Compressão da medula espinhal

Veja também o separado Whiplash and Cervical Spine Injury .

How serious is spinal cord compression?

• Trauma (including car accidents, falls and sports injuries):
  

  • There is usually either vertebral fracture (most common in cervical vertebrae) or facet joint dislocation.

  • Complete transection of the spinal cord can occur.

  • Hemisection of the spinal cord can occur and is known as Brown-Séquard's syndrome. It is usually caused by a penetrating trauma.

• Spinal tumours, both benign or malignant:
  

  • These can include bone tumours, primary or metastatic tumours, lymphomas, multiple myeloma and neurofibromata.

  • Acute myelopathy in patients with cancer can also be caused by irradiation, paraneoplastic necrotising myelitis, ruptured intervertebral disc and meningeal carcinomatosis with spinal cord involvement.

• A prolapsed intervertebral disc:
  

  • L4-L5 and L5-S1 are the most common levels for disc prolapse. Large disc herniations can cause cauda equina syndrome. See the separate Cauda Equina Syndrome article which discusses it in more detail.

  • Cervical disc herniation can also occur.

• An epidural or subdural haematoma:
  

  • There may be a history of trauma, a recent spinal procedure and/or the patient may be on anticoagulant therapy.

• Inflammatory disease, especially rheumatoid arthritis:
  

  • In rheumatoid arthritis there is often considerable weakness of the ligament that holds the odontoid peg. If this ruptures, the atlas can slip forward on the axis and compress the high cervical spine.

• Spinal infection:
  

  • Spinal infections can be acute or chronic.

  • Acute infections are usually bacterial; chronic infections are usually due to tuberculosis or fungal infection.

  • Vertebral osteomyelitis, discitis or haematogenous spread of infection can lead to an epidural abscess.

• Cervical spondylitic myelopathy:
  

  • The ageing process can lead to narrowing of the spinal canal due to osteophytes, herniated discs and ligamentum flavum hypertrophy.

  • In advanced stages, it can cause spinal cord compression.

• Spinal manipulation:
  

  • Damage to the spinal cord may be a very rare complication of chiropractic or osteopathic manipulation of the neck.

Veja o artigo separado sobre Neck Pain (Cervicalgia) and Torticollis, Low Back Pain and Sciatica, Exame da Coluna Vertebral, História e Exame Neurológico, Neurological Examination of the Upper Limbs, Exame Neurológico dos Membros Inferiores artigos.

Suspect spinal cord compression if any of the following features are present:¹

• History of possible underlying cause, eg, severe trauma, known or suspected cancer.

• Neurological symptoms (including radicular pain, any limb weakness, difficulty in walking, sensory loss, or bladder or bowel dysfunction).

• Neurological signs of spinal cord compression (eg, weakness, gait disturbance, Babinski's sign [up-going plantar reflex], hyper-reflexia, clonus, spasticity), or cauda equina compression (see Cauda Equina Syndrome).

• MRI scan of the whole spine. CT scan if MRI contraindicated.²

• Renal function and electrolytes: dehydration.

Further investigations will depend on the likely differential diagnoses for cord compression.

• The most frequent histological types of cancer that give rise to bone metastases are breast, prostate and lung cancer.

• Most of the spinal metastases are diagnosed following the diagnosis of the primary cancer. However, in about 10% of the patients, spinal metastases are the first manifestation of an unknown primary tumour.

• Spinal cord compression occurs in up to 20% of the patients with spinal metastases.

• Metastatic epidural spinal cord compression affects almost 5% of patients with cancer.⁴ However, less than 0.1% of people with back pain who visit their general practitioner have spinal metastases.⁵

• Spinal pain is often present for three months and neurological symptoms for two months before paraplegia, but almost 50% of patients are unable to walk by the time of diagnosis. Of these, almost 70% remain immobile. Of those able to walk at treatment, about 80% remain ambulant.⁵

Apresentação

Factors suggesting spinal metastases or metastatic spinal cord compression include:²

• Câncer:

  • Diagnóstico passado ou atual de câncer.

