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Updated: Jul 12, 2026
Stimulus-specific Cortical Visual Evoked Potential Morphological Patterns
Published on: May 12, 2019
Search for correlations between genotypes and electrophysiological patterns in migraine: the MTHFR C677T polymorphism
1Headache Research Unit, Department of Neurology, CHR Citadelle, University of Liège, Boulevard du 12ème de Ligne 1, 4000 Liège, Belgium. dmagis@chu.ulg.ac.be
Abstract:
Interictally, migraineurs have on average a reduction in habituation of pattern-reversal visual evoked potentials (PR-VEP) and in mitochondrial energy reserve. 5,10-Methylenetetrahydrofolate reductase (MTHFR) is involved in folate metabolism and its C677T polymorphism may be more prevalent in migraine. The aim of this study was to search in migraineurs for a correlation between the MTHFR C677T polymorphism and the PR-VEP profile. PR-VEP were recorded in 52 genotyped migraine patients: 40 female, 24 without (MoA), 28 with aura (MA). Among them 21 had a normal genotype (CC), 18 were heterozygous (CT) and 13 homozygous (TT) for the MTHFR C677T polymorphism. Mean PR-VEP N1-P1 amplitude was significantly lower in CT compared with CC, and tended to be lower in TT with increasing age. The habituation deficit was significantly greater in CC compared with TT subjects. The correlation between the cortical preactivation level, as reflected by the VEP amplitude in the first block of averages, and habituation was stronger in CC than in CT or TT. The MTHFR C677T polymorphism could thus have an ambiguous role in migraine. On one hand, the better VEP habituation which is associated with its homozygosity, and possibly mediated by homocysteine derivatives increasing serotoninergic transmission, may protect the brain against overstimulation. On the other hand, MTHFR C677T homozygosity is linked to a reduction of grand average VEP amplitude with illness duration, which has been attributed to brain damage.
Insights
The MTHFR C677T gene variant influences migraine visual processing. While homozygosity may protect against overstimulation, it
Area of Science:
- Neuroscience
- Genetics
- Ophthalmology
Background:
- Migraineurs exhibit reduced habituation of pattern-reversal visual evoked potentials (PR-VEP) and mitochondrial energy reserves.
- The 5,10-Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, involved in folate metabolism, may be more common in migraine patients.
Purpose of the Study:
- To investigate the correlation between the MTHFR C677T polymorphism and the PR-VEP profile in migraineurs.
Main Methods:
- PR-VEP were recorded in 52 genotyped migraine patients (40 female, 24 without aura, 28 with aura).
- Patients were genotyped for the MTHFR C677T polymorphism (21 CC, 18 CT, 13 TT).
Main Results:
- Mean PR-VEP N1-P1 amplitude was significantly lower in CT compared to CC genotypes.
- Habituation deficit was significantly greater in CC compared to TT genotypes.
- The correlation between cortical preactivation and habituation was stronger in CC than in CT or TT genotypes.
Conclusions:
- The MTHFR C677T polymorphism appears to have an ambiguous role in migraine pathophysiology.
- Homozygosity (TT) may offer protection against brain overstimulation via enhanced VEP habituation.
- However, MTHFR C677T homozygosity is also linked to reduced VEP amplitude with longer illness duration, potentially indicating brain damage.
