Brown-Sequard Syndrome

Brown-Séquard syndrome results from a lesion in one (lateral) half of the spinal cord (for example hemisection or lateral injury of the cord). It often occurs in the cervical cord region. It was first described in the 1840s after Dr. Charles Edouard Brown-Sequard (1817-94) sectioned half of the spinal cord.¹

The syndrome is rare and comprises ipsilateral hemiplegia with contralateral pain and temperature sensation deficits (because of the crossing of the fibres of the spinothalamic tract).

The pure Brown-Séquard syndrome reflecting hemisection of the cord is rarely seen. However a clinical picture with some of the features of the syndrome is more common. The hemisection syndrome may also occur with additional symptoms and signs. Interruption of the lateral corticospinal tracts, the lateral spinothalamic tract, and occasionally the posterior columns clinically causes a spastic weak leg with brisk reflexes and a strong leg with loss of pain and temperature sensation. Spasticity and hyperactive reflexes may not be present with an acute lesion.

The causes of this syndrome are:

• Most commonly trauma (penetrating or blunt)^2,3
• Neoplasia (spinal cord tumour either metastatic or primary)
• Multiple sclerosis
• Degenerative (such as herniation of discs and cervical spondylosis)⁴
• Cysts⁵ and cystic diseases
• Idiopathic spinal cord herniation⁶(spinal cord herniation can also occur after trauma⁷)
• Vascular causes:
  • Haemorrhage (including spinal subdural/epidural and haematomyelia)
  • Ischemia
• Infectious causes:
  • Meningitis
  • Empyema
  • Herpes zoster
  • Herpes simplex
  • Tuberculosis
  • Syphilis
• Other causes include gnathostomiasis (helminthic parasitic disease rarely seen outside the tropics where it may be associated with itch, fever, nausea, vomiting, abdominal pain, non-pitting oedema, and finger swelling), and HTLV-I (tropical spastic paraplegia)
• Rollercoaster riding and chiropractic manipulation⁸ may be a contributing factor if there is a predisposition (such as a cyst)³

Diagnosis of Brown-Séquard syndrome is made on the basis of history and physical examination. Most cases will be caused by trauma. It is important when there is no history of trauma to consider:

• Multiple Sclerosis
• Spinal Cord Infections
• Stroke, Ischaemic

• Laboratory studies may be useful with nontraumatic causes. Overall they are not usually necessary for diagnosis. They may be useful in monitoring clinical course.
• Imaging:
  • Spinal plain radiographs (for bony injury in penetrating or blunt trauma¹¹).
  • MRI can help to define the extent of spinal cord injury. It is particularly helpful when evaluating nontraumatic causes. MRI may be needed in traumatic cases when there is neurological deterioration.¹²
  • CT myelography (useful if MRI is contraindicated).

• Initially a thorough evaluation, including neurological examination, is performed to establish the level of injury.
• Careful cervical spine/dorsal spine immobilisation is necessary.
• No movement of the neck should be permitted.
• It is important to identify cases (such as spinal cord herniation) where surgical intervention can improve prognosis.^4,13,14

Early and late complications associated with spinal injury may occur. These may include:

• Hypotension ("spinal shock")
• Pulmonary emboli (prophylaxis needed)
• Infection (lungs, urine, etc.)
• Depression (common with spinal cord injuries)

The prognosis for Brown-Séquard syndrome is generally poor although it may be better than other froms of spinal cord injury.¹⁵ Aetiology can have a bearing on prognosis. Early treatment with high-dose steroids has shown benefit in some cases.

Charles-Edouard Brown-Séquard, (1817-94) was a very remarkable and eminent neurologist who worked in England, France and the United States. He was one of the founding physicians at the Institute of Neurology in London. He published 577 papers. He initially intended to be a writer, but became a medical student when his manuscripts were rejected repeatedly. He first published the findings which became the "Brown-Séquard Syndrome" in 1849 and he later described a typical case of his syndrome to the BMA annual meeting in 1862 - that of a sea captain stabbed in the neck. He also performed notable work in the emerging field of endocrinology.^{1,16,17,18,19,20}