Neurophysiological Features of the Nociceptive Trigeminal Pathway During Different Phases of Episodic Migraine

Abstract

Migraine is one of the most common primary headaches, caused by functional abnormalities of information processing, which can be investigated by neurophysiological means during the various phases of the migraine cycle. The aim of the work was to study neurophysiological changes by means of nociception-specific blink reflex characteristics of trigeminocervical complex and to compare neuro-physiological data with clinical manifestations during various phases of episodic migraine. Methods. A 24-year old female patient with episodic migraine without aura underwent daily nociceptive stimulation of the trigeminal nerve for 30 days. Clinical data were collected directly from the patient using structured questionnaires. Neurophysiological changes were assessed using electromyography study of trigeminocervical blink reflex that was caused by stimulation of the supraorbital nerve with high current density electrode. Results. Within one month, the patient had two migraine attacks, preceded by the prodromal phase, and at the end of both migraine attacks, postdrome symptoms were present. We observed cyclical changes in the characteristics of component R2 of the nociception-specific blink reflex that coincided with clinical manifestations in different phases of the migraine cycle. Conclusions. 1. Electrophysiological excitability of trigeminocervical complex nociceptors differs significantly during different phases of the migraine cycle. 2. The habituation of component R2 is observed in the period between attacks can be considered as a specific phenomenon that probably is the background for migraine attack occurrence. 3. The highest excitability and facilitation of the trigeminocervical complex (increased amplitude and decreased latency of component R2) were observed during ictal phase that is additional evidence of the key role of the brainstem in migraine pathophysiology.

Headache and Covid-19: Etiopathogenetic Links, Diagnostic Features and Treatmetn Approaches

“…Відповідно до деяких досліджень, у пацієнтів з мігренню під час гострої фази COVID-19 головний біль виникав частіше, ніж у пацієнтів без мігрені [6]. Мігрень є епізодичною, рецидивуючою, генетично обумовленою дисфункцією збудливості головного мозку, що призводить до активації і сенситизації трігеміноцервікального комплексу (ТЦК) [21]. Мігренеподібний фенотип головного болю також був присутній у пацієнтів без мігрені в анамнезі, що може вказувати на набуту активацію тригеміноваскулярної системи інфекцією SARS-CoV-2 [6].…”