Malignant Spinal Cord Compression
What is it?
A real emergency. Tumour, usually a bony metastasis in the vertebra grows and presses on the spinal cord. Initially there may be pain and tenderness at the site of the metastasis. 95% give a history of back pain in the preceding 6-7 weeks. As the tumour grows, increasing pressure on the spinal cord reaches a critical point and often suddenly produces:
- Weakness (usually bilateral)
- Sensory Disturbance (late sign)
- Sphincter Disturbance (late sign)
If undetected or untreated this can rapidly progress to:
- Paralysis (very late sign)
- Numbness (very late sign)
- Double Incontinence (very late sign)
Why is it important?
Early detection and treatment can prevent paralysis and double incontinence. It is not a fatal condition and 30% of patients will survive at least a year. Although rare, it is devastating if diagnosed too late as irreversible paraplegia ensues.
- 70% of patients walking at the time of diagnosis retain their mobility.
- Less than 5% of patients with paraplegia at the time of diagnosis regain any mobility.
How common is it?
Cord compression affects 5% of all cancer patients. CANCER OF THE BREAST, LUNG AND PROSTATE account for 2/3 cases.
|% patients complaining||% found on examination|
|Central back pain ± vertebral tenderness 80%-95%||Then sudden onset of Weakness||76%||87%|
Patients do not always complain - suspect and ask.
(Kramer JA (1992) Palliative Medicine 6 202-211)
What sort of pain?
- Local bone pain in the back, particularly the thoracic spine (80%) often worse lying down, better sitting up.
- Nerve root compression pain (radicular pain). Unilateral (cervical or lumbar) or bilateral (thoracic) sharp, may be jabbing or stabbing.
- Cord compression pain (funicular pain) cuff or garter pain, often in kness, calves or thighs. Diffuse, cold, unpleasant sensation.
Both radicular and funicular pain is made worse by:
- Flexing the neck
- Straight leg raising
- Coughing, sneezing or straining
This is the stage to suspect and diagnose.
Once weakness, sphincter disturbance and sensory deficit have arisen they progress rapidly. The likelihood of a good outcome from treatment reduces rapidly.
What sort of tests?
Plain x-ray of the spine has diagnostic accuracy of 80% (60% for bone scan), x-ray cervical, thoracic, lumbar spine and pelvis.
MRI scan (urgently) - is the imaging modality of choice. A normal plain X-ray and bone scan do NOT exclude malignant cord compression.
Always indicated unless the patient is moribund.
Emergency treatment Dexamethasone
- 16mg over 24hrs I/V or oral
- Reduced after 48-72hrs
- May need sedatives as these high doses can be very excitatory
- Can administer while awaiting investigation
|Definitive treatment (urgent)|
|Surgery particularly if histology suggests non-radiotherapy sensitive tumours e.g. melanoma or spinal instability, histology is uncertain or previous radiotherapy.||Laminectomy ± radiotherapy. (Vertebrae intact)|
|Anterior decompression ± radiotherapy. (Vertebrae significantly eroded)|
|Radiotherapy particularly if histology suggests radiotherapy sensitive tumours.|
|Mobility at present||% Mobile after treatment|
|25% relapse within 6 months|
- Always suspect with thoracic back pain.
- Ask patient about weakness, sensory disturbance, sphincter disturbance.
- Act rapidly.
- Any patient with cancer is at risk
- Especially cancers of breast, lung, prostate, myeloma
- Especially with bony metastases
- Especially with thoracic spine pain
If in doubt, discuss with the palliative care physicians or clinical oncologist.
© Dr. Eileen Palmer, Dr John Howarth Palliative Care for the Primary Health Care Team (2004) Quay Books ISBN 1856422291