Parallel changes in structural and functional measures of optic nerve myelination after optic neuritis

Anneke van der Walt; Scott Kolbe; Peter Mitchell; Yejun Wang; Helmut Butzkueven; Gary Egan; Con Yiannikas; Stuart Graham; Trevor Kilpatrick; Alexander Klistorner

doi:10.1371/journal.pone.0121084

Parallel changes in structural and functional measures of optic nerve myelination after optic neuritis

PLoS One. 2015 May 28;10(5):e0121084. doi: 10.1371/journal.pone.0121084. eCollection 2015.

Authors

Affiliations

¹ Centre for Neuroscience, University of Melbourne, Melbourne, Australia; Department of Neurology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia.
² Centre for Neuroscience, University of Melbourne, Melbourne, Australia.
³ Department of Radiology, Royal Melbourne Hospital, Melbourne, Australia.
⁴ Department of Neurology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia; Department of Neurology, Box Hill Hospital, Melbourne, Australia.
⁵ Monash University, Melbourne, Australia.
⁶ Department of Neurology, Concord Hospital, Sydney, Australia.
⁷ Department of Ophthalmology, Save Sight Institute, University of Sydney, Sydney, Australia; Australian School of Advanced Medicine, Macquarie University, Sydney, Australia.
⁸ Centre for Neuroscience, University of Melbourne, Melbourne, Australia; Department of Neurology, Royal Melbourne Hospital, Melbourne, Australia.
⁹ Department of Ophthalmology, Save Sight Institute, University of Sydney, Sydney, Australia.

Abstract

Introduction: Visual evoked potential (VEP) latency prolongation and optic nerve lesion length after acute optic neuritis (ON) corresponds to the degree of demyelination, while subsequent recovery of latency may represent optic nerve remyelination. We aimed to investigate the relationship between multifocal VEP (mfVEP) latency and optic nerve lesion length after acute ON.

Methods: Thirty acute ON patients were studied at 1, 3, 6 and 12 months using mfVEP and at 1 and 12 months with optic nerve MRI. LogMAR and low contrast visual acuity were documented. By one month, the mfVEP amplitude had recovered sufficiently for latency to be measured in 23 (76.7%) patients with seven patients having no recordable mfVEP in more than 66% of segments in at least one test. Only data from these 23 patients was analysed further.

Results: Both latency and lesion length showed significant recovery during the follow-up period. Lesion length and mfVEP latency were highly correlated at 1 (r = 0.94, p = <0.0001) and 12 months (r = 0.75, p < 0.001). Both measures demonstrated a similar trend of recovery. Speed of latency recovery was faster in the early follow-up period while lesion length shortening remained relatively constant. At 1 month, latency delay was worse by 1.76 ms for additional 1mm of lesion length while at 12 months, 1mm of lesion length accounted for 1.94 ms of latency delay.

Conclusion: A strong association between two putative measures of demyelination in early and chronic ON was found. Parallel recovery of both measures could reflect optic nerve remyelination.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Demyelinating Diseases / pathology*
Demyelinating Diseases / physiopathology
Evoked Potentials, Visual
Female
Humans
Magnetic Resonance Imaging
Male
Optic Nerve / physiopathology*
Optic Neuritis / pathology*
Optic Neuritis / physiopathology
Visual Acuity

Grants and funding

This work was supported by the National Health and Medical Research Council (AK, GFE, AV, HB, SCK), Multiple Sclerosis Research Australia grant (AK) and Sydney Foundation for Medical Research (AK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.