Abstract
Purpose: :
The clinical presentations and features of several disorders that are due to presumed inflammation of the optic nerve sheath (perineuritis) are similar to optic neuritis, but perineuritis is not associated with development of MS and may require systemic investigation. We hypothesized that MRI features can differentiate between the two disorders.
Methods: :
During the period from 2004-2008, we diagnosed 10 patients with optic perineuritis and 170 patients with typical optic neuritis (18-50 yrs). We reviewed the records for presenting symptoms (including pain on eye movement), clinical signs, age, gender, visual acuity, mean deviation for 24-2 Humphrey (MD in db), and optic disc features. We evaluated fat suppressed gadolinium enhanced T1-weighted and short tau inversion recovery (STIR) orbital MRI in all patients for presence of abnormal enhancement of the optic nerve or of the optic nerve sheath alone, and abnormal signal in the optic nerve.
Results: :
For perineuritis patients, the average age was 34 yrs (range: 12-48 yrs); 9 were females; at presentation 8 had visual acuity ≥ 20/40; 5 had optic disc swelling; 9 had pain on eye movement, and MD ranged from -1.3 to -31 db. Treatment with intravenous methylprednisolone or high dose oral prednisone, followed by a gradual withdrawal, normalized the visual acuity and visual field in 5/7 patients. The visual acuity, but not the field, improved in 1; and 1 had progressive vision loss despite high dose steroid therapy. In 3 patients without vision loss, pain resolved with oral nonsteroidal anti-inflammatory agents. All perineuritis eyes (none unaffected eyes) showed abnormal enhancement of the optic nerve sheath but not of the optic nerve. Abnormal optic nerve signal on STIR occurred in 2. No perineuritis patients had abnormal signal of brain white matter. No optic neuritis patients had abnormal enhancement of the optic nerve sheath alone.
Keywords: imaging/image analysis: clinical • optic nerve • neuro-ophthalmology: diagnosis