What are the features of Brown-Sequard syndrome at the left C5 (cervical 5) level?

Features of Brown-Séquard Syndrome at Left C5 Level

Brown-Séquard syndrome at the left C5 level presents with ipsilateral (left-sided) motor weakness/paralysis and loss of proprioception, with contralateral (right-sided) loss of pain and temperature sensation below the level of the lesion.

Clinical Manifestations

Motor Deficits (Left-sided)

• Left-sided weakness/paralysis below the C5 level
• Affects left upper limb (particularly deltoid, biceps) and left lower limb
• Spastic paralysis due to corticospinal tract involvement
• Loss of fine motor control on the left side
• Possible hyperreflexia and positive Babinski sign on the left

Sensory Deficits

• Ipsilateral (Left-sided):

  • Loss of vibration and position sense (proprioception) below C5 level
  • Impaired tactile discrimination and stereognosis
  • These deficits occur due to damage to the posterior columns

• Contralateral (Right-sided):

  • Loss of pain and temperature sensation starting 2-3 segments below the level of injury (approximately T1-T2 level)
  • This occurs due to damage to the lateral spinothalamic tract that crosses at the level of entry

Reflex Changes

• Diminished or absent left biceps and brachioradialis reflexes (C5-C6)
• Hyperreflexia below the level of injury on the left side
• Normal reflexes on the right side except for pain and temperature sensation

Pathophysiology

Brown-Séquard syndrome results from hemisection or lateral injury to the spinal cord 1, 2. At the C5 level, this involves:

1. Damage to the left lateral corticospinal tract → left-sided weakness/paralysis below C5
2. Damage to the left posterior columns → left-sided loss of proprioception and vibration sense
3. Damage to the right spinothalamic tract (which has already crossed from the left) → right-sided loss of pain and temperature sensation

Clinical Course and Prognosis

The prognosis for Brown-Séquard syndrome is generally favorable compared to other spinal cord injury patterns 1, 3. Patients typically show substantial recovery, particularly of motor function. Recovery often follows this pattern:

1. First: Recovery of motor function (ipsilateral side)
2. Second: Recovery of pain and temperature sensation (contralateral side)
3. Last: Recovery of proprioception (ipsilateral side)

Diagnostic Approach

• MRI of the cervical spine is the gold standard for diagnosis, showing hemisection or lateral compression of the spinal cord at C5 level 4
• CT myelography may be used if MRI is contraindicated
• Neurological examination demonstrating the classic pattern of deficits is crucial for diagnosis

Common Causes at C5 Level

• Traumatic injuries (stab wounds, penetrating injuries) 1, 3, 2
• Cervical disc herniation 4
• Spinal cord tumors
• Vascular lesions
• Infectious or inflammatory processes

Clinical Pearls

• Pure Brown-Séquard syndrome is rare; most cases present as "Brown-Séquard plus syndrome" with incomplete or mixed neurological deficits
• Early diagnosis and prompt treatment are associated with better functional outcomes
• Rehabilitation plays a crucial role in recovery
• The syndrome provides an excellent clinical demonstration of spinal cord tract anatomy and function

In summary, Brown-Séquard syndrome at the left C5 level presents with left-sided motor weakness/paralysis and proprioceptive loss with right-sided pain and temperature sensation loss below the level of injury, reflecting the anatomical organization of the ascending and descending tracts in the spinal cord.