Differences in central facilitation between episodic and chronic migraineurs in nociceptive-specific trigeminal pathways.

Jong-Hee Sohn,Chul-Ho Kim,Hui-Chul Choi

doi:10.1186/s10194-016-0637-6

Jong-Hee Sohn, Chul-Ho Kim + Show 1 more

Open Access

https://doi.org/10.1186/s10194-016-0637-6

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Abstract

BackgroundThe trigeminal nociceptive system plays a pivotal role in the pathophysiology of migraines. The present study investigated whether there are differences between patients with episodic migraine (EM) and patients with chronic migraine (CM) in trigeminal pain processing at the brainstem and cortical levels using the nociceptive blink reflex (nBR) and pain-related evoked potentials (PREP).MethodsThis study assessed 68 female migraineurs (38 EM patients and 30 CM patients) and 40 age-matched controls using simultaneous recordings of nBR and PREP during the interictal period.ResultsIn terms of the nBR, EM patients displayed significantly decreased latencies and larger amplitudes and area-under-the-curve (AUC) values for the R2 component, whereas CM patients showed significantly prolonged latencies and smaller amplitudes and AUC values for the R2 component (p < 0.05). In terms of PREP, both the EM and CM patients had decreased latencies (N1, P1), with larger amplitude compared with the controls (p < 0.05), which indicates facilitation at the cortical level. Additionally, the amplitude and AUC values of the R2 component exhibited a negative correlation, whereas the latency of the R2 component for the nBR showed a positive correlation, with the frequency of headaches in migraineurs (p < 0.01).ConclusionsIn the present study, the facilitation in the trigeminal nociceptive pathway of the EM group suggests the occurrence of migraine-specific hyperexcitability. Additionally, the suppression of R2 at the brainstem level in the CM group may relate to impaired or dysfunctional descending pain modulation. These findings suggest that there are adaptive or maladaptive responses due to the chronification of migraine attacks.

Highlights

The trigeminal nociceptive system plays a pivotal role in the pathophysiology of migraines
The frequency of headaches and the duration of the headaches according to the headache questionnaire were 4.81 days/month and 14.71 h/day, in patients with episodic migraine (EM) and 20.03 days/month and 16.00 h/day, respectively, in patients with chronic migraine (CM)
Our results showed R2 suppression at the brainstem level and facilitation at the cortical level (PREP) of trigeminal pain processing in CM patients, and facilitation at both the brainstem and cortical levels in EM patients

Summary

Introduction

The trigeminal nociceptive system plays a pivotal role in the pathophysiology of migraines. Chronic migraine (CM) is a disabling neurological condition, accepted by the main body of the current beta version of the International Classification of Headache Disorders-3 (ICHD-3β) [1]. This classification indicates that the chronicity of the disorder is not a complication of migraine, but rather a transformation from an episodic to a chronic disorder. One previous study did not observe any changes [16], whereas other studies observed abnormal excitability [13, 17] These inconsistencies may result from the use of different study techniques, such as the conventional blink reflex, or different study groups, such as in individuals with combined medicationoveruse headaches. It has been assumed that these abnormalities would be more marked in CM, and that there are distinctions between EM and CM

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