Startle epilepsy is a rare neurologic disease characterized by frequent and spontaneous epileptic seizures (frequently with symmetrical or asymmetrical tonic features) triggered by a normal startle in response to a sudden and unexpected somatosensory (most frequently auditory) stimulus. Falls are common and can be traumatic. In most cases, the disease is associated with spastic hemi-, di-, or tetraplegia and intellectual disability.

A hemangioma is a benign tumor characterized by blood-filled spaces lined by benign endothelial cells. A hemangioma characterized by large endothelial spaces (caverns) is called a cavernous hemangioma (in contrast to a hemangioma with small endothelial spaces, which is called capillary hemangioma).