central herniation

Central herniation is the subtype of downward transtentorial herniation of the brain that involves descent of the diencephalon and midbrain. It usually occurs with other types of downward herniation such as uncal herniation.

Clinical manifestations

The clinical syndrome of central herniation classically manifests as a rostral to caudal progression of deficits attributed to brainstem dysfunction, including cranial nerve III (oculomotor nerve) palsy, diminished level of consciousness, decerebrate or decorticate posturing, rigidity or paralysis, abnormal respiratory pattern, and eventually death.

Pathology

Central herniation is a late/severe sequela of supratentorial mass effect, especially when bilateral or midline. Potential etiologies include neoplasms, severe cerebral edema (e.g. from acute infarct), hemorrhage, and hydrocephalus.

Radiographic features

Cross-sectional imaging (CT or MRI) demonstrates the following abnormalities :

• effacement of the perimesencephalic cisterns (most common finding)
• descent (caudal displacement through the tentorial hiatus) of the diencephalon, usually along with herniation of both temporal lobes (lateral herniation)
• oblong deformity of the midbrain
• descent of the quadrigeminal plate
• descent of the basilar artery
• flattening of the ventral pons against the clivus

Complications of central herniation include the following :

• Duret hemorrhage due to shearing of basilar artery perforator branches
• infarction of the posterior cerebral artery territory
• hydrocephalus due to obstruction of the cerebral aqueduct

See also

• subfalcine herniation
• transalar herniation
• transtentorial herniation
  • downward: uncal herniation and central herniation
  • upward: ascending transtentorial herniation
• tonsillar herniation
• extracranial (transcalvarial) herniation
• paradoxical brain herniation

Siehe auch:

• uncal herniation
• transtentorielle Herniation

und weiter:

• temporal herniation