Plasma levels of glial fibrillary acidic protein and neurofilament light chain in patients with chronic migraine: a multicenter case-control study

Objective: Plasma glial fibrillary acidic protein (pGFAP) and plasma neurofilament light chain (pNfL) levels reflect astrocyte activation and neuronal damage, respectively. Whether these phenomena play a role in migraine is unknown. This study aimed to compare pGFAP and pNfL levels in patients with chronic migraine (CM) and age-matched controls and to analyze their relation with clinical features. Methods: The study evaluated two independent cohorts of patients, including in total 58 CM and 69 controls. pGFAP and pNfL were quantified with single molecule array (Simoa) technology. Demographic and clinical data were collected for each subject; differences in NfL/GFAP levels between CM and controls were evaluated in analyses adjusted for the effect of age and sex; clinical characteristics associated with NfL/GFAP levels were separately evaluated in the two cohorts. Results: In both cohorts, we did not find a significant difference in pGFAP or pNFL levels between CM and matched controls. The study did not find any correlation between pGFAP or pNfL levels and any migraine characteristics (namely presence of migraine aura, attack frequency, migraine intensity, years of disease). Conclusions: Our negative results support the assumption that migraine represents a benign condition, characterized by transient functional brain alterations and not by the accumulation over time of neuroaxonal damage and/or associated astrocyte activation detectable by neurodegeneration marker proteins.