Brown-Séquard Syndrome

Brown-Séquard syndrome is a hemisection of the spinal cord that causes ipsilateral weakness and loss of position and vibration sense, with contralateral loss of pain and temperature sensation beginning one to two levels caudal to the lesion. Pure forms are rare, and incomplete (Brown-Séquard plus) forms are common.

It accounts for 1 to 4% of traumatic spinal cord injuries. Penetrating injury (stab or gunshot wounds) is the classical cause, but compression and inflammatory disease are common in non-traumatic cases.

Causes. Penetrating trauma, blunt cervical spine injury, disc herniation, tumour (primary or metastatic), epidural abscess or haematoma, multiple sclerosis, transverse myelitis, radiation, tuberculosis and vascular lesions.

Prognosis. Better than other incomplete cord injuries: about 90% regain the ability to walk, and bladder and bowel function return in most.

Pathophysiology.

Damage to one half of the cord interrupts the ipsilateral corticospinal tract and dorsal column, while the spinothalamic fibres, which cross within one to two segments of entry, carry contralateral pain and temperature.

The separation of motor and sensory loss on opposite sides gives the syndrome.

• Ipsilateral spastic weakness caudal to the lesion, with hyperreflexia and an extensor plantar response.
• Ipsilateral loss of vibration, joint position sense and light touch.
• Contralateral loss of pain and temperature sensation, starting one to two segments caudal to the lesion.
• Segmental ipsilateral findings at the level: lower motor neuron weakness, band of anaesthesia, and Horner syndrome with cervical lesions.
• Back or neck pain; bladder and bowel function often preserved.

Red flags.

• Progressive weakness, sphincter loss or severe pain (cord compression, an emergency).
• Fever or immunosuppression (epidural abscess or tuberculosis).
• Cancer history, weight loss or night pain (metastasis).
• Penetrating trauma or foreign body.

• Detailed neurological examination with the level of lesion; urgent MRI of the whole spine with contrast.
• CT for bone injury and foreign bodies; CT or MR angiography for vascular injury.
• Blood tests: inflammatory markers, blood cultures if infection is suspected, B12, and tumour markers as relevant; lumbar puncture only after compression is excluded.
• MRI of the brain and cerebrospinal fluid analysis if demyelination is possible.

Differential diagnosis. Central cord syndrome, anterior cord syndrome, transverse myelitis, multiple sclerosis, intramedullary tumour, spinal cord infarction, syringomyelia and functional weakness.

• This is a spinal emergency: immobilise the spine in trauma, maintain airway, breathing and mean arterial pressure of at least 85 mmHg for 5 to 7 days in acute traumatic injury.
• Urgent decompression and stabilisation for compressive lesions (disc, haematoma, abscess, tumour), by spinal surgery.
• Malignant cord compression: dexamethasone 16 mg orally or intravenously once daily with a proton pump inhibitor, started at once, with urgent radiotherapy or surgery. Maximum 16 mg daily for this use, reduced after treatment. Monitor glucose, blood pressure, mood and infection. Avoid with untreated systemic infection; use caution in diabetes and peptic ulcer.
• Infection: drainage and prolonged intravenous antibiotics directed by cultures.
• Demyelination: methylprednisolone 1000 mg intravenously once daily for 3 to 5 days. Maximum 5 g in a course. Monitor blood pressure, glucose, mood and infection. Avoid with active untreated infection.
• Thromboprophylaxis: enoxaparin 40 mg subcutaneously once daily from 24 to 72 hours, once bleeding risk allows. Maximum 40 mg daily (20 mg daily when creatinine clearance is under 30 mL/min). Monitor platelets, renal function and bleeding.
• Spasticity: baclofen 5 mg orally three times daily, increased by 5 mg every 3 days to a usual 30 to 75 mg daily. Maximum 100 mg daily. Monitor sedation and weakness; withdraw slowly; reduce dose in renal impairment.
• Rehabilitation: early mobilisation, gait training, bladder care, pressure care, and occupational therapy.

Monitoring. Neurological examination every 1 to 4 hours in the acute stage; review at 4 to 6 weeks, 3 months and 12 months.

Referral and escalation. Emergency spinal surgery and oncology for compression; neurology for non-compressive causes; spinal rehabilitation.

Special groups. Children: weight based dosing and paediatric spinal services. Pregnancy: imaging and treatment follow the same urgency.