69250all_new

INTRATHECAL BACLOFEN WITHDRAWAL SYNDROME FOLLOWING
POSTERIOR SPINAL FUSION FOR NEUROMUSCULAR SCOLIOSIS:
A CASE REPORT
Pedro Fernandes, M.D.1; Lori Dolan, Ph.D.2; Stuart L. Weinstein, M.D.2 ABSTRACT
paresthesia, hyperthermia, hypotension, hallucinations, Because of the increased number of patients
delusions, confusion, psychosis and seizures.6 Auditory with neuromuscular scoliosis receiving intrathe-
and visual hallucinations have also been reported in pa- cal baclofen therapy, we report a clinical case of
tients with oral baclofen withdrawal.14,15 According to the withdrawal. We hope to make physicians aware of
manufacturer, advanced IBWS may resemble autonomic this potentially serious complication where signs
dysreflexia, sepsis, malignant hyperthermia, neuroleptic and symptoms may be difficult to interpret due to
malignant syndrome, or other conditions associated with population characteristics.
a hypermetabolic state or widespread rhabdomyolysis.16 These symptoms are seen mostly in spinal-cord injury INTRODUCTION
patients where the diagnosis may be difficult to make Intrathecal baclofen (ITB) is increasingly being used due to possible confusion with autonomic dysreflexia. for the treatment of spasticity in cerebral palsy patients. In the pediatric population, we are aware of only one The response rate has been reported as being up to 97 case (following posterior spinal fusion for scoliosis) where percent with use of less than one percent of the systemic baclofen was not delivered despite a normal-functioning dose.1,2,3,4 Intrathecal baclofen withdrawal symptoms pump. This report offered no details concerning the (IBWS) are less frequently reported than withdrawal type of surgery or possible cause for catheter malfunc- from oral baclofen.5 Symptoms are difficult to interpret tion.17 Because of the increased number of patients with and in some cases can be life threatening.5,6,7,8,9,10,11,12 neuromuscular scoliosis receiving intrathecal baclofen Symptoms develop when central nervous system levels therapy, we report a clinical case of withdrawal to make of baclofen decrease over a short period of time. This physicians aware of this potentially serious complication may be precipitated by pump malfunction or failure, cath- where signs and symptoms may be difficult to interpret eter obstruction or failure, or decline in pump reservoir drug level. Of these possible problems, complications related to the catheter itself are by far the most frequent CASE REPORT
and affect up to 40 percent of patients with ITB pumps.13 An 18-year-old female with spastic quadriplegia and Patients usually return to a baseline level of spasticity, scoliosis was treated with posterior spinal fusion and frequently became agitated, and experience sleepless- instrumentation necessitated by curve progression and ness with IBWS. Other symptoms include pruritis, increased difficulty sitting. She had low-normal intel-ligence, mild dysarthria and no psychiatric history. Her first baclofen pump had been inserted four years previ- ously and was revised eight months prior to her spinal fusion because of pump malfunction (Figure 1). Av. Professor Egas Moniz 1649-028Lisbon, Portugal A T2 to sacrum fusion was performed using Luque- Galveston instrumentation. During this procedure, the 2University of Iowa Hospitals and Clinics catheter entrance into the lumbar spine was carefully Department of Orthopaedics and Rehabilitation localized and dissected free in order to protect it dur- ing the procedure. The surgery was uneventful with no lori-dolan@uiowa.edu, stuart-weinstein@uiowa.edu complications and blood loss was estimated at 400cc The initial postoperative course was uncomplicated. University of Iowa Hospitals and ClinicsDepartment of Orthopaedics and Rehabilitation On postoperative day (POD) two the patient had an abrupt onset of multiple symptoms of delirium, includ- ing fluctuating levels of awareness and orientation, but stuart-weinstein@uiowa.edu319-356-1872 Telephone mainly hallucinations. She was dysarthric but was able to describe visualization of insects all over the room. She P. Fernandes, L. Dolan, and S. L. Weinstein Figure 2 (left) and Figure 3 (right). Sitting anterior-posterior and
lateral post-operative radiographs.
tartrate). On POD 4 a pediatric psychiatry consultation was obtained and the hypothesis of ITB withdrawal was suggested. Pump malfunction was now considered. Halo-peridol (2.5 mg at night and 2.5-5 mg PRN as a rescue dose for breakthrough agitation) was ordered. Telem-etrics ruled out pump malfunction (setting: 225μg/day, 9.4 μg/hour). The last refill had been two months before surgery. Cerebro-spinal fluid results were as follows: glucose 54 mg/dl (normal >50% serum level), protein 160 mg/dl (normal, 14 - 45 mg/dl), 150 nucleated cells/μL (normal, <5 cells/μL) and 7534 red blood cells(RBC)/μL (normal =0 RBC/μL) with xanthochromia evident. After the reservoir was filled with a radionuclide, a significant accumulation of the isotope tracer was revealed outside the spinal canal by scintigram (Figures 4, 5). Therefore, Figure 1. Sitting anterior-posterior pre-operative radiograph.
