Uncal herniation is also known as what?

• A. Transtenorial
• B. Subfalcine
• C. Tonsillar
• D. Midline shift

Answer: (A)

Uncal herniation is a form of transtentorial (through the tentorial notch) herniation. The uncus, part of the temporal lobe, herniates downward and inward through the tentorial notch, compressing the midbrain and nearby structures such as the oculomotor nerve, which explains the typical brainstem and cranial nerve findings as this process progresses. Among the options, this term identifies the specific pathway of herniation.

The other patterns refer to different processes: subfalcine herniation involves shifting under the falx cerebri (not through the tentorial notch), tonsillar herniation pushes the cerebellar tonsils through the foramen magnum, and a midline shift describes a radiologic sign of mass effect rather than a distinct herniation route.