Tentorial tear due to birth injury

**Definition:** Lacerations of tentorium cerebelli due to birth trauma, usually resulting in infratentorial haemorrhages; lesser degrees of tentorial injury most commonly associated with subdural bleeds.

**Long definition:** Lacerations of tentorium cerebelli due to birth trauma, usually resulting in infratentorial haemorrhages; or lesser degrees of tentorial injury produced by horizontal or vertical stress on the tentorium after head compression between the vertex and base of the skull or in the occipital-frontal diameter. The stretch of the tentorium leads to rupture of the tributaries of Galen’s vein at its fixed juncture to the straight sinus. Tentorial tear is most commonly associated with a subdural hematoma. A second cause of tentorial tearing is occipital osteodiastasis