Spinal cord compression

Key points:
Early diagnosis and decompression important because prognosis depends primarily on severity of neurological deficit and duration of deficit before decompression.
Signs and symptoms are those of a myelopathy but the common feature of "structural" lesions is pain. Spine or root pain in the presence of myelopathic symptoms strongly implies a surgically remediable cause.

Trauma

- in selected circumstances internal fixation and fusion has a role to play and does impart advantages to the patient, his spine and his rehabilitation. However, neurological outcome is not improved. (More on traumatic cord injury).

Inflammatory conditions

most important is rheumatoid arthritis.
acute cord compression is not common in rheumatoid but there are anecdotal reports of patients collapsing and dying due to gross odontoid subluxation. Usually patients develop symptoms over weeks-months but a few patients develop neurological signs and deteriorate witha progressive myelopathy over a short period of days. A clear history is of paramount importance as widespread joint disease makes accurate clinical examination difficult.
vertical subluxation of the odontoid process makes it possible that the patient will develop lower cranial nerve signs
most common form of C1/2 dislocations is anterior subluxation of C1 on C2. Less frequent abnormalities include posterior subluxation, rotational deformities or lateral subluxations
post-operative mortality and morbidity greatest in those who are most severely afffected neurologically pre-op. (ie quadraparetic and unable to walk) Systemic effects of RA, especially interstitial pneumonitis may adversely affect postsurgical recovery

Infective lesions

infections of spine uncommon
can be classified into vertebral osteomyelitis (more common) or intraspinal infection
incidence of intraspinal infection 1/million/yr in UK. Extradural, subdural or intramedullary in order of frequency). Usually due to Staph in UK, TB in Asia and Africa
spinal extradural neurosurgical emergency. Outstanding clinical feature is spinal pain associated with marked local tenderness of the spine at the level of abscess formation
commonest organisms causing vertebral osteomyelitis: Staph, Strep, E coli, TB. Occasionally due to unusual organisms such as salmonella or brucella. May be complicated by the development of an extradural abscess
investigation of choice: MRI. CT myelography is 2nd best

Degenerative disease

usually due to disc prolapse +/- canal stenosis
for those patients who develop an acute myelopathy due to hyperextension forces superimposed on a narrow spinal canal there is little, if any, convincing evidence that surgical decompression improves neurological recovery
for patients who present with an acute disc prolapse causing cauda equina syndrome prognosis for recovery is based on the severity of the pre-decompression neurological deficit rather than the duration of neurological symptoms. Same is likely to apply to recovery from cervical or thoracic disc induced myelopathy

Neoplasms

usually due to secondaries
multiple levels involved in 17%
most secondaries found in thoracic spine and multiple lesions may be non-contiguous
in most cases myelopathy develops over days to weeks
pain in 90% of patients
acute cord compression does occur if tumour enlarges very rapidly due to haemorrhage or if a vertebral body suddenly collapses
tissue diagnosis important if primary cannot be identified
management depends on a number of factors including histology, tumour load, number of secondaries, estimate of life expectancy
severity of neurological deficit has the greatest influence on prognosis for neurological recovery following decompressive surgery
radiotherapy may take several days to have its optimum effect
urgent surgery is treatment of choice where compression is due to collapsed vertebra

Haematoma

distinctly uncommon
substantial number occur for no particular reason
produce combination of spinal pain and root pain followed by progressive myelopathy over 1-2 days
diagnosis confirmed by MRI or CT myelography
treatment: laminectomy at level of cord compression