Poster 166: Bilateral thigh pain after unilateral deep brain stimulator placement: a case report.

Abstract

Setting: Rehabilitation hospital. Patient: An 81-year-old right-handed woman with bilateral essential tremor. Case Description: The patient underwent deep brain stimulator placement in the ventral intermediate nucleus of the left thalamus at another institution to treat right-sided tremor. The procedure was complicated by injury to the anomalous left subclavian artery. Left upper-extremity arterial emboli resulted and required open thrombectomies. The postoperative course was notable for confusion attributed to anesthesia and urinary tract infection. Because of ongoing functional deficits (patient required moderate assistance with dressing and bathing and minimum assistance to ambulate 75ft with an assistive device), the patient was admitted to inpatient rehabilitation on postoperative day 10 from stimulator placement. On admission to rehabilitation, she complained of bilateral thigh pain, which had developed during hospitalization. The aching thigh pain disrupted sleep and therapies and did not respond to anti-inflammatory, narcotic, or neuropathic pain medications. Lumbar spine imaging revealed degenerative disease without foraminal stenosis. Electromyography of the lower extremities was normal. Head computed tomography confirmed stimulator placement in the left thalamus. Assessment/Results: Bilateral thigh pain resolved after the deep brain stimulator frequency was increased to control upper-extremity tremor. Pain medications were subsequently discontinued successfully. The patient was discharged to home at a modified independence level and could ambulate >1000ft after 22 days of inpatient rehabilitation. Discussion: Complications associated with deep brain stimulator placement can cause functional impairments requiring rehabilitation, and physiatrists should be familiar with side effects associated with deep brain stimulation (DBS). Although parasthesias are a known side effect of deep brain stimulator placement, discomfort is typically treated by decreasing stimulation. This is the first reported case, to our knowledge, of bilateral pain from unilateral DBS that responded to increased frequency of stimulation. Conclusions: Unilateral DBS can cause bilateral pain; increasing DBS frequency can relieve pain.