Isoflurane-induced Neuroinflammation in Children With Hydrocephalus

Inclusion Criteria (HC study patients): * Pediatric patients, aged 6 months-less than 11 years, diagnosed with hydrocephalus undergoing a primary surgical (non-bedside) shunting procedure with general anesthesia. * Participants must have a parent/guardian who is able to provide written informed consent in accordance with human investigation committee guidelines. * The shunting procedure must be an initial VPS placement (not a VPS revision). Inclusion Criteria (MRI with general anesthesia: peripheral blood patients; anesthesia but no surgery): * Otherwise healthy pediatric patients, aged 6 months-less than 11 years, undergoing MRI with general anesthesia for evaluation of non-neurologic, non-inflammatory disease. * Participants must have a parent/guardian who is able to provide written informed consent in accordance with IRB guidelines. Exclusion Criteria (HC study patients): * Any active infection or infection within the last 14 days. * Treatment in the last 48 hours with non-steroidal anti-inflammatory (NSAID) or corticosteroid medications. * Anticoagulant administration in the last 48 hours. * Treatment with any drug known to induce or suppress inflammation. * Clinically unstable patients. * Patients that have an American Society of Anesthesiologists physical status ≥4 (severe, life-threatening disease). * Infants born more than 4 weeks premature. Exclusion Criteria (MRI with general anesthesia: peripheral blood patients; anesthesia but no surgery): * Known central n…