the most likely diagnosis for the symptoms was baclofen withdrawal syndrome caused by a catheter leak. Oral was afebrile, heart rate was 133 beats per minute, blood baclofen with rapid titration up to 60mg/day and halo- pressure was 109/59 mmHg and respiratory rate was peridol were started with resolution of the symptoms 18 per minute. Hemoglobin and hematocrit were 12.2 within 72 hours. The patient was discharged on POD g/dl and 33 percent, respectively. The metabolic workup 8 and was kept on oral baclofen until six months post- was normal. She was on hydromorphone (Dilaudid), operatively when the catheter was revised.
morphine, codeine, acetaminophen, diphenydramine, and promethazine. With the hypothesis of drug-related DISCUSSION
delirium, the morphine was discontinued. Despite these Intrathecal baclofen withdrawal syndrome should al- measures, the patient continued to be symptomatic with ways be considered as a possible complication after pos- increased spasticity and visual hallucinations, and sleep terior spinal instrumentation for cerebral palsy patients disturbance. On POD 3 all hydromorphone, codeine, with a baclofen pump. Compromised communication and diphenydramine was discontinued and she was abilities in these patients and the possible confusion with switched to oral acetaminophen and Ambien® (zolpidem epileptic seizure or post-operative sepsis can challenge Intrathecal Baclofen Withdrawal Syndrome following Posterior Spinal Fusion for Neuromuscular Scoliosis tion, the catheter can be breached accidentally; if this is recognized, it should be repaired by a proper tube connector. During the procedure, the catheter can also be caught by one of the many instruments in the field and pulled out to a level distal to the intended level or even from the spinal canal itself. If a unit rod is used, pas-sage under a taut catheter can be problematic unless a reasonable amount of catheter has been mobilized. This technical difficulty can be avoided if the neurosurgeon leaves extra catheter coiled near the spine, or by using a modular system. For example, Alden et al. reported a case where the catheter was left in place during posterior Figure 4 (left) and Figure 5 (right). Radionuclide study at 0 minutes
and at 94 minutes showing tracer leak outside spinal column.
spinal fusion for scoliosis. The patient was readmitted for hyperthermia and severe spasms with clonus in both upper and lower extremities. Pump interrogation the proper diagnosis. When IBWS is suspected, a com- showed no problems, but catheter exploration and divi- plete work-up may have to be undertaken to delineate sion near the spinal entrance revealed no spontaneous Hallucinations in this setting can be very disturbing, The last alternative that may be considered is to sec- as patients tend to develop paranoic ideas with intense tion the catheter during the procedure and then recon- anxiety. This has also been reported in patients with nect it with the appropriate connector at the end of the Parkinson’s disease who take oral baclofen, but usually procedure. If this is done, it must be coordinated with the disappears soon after reintroduction of the drug.14,15 neurosurgical service to insure that the pump catheter In this case, the probable cause for the withdrawal system is functioning properly afterward. syndrome was a small nick created in the catheter Treatment of IBWS relies on reinstitution of the tubing during the dissection process. To prevent this intrathecal baclofen infusion. In severe cases, bolus complication, three options are available to the surgeon: administration via lumbar puncture may be needed until The catheter can be removed during exposure and catheter reinsertion is attempted. In the case related reintroduced at the end of the procedure with a Thuhy above, the differential diagnosis has to be made between needle; catheter preservation can be attempted through autonomic dysreflexia, malignant hyperthermia and delicate dissection and isolation; or the catheter can be neuroleptic malignant syndrome. Dantrolene (10mg/ sectioned and reattached at the end of the procedure kg) or benzodiazepine infusions can be very effective and even life-saving.9,21 If the problem is recognized early, Although the first option seems straightforward, it has high-dose oral or enteric baclofen (>120 mg/day in six been related to low-pressure headaches secondary to to eight divided doses for adults) can be effective if the presumed cerebrospinal fluid (CSF) leakage. Segal et al. patient’s condition permits.9 In children younger than presented five patients with spastic quadriplegia having 12 years of age, lower doses may have to be used since a baclofen pump who underwent posterior spinal fusion safety is not well established and the manufacturer’s rec- and then developed persistent positional headaches and ommended maximum daily dose is 80 mg. Side effects vomiting, with an inability to sit upright for some time in such as sedation, general nervous system depression two patients. These symptoms were due to cerebrospinal and hypotension should be well monitored. fluid leaks after reintroduction of the catheter. These potentials should always be anticipated when this first CONCLUSION
