Neurodegenerative Diseases USMLE Step 1 Practice Question
A 29 year old woman has progressive numbness over both shoulders and upper arms. She reports burning herself while cooking without noticing until later. Examination shows bilateral loss of pain and temperature sensation over the upper extremities in a cape like distribution with preserved light touch and vibration. Hand grip strength is mildly reduced. Which structure is most likely damaged first?
Answer choices
- ALateral corticospinal tracts
- BSpinocerebellar tracts
- CAnterior white commissureCorrect answer
- DDorsal columns
- ESubstantia nigra
- FSpinothalamic tract (lateral aspects)
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