Spinal Epidural Lipomatosis

Fatty Accumulation Within the Central Canal of the Spine

By William Morgan, DC


I feel that this condition warrants more mainstream exposure than it currently receives. Although this malady is thought to be rare, I am seeing more patients with it, and frequently the MRI report gives only passing acknowledgment of its existence. It is my hope that the next time you read something along the lines of “excess epidural fat accumulation in the canal,” you will take the time to look at the MRI to see the extent of the epidural fat deposition and look more carefully for neurological signs.

Spinal epidural lipomatosis (SEL), the excessive fat deposition in the spinal canal, is responsible for compression of neural tissues (e.g., nerve roots or cord) that can cause nerve root symptoms and myelopathy. SEL is commonly seen in patients with endocrinopathy or obesity or in those receiving protracted steroid therapy. Idiopathic SEL is rare but has also been documented. SEL can cause back pain, nerve root impingement and cord compression. Slowly progressing myelopathy is the normal presentation of a patient with SEL.

MRI Images
The MRI images shown here demonstrate excessive fat deposition posterior to the vertebral bodies and anterior to the spinal canal (Figures 1, 2, 3 and 4). Epidural lipomatosis has been attributed to various compression findings on MRIs, including the “Y” sign (Figure 2). This is caused by the compression of the thecal sac into a trifid shape that looks much like a “Y” (Kuhn, et al.).

Increased obesity in the developed world may contribute to a rise in the occurrence of this condition, but the increase in the prevalence of MRIs has also been cited as a cause for more frequent diagnosis of this condition.

SEL cannot be diagnosed on plain film radiography or on physical examination. Prior to the advent of MRI, lipomatosis was identified serendipitously during spinal surgery.

Obesity and Conservative Care
Conservative care includes stopping steroid therapy and losing weight (in obese patients). However, in severe or refractory cases, a consultation to a spine surgeon may be appropriate.

With increasing rates of obesity in the Western world, we may begin to see a surge in the number of obesity-related cases of spinal epidural lipomatosis.

References

1. Fassett DR, Schmidt MH. Spinal Epidural Lipomatosis: A Review of Its Causes and Recommendations for Treatment.

2. Beges C, Rousselin B, Chevrot A, et al. Epidural lipomatosis. Interest of magnetic resonance imaging in a weight-reduction treated case. Spine 19:251– 254, 1994.

3. Payer M, Van Schaeybroeck P, Reverdin A, et al. Idiopathic symptomatic epidural lipomatosis of the lumbar spine. Acta Neurochir 145:315–321, 2003.

4. Robertson SC, Traynelis VC, Follett KA, et al. Idiopathic spinal epidural lipomatosis. Neurosurgery 41:68–75, 1997.

5. Kuhn MJ, Yussef HT, Swan TL, Swenson LC. Lumbar epidural lipomatosis: the “Y” sign of thecal sac compression Comput Med Imaging Graph. 1994 Sep-Oct;18(5):367-72.

6. Fessler RG, Johnson DL, Brown FD, et al. Epidural lipomatosis in steroid-treated patients. Spine 17:183–188, 1992

Dr. Morgan shares his clinical time among a hospital-based chiropractic clinic and two Washington, D.C., executive health clinics. He is adjunct faculty for F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences and New York College of Chiropractic. He can be reached through his Web site, www.drmorgan.info.

 

Published in April 2012 ACA News.