Br. J. Surg. Vol. 65 (1978) 842-844

Lumbar radiculopathy contralateral to upper lumbar disc herniation : report of 3 cases A. R. CHOUDHURY, J. C. TAYLOR, B. S . WORTHINGTON A N D R. WHITAKER*

SUMMARY Three cases of lumbar radiculopathy contralateral to an upper lumbar disc herniation are reported. This clinical syndrome is explained on the basis ofprominent spondy- lotic changes and stenosis contralateral to the side of disc herniation associated with anatomical anomalies of lumbar nerve roots. The disc herniation causes dis- placement and impaction of the dural sac with the emerging nerve roots in a narrowed lateral recess.

RADICULAR symptomatology is usually ipsilateral in the common lateral type of lumbar disc herniation in its early stages, but after a period of time may become bilateral. Three cases are reported of upper lumbar, lateral disc herniation in patients who presented with lumbar backache associated with radiculopathy of the lower limb contralateral to the side of herniation. Such cases have not been reported previously to our knowledge. The purpose of this communication is to emphasize the occurrence of this clinical syndrome and to explain its causation.

Case reports Case 1 : A 55-year-old man was seen in July 1976 because of lumbar backache and left-sided anterior thigh and leg pain for the past 8 years. His low back pain was aching in nature and persisted at night. In addition, activity caused an increase in lower limb pain resembling claudication. For 8 months he had suffered from weakness and numbness of the left leg. The symptoms had arisen following a fall from a height, and con- servative methods of treatment, including a plaster corset and leg traction, were unsuccessful. Examination revealed restric- tion, especially of left lateral movement of the lumbar spine, a positive left femoral nerve stretch test, left-sided moderate weakness of the quadriceps, a reduced left knee jerk and hypoalgesia over the left L3 and L4 dermatomes. Plain X-rays of the spine showed evidence of spondylosis. A myelogram (Fig. 1) revealed evidence of a right lateral disc herniation at L3-4 level.

A wide, decompressive laminectomy, including excision of the overhanging facet joints and extending from L2 to L5 laminae, was performed and the herniated disc removed. The facet joints were found to be hypertrophied from L2 to L5, causing narrowing of the spinal canal, most prominently at L3 and L4 level on the left side. At this point the dura was indented forwards by the enlarged facets. Only after extending the facetectomy laterally to remove most of the superior facets, thus unroofing completely the lateral recess, did the dura take a normal contour. It was now possible to retract and free the L3 and L4 nerve roots. The disc spaces were explored bilaterally a t all levels. A disc hernia was found at the L3-4 space on the right side, lateral to the posterior longitudinal ligament. This displaced only the dura without encroachment on nerve roots. There were, in addition, osteophytic ridges, varying in degree, a t all levels. The right L4 root was seen to emerge from the dural sac near the lower border of L4 vertebra, taking a horizontal course to its exit foramen (Fig. 2 4 .

All the patient’s symptoms disappeared within a month, and he resumed normal activity after a further month. When seen 16 months later he was well and asymptomatic. Case 2: A 60-year-old man was seen in February 1977 in another hospital because of a 6-week history of hesitancy of micturition and retention of urine for 3 days. For 2 weeks he had suffered from lumbar backache associated with pain

Fig. 1. Case 1. Anteroposterior myelogram showing a rounded filling defect on the right side at the level of the L3-4 disc interspace.

radiating down the right anterior thigh. An intravenous pyelogram and cystoscopy revealed n o abnormality. Plain X-rays of the spine showed minor degenerative arthritis, and a myelogram (Fig. 3) revealed evidence of a left lateral disc herniation at L2-3 level. The patient was then referred to this department.

On admission there was restriction of right lateral lumbar spinal movement and a positive right femoral nerve stretch test. Findings on neurological examination were some wasting of the quadriceps, reduced knee jerk and hyperalgesia over the L2-S3 dermatomes on the right side. Another myelogram again showed a left-sided filling defect at L2-3 level.

A wide decompressive laminectomy, including excision of the overhanging facet joints and extending over the L2 and L3 laminae, was performed and the herniated disc removed. The hypertrophy of the facet joints was most prominent on the right side. The dura was found to be displaced forwards under these facets. Bone removal was extended laterally to include part of the superior facet to unroof the lateral recess completely. The dura now took up a normal contour and the right L2 and L3 nerve roots could be retracted and freed. The disc spaces were explored bilaterally and a hernia found at L2-3 level on the left side, lateral to posterior longitudinal ligament, displacing only the dura and not encroaching on the nerve roots. The left L3 root was seen to emerge from the dural sac at the level of the lower border of the L3 vertebra and took a horizontal course to its exit foramen (Fig. 2B). ~~~~~~ ~~

* Regional Departments of Neurosurgery and Neuroradiology, Derbyshire Royal Infirmary, Derby.

Lumbar radiculopathy and disc herniation 843

L R L R L R

L3

A B C Fig. 2. Diagrammatic illustration of the disc hernias and nerve root anomalies. A , Case 1. Right lateral L3-4 disc hernia together with a transverse (post-fixed) L4 root. B, Case 2. Left lateral L2-3 disc hernia together with transverse (post-fixed) L3 root. C, Case 3. Left lateral L3-4 disc hernia together with conjoined L3 and L4 roots (pre-fixation).

Fig. 3. Case 2. Anteroposterior myelogram showing a rounded filling defect on the left side at the level of the L2-3 disc interspace. Some of the Myodil is extra-arachnoid.

Fig. 4. Case 3. Anteroposterior myelogram showing a rounded filling defect on the left side at the level of the L3-4 disc interspace.

