Optic Neuritis Optic neuritis is an acute inflammation or demyelination of the optic nerve, characterized by an impairment of vision, progressing over hours or days (see Chapter 30 Eye: Visual Disturbances ) The disease is primarily unilateral but an increased incidence of bilateral involvement is found in children Optic neuritis in children is thought to be an autoimmune process following a viral disease At times, a contiguous sinusitis may cause the illness Of patients with unilateral optic neuritis, 20% will eventually be diagnosed with multiple sclerosis On examination, decreased visual acuity and decreased color vision are associated with a relative afferent pupillary deficit to light and a central scotoma in the affected eye The relative afferent pupil defect is demonstrated by the swinging flashlight maneuver The pupil of the affected eye constricts briskly when light is shone into the contralateral eye (the consensual light reflex) and dilates when light is immediately shone into the affected eye With bilateral disease, the change in pupillary reflexes may not be apparent Funduscopic examination discloses a hyperemic, swollen optic disc In rare cases of retrobulbar optic neuritis, funduscopic examination is normal Optic neuritis must be distinguished from papilledema, which is secondary to increased ICP Papilledema is almost always bilateral and associated with normal vision and normal pupil reactivity until late in the disease In cases of bilateral optic neuritis, differentiation may be impossible because funduscopic findings are identical in the two illnesses If any doubt of increased ICP persists, the patient should undergo evaluation by CT or MRI of the brain and, if normal, CSF analysis In optic neuritis, the opening pressure is normal, but there may be a mild lymphocytic pleocytosis or elevated CSF protein level The course of the illness is variable, with most patients recovering to normal or near-normal vision in to weeks Treatment with high-dose systemic corticosteroids is poorly studied in the pediatric population, and has not been shown to improve the ultimate prognosis Treatment may, however, result in a slightly faster resolution of symptoms The efficacy of IV immunoglobulin and plasmapheresis has not been established Facial Nerve Palsy Weakness in the distribution of cranial nerve VII (facial) may be produced by either central (upper motor neuron) or peripheral (lower motor neuron) dysfunction Peripheral disease is most common in children, particularly when the facial weakness is an isolated finding Bell palsy refers to peripheral facial nerve weakness with no identifiable underlying cause It is believed to be caused by