Downward displacement of the hemispheres, basal ganglia, and diencephalon through the tentorial notch is indicative of

Question

a. central herniation.
b. uncal herniation.
c. cingulate herniation.
d. infratentorial herniation.

Answer 1

A
These effects are indicative of central herniation from an expanding mass lesion of the midline, frontal, parietal, or occipital lobes. In uncal herniation, a unilateral, expanding mass lesion, usually of the temporal lobe, increases intracranial pressure, causing lateral displacement of the tip of the temporal lobe (uncus). Cingulate herniation occurs when an expanding lesion of one hemisphere shifts laterally and forces the cingulate gyrus under the falx cerebri. The two infratentorial herniation syndromes are upward transtentorial herniation and downward cerebellar herniation.