title: Delayed P100-Like Latencies in Multiple Sclerosis: A Preliminary Investigation Using Visual Evoked Spread Spectrum Analysis.
abstract: Conduction along the optic nerve is often slowed in multiple sclerosis (MS). This is typically assessed by measuring the latency of the P100 component of the Visual Evoked Potential (VEP) using electroencephalography. The Visual Evoked Spread Spectrum Analysis (VESPA) method, which involves modulating the contrast of a continuous visual stimulus over time, can produce a visually evoked response analogous to the P100 but with a higher signal-to-noise ratio and potentially higher sensitivity to individual differences in comparison to the VEP. The main objective of the study was to conduct a preliminary investigation into the utility of the VESPA method for probing and monitoring visual dysfunction in multiple sclerosis. The latencies and amplitudes of the P100-like VESPA component were compared between healthy controls and multiple sclerosis patients, and multiple sclerosis subgroups. The P100-like VESPA component activations were examined at baseline and over a 3-year period. The study included 43 multiple sclerosis patients (23 relapsing-remitting MS, 20 secondary-progressive MS) and 42 healthy controls who completed the VESPA at baseline. The follow-up sessions were conducted 12 months after baseline with 24 MS patients (15 relapsing-remitting MS, 9 secondary-progressive MS) and 23 controls, and again at 24 months post-baseline with 19 MS patients (13 relapsing-remitting MS, 6 secondary-progressive MS) and 14 controls. The results showed P100-like VESPA latencies to be delayed in multiple sclerosis compared to healthy controls over the 24-month period. Secondary-progressive MS patients had most pronounced delay in P100-like VESPA latency relative to relapsing-remitting MS and controls. There were no longitudinal P100-like VESPA response differences. These findings suggest that the VESPA method is a reproducible electrophysiological method that may have potential utility in the assessment of visual dysfunction in multiple sclerosis.
authors.affiliation: Neural Engineering Group, Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.|School of Engineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Hanni S M
authors.initials: HS
authors.lastname: Kiiski
authors.affiliation: Neural Engineering Group, Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.|School of Engineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Sinéad
authors.initials: S
authors.lastname: Ní Riada
authors.affiliation: Neural Engineering Group, Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.|School of Engineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Edmund C
authors.initials: EC
authors.lastname: Lalor
authors.affiliation: Neural Engineering Group, Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.|School of Engineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Nuno R
authors.initials: NR
authors.lastname: Gonçalves
authors.affiliation: Neural Engineering Group, Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.|School of Engineering, Trinity College Dublin, Dublin, Ireland.
authors.forename: Hugh
authors.initials: H
authors.lastname: Nolan
authors.affiliation: Neural Engineering Group, Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.|Cognitive and Behavioural Neuroscience Research Group, School of Psychology, UCD College of Human Sciences, University College Dublin, Dublin, Ireland.
authors.forename: Robert
authors.initials: R
authors.lastname: Whelan
authors.affiliation: Department of Neurology, St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Róisín
authors.initials: R
authors.lastname: Lonergan
authors.affiliation: Department of Neurology, St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Siobhán
authors.initials: S
authors.lastname: Kelly
authors.affiliation: Cognitive and Behavioural Neuroscience Research Group, School of Psychology, UCD College of Human Sciences, University College Dublin, Dublin, Ireland.
authors.forename: Marie Claire
authors.initials: MC
authors.lastname: O'Brien
authors.affiliation: Department of Neurology, St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Katie
authors.initials: K
authors.lastname: Kinsella
authors.affiliation: Cognitive and Behavioural Neuroscience Research Group, School of Psychology, UCD College of Human Sciences, University College Dublin, Dublin, Ireland.
authors.forename: Jessica
authors.initials: J
authors.lastname: Bramham
authors.affiliation: Cognitive and Behavioural Neuroscience Research Group, School of Psychology, UCD College of Human Sciences, University College Dublin, Dublin, Ireland.|School of Nursing and Human Sciences, Dublin City University, Dublin, Ireland.
authors.forename: Teresa
authors.initials: T
authors.lastname: Burke
authors.affiliation: Cognitive and Behavioural Neuroscience Research Group, School of Psychology, UCD College of Human Sciences, University College Dublin, Dublin, Ireland.
authors.forename: Seán
authors.initials: S
authors.lastname: Ó Donnchadha
authors.affiliation: Department of Neurology, St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Michael
authors.initials: M
authors.lastname: Hutchinson
authors.affiliation: Department of Neurology, St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: Niall
authors.initials: N
authors.lastname: Tubridy
authors.affiliation: Neural Engineering Group, Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland.|School of Engineering, Trinity College Dublin, Dublin, Ireland.|School of Medicine, Trinity College Dublin, Dublin, Ireland.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Reilly
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D018450:Disease Progression; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000503:physiopathology*; D009900:Optic Nerve / Q000503:physiopathology*; D009902:Optic Neuritis / Q000209:etiology / Q000503:physiopathology; D011930:Reaction Time; D013057:Spectrum Analysis / Q000379:methods