EMERGENCY CASEBOOK
Delayed spinal cord compression in ankylosing spondylitis
A 45 year old man with long standing ankylosing spondylitis tripped and fell backwards
against a concrete pillar when walking to catch a bus. He did not lose consciousness and
presented to the casualty department 20 minutes later complaining of pain in his neck and
left shoulder. On examination he was tender over his vertebra prominens and had paraesthesiae
over the left C8 dermatome. No other focal neurology was found. Spinal x rays
showed fusion of most of the cervical and thoracic vertebral bodies but no fractures were
seen. A diagnosis of C8 root compression was made and he was referred to the orthopaedic
team for further assessment.
Four hours later he complained of
numbness up to his umbilicus. On examination
he now had a flaccid paralysis of
his lower limbs and reduced left upper
limb power. A magnetic resonance imaging
scan of his spine revealed an epidural
haematoma extending from C5 to T5 on
the dorsal aspect of the spinal cord (fig
1). The neurosurgical team performed
an emergency cervical laminectomy to
decompress the spinal cord, during
which the C4 spinous process was found
to be fractured.
Minor trauma in patients with ankylosing
spondylitis can result in vertebral
fractures, which bleed into the spinal
canal and form haematomas causing
delayed spinal cord compression.' Because
of the distorted anatomy in ankylosing
spondylitis, spinal fractures maybe
difficult to identify on plain x rays.2 In the Ti weighted MRI scan of cervical spine showing epidural
case described , the vertebral fracture haematoma (arrow) on dorsal aspect of spinal cord.
found during surgery could not be seen
on the cervical films. The fact that the
patient had sustained a serious injury only became apparent when his neurological status
rapidly deteriorated. Thus, when patients with ankylosing spondylitis present to the A&E
department following an episode of trauma, a period of neuro-observation is useful and
should signs of spinal cord compression develop, urgent neurosurgical consultation is indicated.