Neurophysiological approach to central pain modulation in primary headaches

The study of CNS painmodulatingpathways has led toimportant discoveries about the roleof central nociceptive structuressuch as PAG and hypothalamus inthe pathophysiology of episodic andchronic primary headaches.Functional neuroimaging studieshave revealed that primaryheadaches are characterised by differentpatterns of activation of centralpain modulatory structures. Afuture model of headache pathophysiologyinvestigating the contributionof CNS pain–modulatingpathways will probably increase ourunderstanding of pain processing inprimary headaches. Herein wereview the neurophysiologicalapproaches to assess central painmodulation in primary headacheswith emphasis on the diffuse noxiousinhibitory control, a form ofendogenous pain inhibition. Inaddition, patients’ data will be presentedthat highlights the utility ofsuch methods for primaryheadache’s pathophysiology andclinical monitoring.