A 40-year-old female librarian is brought to the emergency depament. Neurologic examination reveals the following: blood pressure 160/90 mm Hg, weakness on the right side of her inferior face, no weakness in upper or lower limbs, tongue deting to right side on protrusion, and uvula deting to the left side when patient says “ah.” In which of the following loci is the lesion causing these symptoms found?
Correct Answer: Genu of internal capsule, left side
Description: A lesion of the genu of the internal capsule destroys coicobulbar fibers. The facial nucleus receives bilateral coicobulbar input, the upper face division receives bilateral input, and the lower face division receives only contralateral input. (so lesion of left genu will present as Right side lower face weakness) The hypoglossal nucleus receives only contralateral coicobulbar input. So lesion of left genu will present as right side hypoglossal paralysis. Hence, when the tongue is protruded, it detes to the right (side of LMN lesion) owing to the unopposed activity of the intact genioglossus. Lesion of Left genu will cause paralysis of opposite (Right) vago-accessory complex. So the uvula detes to Left (intact side / opposite site of LMN lesion) when the patient says "ah.
Category:
Anatomy
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now