Clinical application classification The method is mainly applied to clinical diagnosis, based on the site of cranial injury and the pathomorphological changes of the injury. Firstly, according to the injury site, it is divided into two parts: cranial injury and brain injury, both of which are divided into open and closed injury. Brain injury is divided into open cranial injury and closed cranial injury based on whether the dura is intact or not. The diagnosis of the former is mainly based on dural rupture, cerebrospinal fluid outflow, and traffic between the cranial cavity and the outside world. Skull base fracture combined with cerebrospinal fluid leakage is also called internal open brain injury. Closed brain injury can be divided into two categories: primary and secondary. Classification according to the severity of the disease Clinical application of typing can only make a diagnosis and typing of craniocerebral injury patients for the site of injury and type of pathology, but can not be judged on the severity of the patient’s condition. In 1960, China first developed the “acute closed craniocerebral injury typing” standard, according to the coma time, positive signs and vital signs will be divided into light, medium and severe 3 types, after two revisions have been more perfect, has become a recognized domestic standards.