HYPERSENSITIVITY TO SUBSTANCE-P IN THE ETIOLOGY OF POSTLUMBAR PUNCTURE HEADACHE

Objective.-Postlumbar puncture headache may represent a model which co uld be used to test the hypothesis that headache pain is caused by the release of substance P in patients who are predisposed to headache du e to hypersensitivity to substance P. Methods.-We measured substance P in CSF and plasma in 37 patients undergoing diagnostic lumbar punctur e. In 9 patients. plasma samples were obtained before lumbar puncture, in 28 patients plasma was obtained after lumbar puncture. Patients we re followed up by telephone to determine if they developed postlumbar puncture headache. Patients were also asked about a history of chronic or recurrent headaches. Substance P was determined by radioimmunoassa y. Results.-The mean plasma substance P levels obtained before lumbar puncture was 1.0 +/- 0.1 pg/mL and 1.3 +/- 1.2 after lumbar puncture ( P <0.0005). The mean plasma substance P levels in subjects who develop ed postlumbar puncture headache was 0.6 +/- 0.6 pg/mL compared with 1. 4 +/- 1.5 in subjects who remained headache-free (P<0.05). The mean CS F substance P levels in subjects who developed postlumbar puncture hea dache was 0.7 +/- 0.5 pg/mL compared with 1.2 +/- 0.8 in subjects who remained headache-free (P<0.05). There were no significant differences in substance P levels between chronic headache sufferers and nonheada che subjects. Conclusions.-Postlumbar puncture headache may be mediate d by the release of substance P triggered by lumbar puncture. in patie nts predisposed to headache by a hypersensitivity to substance P. Hype rsensitivity to substance P may also represent a mechanism for headach e pain in other headache disorders.