Intracranial arachnoid cyst in children: Clinical presentation and risk factors for surgical intervention.

INTRODUCTION: Intracranial Arachnoid Cysts (IAC) in children are a common incidental finding on imaging. Most IACs are asymptomatic and can be monitored, however, a small percentage may enlarge and require surgical intervention. This study aimed to identify clinical risk factors in patients with IAC who underwent surgery versus those who did not. METHODS: We conducted a retrospective chart review from 2009 to 2021 at a free-standing children's hospital. A total of 230 patients diagnosed with an IAC aged 0 to 21 years of age were included in the study. Data on demographics, imaging and neurological follow-up were analyzed. RESULTS: Out of 230 patients, 45 (19.6%) underwent surgery. At time of IAC diagnosis, the surgical patients were younger (median age 1.1 years), and their median cyst volume was larger (41.7cm3), compared to non-surgical patients (median age 5.9 years, volume 11.8cm3, respectively). Headache was the most common reason for initial imaging in non-surgical patients (54/185, 29.2%) while prenatal ultrasound (11/45, 24.4%) and macrocephaly (11/45, 24.4%) were the most common reasons for surgical patients. The majority of both surgical and non-surgical patients had the IAC incidentally found (41/45, 91.1% and 181/185, 97.8%, respectively). Surgery relieved symptoms in 38/45 (84.4%) patients. Cyst volume and age were predictors of increased odds of having surgery. DISCUSSION/CONCLUSION: Patients who underwent surgery were younger and had larger cyst volumes at time of diagnosis. The majority of the IAC were found incidentally and remained stable over prolonged follow up. The majority of the patients experienced relief of symptoms post-surgical intervention. There is a greater odds of having surgical treatment with decreased age and greater cyst volume at diagnosis and therefore these patients should be monitored closely for development of symptoms indicating need for surgical intervention.

The role of glutathione and glutathione peroxidase in regulating cellular level of reactive oxygen and nitrogen species.

Glutathione (GSH) and GSH/glutathione peroxidase (GPX) enzyme system is essential for normal intracellular homeostasis and gets disturbed under pathophysiologic conditions including endothelial dysfunction. Overproduction of reactive oxidative species (ROS) and reactive nitrogen species (RNS) including superoxide (O2•-), and the loss of nitric oxide (NO) bioavailability is a characteristic of endothelial dysfunction. The GSH/GPX system play an important role in eliminating ROS/RNS. Studies have provided important information regarding the interactions of ROS/RNS with the GSH/GPX in biological systems; however, it is not clear how this cross talk affect these reactive species and GSH/GPX enzyme system, under physiologic and oxidative/nitrosative stress conditions. In the present study, we developed a detailed endothelial cell kinetic model to understand the relationship amongst the key enzyme systems including GSH, GPX, peroxiredoxin (Prx) and reactive species, such as hydrogen peroxide (H2O2), peroxynitrite (ONOO-), and dinitrogen trioxide (N2O3). Our simulation results showed that the alterations in the generation rates of O2•- and NO led to the formation of a wide range of ROS and RNS. Simulations performed by varying the ratio of O2•- to NO generation rates as well as GSH and GPX concentrations showed that the GPX reducing capacity was dependent on GSH availability, level of oxidative/nitrosative stress, and can be attributed to N2O3 levels, but not to H2O2 and ONOO-. Our results showed that N2O3 mediated switch-like depletion in GSH and the incorporation of Prx had no considerable effect on the ROS/RNS species other than ONOO- and H2O2. The analysis presented in this study will improve our understanding of vascular diseases in which the levels and oxidation states of GSH, GPX and/or Prx are significantly altered and pharmacological interventions show limited benefits.