Clinical features

The clinical features of subacute combined degeneration of the spinal cord are based on:

• symmetrical loss of posterior columns causing an ataxic gait
• symmetrical upper motor neurone signs in the lower limbs with absent reflexes
• other features:
  • peripheral sensory neuropathy
  • optic atrophy
  • dementia

Symptoms may include:

• paraesthesiae
• unsteadiness; perhaps severe enough to prevent walking
• weakness
• stiffness of legs

Signs include:

• spasticity in legs
• hyporeflexia at the knees
• loss of ankle jerks
• extensor plantar responses
• impaired posterior column function

NB: there may also be a sphincter disturbance with a dilated hypotonic bladder and a loss of sense of bladder fullness.