New insights of the fever following subarachnoid hemorrhage and introducing a new thermoregulator like structure in choroid plexuses; preliminary study

Abstract

Objective: Vagal nerves and their thermoreceptors could regulate temperature of brain. Cerebrospinal fluid (CSF) is increased in the early phases of subarachnoid hemorrhage (SAH). We hypothesised that choroid plexuses probably innervated by vagal nerves may play a role on the regulation of brain temperature and studied this subject. Methods: This study was conducted on 32 rabbits, divided into four groups, with five rabbits in the control group (group I), five rabbits in the sham group (Group II), and 22 rabbits in the SAH group. In the SAH group, 7 of the animals were decapitated after 7 days of cisternal blood injections (Group III), and the other 15 animals were decapitated after 21 days of injections (Group IV). Brain temperature via laser thermometer 5 times a day during the experiment was measured. Normal and degenerated neuron density of nodose ganglia, water vesicles numbers of choroid plexuses were stereologicallyanalyzed. Statistical analysis was performed. Results: At histopathologic analysis of present study, thermo regulator like structure was noted and the mean number of this structure was estimated.The mean number of water-filled vesicles, thermo regulator like structure, in SAH-induced animals,brain temperature and degenerated neuron density of nodose ganglia was statistically different between the early decapitated group (group III) and the late decapitated group (group IV) (P < 0.05). Conclusions: We introduce a thermo regulator like structure, describe a new syndrome. In addition, it was noted thatwater-filled vesicles of CP are increased, brain temperature in nearly normal in the early phase of SAH due to likely irritation of vagal nerves. However in the late phase, mean number of water-filled vesicles numbers decreased in accordance with increased brain temperature with degenerative changes of the nodose ganglion. © 2019, Neurological Society R.O.C (Taiwan). All rights reserved.