Migraine, but not subarachnoid hemorrhage, is associated with differentially increased NPY-like immunoreactivity in the CSF

To test whether migraine and subarachnoid hemorrhage (SAH) are associated w ith increased sympathetic tone, we compared the neuropeptide Y-like (NPY-LI ) and chromogranin A-like immunoreactivities (LI) of cerebrospinal fluid (C SF) from migraneurs and SAH patients with those from control subjects. Incr eased sympathetic tone was expected to produce higher co-release of these c o-stored peptides and concordant changes in their CSF levels. In addition, we investigated a possible disturbed nitric oxide homeostasis by measuring CSF nitrites (NO). More than 70% of CSF NPY-LI corresponded to the chromato graphic peak (HPLC) for the intact molecule in all three groups. Migraneurs had 64% higher CSF NPY-LI, but no significant difference in CSF chromogran in A-LI, as compared to controls. In contrast, SAH patients had 74% less CS F chromogranin A-LI and a trend to lower NPY-LI, as compared to controls. N o differences in CSF NO were detected among groups. These results argue aga inst an increased sympathetic tone in patients with either migraine or SAH, and suggest that the higher CSF NPY-LI of migraneurs probably originates f rom central neurons. Furthermore, our findings in SAH patients argue in fav or of a decreased sympathetic tone; this could be a homeostatic response to counterbalance vasoconstriction mediated by other mechanisms. (C) 2000 Els evier Science B.V. All rights reserved.