Recurrent isolated optic neuritis in the pediatric population

Optic neuritis (ON) is an inflammatory disorder of the optic nerve characterized by loss or dimming of vision that typically progresses over several days, frequently preceded by ocular pain and followed usually by recovery over a period of weeks to months. In contrast to adults, children with ON often present with bilateral optic nerve involvement, profound visual loss, and prominent disc swelling [1]. Despite the severe visual loss during the acute events, the recovery rate is usually excellent (over 80% with complete recovery) [1–3]. The etiology of ON in childhood is most often post-infectious, a preceding viral infection being reported between 16 and 46% [5–7] The differential diagnosis of ON in the pediatric population should also include other causes of acute and sub-acute optic neuropathies such as systemic vasculitis (systemic lupus erythematosis, Sjögren's disease), granulomatous diseases (sarcoidosis), toxic, and metabolic causes, compressive or infiltrative lesions (meningioma, glioma), as well as mitochondrial and other genetic abnormalities, especially in cases of progressive visual loss or recurrent events [2,5–7]. A more detailed description of ON and its differential diagnosis can be found in Chapter 20. A sub-group of patients following an initial episode of ON may experience recurrent events of ON (RON) without clinical evidence of a systemic disease or other areas of CNS involvement. This entity of RON was classified as MS in earlier studies [8,9].