Optic nerve sheath meningioma

However, this takes at least several months to occur, and a minority of patients remain stable for a number of years.

[2][3][4] Clinical examination will show an abnormal optic disc, either swollen or atrophic.

Optociliary shunt vessels may be seen; the combination of these with progressive visual loss and optic disc atrophy is known as the Hoyt-Spencer triad.

Reports of patients with ONSM having no change in their vision for multiple years are not uncommon.

The actual number of meningiomas is likely much higher as it is very common in elderly women[citation needed].

[8] Neurofibromatosis type II (NF-2) affects around 9% of ONSM patients, where the incidence in the general population is around 0.03–0.05%.