Examkin

Question

Difficulty: MediumNeurosurgery

A 42-year-old male is brought to the emergency department after a high-speed motor vehicle collision. His initial Glasgow Coma Scale score is 6 (E1, V1, M4), and he is promptly intubated for airway protection. A non-contrast head CT demonstrates extensive traumatic subarachnoid hemorrhage, a large right-sided acute subdural hematoma, and significant midline shift. The neurosurgery team discusses the risk of various herniation syndromes based on the imaging findings. Match the following brain herniation syndromes with their classic neurologic or vascular consequences.

  • Uncal herniationIpsilateral fixed and dilated pupil with contralateral hemiparesis
  • Subfalcine herniationContralateral lower extremity weakness due to anterior cerebral artery compression
  • Tonsillar herniationCardiorespiratory arrest due to medullary compression
  • Central transtentorial herniationProgressive rostrocaudal neurologic deterioration with Cheyne-Stokes respirations

Answer

Uncal herniation matches with ipsilateral fixed and dilated pupil; Subfalcine herniation matches with contralateral lower extremity weakness; Tonsillar herniation matches with cardiorespiratory arrest; Central transtentorial herniation matches with progressive rostrocaudal neurologic deterioration.
Each herniation syndrome has a distinct anatomic trajectory that dictates its clinical presentation. Understanding the spatial relationship between the herniating tissue and adjacent nerves, vessels, or brainstem centers is critical for rapid localization and intervention in severe neurotrauma.

Step-by-Step Solution

1
Identify the anatomic structure involved in Uncal herniation.
The uncus compresses CN III and the cerebral peduncle.
This specific compression produces ipsilateral pupillary dilation and contralateral hemiparesis.
2
Identify the anatomic structure involved in Subfalcine herniation.
The cingulate gyrus herniates under the falx cerebri, compressing the anterior cerebral artery.
The anterior cerebral artery supplies the medial motor cortex, leading to contralateral leg weakness.
3
Identify the anatomic structure involved in Tonsillar herniation.
Cerebellar tonsils herniate through the foramen magnum.
This compresses the medulla oblongata, causing life-threatening cardiorespiratory arrest.
4
Identify the mechanism of Central transtentorial herniation.
Downward pressure on the diencephalon and midbrain.
This causes a progressive top-down dysfunction characterized by Cheyne-Stokes respirations and deteriorating consciousness.

Key Concept

Brain Herniation Syndromes and Anatomic Correlates
Rate this question

Topics

Neurosurgery

More questions from this topic