Deneysel Sıçan Hidrosefali Modelinde Deksmedetomidinin Nöroenflamasyonun Üzerine Etkilerinin Radyolojik Olarak İncelenmesi

Abstract

ABSTRACT Yahya D. Radiological investigation of the effects of dexmedetomidine on hydrocephalus induced neuroinflamation in experimental rat hydrocephalus model, Hacettepe University Faculty of Medicine, Department of neurosurgery, Ankara 2022. Introduction: As a result of ventriculomegaly and increased intracranial pressure in hydrocephalus, there is a decrease in blood flow and ischemia, especially in the periventricular white matter and subventricular zone. Accordingly, a neuroinflammatory condition characterized by the proliferation of astroglial and microglial cells occurs. This chain of events ultimately results in functional loss due to loss of neurons, loss of myelin and decrease in neurogenesis. This neuroinflammation can be seen radiologically in the form of a decrease in cortical and corpus callosum thickness. In vitro studies have shown that dexmedetomidine has anti-inflammatory and neuroprotective effects in varying experimental models. Purpose: In this study, it was aimed to radiologically investigate the effects of dexmedetomidine on neuroinflamation in a hydrocephalus model created by intracisternal kaolin injection. Materials and Methods: In this study, a total of 21 male Sprague- Dawley albino rats weighing between 330-385 g were used. The subjects were divided into 3 separate groups (n=7). The subjects in the first group (Sham group) were given 30μL SF into the cisterna magna. The second (hydrocephalus group) and third ( treatment group) groups’ subjects were injected intracisternally with 25% kaolin suspension dissolved in 30μL SF. Brain MRI was performed on all subjects 14 days after the intracisternal injeciton, and it was confirmed that hydrocephalus developed in the subjects of the second and third groups. Then, for a week, subjects in the second group were injected intraperitoneally with SF, and subjects in the third group were injected intraperitoneally with 40 μg/kg/day of dexmedetomidine. On the 22nd day of the experiment, a brain MRI was perfomed again on all subjects. Evans index, ventricular area measurment, Corpus Callosum thickness, and cortical thickness values were calculated from the images obtained. For statistical analysis of the data GraphPad Prism 9 program was used. Results: All parameters examined (Evans index, ventricular area measurment, corpus callosum thickness, cortical thickness) were found to be statistically significant compared to the sham group. However, there was no significant difference between the hydrocephalus and treatment group. Conclusion: As a result of the statistical analysis, a significant difference was found between the sham group and the groups in which hydrocephalus was fromed (hydrocephalus group and treatment group), which indicates that an effective hydrocephalus has developed. However, there was no significant difference between the hydrocephalus group and the treatment group. In conclusion, there was no radiologically shown effect of dexmedetomidine on the neuroinflammation occurring in hydrocephalus. To confirm these results, we recommend to conduct histopathological studies. Keywords: Hydrocephalus, Kaolin, Dexmedetomidine, Neuroinflammation.