MOSCOW, 15. August /TASS/ Russian scientists have found out that patients with a migraine differ from healthy people by increased vascular reactivity, the response to the exogenous irritants, as reported by the press-service of the University of Informational Technologies, Mechanics, and Optics (ITMO). This peculiarity is commonly expressed in more frequent constriction and extension of arterial walls than usual. The results of the study have been published in The Journal of Headache and Pain.
A migraine is a disease, the most prominent sign of which is severe headaches appearing usually only in one part of a head. Additionally, migraine is often accompanied by nausea, vomiting, vision problems, increased sensitivity and can last up to several days, which affects the quality of life. Up to now, there is no consensus among scientists on the mechanisms of this disease.
Scientists from ITMO University, Federal Almazov North-West Medical Research Centre, Pavlov First Saint Petersburg State Medical University, and Kazan Federal University have supposed that a migraine can be caused not only by disorders of the nervous system but also by problems with the cardiovascular system. To this end, the researchers have conducted a number of tests to estimate autonomic (vasomotor) regulation of blood circulation. 73 patients suffering from a migraine and 71 healthy persons aged about 35 have been invited for the study.
The researchers have exposed patients to the temperature stress by applying ice to the breast and have revealed the main difference between patients with migraines and healthy people to be the enhanced vasomotor vascular reactivity of patients. The blood vessels of patients response to the exogenous irritants (cold) in a more pronounced way by constriction and extension over the normal limit. The increased reactivity of vessels often results in spasms of the arteries and less commonly leads to their extension.
In the experiments, the scientists have applied occlusion plethysmography, the method in the course of those veins of a patient is temporary blocked. The increased size of the limb can be measured over time to provide various parameters of the blood flow. But this method is associated with some discomfort for the patient. Thus, the scientists are now developing the optical device capable of tracking changes in the blood flow by the changes in the skin color. Subtle shifts in the color invisible for the human eye can be monitored with a usual camera and then processed with the special software. This technique is called imaging photoplethysmography and it might be helpful in determining the difference in the pulsation of the arteries which fill the brain with blood, and perhaps in diagnosing migraine.