Dissecting structure-function interactions in acute optic neuritis to investigate neuroplasticity.

Area of Science:

• Neuroscience
• Ophthalmology
• Radiology

Background:

• Optic neuritis (ON) causes variable visual loss, with underlying mechanisms unclear.
• Structural MRI, electrophysiology, and fMRI offer complementary insights into visual pathway integrity.

Purpose of the Study:

• To correlate structural and electrophysiological changes with acute visual loss in ON.
• To investigate the role of cortical activity (fMRI) in modulating visual acuity.

Main Methods:

• Assessed 28 patients with acute unilateral ON using structural MRI, VEP, and fMRI.
• Employed linear regression to identify predictors of visual loss and fMRI activity.
• Controlled for lesion length, VEP amplitude, age, and gender in analyses.

Main Results:

• Optic nerve lesion length and reduced VEP amplitude correlated with greater visual loss.
• Higher visual acuity was associated with bilateral extra-striate occipital cortex activation.
• Cortical activity correlated with vision independently of optic nerve pathology and VEPs.

Conclusions:

• Acute visual loss in ON is primarily driven by optic nerve inflammation and conduction block.
• Enhanced extra-striate cortical activity may compensate for afferent visual pathway damage.
• Findings suggest adaptive neuroplasticity in the dorsal stream contributes to visual function post-ON.