Introduction: Acute hydrocephalus occurs in aneurysmal subarachnoid hemorrhage (SAH) patients, which causes increased intracranial pressure and results in clinical deterioration. In this study, we investigated acute hydrocephalus in a rat model of SAH.
Methods: SAH was induced by endovascular perforation of the left middle cerebral artery in adult male Sprague-Dawley rats (n=36). Sham rats (n=8) had the same procedure without perforation. All rats that survived had magnetic resonance imaging from the frontal horn to the foramen of Luschka at 24 hours after SAH. Hydrocephalus in SAH rats was defined as a ventricular volume greater than three standard deviations above that in the sham animals. Rats were killed after neurological testing and the brains were used for histological examination to determine the percent of ventricular wall damage defined as ependymal surface disruption.
Results: All surviving SAH rats (n=28) had ventricle enlargement (33.6±24.6 vs. 13.5±4.0 mm3 in shams, p<0.01). Thirteen out of the 28 SAH rats had hydrocephalus and all had intraventricular blood accumulation. Neurological testing scores were significantly lower in SAH rats with hydrocephalus and the severity of SAH was correlated with the ventricular volume (r=0.48, p<0.05). Rats with hydrocephalus had more severe ventricular wall damage (7.4±3.4%) than the sham animals (0.6±0.4%, p<0.01) and SAH rats without hydrocephalus (1.1±0.8%, p<0.01).
Conclusions: In summary, SAH caused ventricular enlargement and neurological deficits in a rat model. Acute hydrocephalus occurred in 46% of SAH rats and was associated with ventricle wall damage.
Patient Care: Our research will be useful for exploring in the disorder due to acute hydrocephalus caused by SAH.
Learning Objectives: By the conclusion of this session, participants should be able to discuss the cause of acute hydrocephalus after SAH.