Cervical Myelopathy

Relevant physical signs

• Inspection
  • Wasting of myotonal muscle groups (may be asymmetrical)
  • Fasciculations
  • Surgical scars around the neck
  • Pseudoathetosis
  • Grip and release sign: ask the patient to open and close the fist rapidly 20 times – patients with cervical myelopathy often have difficulty doing this
• Tone
  • Flaccid at the level of the lesion
  • Spastic in the lower limbs
• Reflexes
  • Brisk below the level of the lesion
  • Depressed or absent at the level of the lesion
  • C5/6 lesion: absent biceps reflex, inverted supinator jerk, brisk triceps reflex
  • Hoffman’s sign
  • If all upper limb reflexes are brisk:
    • Test jaw jerk to look if level of lesion is at the brainstem
    • Pectoralis jerk present if the lesion is higher than C3
• Power
  • Preserved above the level of the lesion
  • Pyramidal weakness below the level of the lesion
• Coordination
  • Only test if power is more than 4/5 in the upper limbs
  • Coordination usually preserved in cervical myelopathy
  • If cerebellar signs are present, consider
    • Demyelination – relative afferent pupillary defect, inter-nuclear ophthalmoplegia
    • Degenerative – spinocerebellar ataxia, Friedrich’s ataxia
• Sensation
  • Loss to all modalities of sensation in a dermatomal distribution
  • Dorsal column sensation usually affected first
• Complete examination by:
  • Examining the lower limbs for spastic Paraparesis
  • Examining the cranial nerves
  • Palpating the bladder for urinary retention
  • Doing a digital rectal examination

Differential diagnosis of cervical myelopathy

• Cervical spondylosis
• Inflammatory
  • Transverse myelitis
  • Multiple sclerosis
• Infectious
  • Epidural abscess
  • Taboparesis
• Subacute combined degeneration of the cord (B12 deficiency)
• Friedrich’s ataxia
• Syringomyelia (would expect dissociated sensory loss affecting pain and temperature first)
• Neoplastic: tumour of the spinal cord
• Anterior spinal artery thrombosis (only if dorsal columns preserved)

 Investigations

• Cervical spine radiographs
  • Examine intervertebral disc height
  • Facet joints
  • Look for osteophyte formation
  • Look at absolute sagittal diameter of the spinal cord
• Magnetic resonance imaging of the cervical spine
  • Look for cervical myelopathy
  • Diagnose cervical spondylosis
• B12 levels
• Syphilis antibody
• If demyelinating lesion suspected
  • Lumbar puncture to look for
    • Oligoclonal bands
    • Aquaporin-4 antibodies if concurrent optic neuritis
  • Magnetic resonance imaging of the brain
  • Visual evoked potentials

Management

• Patient education
• Physiotherapy and occupational therapy to maximize and preserve function
• Analgesia
• Referral to neurosurgery for decompression
  • Decompressive discectomy and foraminotomy
  • Hemilaminectomy
  • Laminoplasty

Summary

Sir, this patient has wasting of the proximal muscles of the forearm. The biceps reflex is absent, and there is an inverted supinator jerk. The triceps reflex is brisk. There is pyramidal weakness, and proprioceptive loss. Sensation to pinprick is reduced in a dermatomal fashion. Coordination is not affected. This is most in keeping with cervical myelopathy at the level of C5/6. The most likely causes of this are cervical spondylosis, inflammatory disorders such as transverse myelitis or multiple sclerosis, or vitamin B12 deficiency. Other possibilities include taboparesis, syringomyelia, or a neoplastic process within the meninges of the cord.