Trans-Synaptic Degeneration Following Acute Optic Neuritis in Multiple Sclerosis

Area of Science:

• Neuroscience
• Ophthalmology
• Radiology

Background:

• Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Acute optic neuritis (AON) is a common initial presentation of MS.
• Understanding the long-term consequences of AON, including brain atrophy and visual outcomes, is crucial for patient management.

Purpose of the Study:

• To investigate longitudinal changes in brain volumetric measures and retinal layer thicknesses after AON in people with MS (PwMS).
• To explore the process of trans-synaptic degeneration following AON.
• To determine the clinical relevance of these changes on visual function.

Main Methods:

• Recruited 49 PwMS within 40 days of AON onset and 73 PwMS without recent AON.
• Utilized longitudinal optical coherence tomography and brain MRI for up to 5 years.
• Employed mixed-effects linear regression models to analyze data.

Main Results:

• Accelerated atrophy observed in occipital gray matter, calcarine gray matter, and thalamus in the AON cohort compared to the non-AON cohort.
• No significant differences in whole-brain, cortical gray matter, or T2 lesion accumulation rates between cohorts.
• Greater reduction in retinal ganglion cell+inner plexiform layer thickness post-AON correlated with faster whole-brain, white matter, and thalamic atrophy.
• Faster subcortical gray matter and thalamic atrophy linked to worse visual function outcomes.

Conclusions:

• Provided in-vivo evidence for anterograde trans-synaptic degeneration after AON in PwMS.
• Suggests that trans-synaptic degeneration following AON is associated with clinically relevant visual outcomes.