A 35-year-old woman presents with unilateral loss of pain and temperature sensation from her right arm, with contralateral (left) loss of proprioception and vibration. MRI shows a lesion in the right side of the cervical spinal cord at C5 level. Which syndrome does this represent, and which tract is ipsilaterally affected for proprioception?

• A Brown-Séquard syndrome; ipsilateral (right) posterior column (fasciculus cuneatus) for proprioception/vibration; contralateral (left) spinothalamic tract for pain/temperature, with ipsilateral upper motor neuron signs ✓
• B Central cord syndrome; all modalities equally affected bilaterally with sacral sparing
• C Anterior cord syndrome; bilateral loss of pain/temperature with preserved proprioception; right posterior column loss represents white matter infarction
• D Brown-Séquard syndrome; contralateral (left) posterior column affected and ipsilateral (right) spinothalamic tract affected

Explanation

Brown-Séquard syndrome results from hemicord transection. The posterior columns (dorsal columns) carry ipsilateral proprioception, vibration, and discriminative touch — they ascend ipsilaterally to the nucleus gracilis/cuneatus in the medulla before crossing. Therefore, a right C5 lesion causes RIGHT-sided loss of proprioception/vibration in the right arm. The spinothalamic tract carries pain and temperature — its fibers cross within 1–2 spinal cord segments of entry in the anterior commissure; therefore, a right C5 lesion disrupts left-sided pain/temperature fibers (already crossed) in the right spinothalamic tract. Additionally, ipsilateral (right) upper motor neuron signs occur below the lesion. Option D has the posterior column side reversed. Option B describes central cord syndrome (sacral sparing, bilateral). Option C describes anterior cord syndrome (bilateral motor and pain/temperature loss, preserved proprioception).

Reference: Guyton & Hall, Textbook of Medical Physiology, 14th ed.

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Written and medically reviewed by the StethoPrep medical team.