Anesth Analg 2000;91:429-431
© 2000 International Anesthesia Research Society
REGIONAL ANESTHESIA AND PAIN MEDICINE
Intrathecal Baclofen Pump Implantation Complicated by Epidural Lipomatosis
Hussein A. Huraibi, MD*,
Joseph Phillips, MD, PhD
,
Robert J. Rose, MD*,
Henry Pallatroni, MD,
Heloise Westbrook, MD, PhD*, and
Gilbert J. Fanciullo, MD*
Departments of
*Anesthesiology and
Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
Address correspondence to Gilbert J. Fanciullo, MD, Pain Management Center, Dartmouth-Hitchcock Medical Center, One Medical Center Dr., Lebanon, NH 03756. Address e-mail to Gilbert.J.Fanciullo{at}Hitchcock.org
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Abstract
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Implications: Intrathecal baclofen is a useful therapy in patients with spasticity. We describe a patient who underwent an intrathecal pump implant, complicated by epidural lipomatosis that ultimately required a single level laminectomy and fat debulking before successful implantation.
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Introduction
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Intrathecal (IT) baclofen decreases spasticity in patients with cerebral palsy, multiple sclerosis, and spinal cord and brain injuries (1–3). IT baclofen therapy can effectively alleviate spasticity and mitigate unacceptable side effects of oral antispasmodics (i.e., somnolence, muscle weakness, confusion, and nausea) when they may have proven effective, but caused unacceptable adverse reactions (2,3). We describe a patient with severe spasticity caused by cerebral palsy whose IT baclofen pump implantation was complicated by epidural lipomatosis, a pathologic accumulation of normal, unencapsulated adipose tissue in the epidural space.
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Case Report
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A 16-yr-old nonverbal patient with cerebral palsy and mental retardation complicated by severe muscular spasticity of all four extremities was referred to the pain center for a consideration of IT baclofen therapy. Large doses of oral baclofen alone had reduced most of his spasticity, but with excessive sedation. Dressing, feeding, and urinary bladder catheterization had become difficult because of the severe spasticity.
Before IT baclofen administration, the patient’s extremities were rigid in extension and flexion with considerable increase in tone with passive movement. An IT injection of 75 µg of baclofen diluted to a volume of 3 mL with preservative-free normal saline resulted in a substantial reduction in his spasticity. Ninety minutes after injection, he had only a slight increase in tone. His IT access was technically difficult, requiring multiple, nonbloody attempts to pass between bony structures starting at L5-S1, ultimately gaining access more cephalad through the L2-3 interspace, where clear cerebrospinal fluid was obtained. Potential risks of permanent IT baclofen therapy, which include spinal headache, skin infection, bacterial meningitis, epidural hematoma, and nerve injury, were discussed. Benefits include reducing spasticity, optimizing function, and potentially avoiding side effects (4). After careful consideration, it was decided to proceed.
Under monitored anesthesia care, and with the patient in the left lateral recumbent position, 1% Xylocaine-MPF (Astra USA, Inc., Westborough, MA) was used to infiltrate the overlying tissues of the L3-4 interspace. Multiple attempts to access the IT space by using midline and paramedian approaches with a 15-gauge Touhy needle at the L3-4, L4-5, and L5-S1 interspaces were not successful under fluoroscopic guidance. A neurosurgeon familiar with our case and often involved in complex pain cases was asked to assist. With local anesthetic infiltration, dissection was performed down to the spinous process and lamina of L4. The dorsal most portion of the lamina was removed, and an unusual amount of epidural fat was noted. A 4.2F catheter (InDura Model 8703W; Medtronic, Inc., Minneapolis, MN) was threaded approximately 5 cm intrathecally and, after aspiration of clear fluid, 3 mL of Isovue® M300 (Bracco Diagnostics Inc., Princeton, NJ) was injected. A fluoroscopic image depicted well delineated, bilaterally ascending columns, which were thought to have represented either a subdural placement or a very narrow thecal sac. Further attempts precipitated elevations in pulse rate and blood pressure and similar radiographs. The catheter was removed and the procedure was aborted.
A magnetic resonance image was obtained, and it showed marked thoracolumbar epidural lipomatosis profoundly compressing the thecal sac, resulting in significant spinal cord atrophy, which could be seen in a sagittal and cross-sectional view (Figs. 1 and 2). A multilevel laminectomy, excision of epidural fat, and placement of an IT catheter with a programmable infusion pump (SynchroMed; Medtronic, Inc.) was planned. A single-level laminectomy at L4 was performed under local anesthesia, and epidural fat was removed to facilitate the placement of an IT catheter. This was successfully connected to the implanted infusion pump (SynchroMed) and was initially programmed to deliver an IT dose of 150 µg/day of baclofen. The dose was increased incrementally until a rate of 234 µg/day provided relief similar to that obtained during his trial.
