Question

A patient presents with ipsilateral weakness and loss of proprioception, along with contralateral loss of pain and temperature sensation below a certain spinal level. What is the most likely cause of this pattern?

• A. Intradural Extramedullary tumor
• B. Intramedullary tumor
• C. Extradural compression
• D. Syringomyelia

Hint:

Brown-Séquard Syndrome = Ipsilateral Motor/Proprioception loss + Contralateral Pain/Temperature loss.
Always link this syndrome with Meningiomas and Schwannomas, the classic intradural extramedullary lesions.

Answer 1

The Correct Option is A

Concept:
The clinical presentation describes a highly specific neurological symptom complex: ipsilateral loss of motor function and proprioception combined with contralateral loss of pain and temperature sensation.
This triad is the pathognomonic definition of Brown-Séquard syndrome (spinal cord hemisection). The clinician must identify which class of spinal tumor most commonly produces this unilateral compression pattern.
Explanation:
• Brown-Séquard syndrome occurs when exactly one lateral half of the spinal cord is damaged or externally compressed.

• The ipsilateral weakness results from damage to the descending lateral corticospinal tract, which decussated earlier in the medulla.

• The ipsilateral loss of proprioception results from damage to the ascending dorsal columns, which do not cross until they reach the brainstem.

• The contralateral loss of pain and temperature sensation results from damage to the ascending lateral spinothalamic tract, which decussates within the spinal cord just one or two levels above its entry point.

• Intradural Extramedullary tumors (such as meningiomas and schwannomas) are the classic non-traumatic causes of this syndrome.

• These tumors grow inside the dural sac but outside the spinal cord parenchyma, slowly pressing on one lateral aspect of the cord from the outside in, creating a clean hemisection effect.

• Intramedullary tumors (like ependymomas) grow from within the center of the cord, typically presenting with early, bilateral loss of pain and temperature (affecting the crossing fibers in the anterior white commissure).

• Extradural tumors (like bone metastases) typically cause circumferential, bilateral cord compression.

• Syringomyelia causes a "cape-like" bilateral loss of pain and temperature due to central canal expansion.
Final Answer:
The clinical pattern of Brown-Séquard syndrome is most classically caused by unilateral compression from an Intradural Extramedullary tumor.