Learning objectives
- Explaining the special anatomy of the optic nerve.
- Specify the MRI protocole for exploring optic nerve.
- Explaining the role of MRI in the diagnostic approach of optic neuritis by opposing different patterns that can be found in demyelinating diseases multiple sclerosis and neuromyelitis optica.
- Listing some of the differential diagnosis of optic neuritis
- Explaining correlation between MRI findings and the severity of the optic neuritis and its prognosis
Background
Optic neuritis (ON) is an acute demyelinating inflammatory disorder, of the optic nerve, it can be an isolated phenomenon or secondarly associated with demyelinating disease of the central nervous system such as multiple sclerosis (MS) and neuromyelitis optica (NMO).
It represent the most common cause of vision loss in young adults.
Optic neuritis is the initial presentation of MS in % of cases.
50% of patients with MS experience ON.
We distinguish here optic neuropathy which is a more general term that includes other affections...
Findings and procedure details
1- ANATOMY OF THE OPTIC NERVE:
The optic nerve are the second pair of cranial nerves and they represent an extension of the central nervous system, it’s formed by axons of the retinal ganglion cells which become myelinated by oligodendrocytes as they leave the optic disc. The optic nerve can be divided into four segments:
•Intraocular: when it emerges through the scleral opening
•Intraorbital: the longest segment, communication between subarachnoid space around the optic nerve with that in suprasellar cistern
•Intracanalicular: passes through bony optic...
Conclusion
Optic neuritis is a frequent revealing event in both MS and NMOSD Exploring the optic nerve is essential in any imaging of demyelinating disease of nervous system.
T2 weighted and T1 fat saturated gadolinium enhancing sequences are mandatory for exploring the ON. Essential Coronals +++
Optic neuritis in multiple sclerosis is generally unilateral, less extensive and affects the orbital segment of ON. •Optic neuritis in NMOSD is way more extensive, higher frequence of bilateral ON and affects preferably the intracranial segments of ON along side...
Personal information and conflict of interest
H. Jamoussi; Tunis/TN - Author at Neurolodgy department of CNH J. Masmoudi; Sfax/TN - Author at Radiolodgy deparmentof CNH - Speaker at Radiolodgy deparmentof CNH A. Sellami; Sfax/TN - Author at Radiolodgy deparmentof CNH N. Neifar; Sfax/TN - Author at Radiolodgy deparmentof CNH A. Bouhamed; Sfax/TN - Author at Neurolodgy department of CNH N. Ben Ali; Tunis/TN - Author at Neurolodgy department of CNH M. Fradj; Tunis/TN - Author at Neurolodgy department of CNH G. Ons; Tunis/TN - Author at Radiolodgy deparmentof CNH M. Jrad;...
References
Khanna, S., Sharma, A., Huecker, J., Gordon, M., Naismith, R. T., & Van Stavern, G. P. (2012). Magnetic resonance imaging of optic neuritis in patients with neuromyelitis optica versus multiple sclerosis.Journal of Neuro-Ophthalmology,32(3), 216-220.
Cellina, M., Floridi, C., Rosti, C., Orsi, M., Panzeri, M., Pirovano, M., ... & Gibelli, D. (2019). MRI of acute optic neuritis (ON) at the first episode: Can we predict the visual outcome and the development of multiple sclerosis (MS)?.La radiologia medica,124(12), 1296-1303.
Gajamange, S., Stankovich, J., Egan, G., Kilpatrick, T.,...
