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Cognitive event-related potentials in multiple sclerosis: Correlation with MRI and neuropsychological findings
Multiple Sclerosis and Related Disorders, Volume 10, November 2016, Pages 192 - 197
Cognitive event-related potentials (ERPs) have been previously correlated with T2 lesion load (Τ2LL) in patients with multiple sclerosis (MS). It is currently unknown, however, whether ERPs also correlate with brain atrophy or the presence of T1 hypointense lesions (“black holes”) which reflect tissue destruction and axonal loss. The primary aim of the current study is to explore the effect of neuroradiological parameters such as brain atrophy, T1 and T2 lesion load on auditory ERPs in MS patients. In addition, we correlated cognitive impairment with neurophysiological (ERP) and neuroradiological (MRI) variables and investigated whether a combination of ERP and MRI parameters is capable of distinguishing patients suffering from secondary progressive (SP), primary progressive (PP) and relapsing-remitting (RR) MS.
Materials and methods
The study sample consisted of fifty nine MS patients (mean age±SD: 37.82±1.38 years; average disease duration: 6.76±5.3 years) and twenty six age-matched controls (mean age±SD: 41.42±15.39 years). The patients’ EDSS and NRS scores were 3.77±2.14 (range: 1–7.5) and 75.88±11.99 (range: 42–94) respectively. ERPs were recorded using the auditory “odd-ball” paradigm. T1 and T2 lesions were automatically segmented using an edge-finding tool and total lesion volumes were calculated. MRI measures of brain atrophy included third ventricle width (THIRDVW) and the ratio of mid-sagittal corpus callosum area to the mid-sagittal intracranial skull surface area (CC/MISS). Statistical analysis was performed using multiple regression, principal component (PCA) and discriminant analysis.
T1 lesion load emerged as the most significant predictor of P300 and N200 latency. The rest of the endogenous ERPs parameters (P300 amplitude, N200 amplitude) were not significantly correlated with the MRI variables. PCA of pooled neuroradiological and neurophysiological markers suggested that four components accounted for 64.6% of the total variability. Discriminant analysis based on ERP & MRI markers classified correctly 79.63% of patients in RR, PP and SP subgroups.
T1 lesion load is the most significant MRI correlate of auditory ERPs in MS patients. Importantly, ERPs in combination with MRI variables can be usefully employed for distinguishing patients with different subtypes of MS.
- The impact of T1 and T2 lesion loads as well as brain atrophy markers on auditory ERPs in MS patients was studied.
- T1 lesion load is the most significant MRI correlate of auditory ERPs in MS patients.
- ERPs in combination with MRI variables, can be usefully employed for distinguishing different MS subtypes.
Keywords: Multiple sclerosis, MRI, Event-related potentials, Brain atrophy, Cognitive impairment.
a Laboratory of Clinical Neurophysiology, AHEPA Hospital, Aristotle University of Thessaloniki, Greece
b Laboratory of Mathematics and Statistics, Agricultural University of Athens, Greece
c Department of Psychology, Aristotle University of Thessaloniki, Greece
d 3rd Department of Neurology, Aristotle University of Thessaloniki, “G Papanikolaou” General Hospital, Exohi, Greece
e Department of Radiology, Faculty of Medicine, University of Crete, University Hospital, Heraklion 71110 Stavrakia, Greece
f Department of Radiology, “G Papanikolaou” General Hospital, Exohi, Greece
⁎ Corresponding author.
© 2016 Elsevier B.V., All rights reserved.