The vast majority of skull base fractures are linear fractures, with individual depression fractures, which are classified according to their sites: 1. anterior cranial fossa fractures 2. middle cranial fossa fractures 3. posterior cranial fossa fractures Symptoms 1. anterior cranial fossa fractures: often involving the frontal orbital plate and sieve bone, causing bleeding out through the anterior nostril; or flowing into the orbit, the periorbital subcutaneous and bulbous conjunctival membranes form petechiae, called “panda This is called the “panda” eye sign. When the meninges rupture at the fracture, cerebrospinal fluid may flow out from the anterior nostril through the frontal sinus or sieve sinus, which becomes cerebrospinal fluid nasal leakage, and air may also enter the cranial cavity retrogradely to form intracranial pneumatosis. Fracture of sieve plate and optic nerve canal can cause olfactory nerve and optic nerve injury. Fracture of the middle fossa of the skull: it often involves the rock part of the temporal bone, and when both the meninges and periosteum are ruptured, the cerebrospinal fluid flows out from the tympanic membrane through the middle ear to form cerebrospinal fluid aural leakage; if the tympanic membrane is intact, the cerebrospinal fluid flows to the nasopharynx through the eustachian tube, often combined with the injury of the Ⅶ or Ⅷ cranial nerve. If the fracture involves the butterfly and medial temporal bone, the pituitary gland and the Ⅱ, Ⅲ, Ⅳ, Ⅴ and VI cranial nerves may be injured. If the cavernous sinus segment of the internal carotid artery is injured, a pulsating proptosis may occur due to the formation of an internal carotid artery cavernous sinus fistula; if the internal carotid artery ruptures at the rupture hole or at the internal carotid canal, fatal rhinorrhea or ear hemorrhage may occur. 3. Posterior cranial fossa fracture: If the fracture involves the posterior lateral part of the temporal bone rock, subcutaneous petechial hemorrhage in the mastoid area will appear 2 to 3 days after the injury. If the fracture involves the base of the occipital bone, swelling and subcutaneous petechial hemorrhage in the lower part of the occipital area may appear several hours after the injury; if the fracture involves the posterior edge of the foramen magnum or the tip of the rock bone, individual or all of the posterior group of cranial nerves (i.e., Ⅸ to Ⅻ cranial nerves) may be involved, such as hoarseness and difficulty in swallowing. Only 30-50% of the fracture lines can be seen on cranial radiographs, and if necessary, cranial basal radiographs, tomography or CT scans can be performed. Treatment Most of these fractures do not require special treatment, but rather focus on the management of combined brain injury and other concurrent injuries. Ear and nose bleeds and cerebrospinal fluid leaks should not be plugged or flushed to avoid intracranial infection. Most cerebrospinal fluid leaks stop on their own in about two weeks. If it persists for more than four weeks or if it is accompanied by intracranial pneumonia that does not subside, surgery should be performed promptly to repair the cerebrospinal fluid fistula and close the fistula. In cases of optic nerve or facial nerve injury caused by compression of fragmented bone fragments, the bone fragments should be removed by surgery as soon as possible. Fractures of the skull base with cerebrospinal fluid leakage are open injuries and require antibiotic treatment.