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?
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
- 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.