A 22-year-old man is brought to the emergency department after a bar fight during which he received a knife wound to his neck. The patient is in moderate distress but is alert and can follow commands. Vital signs are stable. Neurologic examination shows right-sided hemiplegia. Loss of proprioception and vibratory sensation is present below the C8 dermatome on the right side. On the left side, there is loss of pain and temperature sensation below the T2 dermatome. MRI of this patient's spine will most likely reveal which of the following?
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This patient has a penetrating injury resulting in right-sided hemisection of the spinal cord at the C8 level. Spinal cord hemisection classically causes Brown-Séquard syndrome, which is characterized by the following tract lesions and clinical signs:
Spinal cord injury above T1 can also cause ipsilateral Horner syndrome (ie, ptosis, miosis, anhidrosis) if there is concurrent damage to the oculosympathetic pathway.
(Choice A) Complete transection of the spinal cord would result in bilateral loss of all sensation and voluntary movement below the level of the lesion.
(Choice B) A lesion of the dorsal sensory roots would lead to ipsilateral loss of sensation and areflexia from the specific dermatome(s) affected.
(Choice C) A lesion of the dorsal columns on the right side would result only in ipsilateral loss of vibratory, proprioceptive, and light touch (ie, 2-point discrimination) sensation below the level of the lesion.
(Choice D) A lesion of the medial longitudinal fasciculus is associated with internuclear ophthalmoplegia, which is commonly seen in multiple sclerosis; it presents with impaired horizontal eye movement and weak adduction of the ipsilateral eye with simultaneous abduction nystagmus of the contralateral eye.
Educational objective:
Brown-Séquard syndrome results from hemisection of the spinal cord. It is characterized by ipsilateral paralysis due to corticospinal tract injury; ipsilateral loss of vibratory, proprioceptive, and light touch sensation (dorsal columns); and contralateral loss of pain, temperature, and crude touch sensation (spinothalamic tract) below the level of the injury.