Can Serum Magnesium Level and Visual Evoked Potentials (P100) be a Predictive in Migraineurs?: Evidence Based Study

Few dating back, the role of visual evoked potentials changes and reduced level of intracellular magnesium have appeared in migraine patients both throughout the attacks and in the interictal periods. Moreover, there is a lack of evidence regarding the correlation between magnesium levels and visual evoked potentials. To assess the changes in the levels of magnesium in migraineurs compared to a healthy control group is our prime intention. Also, to correlate serum magnesium levels with visual evoked potentials changes within the migraineurs is a secondary part of the study.

After applying inclusion and exclusion criteria as per the study protocol, in total, 80 subjects were enrolled in the study. Of which 40 were migraineurs diagnosed as per the International Headache Society criteria for severe migraine headache. Rest of 40 was nonmigraineurs served as a control group of the study. All included patient was submitted to demographic profile, previous history of the disease and drug intake, thorough clinical investigation and baseline laboratory parameters. Apart from this, the measurement of visual evoked potentials changes (4^th block) and magnesium levels were done as per our standard operating procedures.

In migraineurs, serum total Mg level was considerably lower compared to the control group (1.79 ± 0.14 mg/dl versus 2.10 ± 0.17 mg/dl, P < 0.0001) and amplitude of P100 (P < 0.0001) was negatively correlated to reduced serum Mg level (P < 0.0001).

As expected, both elevated visual evoked potential amplitude and reduced level of brain magnesium can be a demonstration of neuronal hyperexcitability of the optic pathways associated with a dropped threshold for migraine attacks.