Optic neuritis is a demyelinating inflammation of the optic nerve. Acute pain is mainly due to optic neuritis, trigeminal neuralgia, Lhermitte's sign or dysesthesias. Cases of persistent neuritis and compression neuropathy were reported after significant microwave exposures. Optic neuritis is inflammation of the optic nerve. Cranial neuritis is an inflammation of cranial nerves. Almost half of patients with optic neuritis have white matter lesions consistent with multiple sclerosis. Vestibular neuritis also known as labyrinthitis affects approximately 35 million people per year. Vestibular neuritis is generally a self-limiting disease. It has also been associated with Bell's palsy, and vestibular neuritis. The treatment for vestibular neuritis depends on the cause. Other reported serious adverse events are retinal changes, optic neuritis and alterations of liver functions. In brachial plexus neuritis, conservative management may be more appropriate. Another potential use of methylprednisolone is for vestibular neuritis. Those that do survive often have chronic conditions of encephalitis and neuritis . Optic papillitis is a specific type of optic neuritis.