Brown-Séquard syndrome

Overview

Brown-Séquard syndrome is a rare neurological condition resulting from damage to one side of the spinal cord (hemisection), typically due to trauma. It causes a distinct pattern of neurological deficits below the level of the lesion: weakness or paralysis on the same side as the injury and loss of pain and temperature sensation on the opposite side. This occurs because the spinal tracts responsible for motor control and sensory perception cross over at different levels in the central nervous system. First described by Charles-Édouard Brown-Séquard in the 19th century, this syndrome provides valuable insight into spinal cord physiology and anatomy.

Causes

Brown-Séquard syndrome is most commonly caused by trauma but may also arise from various other conditions affecting the spinal cord. Common causes include:

• Penetrating spinal trauma – such as stab or gunshot wounds affecting one side of the cord

• Spinal cord tumors – compressing or invading one side of the cord

• Spinal cord infarction – stroke affecting a unilateral spinal artery

• Multiple sclerosis – demyelinating lesions confined to one side

• Epidural abscesses or hematomas – causing asymmetric cord compression

• Syringomyelia – a cyst or cavity that affects spinal cord tissue, potentially in a unilateral distribution

• Vertebral fractures – causing asymmetric injury or compression of the cord

Symptoms

The hallmark of Brown-Séquard syndrome is a combination of ipsilateral and contralateral neurological deficits below the level of the spinal lesion. Common symptoms include:

• Ipsilateral (same side as lesion):

  • Motor weakness or paralysis (hemiparesis or hemiplegia)

  • Loss of proprioception (sense of body position)

  • Loss of vibration and fine touch sensation

  • Hyperreflexia and spasticity over time

• Contralateral (opposite side of lesion):

  • Loss of pain and temperature sensation (spinothalamic tract involvement)

• At the level of the lesion:

  • Flaccid paralysis or decreased reflexes

  • Loss of sensation in a dermatomal distribution

Severity and exact presentation may vary depending on the location and extent of spinal cord involvement.

Diagnosis

Diagnosis of Brown-Séquard syndrome is based on clinical evaluation and confirmed with imaging and neurological testing. Diagnostic steps include:

• Neurological examination – to identify characteristic patterns of motor and sensory deficits

• Magnetic Resonance Imaging (MRI) – the preferred imaging modality to visualize spinal cord damage, tumors, or lesions

• Computed Tomography (CT) scan – especially useful in trauma cases to detect bone fractures or hematomas

• Electrophysiological studies – such as somatosensory evoked potentials (SSEPs) to assess functional deficits

• Blood tests or lumbar puncture – in suspected infectious or inflammatory causes

Treatment

Treatment of Brown-Séquard syndrome focuses on addressing the underlying cause and supporting neurological recovery. Management may include:

• Acute medical or surgical intervention:

  • Surgical decompression for trauma, tumors, or abscesses

  • Antibiotics for infectious causes (e.g., epidural abscess)

  • Corticosteroids or immunosuppressive therapy for inflammatory conditions like multiple sclerosis

• Supportive care:

  • Pain management

  • Bladder and bowel management

  • Prevention of pressure ulcers and infections

• Rehabilitation:

  • Physical therapy to improve strength and mobility

  • Occupational therapy for daily living activities

  • Assistive devices such as braces, walkers, or wheelchairs if needed

Prognosis

The prognosis for Brown-Séquard syndrome is generally more favorable than other spinal cord syndromes. Many patients regain significant motor function, particularly in the ipsilateral limbs. Pain and temperature sensation recovery on the contralateral side also improves over time. Early diagnosis and prompt treatment greatly enhance the likelihood of functional recovery. However, residual deficits, spasticity, or bladder dysfunction may persist in some individuals. Long-term prognosis depends on the cause, location, and extent of spinal cord damage, as well as the quality and duration of rehabilitation.