Polycranial neuritis, also known as multigroup cerebral neuritis, refers to unilateral or bilateral majority neuropathy of the brain caused by various etiologies. It is often caused by tumors (nasopharyngeal carcinoma, meningioma), cerebrovascular diseases (aneurysm, vasculitis), infections (arachnoiditis, limited dural meningitis), and trauma to the skull base. Firstly, nerve-nourishing vitamin B1, adenosine cobalamin or methylcobalamin are given as medication, while physical therapy and acupuncture can also be used. The key to treatment is to find the cause of the disease. If the cause is a tumor, radiotherapy, chemotherapy or surgery is needed; if the cause is vasculitis, hormonal anti-inflammatory therapy can be given; if the cause is trauma to the skull base, surgery is also needed. Common clinical examples of polycystic neuritis include cavernous sinus syndrome, supraorbital fissure syndrome, orbital apical syndrome, rock apical syndrome, pontocerebellar horn syndrome, and jugular foramen syndrome.