Introduction

1. Establishing a Structured and More Patient-Centered System for Reporting Complications Associated With Intrathecal Baclofen Therapy: A Systematic Review Nestor D. Tomycz M.D., Raj Nangunoori B.S., Joseph Hobbs M.D., Donald M. Whiting M.D., Michael Y. Oh M.D. Department of Neurosurgery, Allegheny General Hospital, Pittsburgh, PA, U.S.A.

2. Introduction • Baclofen: an analogue of γ-aminobutyric acid (GABA) • Oral baclofen • In 1984, Penn and Kroin demonstrated the effectiveness of intrathecal baclofen • Intrathecal baclofen (ITB) has become routine in the management of spasticity and dystonia arising from either spinal or cerebral origin

3. Objective • Dearth of literature which effectively characterizes complications related to ITB therapy • No coherent system for reporting ITB complications • To better characterize complications related to ITB therapy and to devise a simple, comprehensive, and more patient-centered scheme for complication reporting

4. Methods • MEDLINE search: January 1985 to May 2010 • N≥10 and if complications were reported • Articles were excluded if N<10 and if there were multiple articles by the same author with an overlap in patient populations • 310 articles found, 28 met criteria • Reclassified complications into 4 categories: technique, device, drug, and infection

5. Methods • Technique: due to the operative procedure itself • CSF-related complications (CSF wound leaks, pseudomeningoceles), hematoma/seroma, and wound dehiscence • Drug: subjective complaints and symptoms related to baclofen • Nausea, vomiting, somnolence, hypotonia, hypertonia, gastrointestinal disturbances, respiratory depression, and coma, overdose and withdrawal • Device: problems with the hardware itself • pump (flipping, failure), catheter (kinks, breaks, tears, and migration) • Infections: related to the pump or catheter incision • Wound infection/dehiscence was categorized here due the cause and effect relationship to the two, “wound dehiscence” was otherwise categorized as a complication of surgical technique.

6. Results • 28 papers met criteria for systematic review and included prospective trials, retrospective studies, and case series • 2,623 unique patients, 1,637 complications • Combined complication incidence: 62.4% • Range in total complication incidence: 10-570% • Device complications (n=587, 35.5%) were the most frequent followed by drug (n=544, 33.2%) followed by technique (n=293, 17.8%), and infection (n=213, 13.4%)

7. Results • Among technique complications, CSF-related complications (n = 113, 6.9%) were the most common followed by hematoma/seroma (n = 14, 0.9%) • Among drug complications, non-postural headache, nausea, vomiting, dizziness, and drowsiness were the most commonly reported (n = 212, 13.0%) • Baclofen overdose/withdrawal: n = 28, 1.7% • Among device complications, catheter-related problems were the most common (n = 193, 11.8%) • 8/28 studies (28.6%) reported no drug complications

13. Discussion • Our primary objective: report the combined incidence of complications related to ITB therapy and to devise a classification scheme that is more patient-centered • We selected the 4 categories for classification for their simplicity and comprehensiveness • We found a combined complication incidence of 62.4%

14. Conclusion • The incidence of complications related to ITB remains high • Much of the reporting on ITB complications has neglected patient-centered complaints (especially drug complications) • Although ITB has been touted as having a lower side effect profile than oral baclofen, drug complications from ITB are not rare • Improvements in ITB may be prompted by better complication reporting • The 4-tiered complication scheme for ITB will help patients better appreciate the risks of ITB