A skull base fracture, as the name implies, is a fracture that occurs at the base of the skull and is predominantly linear, either confined to one cranial fossa or running transversely through both skull bases or longitudinally through the anterior, middle, and posterior cranial fossae. Because the fracture line often involves the paranasal sinuses, the rocky bone, or the mastoid airspace, the cranial cavity and these sinus cavities communicate to form an occult open fracture, which can lead to secondary intracranial infection. The majority of skull base fractures are caused by the extension of the skull cap fracture line to the skull base, and a few can be caused by cranial crush injuries. The diagnosis of skull base fracture mainly relies on clinical manifestations, and X-ray plain film is not easy to show the skull base fracture, which is not helpful for diagnosis; CT scan can clearly show the fracture site with the adjustment of window width and window distance, which is of great value. Anterior fossa fracture The bottom of the anterior fossa of the skull is the orbital roof, which is very weak and easily broken. After the fracture of the anterior fossa, blood may infiltrate downward into the orbit, causing suborbital hemorrhage and delayed subcutaneous petechial hemorrhage of the eyelid, which usually appears a few hours after the injury and is purple-blue in color, commonly known as “panda eyes”, and is important for diagnosis. When the anterior fossa fracture involves the sieve fossa or sieve plate, it may tear the dura mater and the mucosa of the nasal cavity, resulting in cerebrospinal fluid nasal leakage and/or pneumocranial, making the cranial cavity communicate with the outside world, so there is a possibility of infection, which should be regarded as an open injury. The early cerebrospinal fluid nasal leakage is mostly bloody and must be distinguished from epistaxis by comparing the red blood cell count in the leaking fluid with the surrounding blood or by using urine glucose test paper to determine whether it contains sugar, which is easily diagnosed. In addition, anterior fossa fractures are often associated with unilateral or bilateral olfactory disturbances, intraorbital hemorrhage may cause protrusion of the eye, and if the optic nerve is affected or the optic canal is fractured, visual impairment of varying degrees may also occur. The fracture of the anterior cranial fossa itself requires no special treatment, and the treatment is mainly directed at the concomitant diseases and sequelae caused by the fracture. In the early stage, prevention of infection should be the main focus, and antibacterial drugs that can cross the blood-brain barrier can be used along with good cleaning and care of the five senses, avoiding forceful nose blowing and placement of nasogastric tubes. In a semi-sitting position, the nasal leak is allowed to flow out naturally or swallowed, so that the brain tissue settles at the leaky hole at the base of the skull after the cranial pressure drops to promote its healing, and the nasal cavity should not be stuffed. Through the above treatment, the nasal leak can be closed and healed by itself within 2 weeks, but for patients with long-term leakage of more than 4 weeks, or patients with repeated meningitis and massive overflow, repair surgery should be performed. Medial fossa fracture is a fracture of the middle fossa of the skull with the rocky part of the temporal bone, the wing of the pterygoid bone in front, the upper edge of the rocky bone and the dorsal part of the saddle in the back, the squamous part of the temporal bone in the side, and the pterygoid saddle in the center. Fractures of the middle fossa often involve the rock bone and damage the inner ear structures or middle ear cavity, so patients often have hearing impairment and peripheral facial nerve paralysis. Because of the complex bone structure of the skull base, unevenness and many fissures, it is difficult to show the fracture line by X-ray examination, and CT scan examination has some value for skull base fracture. The treatment principle of skull middle fossa fracture is the same as that of anterior fossa fracture, and the main focus is still to prevent infection. Patients with cerebrospinal fluid ear leakage should clean and disinfect the skin of the outer ear, then cover it with sterilized skim cotton or gauze and exchange it regularly. The patient should be placed in a semi-sitting position with the head on the affected side to promote self-healing. For patients with cavernous sinus arteriovenous fistula, the Mata’s test can be used early, i.e., compression of the affected common carotid artery in the neck for 15-30 minutes four to six times a day, which is effective in some cases with small fistulas. However, arteriovenous fistulas that have been in place for a long time, have worsened symptoms, or have late onset should be treated with early surgery. Individual patients with severe epistaxis immediately after injury can die from shock or asphyxia, so emergency treatment is needed. Immediate endotracheal intubation should be performed to remove blood from the airway to ensure breathing; the nasal cavity should be filled immediately, and the posterior nasal orifice should be blocked via the pharynx in a fashion; blood loss should be replenished quickly; the common carotid artery should be compressed on the affected side of the neck, and surgical ligation should be performed if necessary to save life. Posterior fossa fracture The posterior fossa fossa is behind the rock cone in front of the skull, with the foramen of the inner ear passing through the facial nerve and the auditory nerve, followed by the foramen of the jugular vein below it, with the linguopharyngeal nerve, vagus nerve, paranasal nerve and ethmoid sinus passing through it, with the occipital bone scales on both sides, and the large foramen of the occipital bone in the center of the base, with the sublingual nerve exiting the skull through its foramen in front and outside. The main signs are swelling of the neck muscles, delayed subcutaneous petechiae in the mastoid area and mucosal stasis and edema in the posterior pharyngeal wall. CT and MRI scans are also important for posterior fossa fractures, especially for injuries in the craniocervical junction. In the treatment of posterior fossa fracture, the acute stage is mainly for the fracture or dislocation of occipital foramen and high cervical vertebrae, and if there is respiratory dysfunction and/or cervical spinal cord compression, tracheotomy, cranial traction, assisted respiration or artificial respiration if necessary, or even decompression of the posterior fossa and cervical vertebrae should be performed early.