Optic nerve T2-hyperintensity: a nonspecific marker of optic nerve damage
Fernando Labella Alvarez1, Rasha Mosleh1, Walid Bouthour1, Amit Saindane4, Michael Dattilo1, Nancy Newman2, Valerie Biousse3
1Department of Ophthalmology, 2Department of Ophthalmology, Department of Neurology, Department of Neurological Surgery, 3Department of Ophthalmology, Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA, 4Department of Radiology and Imaging Sciences, Department of Neurological Surgery, Emory University School of Medicine
Objective:
To determine the significance of optic nerve (ON) T2-hyperintensity and optic atrophy on MRI.
Background:
The best imaging modality to investigate optic neuropathy etiologies is an orbital MRI. In acute optic neuritis, ON T2-hyperintensity and contrast enhancement (CE) are seen in 77% and 90% of patients, respectively. However, in chronic optic neuropathies, ON T2-hyperintensity and atrophy are typically seen. Interestingly, isolated ON T2-hyperintensity is often presumed to be due to optic neuritis, prompting unnecessary investigations and frequent referrals to neuro-ophthalmology.
Design/Methods:

Retrospective study of consecutive patients who underwent brain/orbit MRI with/without contrast at our institution between 07/01/2019-06/30/2022. Patients with ON T2-hyperintensity or atrophy were included. Medical records were reviewed to determine the etiology, if any, of the T2-hyperintensity and/or atrophy. 

Results:

491 patients were included (mean age 52±17 years; 57% men).

381/724 ONs had T2-hyperintensity without atrophy; diagnoses: inflammatory (100), compressive (94), glaucoma (19), multifactorial (47), other (69), unspecified (15), normal (37).

219/724 ONs had T2-hyperintensity and atrophy; diagnoses: inflammatory (36), compressive (50), glaucoma (30), multifactorial (39), other (36), unspecified (12), normal (16).

124/724 ONs had atrophy without T2-hyperintensity; diagnoses: inflammatory (13), compressive (12), glaucoma (32), multifactorial (21), other (24), unspecified (7), normal (15).

68/724 eyes with T2-hyperintensity or atrophy had a normal ophthalmologic examination.

Conclusions:

ON T2-hyperintensity on MRI is a non-specific finding; it can be seen in various acute and chronic optic neuropathies. ON T2-hyperintensity with ON atrophy without associated CE can occur secondary to chronic optic neuropathies, such as compressive and glaucomatous optic neuropathies, and is not highly associated with inflammatory optic neuropathies. Therefore, these radiological findings should not automatically prompt an urgent neuro-ophthalmology evaluation or further work-up for optic neuritis, such as a lumbar puncture. However, in the absence of a known cause of the optic neuropathy, an optic neuropathy work-up should be performed.

10.1212/WNL.0000000000202628