Neuroplasticity predicts outcome of optic neuritis independent of tissue damage.
OBJECTIVE
To determine whether lateral occipital complex (LOC) activation with functional magnetic resonance imaging (fMRI) predicts visual outcome after clinically isolated optic neuritis (ON). To investigate the reasons behind good recovery following ON, despite residual optic nerve demyelination and neuroaxonal damage.


METHODS
Patients with acute ON and healthy volunteers were studied longitudinally over 12 months. Structural MRI, visual evoked potentials (VEPs), and optical coherence tomography (OCT) were used to quantify acute inflammation, demyelination, conduction block, and later to estimate remyelination and neuroaxonal loss over the entire visual pathway. The role of neuroplasticity was investigated using fMRI. Multivariable linear regression analysis was used to study associations between vision, structure, and function.


RESULTS
Greater baseline fMRI responses in the LOCs were associated with better visual outcome at 12 months. This was evident on stimulation of either eye (p = 0.007 affected; p = 0.020 fellow eye), and was independent of measures of demyelination and neuroaxonal loss. A negative fMRI response in the LOCs at baseline was associated with a relatively worse visual outcome. No acute electrophysiological or structural measures, in the anterior or posterior visual pathways, were associated with visual outcome.


CONCLUSIONS
Early neuroplasticity in higher visual areas appears to be an important determinant of recovery from ON, independent of tissue damage in the anterior or posterior visual pathway, including neuroaxonal loss (as measured by MRI, VEP, and OCT) and demyelination (as measured by VEP).
Jenkins
Thomas M
TM
Department of Brain Repair and Rehabilitation, University College London (UCL) Institute of Neurology, University College London, London, UK.
Toosy
Ahmed T
AT
Ciccarelli
Olga
O
Miszkiel
Katherine A
KA
Wheeler-Kingshott
Claudia A
CA
Henderson
Andrew P
AP
Kallis
Constantinos
C
Mancini
Laura
L
Plant
Gordon T
GT
Miller
David H
DH
Thompson
Alan J
AJ
D000328:Adult; D001369:Axons / Q000473:pathology / Q000502:physiology; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D003711:Demyelinating Diseases / Q000473:pathology / Q000503:physiopathology; D005074:Evoked Potentials, Visual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009473:Neuronal Plasticity; D009900:Optic Nerve / Q000473:pathology / Q000503:physiopathology; D009902:Optic Neuritis / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D011379:Prognosis; D013997:Time Factors; D041623:Tomography, Optical Coherence; D014786:Vision Disorders / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D014795:Visual Pathways / Q000473:pathology / Q000503:physiopathology; D055815:Young Adult