Question 14

A  24-year-old   male   mountain  bike   rider  crashes   into   a   tree,  resulting  in   a   severe hyperextension neck injury, and fractured lower left ribs.  He now presents to hospital  with shock and a painful distending  abdomen. He returns from the operating theatre after a splenectomy.   

After another 24 hours it is apparent that he has a complete spinal cord lesion at C4.

What signs of this lesion are likely to be present?

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College Answer

Tone: Tone may well still be decreased (though with time this will increase, with posturing developing in an upper motor neurone distribution: some flexion of upper limb if incomplete level to C6). Anal tone would be lax with a complete lesion.

Power: Quadriparesis would be expected, with no movement below deltoid. Respiratory muscles may be significantly compromised.

Reflexes: Reflexes may still be absent, though with time will increase. The plantar reflex should be upgoing.

Sensation: A sensory level is expected between C2 to C6, to all modalities (eg. touch, pain, temperature, joint position sense and vibration).

Other signs: Warm vasodilated peripheries, Skin venodilation , Priapism, Hypotension, Bradycardia, Tendency to Hypothermia, Rocker-boat respiratory pattern (with increased use of respiratory accessory muscles, and absent intercostals).


A C4 lesion should produce the following features:

  • Incomplete diaphragm paralysis, purely diaphragmatic breathing pattern
  • Complete motor paralysis of all 4 limbs
  • Complete sensory loss in whole body below the C4 sensory level (shoulder)
  • Cardiovascular instability: bradycardia and hypotension
  • Acute gastric dilatation and paralytic ileus
  • Priapism
  • Urinary retention
  • Loss of bowel continence
  • Horner's syndrome

Physiological consequences of spinal cord transection are well discussed elsewhere.


The Spinal Cord Medicine Clinical Practice Guidelines series (provided by Paralysed Veterans of America) has a nice brochure of what one is to expect with a C4 injury.