Hyperbaric oxygen therapy fails to reduce hydrocephalus formation following subarachnoid hemorrhage in rats
1 Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda CA 92354, USA
2 Department of Neurosurgery, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda CA 92354, USA
Medical Gas Research 2014, 4:12 doi:10.1186/2045-9912-4-12Published: 9 July 2014
Background & purpose
Approximately 40% of hemorrhagic stroke survivors develop hydrocephalus. Hyperbaric oxygen (HBO) has been shown to be anti-inflammation following experimental stroke; however, its effect upon post-hemorrhagic hydrocephalus formation is not known. The objective of this study is to investigate whether HBO therapy can effectively reduce hydrocephalus formation and improve neurobehavioral functions in a rat model of subarachnoid hemorrhage (SAH).
Thirty-eight male Sprague–Dawley rats (300-320 g) rats survived for 21 days from SAH by endovascular perforation or sham surgery were used. At 24 hours after SAH, HBO (3 atmospheres absolute) or normobaric oxygen (NBO) administrated for 1 hour once daily for a total of 7 days. Wire hanging and rotarod testing were conducted at 14 days after SAH, and cognitive functions were evaluated via the Morris water maze, between day 17 to day 21 after surgery. At day 21, rats were sacrificed and cerebroventricular volumes were measured histologically.
Hydrocephalus exacerbated neurological deficits after SAH, and HBO multiple treatment tendentially improved the neurobehavioral functions. Spatial learning and memory deficits were noticed after SAH, and rats with hydrocephalus showed worse learning and memory abilities and HBO treatment showed a minor improvement. In the SAH group (room air) 4 rats showed an increased ventricular volume at day 21 after SAH-induction (n = 10). HBO or NBO therapy did not alter the occurrence of hydrocephalus after SAH, as 4 rats in each of these groups showed an increased ventricular volume (n = 10 per group).
Multiple HBO therapy does not ameliorate hydrocephalus formation in a rat model of SAH; however, HBO tendentially improved the neurological functions and spatial learning and memory abilities in rats with hydrocephalus.