What neurologic finding is consistent with a diagnosis of Brown-Séquard syndrome in a patient with a spinal lesion?

Brown-Séquard Syndrome: Neurological Findings

Loss of motor and vibration on the left and pain on the right is consistent with a diagnosis of Brown-Séquard syndrome in a patient with a penetrating spinal injury.

Pathophysiology of Brown-Séquard Syndrome

Brown-Séquard syndrome (BSS) is characterized by hemisection of the spinal cord, resulting in a specific pattern of neurological deficits based on the anatomical organization of the spinal tracts:

1. Ipsilateral findings (same side as the lesion):

   • Motor weakness/paralysis (corticospinal tract)
   • Loss of vibration sensation (posterior columns)
   • Loss of proprioception (posterior columns)
   • Hyperreflexia below the level of the lesion (upper motor neuron signs)

2. Contralateral findings (opposite side to the lesion):

   • Loss of pain sensation (spinothalamic tract)
   • Loss of temperature sensation (spinothalamic tract)
   • These deficits typically begin 2-3 levels below the injury 1

Clinical Presentation and Diagnosis

In the case presented, the 19-year-old man has a penetrating wound to the spine just left of midline. This is the classic mechanism for BSS, as penetrating trauma is one of the most common causes 1, 2. The hemisection of the spinal cord on the left side would produce:

• Left-sided motor weakness (ipsilateral corticospinal tract damage)
• Left-sided loss of vibration and proprioception (ipsilateral posterior column damage)
• Right-sided loss of pain and temperature sensation (contralateral spinothalamic tract damage)

This pattern occurs because:

• Motor fibers cross at the level of the medulla (above the spinal cord)
• Posterior column fibers (vibration, proprioception) ascend ipsilaterally
• Spinothalamic fibers (pain, temperature) cross shortly after entering the spinal cord

Differential Diagnosis

When evaluating a patient with suspected BSS, consider:

1. Complete spinal cord injury
2. Central cord syndrome
3. Anterior cord syndrome
4. Posterior cord syndrome
5. Cauda equina syndrome

Management Approach

1. Immediate stabilization:

   • Maintain spinal immobilization
   • Assess and secure airway, breathing, circulation
   • Evaluate for associated injuries

2. Diagnostic imaging:

   • MRI of the spine is the preferred imaging modality to assess the extent of cord damage 3
   • CT may be needed to evaluate bony injury

3. Medical management:

   • High-dose methylprednisolone may be considered for acute spinal cord injury 2
   • Prophylactic antibiotics for penetrating trauma

4. Surgical intervention:

   • Removal of foreign body if present
   • Decompression of the spinal cord if indicated
   • Stabilization if there is associated instability

Prognosis

The prognosis for BSS is generally better than for complete spinal cord injuries. Early surgical intervention when indicated and intensive rehabilitation can lead to good functional recovery 4, 5. In traumatic cases, patients often show significant neurological improvement with appropriate management 1, 2.

Key Points to Remember

• BSS is characterized by ipsilateral motor and posterior column sensory loss with contralateral pain and temperature loss
• Penetrating trauma is a classic cause of BSS
• Early diagnosis and appropriate management improve outcomes
• The pattern of neurological deficits directly reflects the anatomy of the spinal tracts

In this case, the correct neurological finding consistent with Brown-Séquard syndrome is loss of motor and vibration on the left (ipsilateral to the injury) and pain on the right (contralateral to the injury).