Bilateral subthalmic nucleus deep brain stimulation with microelectrode recordings in the setting of mild inherited Hemophilia B: A case report.

Hemophilia B is an X linked recessive deficiency of factor IX that presents with a range of clinical severity that co-relates with factor levels. Although guidelines exist to guide perioperative hemostasis in such patients, there is scarce data on elective high-risk neurosurgeries, resulting in a reluctance to offer these patients elective neurosurgeries. These patients thus rarely if ever undergo such procedures. We report a unique case of undiagnosed mild hemophilia B in a gentleman that was found incidentally at age 64 during pre-operative workup. This gentleman had intractable Parkinson's disease for which subthalmic deep brain stimulation was indicated. He was found to have a prolonged APTT on initial lab testing. After subsequent workup, and having excluded the presence of inhibitors, he was diagnosed with Hemophilia B. With the use of Factor IX concentrates (AlphaNine®) and close clinical, laboratory and radiological monitoring a plan was made for this patient to undergo this procedure. Our patient successfully underwent subthalmic deep brain stimulation with microelectrode recordings and intraoperative test stimulation in a two-step procedure, followed by single channel implantable neurostimulator and extension wire implantations 2 weeks later. The successful peri-operative course of this patient using this novel approach is described, and the need for future data in this regard is emphasized.