Multiple sclerosis is a demyelinating disease of the central nervous system. The prevalence is about 0.6-10% in Northern Europe and North America, much higher than in other regions. Etiology The etiology is unknown. The basis for supporting immune dysfunction is a decrease in the number of T suppressor lymphocytes in the peripheral blood. The reason for thinking that it is related to viral infection is that the pathological changes of multiple sclerosis are similar to those of the lentiviral infection disease-Visna in sheep, but no direct evidence of viral infection has been found so far, and the pathogenesis has not been determined, and it is generally believed that the possible mechanism is that the patient has suffered from some kind of viral infection at an early stage, resulting in self-antigenic changes, and in addition there are viruses that have a very similar antigen to that of CNS myelin, both of which can lead to a decrease in T suppressor lymphocytes in the peripheral blood. Both of these can lead to misrecognition and trigger autoimmune mechanisms. Some patients have prodromal symptoms such as headache, dizziness, and upper respiratory tract infection. The duration of the disease varies, with most patients having a slow onset of symptoms, with remission and relapse being the most important features of the disease, while others have persistent or stepwise exacerbation of symptoms without significant remission. According to the lesion site, the disease is generally divided into the following four types. 1. Spinal cord type: mainly affecting the lateral and posterior fascicles. Patients often first complain of back pain, followed by central paralysis of the lower limbs, deep and superficial sensory impairment below the level of damage, urinary retention and impotence. In the case of damage to the posterior cervical fasciculus, forward bending of the patient’s head may cause discrete electric shock-like numbness or pain from the upper back to the lower limbs, which is known as Lhermitt’s sign. There can also be spontaneous and short-lived tonic spasms and pain episodes spreading from a localized area to one or both sides of the trunk and limbs, which is called tonic painful spasticity episodes. 2, optic nerve spinal cord type: also known as optic nerve myelitis. It used to be considered as a separate disease, but recently it has been recognized as a clinical type of multiple sclerosis due to the same pathological changes. This type of disease may begin with damage to the optic nerve and optic nerve crossings, or with damage to the spinal cord, which may occur months or even years apart. It is also possible to see damage to both at the same time. The onset of the disease may be rapid or slow. Optic nerve damage manifests as pain during eye movement, vision loss or total blindness, and normal or pale optic nerve papillae, often in both eyes. The spinal cord damage is the same as the spinal cord type. Brainstem-cerebellar type: manifestations include vertigo, diplopia, nystagmus, dysarthria, central or peripheral facial paralysis, pseudo medullary paralysis or medullary paralysis, crossed paralysis or hemiparesis, locomotor ataxia, and limb tremor, dance, and so on. 4. Cerebral type: less common. The main manifestations are hemiparesis, bilateral hemiparesis, aphasia, seizures, cortical blindness. Mental disorders commonly include emotional instability, involuntary crying and laughing, paranoia, rigidity and mental retardation. Examination 1. Laboratory tests are of auxiliary significance to clinical diagnosis. Cerebrospinal gelatin test shows paralyzing curve and negative Wahl reaction; cerebrospinal fluid oligoclonal IgG zone appears and γ-globulin is increased. 2, evoked potentials suggest that the central nervous system somatosensory, visual, auditory and other conduction pathways may be lesions. 3.Cranial CT and magnetic resonance show lesions around the ventricles. Treatment 1, immunosuppressive therapy: dexamethasone 5-10mg intravenous drip, 1 / day, 10-20 times can be changed to oral; azathioprine 1.5-2.5mg / kg / day, three times orally, can be applied alone, can also be applied in combination with corticosteroids; cyclophosphamide 200mg, every other day intravenous injection, 7-10 times. 2.Plasma exchange therapy: it can improve the symptoms in acute stage. 3.Others: Valium has some curative effect on painful spasm. Physical and sports therapy can be given to those with limb paralysis.