Clinical Review Lesson of the week

Degenerative cervical disc disease causing cord compression in adults under 50

BMJ 2001; 322 doi: https://doi.org/10.1136/bmj.322.7283.414 (Published 17 February 2001) Cite this as: BMJ 2001;322:414
  1. P I Bentley, senior house officer,
  2. C J Grigor, senior house officer,
  3. J D McNally, specialist registrar,
  4. S Rigby, specialist registrar,
  5. C S Higgens, consultant,
  6. A O Frank, consultant,
  7. A Keat, consultant (andrew.keat{at}nph.npstm-tr.nthames.nhs.uk)
  1. Department of Rheumatology, Northwick Park and St Mark's NHS Trust, Harrow HA1 3UJ
  1. Correspondence to: A Keat
  • Accepted 20 January 2000

Cervical disc prolapse is a cause of an insidious myelopathy without necessary neck symptoms

Patients who present with a combination of back pain and neurological symptoms in the legs naturally prompt an initial search for pathology at the level of the lumbar spine, with lumbar disc prolapse being the most likely cause in patients under 50. Upper motor neurone signs in the legs, however, indicate that the abnormality must be above L1 on the neural axis. We describe three adults (aged 28-40) with these symptoms who were subsequently found to have severe degenerative cervical disc prolapse requiring prompt surgery.

Case reports

Case 1

A Sri Lankan man with insulin dependent diabetes initially presented at the age of 40 with lower back pain radiating to the left leg, in association with paraesthesia of both feet. Straight leg raising on the left was limited to 60° and the left foot had mild weakness. Reflexes of the lower limbs were symmetrically brisk, with equivocal plantar responses, and “stiffness” in the legs was attributed to painful movements. Results of sensory tests on the feet were normal. Symptoms of constipation and nocturia were ascribed to analgesics and diabetes. Computed tomography of the lumbar spine identified a disc prolapse at L4-5 with spinal stenosis, but magnetic resonance imaging failed to identify clear root compression and so surgery was not indicated.

He was referred again four years later, now using a wheelchair because of continued lower back pain and weakness in both legs. Repeat computed tomography of the lumbar spine showed little change. However, the legs were now definitely spastic and the plantar responses were now clearly extensor. Furthermore, the patient had early flexion contractures in both hips, both knees, and the left hand. A magnetic resonance image of the cervical spine showed a generally narrow spinal canal with three disc herniations between C4 and C7; there was maximal cord compression at C6-7 (figure). Furthermore, plain radiography showed ossification of the posterior longitudinal ligament in the cervical region. He was transferred for urgent decompression laminoplasty, but unfortunately his leg contractures had become irreversible, rendering him permanently disabled.


Embedded Image

T2 weighted magnetic resonance image showing cord compression secondary to extruded disc material and neighbouring osteophytes that is maximal at C6-7 (Case 1)

Case 2

A 28 year old Sri Lankan man presented with a three month history of progressive difficulty in walking and pain in the lower back and both knees. He also described altered sensation in both legs, as well as at the right shoulder, and “pins and needles” in both little fingers. On examination, both legs were spastic and wasted with extensor plantar responses, although power was graded 5/5 throughout. Examination of the cervical spine and neurology of the arms showed no abnormalities. Magnetic resonance imaging of the entire spine showed a large disc protrusion at C5-6 that impinged considerably on the cord; no changes caused by spondylosis were found. The patient underwent an anterior discectomy with a successful outcome.

Case 3

A 40 year old Indian man was referred with a three month history of unsteadiness on his feet, weakness in the left leg, and a burning sensation between the left knee and ankle. During the previous week he had developed neck pain that had come on suddenly with a jolt while he was standing on a train. Since then, he had noted that extending his neck caused a burning pain in both hands and down the length of the back. Examination showed pyramidal signs in both legs and weakness in left hip flexion. Tendon reflexes in the left arm were pathologically brisk and the right abductor digiti minimi showed mild weakness. The patient had a short neck and had pain on extension. Radiography of the cervical spine showed anterior osteophytes but no narrowing of the disc space. A magnetic resonance image of the same region showed a 50% cord compression secondary to a prolapsed disc at C6-7, as well as posterior disc bars along the three intervertebral spaces between C4 and C7. He proceeded to a decompression laminectomy, which resulted in gradual restoration of function.

Comment

The main features of cervical disc disease—neck pain, upper limb radiculopathy, and cord compression—may be obscured by subtle or misleading presentations.1 If nerve damage is not identified early then opportunities for effective treatment may be missed.2 In our three cases, the diagnosis was hampered because symptoms related principally to the lower back and legs. Furthermore, all three patients were under 50 years old (when cervical spondylosis is unlikely), and other causes of cervical disc disease—for example, trauma and tuberculosis—were notably absent.

Neck pain is a common accompaniment of cervical spondylosis or traumatic lesions but is typically absent in prolapse of the soft cervical disc, which has a slow, steady course and spares adjacent structures such as the facet joints.3 When cervical root lesions are present the symptoms may suggest alternative conditions such as angina pectoris (C3 and C4 supplying the upper chest; C5 to C8 supplying the arm) or shoulder lesions (C4 or C5). Motor dysfunction of the hands often manifests itself as “clumsiness” that mimics cerebral apraxia, rather than as objective weakness.4 Sensory disturbance in the hand may be misinterpreted as astereognosis rather than as numbness.4 Even when a root lesion is apparent, the clinically predicted site of the lesion may differ considerably from the actual site of the lesion shown by subsequent neuroimaging. 5 6

Cervical myelopathy may lead to an unsteady, stiff legged, broad based gait, which with hesitant, jerky, or shuffling movements simulates lesions in higher parts of the central nervous system. 1 2 This is partly due to damage to the posterior columnar, spinocerebellar, and corticospinal tracts, although the corticospinal tract is affected first in cord compression because it has a watershed arterial supply. Spasticity in the legs is more common than objective weakness, and sphincter disturbance is uncommon. 3 7 8 Pain and numbness in the soles of the feet is a common presentation of sensory disturbance.9 Other unusual but recognised presentations of cervical disc degeneration include headache, hemiparesis, hemidiaphragm paralysis, and Horner's syndrome because of involvement of the sympathetic chain.7 If anterior osteophytes are prominent, dysphagia due to oesophageal encroachment may be a feature.

Lower back pain is common in the population, and in two of our patients this served to distract from the true diagnosis. Moreover, this symptom might be expected to occur more often in patients with cervical spine degeneration: about 20% of patients with cervical spondylosis have coexisting lumbar spinal stenosis. 10 11 If the lumbosacral roots and cervical cord are simultaneously compressed, the resultant neurological picture may seem to be contradictory with upper and lower motor neurone signs in the legs.11

Prolapse of the soft cervical disc and cervical spondylosis are not rare in men. Prolapse of the soft cervical disc does not tend to have associated changes on radiography, and so this investigation cannot be relied on to exclude pronounced disc disease.8 Asian men seem especially prone to cervical cord compression because this group has a constitutionally narrower spinal canal and a higher incidence of ossification of the posterior longitudinal ligament, which predisposes to disc prolapse. 12 13

Acknowledgments

Contributors: PIB reviewed the literature and wrote the discussion. CJG wrote the individual case reports. JDM and SR initiated the idea and contributed core ideas. AOF and CSH wrote up individual cases. AK supplemented and revised the text; he acts as guarantor.

Footnotes

  • Funding None.

  • Competing interests None declared.

References

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