Methylcobalamin, which is generally available in pharmacies, is a commonly used drug that is a nerve-nourishing agent. It is mainly used for patients with sensory dysfunction. Common diseases including Green-Barre syndrome, acute myelitis, spinal cord compression, subacute joint degeneration of the spinal cord, idiopathic facial nerve palsy, trigeminal neuralgia, greater occipital neuralgia, and patients with temporal neuralgia can be applied. Peripheral neuropathy can also be applied if there is peripheral neuritis, as well as vitamin B1, vitamin B6, or adenosine cobalamin, among others. It can also be applied if the patient is considering cerebrovascular diseases, such as cerebral hemorrhage and cerebral infarction, which cause sensory disorders in the lateral limbs, such as numbness and pain, and also for sensory abnormalities caused by encephalitis, which generally have fewer side effects.