Analysis of visual evoked potential habituations and blink reflex in patients with migraine during attacks and the period between attacks

Headache is one of the most common forms of pain affecting people. And migraine is the most common cause of headaches, which reduce the quality of life, and again it is the most common presenting symptom in patients admitted to health care centers due to headache. An effective treatment is extremely important because of the prevalence of migraine in the population, its disturbing nature that cause serious loss of labor, and even its potential that prepare a ground for the severe neurological disorders. As is known, the most effective treatment options for diseases are the treatments applied for the physiopathogenesis of the disease. There are numerous studies in the literature to clarify the etiology, physiology and pathology of migraine, because of its known social and individual characteristics. However, migraine pathogenesis is poorly understood despite the many ongoing studies. The performed electrophysiological studies have contributed to obtain clues about the migraine pathophysiology. In our study, total of 35 migraine patients of which 8 with aura and 27 without aura, evaluated according to IHS criteria, were included and 25 healthy individuals were also included for control purposes. Analysis of visual evoked potential (VEP) and blink reflex in the migraine group, during attacks and the period between attacks, have been conducted in our study. The control group also underwent the VEP and blink reflex analysis. The VEP latency and amplitude measurement results and the blink reflex latency measurements were compared in the periods between attacks and during the attacks of migraine patients. In addition, the result from the period between attacks of migraine patients was compared with the results of measurements from the control group. The VEP latency was found significantly longer in the group of migraine patients in the attack period compared to the period between the attacks (p <0.001). And in the comparison of the VEP analysis of both the control group and the migraine patients, during the period between attacks, there were no significant difference in the left VEP latency and amplitude (p>0.05), right VEP amplitude was lower than the control group (p <0.05). There was no significant difference in the right VEP latency (p> 0.05). No significant difference was observed between the control group and the migraine patients in the period between the attacks in terms of the blink reflex assessment (p> 0.05). There was also no significant difference observed in the blink reflex assessment of patients with migraine, in the period between the attacks and during the attack (p> 0.05). Also in our study, no significant correlation was found between disease duration and frequency of attacks and VEP and blink reflex in the patients group, during attacks and in the period between attacks (p> 0.05). Our study suggests that the visual pathways are affected in the migraine patients during attacks, and these effects may be caused by sterile inflammation present in these pathways. However, no differences were found in the trigeminal pathways during attack and post-attack period. Furthermore, there was no difference in the sensitization of visual pathways and trigeminal system between the control group and migraine patients during the period between attacks. As a result, the central sterile inflammation in migraine patients during the attacks was demonstrated with VEP.