Metastatic spinal cord compression

Metastatic spinal cord compression (MSCC) is a well-recognised complication of malignancy. It is the compression of the spinal cord or cauda equina via direct pressure from unstable or collapsed spinal vertebral caused by metastatic spread or direct malignant invasion which compromises the neurological function. There are approximately 4000 cases each year in England and Wales (National Institute for Health and Care Excellence (NICE), 2008).

MSCC occurs due to pressure on the spinal cord or its blood supply and may rise from loss of structural integrity including pathological fracture or collapse, soft tissue tumour taking up space in the spinal canal, an epidural tumour or a combination of both causing intrusion on the cord itself. Those that develop severe neurological symptoms such as paraplegia have a substantially diminished quality of life (National Collaborating Centre for Cancer, 2008).

Signs and symptoms

Patients may initially present with symptoms consistent with spinal or nerve root pain. These symptoms include sharp or dull pains, sensory changes such as perceived temperature change hypersensitivity, vibration or burning. Things can then develop further into weakness and sensory loss. Depending on where the lesion is within the spine, it gives a different set of symptoms. If it is in the cervical spine there can be sensory or motor deficit to the arms. If it is in the thoracic or lumbar spine then leg weakness and sensory change is more likely. Careful consideration of bladder and bowel function is important as these are more likely to be late signs. These late signs are:

• hesitancy
• frequency
• painless retention
• overflow incontinence - these patients lose the ability to feel when their bladder is full as the nerves have been compressed in the spine

Other red flags include:

• sudden

The most common cancers to spread to the bone include thyroid, breast, lung, kidney and prostate. Of these, the most likely to spread to the spine are lung, prostate and breast. Once a cancer has spread to the bone it tends to be quite advanced however people who present with the symptoms above should not be disregarded for metastatic spread if they have not had a formal cancer diagnosis. Patients can present with no known cancer but end up with the devastating news that the cause of their symptoms is due to the metastatic spread of a cancer they did not even know they had.

Differential diagnosis of MSCC include:

• prolapsed disc
• traumatic event
  • fractures
• ankylosing spondylitis
• osteoporotic vertebral fractures
• degenerative spinal disease
• myeloma
• pregnancy induced
• infection such as epidural abscesses
• spinal haematomas

Diagnosis starts with careful examination and history taking to ascertain if MSCC could be a differential diagnosis. If malignancy is known in the patients past medical history, then one should enquire about previous treatments and their staging. If there is any clinical suspicion, then the imaging modality of choice is MRI whole spine. The reason that the whole spine is imaged is that up to 15% of patient with MSCC will have multilevel involvement that may not be clinically apparent (Maccauro et al, 2011).

Motor or sensory ‘levels’ can be determined by careful examination. For example, someone who has a lesion in their lower back in the second lumbar vertebra might experience numbness to the tops of their legs and weakness to leg flexion (lifting a leg straight off a bed).

If there is neurological deficit such as bladder or bowel dysfunction, leg weakness or sensory changes an MRI scan

Often these patients are in severe pain and therefore require strong analgesia. Working up the World Health Organisation pain ladder is a good option. Over the years various analgesics have been trialled to improve the pain associated with bone metastasis. These include:

• non-steroidal anti-inflammatory drugs (NSAIDs)
• opioids
• bisphosphonates
• tricyclic antidepressants
• corticosteroids
• growth factors

Patients with severe mechanical pain that is consistent with instability should be nursed on flat bedrest with log rolling which is a method of turning a patient without twisting or bending the spine. Local policies on spinal cord injuries should be adhered to when moving a patient.

If there is no neurological deficit once any spinal shock (areflexia, extreme pain and abnormal posturing) has settled, patients can be gradually sat up over the course of 4 hours to around 60 degrees with close neurological observation. If their symptoms remain stable unsupported sitting and mobilisation can be slowly

The primary malignancy needs to be established including CT scanning and tumour biopsy, if necessary, when planning definitive treatment however ideally treatment needs to be started within 24 hours of the confirmed diagnosis. Staging of the malignancy is also important for planning definitive treatment.

Performance status of the patient is important as their functional ability, general fitness, previous treatments, and ability to tolerate an anaesthetic need to be assessed as well as an overall prognosis when planning treatment.

Patients with non-mechanical back pain associated with metastatic deposits in the spine can be offered radiotherapy which helps as a palliative analgesic.

Vertebroplasty and kyphoplasty can be considered if there is evidence of instability, mechanical back pain that is resistant to previously mentioned analgesics, or vertebral body collapse. If the patient is unfit for surgery then radiotherapy and external spinal support can be offered such as orthotic braces.

If the patient is

References

Helweg-Larsen S, Sørensen PS. Symptoms and signs in metastatic spinal cord compression: a study of progression from first symptom until diagnosis in 153 patients. Eur J of Cancer. 1994; 30(3): 396–398. https://doi.org/10.1016/0959-8049(94)90263-1

National Institute for Health and Care Excellence. Metastatic spinal cord compression in adults: risk assessment, diagnosis and management. 2008. https://www.nice.org.uk/guidance/cg75/chapter/Introduction (accessed 15 December 2022)

Maccauro G, Spinelli, MS, Mauro S et al. Physiopathology of Spine Metastasis. Int J Surg Oncol. 2011:107969. https://doi.org/10.1155/2011/107969

National Collaborating Centre for Cancer (UK). Metastatic Spinal Cord Compression: Diagnosis and Management of Patients at Risk of or with Metastatic Spinal Cord Compression. Cardiff (UK): National Collaborating Centre for Cancer (UK); 2008.

Quraishi, NA, Esler C. Metastatic spinal cord compression. BMJ. 2011;342(7805). https://doi.org/10.1136/BMJ.D2402

White BD, Stirling AJ, Paterson E et al. Diagnosis and management of patients at risk of or with metastatic spinal cord compression: summary of NICE guidance. BMJ. 2008; 337:a2538.  https://doi.org/10.1136/bmj.a2538

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