Extracranial source of increased CGRP in migraine children?

摘要

Dear Sir In a recent paper Fan etal. (1) reported results of calcitonin gene-related peptide (CGRP) sampled from cubital veins in paediatric migraine patients during and outside attacks. They suggested that increased CGRP measured during migraine attacks can be used as a biomarker for migraine in children (1). The results are given as pg/ml in plasma and CGRP levels were 198 pg/ml during migraine attacks and 43 pg/ml outside attacks for the nine children investigated both during and outside a migraine attack (1). These results correspond to 53 pmol/l and 12 pmol/l, respectively. When CGRP is increased in plasma during migraine it is presumed to originate in the cephalic circulation. Thus CGRP was found to be increased in the external jugular vein in two studies, 60 (2) to 90 pmol/l (3), whereas this was not the case in three studies with intrapatient comparison, 33, 81 and 86 pmol/l (4,5). For a review, see (6). In one study (n = 5) there was a maximum concentration of CGRP in internal jugular blood during migraine attacks of 77 pmol/l (7), but in another study (n = 4) with both internal carotid arterial and internal jugular venous blood determinations of CGRP (mean = 65 pmol/1) in migraine with aura there was no increase during the onset of migraine (8).