Plasma and CSF Endorphin Levels in Primary and Symptomatic Headaches

The role of opiates in pain perception and neuroendocrine responses to environmental stimuli is well known, so that plasma and CSF endorphin levels may represent useful markers of endogenous analgesia and adaptive body mechanisms. The present study concerns various forms of headache: primary (Common Migraine: CM; Migraine with Interparoxysmal Headache: MIH; Cluster Headache: CH) and symptomatic (Chronic Post Traumatic Headache: CPTH; Ischemic Cerebrovascular Headache: ICVH). A group of age‐matched healthy subjects was used as controls (C). The results show a significant decrease of plasma B‐EP levels only in MIH patients (p<0.001), while in the CSF a significant reduction of B‐EP is present in MIH (p<0.001) and CM (p<0.005) subgroups, coupled with an inverse relationship between peptide levels and headache severity scores. In the symptomatic headaches, in which a normal functioning of the pain control systems may be presumed, no difference is present when compared to normal subjects. These data support the hypothesis that migraine syndrome is a “pain disease” sustained by precarious, either genetic or acquired, biochemical mechanisms.