Pharmacotherapy for Phantom Limb Pain: A Systematic Evidence-Based Review

PM&R

Poster 462 Pharmacotherapy for Phantom Limb Pain: A Systematic Evidence-Based Review. Zack McCormick, MD (The Rehabilitation Institute of Chicago, Chicago, IL, United States); George C. Chang Chien, DO; Mark Huang, MD; R.N. Harden, MD. Disclosures: Z. McCormick, No Disclosures: I Have Nothing To Disclose. Objective: While evidence-based reviews of pharmacotherapy for neuropathic pain in general have been conducted, there has been minimal systematic review of the pharmacologic treatment of phantom limb pain (PLP) specifically. Design: We conducted a systematic review of original research papers in PubMed specifically investigating the pharmacologic treatment of PLP. Literature was sourced from PubMed. Studies without human subjects, "neuropathic" but not "phantom limb" pain, or without pain scores or functional outcomes measures as primary outcomes were excluded. Main Outcome Measures: A level of evidence was ascribed to individual treatments according to the United States Department of Health and Human services guidelines. These guidelines denote randomized controlled trials as level 1, controlled, non-randomized prospective studies as level 2, observational studies with controls as level 3, and observational studies without controls as level 4 evidence. Results or Clinical Course: We found level 2 evidence for gabapentin, both oral (PO) and intravenous (IV) morphine, IV and epidural Ketamine, level 3 evidence for acetaminophen, nonsteroidal anti-inflammatories, amitriptyline, dextromethorphan, PO and locally injected memantine, and level 4 evidence for methadone, tramadol, intrathecal (IT) buprenorphine, IT and epidural fentanyl, duloxetine, mirtazapine, clonazepam, pregabalin. Conclusions: There is no level 1 evidence specifically for the pharmacologic treatment of PLP. There is level 2 evidence for gabapentin, morphine and epidural ketamine. Poster 463 Lumbar ESI Causing Acute Paraparesis in a Patient With Previously Undiagnosed Spinal Dural Arterovenous Fistula: A Case Report. Thiru M. Annaswamy, MD, MA (Dallas VA Medical Center, UT Southwestern Medical Center, Dallas, TX, United States). Disclosures: T. M. Annaswamy, Evidence Committee Chair; Evidence-Based Practice Committee Member,Other Case Description: A 48 y/o man with CLBP recently noted gradual onset of sensory and motor loss in his legs. He was seen in spine clinic and referred for lumbar epidural steroid injection (LESI) to relieve pain from nerve root compression suggested on MRI. During informed consent for LESI, patient stated no pain, but after benefits & risks were explained, he consented to procedure and a left L2-3 LESI was performed. Setting: Hospital based spine clinic Results or Clinical Course: 4 hours post LESI he was seen in the ER with acutely worsening leg weakness and numbness below

Vol. 5, Iss. 9S, 2013

S299

waist, and urinary/bowel incontinence, without pain. MRI Tspine: Abnormal signal in central cord from T4-T10, especially the conus, suggestive of edema from venous hypertension. Multiple serpentine intradural flow voids seen along the cord concerning for spinal dural AV fistula (SDAVF) with cord ischemia/infarction. MRI L-spine: Multilevel degenerative disc disease similar to prior exam. No epidural fluid collections or abnormal enhancement. Abnormal signal seen in the conus which in retrospect appears present on the prior lumbar spine MRI. Serpiginous vessels with enhancement noted with suggestion of same finding on prior MRI with flow voids. Patient was admitted. Spinal arteriogram revealed an SDAVF filling from the left lateral sacral artery, which was subsequently embolized using 0.3 cc of Onyx by interventional radiology; no evidence of dural AV fistula supply from this vessel post embolization. Patient subsequently rehabilitated in a spinal cord injury unit and went home with a walker. Discussion: SDAVFs can cause myelopathy after ESI by venous hypertension, venous engorgement, and eventually ischemia of the spinal cord. Epidural space pressure is normally zero or negative. LESI normally has little effect on pressure because of the antibackflow mechanisms and the large epidural potential space. However, in patients with SDAVFs, the antibackflow mechanisms are impaired, and therefore injection of steroids can result in venous hypertensino and eventual spinal cord ischemia. Conclusions: ESIs are contraindicated in patients with SDAVFs as they can result in acute paraparesis and spinal cord ischemia. Patients with LBP but relatively painless weakness in legs should be evaluated carefully and other causes for weakness ruled out before considering LESI for pain relief. Poster 464 Trigeminal and Accessory Neuropathy after Cervical Epidural Injection: A Case Report. Raghu Maddela, MD (Montefiore Medical Center, Bronx, NY, United States); Steven A. Sparr, MD; Sayed E. Wahezi, MD. Disclosures: R. Maddela, No Disclosures: I Have Nothing To Disclose. Case Description: A 54-year-old female home maker with refractory neck and arm pain underwent right sided C5, 6 inter-laminar cervical epidural steroid injection (IC-ESI) at an outside institution. Post procedure, in the recovery room, she reported severe neck pain, right sided facial numbness and weakness of the right shoulder, arm and leg. Patient was transferred to our institution for evaluation. Same day, post procedure MRI displayed cervical spinal cord edema extending to cervico-medullary junction. No change in symptoms were noted on day two and repeat MRI demonstrated cord expansion corresponding to skin needle site insertion; intramedullary injection during IC-ESI was the proposed cause. Patient was started on IV steroids and physical therapy for gait training. Daily improvement in the symptoms was recorded thereafter. No surgical intervention was recommended. She was discharged to acute rehabilitation on hospital day 4. Setting: Tertiary care hospital Results or Clinical Course: At three month follow up facial numbness was resolved. Leg and shoulder shrug weakness