Neurology · Spinal Cord Injury

Brown-Séquard Syndrome

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Brown-Séquard syndrome is a hemisection of the spinal cord most commonly caused by penetrating trauma such as a stab wound or gunshot wound.

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Patients exhibit ipsilateral loss of motor function and proprioception/vibration sense due to damage to the corticospinal tract and dorsal columns.

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Patients exhibit contralateral loss of pain and temperature sensation starting one to two levels below the level of the lesion due to damage to the lateral spinothalamic tract.

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The lateral spinothalamic tract fibers ascend and decussate within the spinal cord one to two levels above the level of entry, explaining why contralateral pain/temperature loss begins one to two levels below the lesion.

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Ipsilateral loss of fine touch and vibration occurs because the dorsal column-medial lemniscal pathway does not decussate until it reaches the medulla.

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Ipsilateral Horner syndrome may be present if the lesion occurs at or above the T1 level, disrupting the sympathetic chain.

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Magnetic resonance imaging (MRI) of the spine is the diagnostic study of choice to confirm the level and extent of the spinal cord injury.

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A 24-year-old male is brought to the emergency department after being stabbed in the back during an altercation. Physical examination reveals weakness of the right leg and loss of vibration and proprioception on the right side. Additionally, the patient demonstrates loss of pain and temperature sensation on the left side starting at the level of the umbilicus. The patient has intact sensation on the right side and intact motor function on the left side.

What is the most likely diagnosis?

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Brown-Séquard syndrome

The patient presents with the classic triad of ipsilateral motor/proprioception loss and contralateral pain/temperature loss, which is the classic presentation of a spinal cord hemisection.

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Etiology / Epidemiology

Caused by hemicord injury (hemisection), most commonly from penetrating trauma (stabs/gunshots).

Clinical Manifestations

Ipsilateral loss of motor/proprioception and contralateral loss of pain/temperature below the lesion.

Diagnosis

MRI spine is the gold standard for visualizing the cord lesion.

Treatment

High-dose corticosteroids (controversial) and surgical stabilization for unstable fractures.

Prognosis

Variable recovery; incomplete injuries have a better prognosis than complete cord transections.

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Epidemiology & Etiology

Primarily affects young adults due to penetrating trauma such as knife or gunshot wounds. Non-traumatic causes include cervical disc herniation, tumors, or multiple sclerosis plaques. It represents a classic form of incomplete spinal cord injury.

Pertinent Anatomy

The syndrome results from damage to the lateral half of the spinal cord. The corticospinal tract (motor) and dorsal columns (vibration/proprioception) are affected ipsilaterally. The spinothalamic tract (pain/temperature) fibers ascend and decussate within one to two levels of entry, so contralateral pain/temperature loss begins one to two levels below the lesion.

Pathophysiology

Ipsilateral motor paralysis occurs due to interruption of the descending corticospinal tract. Ipsilateral loss of fine touch and vibration occurs via the dorsal column-medial lemniscal pathway. Contralateral pain and temperature loss occurs because the spinothalamic tract fibers cross 1-2 levels above the site of injury.

Clinical Manifestations

Patients present with ipsilateral hemiplegia and loss of proprioception/vibration. Contralateral loss of pain and temperature sensation begins 1-2 levels below the lesion. Autonomic instability or respiratory distress may occur if the lesion is at the cervical level.

Diagnosis

The MRI spine is the diagnostic modality of choice to identify the level and extent of cord compression. CT myelography may be used if MRI is contraindicated. Clinical diagnosis is confirmed by the classic dissociated sensory loss pattern.

Treatment

Management focuses on surgical decompression and stabilization of the spine. Methylprednisolone is sometimes administered within 8 hours of injury, though its use remains controversial. Avoid hypotension to maintain spinal cord perfusion pressure.

Prognosis

Prognosis depends on the severity of the initial injury and the presence of spinal shock. Most patients regain significant motor function over time. Physical therapy is essential for long-term functional recovery.

Differential Diagnosis

Anterior Cord Syndrome: bilateral loss of pain/temperature with preserved proprioception

Central Cord Syndrome: disproportionate upper extremity motor weakness

Syringomyelia: cape-like distribution of pain/temperature loss

Cauda Equina Syndrome: saddle anesthesia and bowel/bladder dysfunction

Transverse Myelitis: bilateral motor and sensory deficits across a specific dermatome