Prevost Sign in MCA Stroke

[Ronin786]

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Prevost sign is where the eyes will deviate towards the side of the lesion.

I'm having trouble understanding how that happens. If you have a left MCA stroke, you can have homonymous hemianopia, where the right field of vision will be gone. Wouldn't the eyes deviate to the right to make up for this?

According to MTB and everywhere ive seen, they deviate to the left, which doesnt make sense if you cant see the right side.

 

[Transposony]

In left MCA stroke, patient will have right homonymous hemianopia and since the fields of vision are reversed (left side objects project to right side retina) the patient will have trouble seeing the left side therefore leading to eye deviation to left.
Hope this helps.

The Prévost's sign refers to deviation of the eyes away from the hemiparesis in acute cortical hemiparetic stroke. Therefore, the eyes are deviated towards the involved hemisphere and may be exaggerated when the head is turned in the same direction. It is most pronounced with non-dominant hemisphere (thus right) lesions.