The Effect of Sneezing on the Reduction of Infarct Volume and the Improvement of Neurological Deficits in Male Rats

Background: Sneezing transiently elevates cerebral blood flow. We speculated that induced sneezing, following embolism would restore arterial flow, thereby diminishing infarct volume and improving neurological deficits. Materials and Methods: Male rats were subjected to middle cerebral artery occlusion (MCAO) using prepared clots (embolization) and randomized into four equal groups as follows: (1) pre-MCAO-induced sneezing (PRMIS), (2) post-MCAO-induced sneezing (POMIS), and (3) pre- and POMIS (PRPOMIS) and the control group (eight rats per group). In the treatment groups, rats' sneezing episodes were induced before MCAO in PRMIS group or before regaining consciousness from surgical anesthesia in other treatment groups by cutting their whiskers during their anesthesia and subsequently inserted them into the rats' nostrils. Infarct volume was evaluated by 2, 3, 5-triphenyl tetrazolium chloride staining, and neurological deficits and brain edema were assessed by Bederson scale deficit scores 24-h post-MCAO. Results: The infarct volume and brain edema reduced and neurological deficits improved in the induced sneezing groups as compared with the MCAO control group. Compared to the control group, the highest improvements in the infarct volume and neurological deficits were seen in the PRPOMIS group, and POMIS group showed the most significant differences concerning the results of both ischemic and nonischemic brain edema. The highest protective effect was observed in the central region of the MCA territory. Conclusions: The reduction in ischemia-induced brain injury, brain edema, and neurological deficits by sneezing suggest that brief episodes of acute hypertension after stroke can increase blood flow to the ischemic area and improve recovery.