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Figure 1. Cross-sectional and sagittal view of extensive epidural lipomatosis. The left image (arrow) depicts marked spinal cord atrophy and compression by the epidural fat. The right image (arrow) depicts the extensive lumbar involvement.
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Figure 2. Thoracolumbar sagittal view demonstrating the extensive nature of the epidural lipomatosis. Notice the extent of its thickness when compared with the spinal cord (arrow).
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Discussion
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The prevalence of epidural lipomatosis is unknown. Hogan (5) examined 28 fresh cadavers using cryomicrotome sectioning and found epidural lipomatosis in two subjects. One had been treated with chronic steroids for a brain tumor. Stern et al. (6) conducted a review of the literature from 1979 to 1991 and found that 75%, or 35 of 47 patients, of reported cases of epidural lipomatosis occurred in those who were taking steroids chronically for medical diseases. It has been reported in patients with a history of chronic corticosteroid therapy (6,7), in morbidly obese patients (6,8), in those treated with epidural steroid injections (9), and in those without distinguishing characteristics (10,11).
Abnormal epidural fat deposition is often found in patients with exogenous or endogenous Cushing syndrome (7,8,10). Patients with abnormal accumulations of epidural fat may present with nonspecific back pain with or without radiculopathy or, more ominously, with spinal cord or cauda equina compression symptoms consisting of lower extremity weakness, bowel and bladder incontinence, paresthesia, and/or paraplegia (6,12). A clinical study of 25 patients diagnosed with epidural lipomatosis found that the most common characteristics at presentation were pain (88%), weakness (64%), numbness (36%), sensory loss (52%), abnormal reflexes (52%), and incontinence (16%) (8). Laminectomy with fat debulking was the treatment of choice. Most regained normal function if the index of suspicion was high and the treatment was expeditiously performed before irreversible neurological impairment occurred (6).
In the case of our patient, it was impossible to determine if pain, abnormal reflexes, or incontinence preceded the accumulation of epidural fat. There was no documented reason for the accumulation of abnormal amounts of epidural fat. He was not taking steroids, he was not obese, he had not received epidural steroid injections. Despite the presence of this abnormality, and the subsequent difficulty accomplishing the therapeutic goal, the system was successfully implanted, and a good clinical outcome was achieved.
The placement of IT catheters for baclofen administration is a proven modality for treatment of spasticity refractory to usual therapies. Unsuspected pathology, such as epidural lipomatosis, may make placement difficult. The incidence of epidural lipomatosis is unknown, but is more common in those individuals who have been treated with steroids, those who have had epidural steroid injections, or those who are obese.
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References
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Caviness VS Jr. Developmental disorders of the CNS. 13th ed. In: Isselbacher KJ, Braunwald E, Wilson JD, et al. Harrison’s principle of internal medicine. New York: McGraw-Hill, 1994:2342.
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Armstrong RW, Steinbok P, Cochrane DD, et al. Intrathecally administered baclofen for treatment of children with spasticity of cerebral origin. J Neurosurg 1997;87:409–14.[Web of Science][Medline]
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Albright AL, Cervi A, Singletary J. Intrathecal baclofen for spasticity in cerebral palsy. JAMA 1991;265:1418–22.[Abstract/Free Full Text]
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Gianino JM, York MM, Paice JA. Intrathecal drug therapy for spasticity and pain. New York:Springer, 1996.
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Hogan QH. Epidural anatomy examined by cryomicrotome section. Reg Anesth 1996;21:5:395–406.
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Stern JD, Quint DJ, Sweasey TA, Hoff JT. Spinal epidural lipomatosis: two new idiopathic cases and a review of the literature. J Spinal Disord 1994;7:4:343–9.
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Sivakumar K, Sheinart K, Lidov M, Cohen B. Symptomatic spinal epidural lipomatosis in a patient with Cushing’s Disease. Neurology 1995;45:2281–3.[Abstract/Free Full Text]
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Robertson SC, Traynelis VC, Follett KA, Menezes AH. Idiopathic spinal epidural lipomatosis. Neurosurgery 1997;41:68–74.[Web of Science][Medline]
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Sandberg DI, Lavyne MH. symptomatic spinal epidural lipomatosis after local epidural corticosteroid injections: case report. Neurosurgery 1999;45:162–4.[Web of Science][Medline]
-
Quint DJ, Boulos RS, Sanders WP, et al. Epidural lipomatosis. Radiology 1988;169:485–90.[Abstract/Free Full Text]
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Bednar DA, Esses SI, Kucharczyk W. Symptomatic lumbar epidural lipomatosis in a normal male. Spine 1990;15:52–3.[Web of Science][Medline]
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Kuhn MJ, Youssef HT, Swan TL, Swenson LC. Lumbar epidural lipomatosis: the "Y" sign of thecal sac compression. Comput Med Imaging Graph 1994;18:5:367–72.
Accepted for publication April 27, 2000.
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Abstract
Introduction
