Nociceptive-specific blink reflex and glyceryl trinitrate infusion in healthy volunteers

• Published in: European journal of neurology Vol. 10; no. 3; pp. 295 - 299
• Main Authors: Kowacs, F., Giffin, N. J., Putzki, N., Goadsby, P. J., Kaube, H.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.05.2003
• Subjects: Adult; Area Under Curve; blink reflex; Blinking - drug effects; Cross-Over Studies; Double-Blind Method; Electric Stimulation; experimental headache; Female; glyceryl trinitrate; Headache - etiology; Humans; Infusions, Intravenous; Male; Nerve Fibers, Myelinated - physiology; nitric oxide; Nitroglycerin - adverse effects; Nitroglycerin - pharmacology; Nociceptors - physiology; Sensitivity and Specificity; Time Factors; Vasodilator Agents - adverse effects; Vasodilator Agents - pharmacology
• ISSN: 1351-5101; 1468-1331
• DOI: 10.1046/j.1468-1331.2003.00591.x

Glyceryl trinitrate (GTN) is known to induce early headache in healthy humans after intravenous infusion. Moreover, in animal models subcutaneous administration produces an increase in Fos expression in brainstem areas that are involved in trigeminal pain processing. In a double‐blind crossover study, we tested the blink reflex before, during and immediately after GTN and placebo intravenous infusion in eight healthy volunteers using a new stimulation electrode that preferentially activates A‐δ nociceptive afferent fibres. The initial hypothesis that GTN could induce an increase in the magnitude of the nociceptive blink reflex R2 component by stimulating activity of trigeminal nucleus caudalis wide dynamic range interneurones was not confirmed. Although mild headache was induced in six subjects, there was no significant change between the R2 area under the curve before and after drug vs. placebo.