MATERIAL and METHODS: Twenty-one Wistar rats were randomly divided into three experimental groups: control (group 1) and fluorescein-sodium groups with different doses (groups 2 and 3). In the control group, craniectomy following with durotomy was performed with the help of a loupe microscope, and a dry sponge was overlayed to the brain tissue. In the study groups, the open dura was covered with a sponge soaked with 0.02 mg (group 2) and with 0.2 mg (group 3) fluorescein sodium following craniectomy. Three weeks postoperatively, rats were sacrificed for the histopathologic evaluations.

RESULTS: Fluorescein-induced apoptosis occurs in a dose-dependent manner in rats’ neurons. It was determined that neuron and neuroglial cell TUNEL staining was statistically different among the three groups (p<0.001). Our results indicated that fluorescein induces apoptosis, resulting in increased nuclear factor kappa beta (NF-κβ) expression in a dose-dependent manner.

CONCLUSION: Fluorescein sodium is used frequently during surgery for CSF fistulas. However, information in the literature about its safety is insufficient. Our study holds promise for the development of new studies on the reliability of this agent. Keywords : Fluorescein-sodium, Rhinorrhea, Neurotoxic effect, CSF fistula