This is the new name for the conditon formerly known as cervical spondylotic myelopathy, and is spinal cord dysfunction from compression in the neck due to degenerative change (disc herniation, ligament hypertrophy/ossification, osteophyte formation).
Presentation
Gradual onset and worsening of symptoms, which vary and may include:
- Neck pain and/or stiffness
- Limb or body pain; unilateral or bilateral
- Upper limb weakness, numbness, or loss of dexterity; may be unilateral or bilateral.
- Lower limb weakness, sensory loss, or stiffness; may be unilateral or bilateral.
- Paraesthesia
- Autonomic symptoms; bowel or bladder incontinence, erectile dysfunction, or difficulty PUing
- Unsteadiness/poor balance, sometimes leading to falls.
- Atypical symptoms; headaches, muscle cramps.
Symptoms can be insidious and the course, although generally downhill, is variable; patients may have mild stable symptoms for long periods of time, or a more rapid decline. Patients will typically have increasing loss of dexterity (difficulty with tasks such as doing up buttons, writing, using mobile phones) and/or mobility (may need walking aids/have frequent falls).
Examination
- Pyramidal weakness (UL worse in extensors, LL worse in flexors)
- Limb hyperreflexia
- Spasticity (claspknife sign)
- Clonus – esp Achilles tendon
- Babinski’s (upgoing plantars)
- Hoffman’s sign (flick the nail of the middle finger to flex it sharply, see whether there is any reflex contraction of the thumb and/or index on that hand)
- Segmental weakness at the level of compression
- Sensory loss (limb and/or trunk)
- Lhermitte’s sign (neck flexion or extension causes electric shock sensation down the spine/into the limbs – this is an indication that the problem is quite severe)
- Gait disturbance
Diagnosis
Requires MRI of the cervical spine, not surprisingly. This may be routine in patients with mild stable symptoms, but needs to be urgent in patients with progressive symptoms and/or symptoms substantially affecting quality of life. If MRI can’t be ordered directly, refer to neurology first if needed.
Note that scan findings do not correlate well with disease severity; mild compression can cause severe disease.
Treatment
Spinal decompression (although a wait-and-see approach may be appropriate for patients with mild, stable DCM).
Maximal recovery has usually taken place by around 6 – 12 months post-op; residual symptoms at this point are likely to be permanent.
DCM as an incidental finding
This is quite common, and does not need any treatment if asymptomatic; however, patients should be reviewed for symptoms and made aware of symptoms that need prompt reporting in the future.
BMJ: Degenerative cervical myelopathy
