Epidural lipomatosis refers to an excessive accumulation of fat within the spinal epidural space resulting in compression of the thecal sac. In severe cases, compression may be symptomatic. The lumbar region is most frequently affected.
The demographics of affected individuals reflect the underlying causes: 5:
- glucocorticoid excess
- long term steroid administration (e.g. for asthma): 55% - most common
- endogenous Cushing syndrome: 3%
- obesity: 25%
- idiopathic: 17%
Symptoms are often non-specific and may be similar to other degenerative spinal conditions resulting in stenosis. Patients may present with a combination of pain, radicular symptoms, weakness, and paresthesia.
Macroscopic pathology is characterised by the abnormal accumulation of unencapsulated adipose tissue in the extradural space.
Epidural lipomatosis typically involves the lower lumbar and/or lower thoracic levels. Although the disease can be visualized with both CT and MRI, the latter is better able to identify impingement upon the cauda equina.
There is an often generalised excess of fat seen in the extradural space. As a result, the dural sac can appear narrowed or even resemble a "Y" shaped configuration.
Signal characteristics follow fat on all sequences:
- T1: high signal
- T1 (FS): shows fat suppression
- T2: high signal
Treatment and prognosis
In most instances no specific treatment is required, although review of need for steroid and weight loss are sensible interventions.
The use of epidural steroid injection is controversial. Some authors argue against it, on the grounds of existing compression and implication of steroids in the pathogenesis of epidural lipomatosis 5. Others report successful pain management 6.
In some patients symptoms are severe and operative decompression is required, and is usually successful 7,8.
- 1. Selmi F, Davies KG, Sharma RR et-al. Idiopathic spinal extradural lipomatosis in a non-obese otherwise healthy man. Br J Neurosurg. 1994;8 (3): 355-8. Pubmed citation
- 2. Geers C, Lecouvet FE, Behets C et-al. Polygonal deformation of the dural sac in lumbar epidural lipomatosis: anatomic explanation by the presence of meningovertebral ligaments. AJNR Am J Neuroradiol. 2003;24 (7): 1276-82. Pubmed citation
- 3. Robertson SC, Traynelis VC, Follett KA et-al. Idiopathic spinal epidural lipomatosis. Neurosurgery. 1997;41 (1): 68-74. Pubmed citation
- 4. Flisberg P, Thomas O, Geijer B et-al. Epidural lipomatosis and congenital small spinal canal in spinal anaesthesia: a case report and review of the literature. J Med Case Rep. 2009;3 (1): 128. doi:10.1186/1752-1947-3-128 - Free text at pubmed - Pubmed citation
- 5. Rustom DH, Gupta D, Chakrabortty S. Epidural lipomatosis: A dilemma in interventional pain management for the use of epidural Steroids. J Anaesthesiol Clin Pharmacol. 2013;29 (3): 410-1. doi:10.4103/0970-9185.117070 - Free text at pubmed - Pubmed citation
- 6. Botwin KP, Sakalkale DP. Epidural steroid injections in the treatment of symptomatic lumbar spinal stenosis associated with epidural lipomatosis. Am J Phys Med Rehabil. 2005;83 (12): 926-30. Pubmed citation
- 7. Payer M, Van Schaeybroeck P, Reverdin A et-al. Idiopathic symptomatic epidural lipomatosis of the lumbar spine. Acta Neurochir (Wien). 2003;145 (4): 315-20. doi:10.1007/s00701-003-0001-x - Pubmed citation
- 8. Bodelier AG, Groeneveld W, van der Linden AN et-al. Symptomatic epidural lipomatosis in ectopic Cushing's syndrome. Eur. J. Endocrinol. 2005;151 (6): 765-9. Pubmed citation