USMLE Step 1 · Neurology

Brown-Sequard syndrome vs Anterior, central, and posterior cord syndromes

How to tell Brown-Sequard syndrome and Anterior, central, and posterior cord syndromes apart when a board question makes them look alike.

Fastest separator

Brown-Sequard is hemicord split findings; anterior is motor plus pain/temp bilaterally; central is arms/cape; posterior is dorsal-column loss.

Side by side

Brown-Sequard syndromeAnterior, central, and posterior cord syndromes

Key clue

Brown-Sequard syndrome is spinal cord hemisection with ipsilateral UMN weakness and loss of vibration/proprioception below the lesion plus contralateral pain-temperature loss below the lesion.

Anterior cord syndrome causes bilateral motor and pain-temperature loss with dorsal column sparing; central cord causes upper extremity weakness and cape-like pain-temperature loss; posterior cord causes vibration/proprioception loss and sensory ataxia.

Mechanism

Hemisection interrupts ipsilateral corticospinal and dorsal column tracts and contralateral spinothalamic fibers after they cross segmentally.

Anterior cord injures corticospinal/spinothalamic tracts, central cord injures crossing spinothalamic fibers and medial motor fibers, and posterior cord injures dorsal columns.

Labs and tests

Trauma or lesion with ipsilateral weakness/proprioception loss and contralateral pain-temperature loss supports Brown-Sequard syndrome.

Dorsal column sparing supports anterior cord; cape-like dissociated sensory loss supports central cord; isolated proprioception/vibration loss supports posterior cord.

The trap

Cord syndromes share weakness or sensory loss, so tract modality and side localize the lesion.

The repair move

Map each tract to its crossing point before naming the syndrome: corticospinal crosses at the medulla (deficits ipsilateral below the cord lesion); spinothalamic crosses within 1 to 2 levels at the cord (deficits contralateral below the lesion); dorsal columns cross at the medulla (deficits ipsilateral below). Then read the syndrome: Brown-Sequard (hemicord) gives ipsilateral motor and dorsal column loss with contralateral pain and temperature loss; anterior cord gives bilateral motor and pain/temperature loss with preserved dorsal columns (anterior spinal artery occlusion); central cord gives cape-like bilateral pain/temperature loss with motor weakness greater in arms than legs (syringomyelia, hyperextension injury in elderly with cervical spondylosis); posterior cord gives bilateral dorsal column loss only (tabes dorsalis from tertiary syphilis; B12 subacute combined degeneration affects dorsal columns plus lateral corticospinal).

Try a free question

Core

A patient has a hemicord injury after a stab wound. Below the lesion there is ipsilateral weakness and loss of vibration/proprioception with contralateral loss of pain and temperature. Which syndrome is most likely?

Show answer and explanation

Answer: A. Brown-Sequard syndrome. Ipsilateral motor/dorsal column loss with contralateral pain-temperature loss is Brown-Sequard syndrome.

Why the other choices are tempting

B. Anterior cord causes bilateral motor and pain-temperature loss with dorsal column sparing.
C. Central cord causes upper extremity weakness and cape-like pain-temperature loss.
D. Posterior cord causes dorsal column loss without the hemicord split pattern.
E. Cauda equina is lumbosacral nerve root dysfunction with saddle anesthesia and bladder symptoms.

Flashcards

Tap a card to flip it.

What pattern points to Brown-Sequard syndrome?

Ipsilateral weakness and vibration/proprioception loss with contralateral pain-temperature loss points to Brown-Sequard syndrome.

What is spared in anterior cord syndrome?

Dorsal column vibration and proprioception are relatively spared in anterior cord syndrome.

Quick answers

What is the fastest way to tell Brown-Sequard syndrome from Anterior, central, and posterior cord syndromes?