  • Suspeita de diagnóstico de câncer.

• Características da dor que sugerem metástases na coluna:

  • Dor nas costas intensa e persistente.

  • Dor nas costas progressiva.

  • Dor nas costas agravada por esforço (por exemplo, tossir, espirrar ou evacuar).

  • Dor nas costas à noite perturbando o sono.

  • Sensibilidade localizada.

  • Claudicação (dor muscular ou cãibras nas pernas ao caminhar ou se exercitar).

• Symptoms and signs suggesting cord compression:

  • Bladder or bowel dysfunction.

  • Gait disturbance or difficulty walking.

  • Limb weakness.

  • Neurological signs of spinal cord or cauda equina compression.

  • Numbness, paraesthesia or sensory loss.

  • Radicular pain.

Immediately contact the metastatic spinal cord compression coordinator if a person with a past or current diagnosis of cancer presents with the symptoms or signs of cord compression. Treat this as an oncological emergency.

Gestão^{1 2}

• Metastatic extradural spinal cord compression is treated with radiotherapy, corticosteroids, and surgery, but there is uncertainty regarding their comparative effects.⁶

• If spinal metastases are thought to be the cause of the pain, seek urgent (within 24 hours) specialist advice from a metastatic spinal cord compression co-ordinator if available, or alternatively a palliative care consultant or oncologist.

• If there are associated neurological features suggestive of spinal cord compression, seek immediate specialist advice.

• Unless contra-indicated (including a significant suspicion of lymphoma), offer all people with metastatic spinal cord compression a loading dose of 16 mg of dexamethasone as soon as possible after assessment.

The principles of management include:

• Nurse the patient flat with the spine in neutral alignment (eg, using logrolling or turning beds) until spinal stability and neurological stability are ensured.

• Give a course of dexamethasone unless contra-indicated until a definitive treatment plan is made.

• Manage postural hypotension with positioning and devices to improve venous return; avoid overhydration.

• Insert a catheter to manage bladder dysfunction.

• Use breathing exercises, assisted coughing, and suctioning to clear airway secretions.

• Follow the National Institute for Health and Care Excellence (NICE) guidance for the prophylaxis of venous thromboembolism, o prevention and treatment of pressure ulcers and the management of bowel dysfunction.

• Offer and provide psychological and spiritual support as needed (including after discharge).

• Analgesia, palliative radiotherapy, spinal orthoses, vertebroplasty or kyphoplasty, or spinal stabilisation surgery may be required for pain control.

• Bisphosphonates should be offered to all patients with vertebral involvement from myeloma and breast cancer and to patients with prostate cancer in whom conventional analgesia is inadequate.

• Specialised pain control procedures may be needed for intractable pain (eg, epidural analgesia).

• If definitive treatment of the spinal cord compression is appropriate, it should be started before patients lose the ability to walk or before other neurological deterioration occurs, and ideally within 24 hours.

• Definitive treatment may be using surgery (eg, laminectomy, posterior decompression ± internal fixation) or using radiotherapy.

• Discharge should be fully planned and community-based rehabilitation and support should be available when the patient returns home. This includes support and any necessary training of carers and families.

Complications will depend on the site of spinal cord compression and the severity of associated neurological dysfunction. Complications may include:

• Pressure sores: careful and frequent turning of the patient is essential.

• Hipotermia.

• Potential lung complications include pneumonia por aspiração, síndrome do desconforto respiratório agudo, atelectasis, ventilation-perfusion mismatch and decreased coughing with retention of secretions.

• Depression associated with restriction of activities of daily living.

• The spinal cord has very limited powers of regeneration.

• Prognosis for neurological deficit depends on the magnitude of the spinal cord damage present at the onset.

• As well as neurological dysfunction, the prognosis is also determined by the prevention and effective treatment of infections - eg, pneumonia, and urinary tract infections.

• The prognosis will also depend on the underlying cause of cord compression.