Kernohan's Notch - Causes

Causes

The Kernohan's notch is a secondary phenomenon that results from a major primary injury. Non-tumoral, non-traumatic, intracranial haemorrhage rarely causes this phenomenon.

A wide range of serious injuries can cause an increase in intracranial pressure to trigger the formation of a Kernohan's notch. In general, this phenomenon occurs in patients with advanced brain tumor or severe head injury. In the case of severe head injury, a clot can occur over the surface of the brain and can often cause shift of the middle part of the brain against the tentorium, which creates the Kernohan's notch. Chronic subdural hematomas have been known to be a familiar cause of Kernohan's notch.

MRIs have shown evidence of Kernohan's notch from patients with traumatic head injury that are related to acute space-occupying lesions such as subdural hematoma, epidural hematoma, depressed skull fracture, or spontaneous intracerebral hematoma.

Also, it is important to note that the anatomical size of tentorial notches vary considerably between individuals; however, very little evidence supports that a more narrow notch creates a predisposition towards Kernohan's notch.