Case 20 Answers

Basic Human Neuroanatomy

A Clinically Oriented Atlas

Case 20 Answers

1. What is the localizing significance of the fact that essentially all sensory modalities are involved in this case, as opposed to the sparing of one or more of the modalities?

The lesion is above the middle third of the pons on the left side.

2. What is the meaning or significance of this patient holding her right upper limb in very unusual, somewhat uncomfortable positions, and the irregular, constant movement of the right fingers when the eyes are closed?

These are due to joint position sense impairment in the RUE.

3. Indicate the possible anatomical locations of the pathologic process in this case.

Left tegmentum of the upper half of the pons or midbrain, left VPM/VPL nuclei of the thalamus, left posterior limb of the internal capsule, left postcentral gyrus

4. Indicate the specific structures possibly involved by the pathologic process.

Left medial, spinal, and trigeminal lemnisci, left VPM/VPL, left postcentral gyrus

5. This patient’s signs and symptoms constitute a classic neurologic syndrome. What is the name of that syndrome, and what is its usual cause?

Pure hemisensory stroke.
Lacunar infarct, involving the VPM/VPL nuclei of the thalamus.

6. In general, what type of pathologic process do you think is involved in this case?

Vascular – Central (penetrating) branches of the posterior cerebral artery (posterolateral group)

7. What diagnostic procedure(s) would you undertake at this point?

References

1. Fisher CM. Neurology 1965;15:76-80.
2. Fisher CM. Neurology 1982;32:871-876.
3. Jickling GC, Stamova B, Ander BP, et al. Ann Neurol 2011;70:477-485.
4. Bezerra DC, Sharrett AR, Matsushita K, et al. Neurology 2012;78:102-108.

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