A patient presents with loss of proprioception and vibratory sensation below the lesion level on the ipsilateral side, accompanied by spastic paralysis and hyperreflexia below the lesion on the ipsilateral side, and loss of pain and temperature sensation on the contralateral side starting a few segments below the lesion. This clinical picture is most consistent with damage to which spinal cord region?

The correct answer to the question "A patient presents with loss of proprioception and vibratory sensation below the lesion level on the ipsilateral side, accompanied by spastic paralysis and hyperreflexia below the lesion on the ipsilateral side, and loss of pain and temperature sensation on the contralateral side starting a few segments below the lesion. This clinical picture is most consistent with damage to which spinal cord region?" is Option D: Hemi-section of the spinal cord (Brown-Séquard syndrome).

The other options — A) Anterior horn, B) Dorsal column, C) Lateral corticospinal tract — are incorrect for this USMLE Exam Prep question. As explained above: Brown-Séquard syndrome, resulting from spinal cord hemi-section, causes ipsilateral loss of proprioception/vibration (dorsal column) and motor function (corticospinal tract), and contralateral loss o…