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Year : 2013  |  Volume : 61  |  Issue : 5  |  Page : 562-

The significance of redundant nerve roots of cauda equina

S Rajesh Reddy, BG Ratnam, Rahul Lath, Alok Ranjan 
 Department of Neurosurgery, Apollo Hospital, Jubilee Hills, Hyderabad, Andhra Pradesh, India

Correspondence Address:
S Rajesh Reddy
Department of Neurosurgery, Apollo Hospital, Jubilee Hills, Hyderabad, Andhra Pradesh
India




How to cite this article:
Reddy S R, Ratnam B G, Lath R, Ranjan A. The significance of redundant nerve roots of cauda equina.Neurol India 2013;61:562-562


How to cite this URL:
Reddy S R, Ratnam B G, Lath R, Ranjan A. The significance of redundant nerve roots of cauda equina. Neurol India [serial online] 2013 [cited 2022 Aug 8 ];61:562-562
Available from: https://www.neurologyindia.com/text.asp?2013/61/5/562/121958


Full Text

Sir,

A 60-year-old male patient presented with the symptoms of neurogenic claudication of 3 years duration with a claudication distance of 10 m at admission. Examination revealed no neurological deficits at rest. Magnetic resonance imaging (MRI) lumbar spine showed spinal canal narrowing in the lumbar region with redundant nerve roots forming coiled loops within the thecal sac [Figure 1]a and b. Axial image showed disc bulge, hypertrophied facets, trefoil shape of thecal sac, decreased ratio of cerebrospinal fluid (CSF) to nerve roots and the absence of nerve root sedimentation suggesting severe spinal stenosis at L4/5 level [Figure 1]c. Patient underwent lumbar laminectomy and bilateral neural foraminotomy. Intra operatively, the dura mater was thin and compressed by the hypertrophied facets and ligamentum flavum. In spite of caution taken during the decompression of the thecal sac, there was a small (<5 mm) accidental dural tear through which the redundant nerve roots had prolapsed out like a bag of worms. Under normal circumstances, only CSF would leak through such a defect. However, in our patient there was significant compression of the thecal sac from outside as well as from within (from the redundant nerve roots) which predisposed them to herniate out. The dural tear had to be extended to push the nerve roots in and the dural closure was reinforced over a fat graft. Patient had an uneventful post-operative recovery with relief of symptoms.{Figure 1}

Redundant nerve roots refer to thickened, tortuous and elongated roots of the cauda equina above the level of a long standing, severe extradural compression. This condition was first described on myelography in 1967 as severe extradural blocks associated with lumbar spinal stenosis and multiple filling defects above the block due to serpiginous elongated nerve roots. Acquired elongation of nerve roots due to the mechanical trapping at the level of lumbar spinal stenosis is assumed to be the possible mechanism. It is believed that the cause is a squeezing force due to the chronic compression and is precipitated by heavy manual work. [1]

Patients with redundant nerve roots are older, exhibit a longer period from the onset of the symptoms to the time of MRI, and experience more symptoms. [1],[2] Redundant roots are associated with severe, long standing extradural compression and might be confused with a vascular malformation or as plexiform neurofibroma of cauda equina. [3] Extreme caution should be taken during surgery and one must be prepared for potential duraplasty because redundant nerve roots are difficult to replace into the dural sac once they herniate through a dural tear. Analysis of surgical outcomes showed that patients of lumbar canal stenosis without redundant nerve roots had a slightly better (but not statistically significant) surgical outcome than patients with redundant nerve roots. [4]

References

1Suzuki K, Ishida Y, Ohmori K, Sakai H, Hashizume Y. Redundant nerve roots of the cauda equina: Clinical aspects and consideration of pathogenesis. Neurosurgery 1989;24:521-8.
2Ono A, Suetsuna F, Irie T, Yokoyama T, Numasawa T, Wada K, et al. Clinical significance of the redundant nerve roots of the cauda equina documented on magnetic resonance imaging. J Neurosurg Spine 2007;7:27-32.
3Hakan T, Celikoðlu E, Aydoseli A, Demir K. The redundant nerve root syndrome of the Cauda equina. Turk Neurosurg 2008;18:204-6.
4Min JH, Jang JS, Lee SH. Clinical significance of redundant nerve roots of the cauda equina in lumbar spinal stenosis. Clin Neurol Neurosurg 2008;110:14-8.