Accuracy of cranial ultrasound in the assessment of hydrocephalus evaluation in experimental rats after hemorrhagic stroke

Abstract

Background. Subarachnoid hemorrhage (SAH) is the third most common subtype of stroke. Among complications, the most important include hydrocephalus, rebleeding, delayed ischemia, intracerebral hemorrhage, and intraventricular hemorrhage. Post-hemorrhagic hydrocephalus (PHH) can develop in as many as 66% of adults with intraventricular extension of blood, and it is also associated with worse functional outcomes. The pathophysiology of hydrocephalus after SAH remains unclear. Small animal models in basic and preclinical sciences constitute an integral part of testing new hypotheses before translation to clinical practice. The need for newer procedures for PHH prevention is imperative, as the limitations of traditional treatment methods (e.g., shunting, endoscopy) have become increasingly apparent. High-frequency brain ultrasound imaging provides a non-invasive method of superior spatial resolution for imaging brain ventricles in small animals. Objectives. Cranial ultrasound in an experimental small animal hemorrhagic stroke model of cisterna magna double-injection was tested to see its validity in the assessment of communicative hydrocephalus. Methods. Experimental animals were divided into two groups. The first group (control group - CG) was without surgery (10 rats). In the second group (20 rats), a 0.15 ml blood injection into cistern magna was followed by a 0.15 ml blood second injection 48 hours later. During the research 46 US, we performed. We defined hydrocephalus as Levene index on ultrasound, which was > +3 SDs above the mean in control animals. Results. Thirty-seven operations were done on 20 rats. Hydrocephalus in the surgical group occurred in 56% of rats, according to the ultrasound investigations. In eleven experimental animals, Levene index values were above 3SD of the mean in the control animal; in the surgical group, the difference in Levene indexes between pre- and post-operation was “+31%” (p-value less than 0,0001). Conclusion: Based on the findings, cranial ultrasound is a valid and precise method for assessing posthemorrhagic hydrocephalus in small experimental animals.