The cerebellum and trauma
Trauma to the cerebellar hemisphere results in loss of control of balance and coordination. There is limited space in the back of the skull where the cerebellum resides. With cerebellar swelling from trauma, tonsilar herniation may occur (discussed below) most commonly resulting in death or severe disability.
Major areas of the cerebellum
When discussing trauma and the cerebellum, clinicians usually refer to 2 areas of the cerebellum sometimes 3 areas, the Cerebellar Hemispheres, the Cerebellar Tonsils, and occasionally the Folia.
The Cerebellar Hemisphere
Trauma to the cerebellar hemisphere results in loss of control of balance and coordination on the same side of the body. Direct trauma to the back of the head is the usual cause and results in epidural or subdural hematomas over and/or around the cerebellar hemisphere.
Cerebellar Tonsil: Central Herniation, "Coning", Tonsilar Herniation
When pressure increases around the cerebellum, one or both cerebellar tonsils may herniate downward through the opening in the base of the skull (the foramen magnum), the only major opening to relieve the increase pressure in the contained space. The medulla of the brainstem also gets compressed in this downward herniation; tiny blood vessels going to the brainstem get stretched and damaged resulting in bleeding and stroking of the brainstem. Breathing and circulation centers are controlled by this area of the brainstem and are injured, death usually occurs.
The Cerebellar Folia
The folia are the many folds seen on the hemisphere surface hiding the underlying cortex. With cerebellar swelling, these folds expand and become less distinct when visualized on radiographic studies.