Fractures which extend through the base of the skull, usually involving the petrous bone. Battle's sign (characterized by skin discoloration due to extravasation of blood into the subcutaneous tissue behind the ear and over the mastoid process), CRANIAL NEUROPATHIES, TRAUMATIC; carotid-cavernous sinus fistula; and cerebrospinal fluid otorrhea are relatively frequent sequelae of this condition. (Adams et al., Principles of neurology, 6th ed, p876)