FRCA Notes


Spinal Cord Pathology

The most pertinent curriculum item is perhaps: 'knowledge of the...effects of spinal cord section'.

Resources


  • Neurological level of injury is the most distal uninvolved spinal cord segment i.e. not necessarily the level of bony trauma

Complete section

  • Total loss of sensation from below the level of the lesion
  • Initial flaccid paralysis (spinal shock) leading to spastic paralysis
  • Immediate loss of reflexes, which begin to recover at 2 weeks but may take up to 6 weeks to recover
    • Flexor and anogenital reflexes are the first to recover
  • Arterial blood pressure becomes labile due to autonomic hyperactivity
  • Loss of voluntary sphincter tone
  • Lesions at the level of C4 and above tend to be fatal due to diaphragmatic paralysis via the phrenic nerve

Spinal cord hemi-section (Brown-Sequard syndrome)

  • Caused by lateral cord damage e.g. osteophyte impaction on half of the cord producing sensorimotor damage at the level of the injury
  • Leads to:
    • Ipsilateral paralysis (due to transection of the lateral corticospinal [pyramidal] tract)
    • Ipsilateral dorsal column effects (proprioception, touch, vibration)
    • Contralateral spinothalamic effects (pain and temperature)

Anterior spinal artery syndrome (a.k.a. anterior cord syndrome)

  • Interruption of blood flow through the (single) anterior spinal artery
  • May occur due to occlusion of the artery of Adamkiewicz
  • Clinical features:
    • Paraplegia (i.e. bilateral loss of motor function) below the level of lesion
    • Bilateral loss of temperature/pain sensation below the level of the lesion
    • Bilateral loss of sympathetic outflow, leading to hypotension
    • Loss of parasympathetic outflow causes bowel incontinence, urinary retention and sexual dysfunction

  • There is preservation of the dorsal columns i.e. fine touch and proprioception are unaffected

Central cord syndrome

  • Arises due to disruption of the central grey matter of the spinal cord e.g. from bleeding, oedema, infarction
  • Typically follows some C-spine injury, leading to an incomplete spinal cord injury
  • Causes:
    • Variable degree of sensory loss below the level of the injury, but typically affects spinothalamic pathways to a greater extent
    • Motor deficit, typically greater in the upper limbs vs. the lower limbs
  • Sacral nerve fibres are positioned laterally in the cord and the patient may demonstrate sacral sparing of sensory loss

Posterior cord syndrome

  • A rare syndrome associated with damage to the posterior spinal arteries
  • Produces loss of fine touch, vibration and proprioception below the level of the lesion

Cauda equina syndrome

  • Damage to the cauda equina below the conus medullaris (L5 - S1) causes the characteristic syndrome of:
    • Upper motor neurone weakness and altered sensation in both lower limbs
    • Saddle anaesthesia
    • Decreased anal sphincter tone
    • Bladder dysfunction
    • Bowel dysfunction
    • Sexual dysfunction

Syringomyelia

  • A cystic degenerative condition affecting the centre of the upper part of the spinal cord
  • Initially affects the decussating spinothalamic pathways and therefore bilateral upper limb pain and temperature sensory loss is the presenting symptom

Lumbosacral anterior horn cell damage

  • Reduced lower limb tendon jerk reflexes