Spinal cord tracts, brainstem cross-sections, and classic lesion localization tested on USMLE Step 1, distinct from the clinical deficit focus of USMLE Neuro.
40 cards · basic cards · AI-written, checked twice. Edit anything.
- What is the primary function of the lateral corticospinal tract?
- Voluntary motor control of limb (skeletal) muscles
- Where does the corticospinal tract decussate?
- Pyramidal decussation, at the cervicomedullary junction (caudal medulla)
- In which part of spinal cord white matter does the lateral corticospinal tract travel?
- Lateral funiculus
- What sensory modalities does the dorsal column-medial lemniscus pathway carry?
- Fine touch, vibration, and proprioception
- Where do dorsal column fibers decussate as they become the medial lemniscus?
- Internal arcuate fibers, in the medulla
- Which dorsal column fasciculus carries sensation from the lower body?
- Fasciculus gracilis
- Which dorsal column fasciculus carries sensation from the upper body?
- Fasciculus cuneatus
- What sensory modalities does the spinothalamic tract carry?
- Pain, temperature, and crude touch
- Where does the spinothalamic tract decussate?
- Anterior white commissure, one to two spinal levels above the level of entry
- In which part of spinal cord white matter does the spinothalamic tract travel?
- Anterolateral funiculus
- What is the general function of the spinocerebellar tracts?
- Carry unconscious proprioceptive information to the cerebellum
- Does the dorsal (posterior) spinocerebellar tract decussate?
- No, it remains uncrossed and travels ipsilaterally
- In Brown-Sequard syndrome, what is lost ipsilateral to a spinal hemicord lesion?
- Motor function and proprioception/vibration sense below the lesion
- In Brown-Sequard syndrome, what is lost contralateral to a spinal hemicord lesion?
- Pain and temperature sensation, a level or two below the lesion
- What is the classic sensory deficit pattern in syringomyelia?
- Bilateral loss of pain and temperature sensation in a cape-like distribution