Lead wire fracture associated with normal therapeutic impedance measurements in a patient with a kinetra neurostimulator.

Objectives. We present a case report of a patient with complete lead wire fracture with approximately 3-mm separation of the wire fragments that had three electrode impedance measurements and therapy impedance measurement that would be consistent with an intact wire. Materials and Methods. Retrospective chart review. Results. The patient experienced abrupt worsening of gait freezing while tremor control remained stable. Despite normal therapeutic impedance measurement, clinical suspicion for a hardware problem remained due to her description of brief dystonic hand posturing witnessed during impedance measurements in the clinic. This led to further diagnostic evaluation and eventual surgical replacement of the lead wire. Conclusions. Impedance measurements are not absolutely reliable for the detection of hardware malfunction in a patient with a Kinetra neurostimulator.