1. Is there evidence of peripheral nervous system involvement in this case, and, if so, what is the level(s) of that involvement?
No
2. Is there evidence of spinal cord involvement in this case and, if so, at what level?
No. A spinal cord lesion would have to be located in the left lateral funiculus of the thoracic or upper lumbar cord, involving the lateral corticospinal tract but sparing the spinothalamic tract. These two structures are both in the vascular territory of the anterior spinal artery; so it is unlikely that one would be involved and not the other.
3. Could this patient’s signs and symptoms be localized to any other place in the central nervous system? If so, what is the precise localization of her neurologic lesion, including the side of involvement? Indicate the specific structure(s) involved by this lesion.
Yes. An isolated left lower limb weakness could be caused by a lesion involving the anterior (motor) part of the right paracentral lobule. Such a lesion would interrupt the origin of the corticospinal fibers to the contralateral lower limb (review the "motor homunculus" on the primary motor cortex [area 4]).
4. In general, what type of pathologic process is involved in this case? If vascular, what vessel is involved?
Vascular – Terminal cortical branches of the right anterior cerebral artery supplying the anterior part of the paracentral lobule. In this case, the etiology of the small stroke was either vasospasm from her cocaine use or a cardioembolic infarct due to atrial fibrillation.
5. What diagnostic procedure(s) would you undertake at this point?
Click here for images
