Saturday 25 September 2010

MRCP revision battle 20.3: Subacute combined degeneration of the spinal cord

Subacute combined degeneration of the spinal cord is one of those conditions which does exactly what it says on the tin:
  • subacute - it's onset is insidious
  • combined degeneration - both dorsal and lateral columns affected
  • of the spinal cord

The loss of dorsal columns causes sensory and LMN signs, while the lateral (corticospinal) column loss cause motor and UMN signs.


Clinically the classical triad is:
  • extensor plantars (UMN)
  • absent knee jerks (LMN)
  • absent ankle jerks (LMN)

Pain and temperature sensation are preserved as the spinothalamic tracts are preserved.


Subacute combined degeneration of the spinal cord is caused by B12 deficiency.   Treatment is with B12, with varying levels of success.


Now it seems only sensible to have a quick recap of B12....