The patient’s symptoms had disappeared 6 weeks later when he resumed normal activity. When seen 10 months later he was well and asymptomatic.

had suffered from pain radiating down the right anterior thigh and inner leg which was aggravated by activity. Traction in hos~i ta l made the Dain worse. Examination revealed restriction

Case 3: A 36-year-old man was seen in May 1977 because of recurrent episodes of lumbar backache for the previous 7 years. His symptoms had developed after lifting a heavy weight, and treatment had been rest and physiotherapy. For 6 months he

of iight lateral lumbar spinal movement and a positive right femoral nerve stretch test. Findings on neurological examina- tion were normal except for hypoalgesia over L3 dermatome. Plain X-rays of the spine were normal, but a myelogram (Fig. 4)

844 A. R. Choudhury et al.

revealed evidence of a left lateral disc herniation at L3-4 level.

A wide decompressive laminectomy with excision of the overhanging facet joints and extending from L3 to L4 laminae was performed and the herniated disc was removed. The hyper- trophy of the facet joints was found to be most prominent on the right side. The dura was displaced forwards under the facets and bone removal was extended laterally to include part of the superior facets in order to unroof the lateral recess. The dura now took a normal contour and the right L3 and L4 nerve roots could be retracted and freed. The disc spaces were explored on both sides and a hernia was found at L3-4 level on the left side, lateral to the posterior longitudinal ligament. The dura only was displaced by this hernia, which did not in- volve the L3 root above, which was grossly enlarged; the L4 root was absent (Fig. 2C).

Symptoms had disappeared a month later, and the patient resumed normal activity after another 2 weeks. When seen 7 months later he was well and asymptomatic.

Discussion Exploration through a wide laminectomy with excision of overhanging facet joints showed disc herniation lateral to the posterior longitudinal ligament in these cases. There was marked segmental narrowing of the canal contralateral to the side of herniation, owing to pronounced spondylotic changes in the facet joints, and the dural sac was displaced and impacted in the narrowed lateral recess with its emerging nerve roots. The adjacent lower roots, i.e. L4 in Case 1 and L3 in Case 2, were seen coming off the dural sheath near the lower border of L4 and L3 vertebrae respectively. They took a straight lateral course to emerge through the intervertebral foramina like the transverse roots described by Cannon et al. (1962), and thus escaped compression from the herniated discs. In Case 3 the L4 root was not seen but the L3 root was found to be unusually large, and this root was similar to the con- joined root described by Cannon et al. (1962). These changes in nerve roots may be explained on a basis of pre- and post-fixation. The roots of the cauda equina can be demonstrated by radiculography ; this would have been a preferable method of investigation had it been available at the time.

The lumbar nerve root with its sheath comes off the dural sac near the upper border of the vertebra and courses downwards in the lateral recess before it emerges through the intervertebral foramen above the level of the disc. Thus, in the common lateral disc herniation the adjacent lower root on the same side is affected, i.e. in the case of the third lumbar disc the fourth lumbar root is affected. A compression mono- radiculopathy is, therefore, the usual manifestation of a lateral disc hernia in its early stages.

After a period of time secondary spondylotic changes of the posterior facet joints with consequent segmental narrowing of the spinal canal occur, and cause a poly-radicular compression neuropathy. Nar- rowing is bilateral, usually more pronounced ipsi- laterally, but occasionally may be contralateral to the disc herniation (Paine and Huang, 1972). Again, secondary spondylosis may be seen concomitantly with acute disc herniation, suggesting a more long- standing degenerative process (Friberg, 1948 ; Munro, 1956; Lewin, 1964; Paine and Huang, 1972). The history of radiculopathy was short in the present Cases 2 and 3 and the spondylotic changes were both prominent and contralateral to the side of the hernia- tion, indicating a long-standing degenerative process associated with an acute disc herniation. A long history of radiculopathy associated with multiseg- mental narrowing of the lumbar canal in Case 1 indi- cates herniation in a primary spondylotic canal. Such prominent spondylotic changes, especially contra- lateral to the side of disc herniation, when associated with anatomical anomalies of the nerve roots may explain the symptoms on the side opposite to that of the disc hernia. The ipsilateral nerve root immediately related to the disc hernia remains uninvolved because of its abnormality.

Anomalies are found more commonly in the upper lumbar roots than in the lower (Zagnoni, 1949), and this may explain the occurrence of a contralateral syndrome in the rare, upper lumbar disc hernia. Acknowledgement We would like to express our gratitude to Miss Barbara Tustin Smith for her help in the preparation and typing of the manuscript.

References CANNON B. W., HUNTER S. E. and PICAZA J. A. (1962) Nerve root

anomalies in lumbar disc surgery. J. Neurosurg. 19, 208- 216.

FRIBERG s. (1948) Anatomical studies on lumbar disc degenera- tion. Acta Orthop. Scand. 17, 224-230.

LEWIN T. (1964) Osteoarthritis in lumbar synovial joints: a morphologic study. Acta Orthop. Scnnd. (Suppl). 73, 1-112.

MUNRO D. (1956) Lumbar and sacral compression radiculitis (herniated lumbar disc syndrome). N. Engl. J. Med. 254,

PAINE K. w. E. and HUANG P. w. H. (1972) Lumbar disc syndrome. J. Neurosurg. 31, 75-92.

ZAGNONI c. (1949) Reperto di un tip0 non conosciuto di anastomosi nervosa delle radici spinali. Atti SOC. Med. Ct'air. Padova 27, 48-52.

243-252.

Paper accepted 22.5.1978.