients. Two patients were treated with removal of the wires alone, and 1 patient did not opt for surgery and the tethering has persisted. Conclusion: Wire tethering, or ‘bowstringing’, is an underrecognized complication of DBS hardware implantation often necessitating surgical revision. The possible etiology of wire tethering is discussed as well as suggestions for its avoidance.

Deep brain stimulation�s anatomy: step by step evaluation of the extracerebral surgical technique

“…Wire tethering, or 'bowstringing', is an under-recognised complication of DBS-hardware implantation, often necessitating surgical revision 7 . Other problems arising from the extracerebral DBS implanted materials are: impairment of certain movements, cosmetic deformities, discomfort caused by the car safety belt, discomfort when directly lying on the IPG and lead-extension related pain 2 .…”

Aim for the Suprasternal Notch: Technical Note to Avoid Bowstringing after Deep Brain Stimulation

“…Bowstringing after deep brain stimulation (DBS) typically presents with tightness or pain, associated with prominence of the extension cable track and limitation of movement [1]. Such tethering of the DBS extension cables can negatively affect patient comfort and may even precede lead dislocation or fracture [2].…”

“…Such tethering of the DBS extension cables can negatively affect patient comfort and may even precede lead dislocation or fracture [2]. Symptom onset varies from 0.5 to 32 months after initial implantation [1,3]. The severity of bowstringing is variable, making it difficult to estimate its incidence.…”

“…The severity of bowstringing is variable, making it difficult to estimate its incidence. However, the reported incidence rates of significant bowstringing in large single-centre series were 0.6, 1.8 and 2.6% of patients [1,3,4]. …”

“…The literature suggests that the incidence of bowstringing appears to be higher when two extension cables pass down the same side of the neck to a dual-channel implantable pulse generator (IPG), rather than when single cables bilaterally on either side of the neck lead to single-channel IPGs [1]. Possible additional risk factors include a history of dyskinesias, dystonia and psychiatric disease.…”