Increasing numbers of patients with spastic cerebral For a number of years, the senior author has per- palsy are being treated with ITB. Those scheduled for formed posterior spinal fusion by isolating the catheter, posterior spinal fusion and instrumentation should be mobilizing as much of it as possible, and protecting it made aware of the potentially devastating complications during surgery (the second alternative). Although this associated with interruption of intrathecal baclofen which method avoids the morbidity associated with CSF leaks may occur as a complication of surgery. Surgeons must and the need for additional procedures to restore the be aware of this potential risk and develop strategies pump catheter system, this approach has some potential to prevent interruption of baclofen delivery and to deal complications. Injury to the catheter may occur at many with a disruption, should it occur. Early recognition of points in the procedure. During dissection and mobiliza- ITB withdrawal syndrome is mandatory, as it can be a P. Fernandes, L. Dolan, and S. L. Weinstein potentially life-threatening complication. Full investiga- 11. Kao LW, Amin Y, Klirk M, Turner M. Intrathecal
tion, according to established protocols, is essential to baclofen withdrawal mimicking sepsis. J. Emerg Med rule out all possible causes for ITB delivery failure. 12. Tur ner MR, Gainsborough N. Neuroleptic
REFERENCES
malignant-like syndrome after abrupt withdrawal of Greenberg MI, Hendrickson RG. Baclofen with-
baclofen. J Psychopharmaco 2001;15(1):61-63.
drawal following removal of an intrathecal baclofen 13. Penn RD, York NM. Catheter systems for intrathe-
pump despite oral baclofen replacement. Clin Toxicol- cal drug delivery. J Neurosurg 1995; 83:215-7.
14. Lees AJ, Clarke CRA, Harrison MJ. Hallucinations
Swigar ME, Bowers MB. Baclofen withdrawal and
after withdrawal of baclofen. Lancet 1977; 1(8016): neuropsychiatric symptoms: a case report and review of other case literature. Compr Psychiatry 1986; 27: 15. Stien R. Hallucinations after sudden withdrawal of
baclofen. Lancet 1977; 2(8027): 444-5.
Hyser CL, Drake ME. Status epilepticus after ba-
16. Food and Drug Administration Med Watch. 2002
clofen withdrawal. J Natl Med Assoc 1984; 76(5):533- Safety Alert – Lioresal (baclofen injection). Accessed November 28, 2007. http://www.fda.gov/medwatch/ Garbedian-Ruffalo SM, Ruffalo RL. Adverse ef-
fects secondary to baclofen withdrawal. Drug Intell 17. Alden TD, L ytle RA, Park TS, Noetzel MJ,
Clin Pharma 1985; 19:304-306.
Ojemann JG. Intrathecal baclofen withdrawal: case
Rivas D, Chancellor MB, Hill K, Freedman M.
report and review of the literature. Child’s Nerv Syst Neurological manifestations of baclofen withdrawal. J Urology 1993; 150:1903-1905.
18. Pasquier Y, Cahana A, Schnider A. Subdural
Olmedo R, Hoffman RS. Withdrawal syndromes.
catheter migration may lead to baclofen pump dys- Emerg Med Clin North Am 200; 18(2): 273-88.
function. Spinal cord 2003; 41:700-7002.
Barker I, Grant IS. Convulsions after abrupt with-
19. Bardutzky J, Tronnier V, Schwab S, Meinck HM.
drawal of baclofen. Lancet 1982;2:556-7.
Intrathecal baclofen for stiff-person syndrome: life- Mandac BR, Hurvitz EA, Nelson V. Hyperthermia
threatening intermittent catheter leakage. Neurology associated with baclofen withdrawal and increased spasticity. Arch Phys Med Clin North AM, 2000:18:273- 20. Segal LS, Wallach DM, Kanev PM. Potential
complications of posterior spine fusion and instru- Coffey RJ et al. Abrupt withdrawal syndrome from
mentation in patients with cerebral palsy treated with intrathecal baclofen: recognition and management intrathecal baclofen infusion. Spine 2005; 30(8):E219- of a potentially life-threatening syndrome. Arch Phys Med Rehabil. 2002; 83:735-41.
21. Reeves RK, Stolp-Smith KA, Christopherson
10. Green LB, Nelson VS. Death after acute withdrawal
MW. Hyperthermia, rhabdomyolysis, and dissemi-
of intrathecal baclofen: case report and literature nated intravascular coagulation associated with ba- review. Arch Phys Med Rehabil 1999;80:1600-4.
clofen pump catheter failure. Arch Phys Med Rehabil1998;79:353-356.

Source: http://www.uiortho.com/ioj/2008/03Baclofen.pdf