The presence of central sensitization in the continuum of migraine : a case control study

Introduction: Migraine is conceptualized as a continuum, with at the one hand episodic migraine and at the other hand chronic migraine (CM) which is more frequent (1). Recent studies support the presence of central sensitization (CS) in migraine patients (2,3), but controversial evidence exists about where in the continuum exactly CS appears and which mechanisms are underlying. Therefore this study aims to determine the occurrence and mechanisms of CS within the migraine continuum. Methods: Self-reported and psychophysiological data will be collected from 30 migraine patients and 30 healthy controls. Pain sensitivity will be evaluated using Quantitative Sensory Testing including mechanical and thermal thresholds. Pain facilitation and inhibition will be assessed by using respectively temporal summation and conditioned pain modulation paradigms. Assessments are performed unilateral at the painful side and interictally. Results: Widespread pain and impaired pain facilitation and inhibition are expected to be more pronounced in patients with more migraine days (further along the continuum) than in those with less migraine days. Discussion: This research will show whether signs of CS are present in migraine patients, where in the migraine continuum these symptoms are appearing, and whether impaired pain inhibition and/or facilitation underlie these symptoms