A Comprehensive Review of Arachnoid Cysts

Arachnoid cysts are cerebrospinal fluid (CSF)-filled sacs that develop within the arachnoid membrane surrounding the brain or spinal cord, often remaining asymptomatic but occasionally causing neurological symptoms due to mass effect or CSF flow obstruction. The optimal management of these cysts remains debated, balancing conservative observation with surgical intervention. This review analyzes the epidemiology, pathophysiology, clinical presentation, diagnostic strategies, treatment options, and future management directions for arachnoid cysts. With a prevalence of approximately 1-2% and a male predominance, these cysts most commonly occur in the Sylvian fissure and posterior fossa. Magnetic resonance imaging (MRI) serves as the gold standard for diagnosis, with diffusion-weighted imaging and cine phase-contrast MRI playing critical roles in differentiating communicating versus non-communicating cyst types and assessing CSF dynamics. Asymptomatic cysts are typically managed conservatively with periodic neuroimaging follow-up, while surgical intervention is reserved for symptomatic cases, particularly those associated with hydrocephalus, seizures, or focal neurological deficits. Treatment strategies include endoscopic fenestration, microsurgical fenestration, and cyst-peritoneal shunting, with endoscopy offering a less invasive option but carrying a higher recurrence risk. Advances in neuroimaging, surgical techniques, and artificial intelligence-driven predictive modeling are refining treatment approaches, while emerging research into molecular mechanisms and minimally invasive robotic-assisted surgery may further optimize outcomes. Future developments in personalized, risk-stratified management protocols may reduce the need for invasive interventions and improve long-term prognoses.