1. Department of Neurology Universitätsklinikum Charité, Humboldt University, Berlin, Germany
2. ^†Institute for Microbiology and Hygiene, Universitätsklinikum Charité, Humboldt University, Berlin, Germany
3. ^*Stroke and Neurovascular Regulation, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, U.S.A.

Correspondence: Joerg R Weber, Department of Neurology, Universitätsklinikum Charité, Humboldt University, Schumannstr. 20/21, D-10098 Berlin, Germany.

Received 16 April 1996; Revised 12 June 1996; Accepted 27 June 1996.

Abstract

We investigated whether trigeminal nerve fibers contribute to enhanced regional cerebral blood flow (rCBF) in a rat model of experimental bacterial meningitis. rCBF was measured continuously for 6 h by laser Doppler flowmetry through thinned bone over the frontal cortex. Meningitis was induced with pneumococcal cell wall components and confirmed by a significant increase of (a) leukocytes within the cerebrospinal fluid, (b) brain water content, (c) intracranial pressure and (d) rCBF. The increase of rCBF was significantly attenuated (p < 0.05) at 3, 4, 5, and 6 h in animals after a chronic (200 21% versus 138 13% at 6 h on the intact and denervated sides, respectively) but not after an acute section of the nasociliary branch of the trigeminal nerve. We conclude that elevations in blood flow during the early phase of bacterial meningitis are mediated in part by the trigeminal nerve, probably by local perivascular release of neuropeptides from afferent axons innervating the meninges.