Herniation syndromes

Question 1

Uncal herniation
1) Uncal herniation is caused by what?
2) This mass pushes what against what?
3) Which cranial nerve does this compress, and what 2 features does this result in?
4) These features can be followed by contralateral hemiparesis - this is due to pressure on what?

Answer 1

1) Lateral supratentorial mass
2) Uncus against the midbrain
3) CN III - dilated pupil and ophthalmoplegia
4) Cerebral peduncle

Question 2

Cerebral tonsil herniation
1) This is caused by increased pressure in the posterior fossa forcing what through what foramen?
2) Name 2 of the features that would occur first
3) Name 1 of the features that would occur later

Answer 2

1) Cerebral tonsils through the foramen magnum
2) Ataxia, CN VI nerve palsy and an upgoing plantar reflex
3) Loss of consciousness, irregular breathing

Question 3

Subfalcine (cingulate) herniation
1) What causes a subfalcine herniation?
2) The cingulate gyrus is forced under what?
3) If this compresses the anterior cerebral artery and causes a stroke, where would muscle weakness be seen?

Answer 3

1) Frontal mass
2) Falx cerebri
3) Contralateral leg weakness