Levels of nerve growth factor in cerebrospinal fluid of chronic daily headache patients.

Nerve growth factor (NGF) levels were determined in the CSF of patients with chronic daily headache (CDH) and correlated with levels of sensory neuropeptides. Patients with CDH showed higher NGF levels in the CSF compared with control subjects (p < 0.0001). Higher CSF levels of substance P (SP) (p < 0.002) and calcitonin-gene-related peptide (CGRP) (p < 0.0001) were also found. There was a significant positive correlation between NGF and both SP and CGRP values. These findings suggest that NGF is involved in the long-lasting sensitization and sustained activation of the trigeminal system in CDH.