Endoscopic Fenestration of an Intra-ventricular Arachnoid Cyst in a Young Male – A Rare Entity

Abstract

Introduction: Among intracranial space-occupying lesions, arachnoid cysts compromise 1% only. Abnormal collection of cerebrospinal fluid occurs in these types of cysts leading to pressure symptoms. Developmental abnormalities of cerebrospinal structures in early fetal life lead to the primary type of arachnoid cysts, while the second type of arachnoid cyst is formed after some neurological insult like head injury, tumor, meningitis, or brain surgery. In 60 – 90% of cases, the primary type predominates and presents with pressure symptoms before the age of 20 years. The adjudged incidence is 1.4% in adults, the least frequent being intraventricular location. Clinical Case: A 23-year-old male presented with a long-standing left-sided cranial vault headache, right-sided focal seizures, and progressive right- hemiparesis. Neurological evaluation revealed upper motor neuron signs on the right side of the body. A computerized axial tomography raised the suspicion of an arachnoid cyst for which magnetic resonance imaging was done which revealed a large intraventricular cyst of lateral ventricles causing mass effect over the ipsilateral hemisphere and mild obstructive hydrocephalous. Surgical intervention was required as per symptomology (intractable headache, seizures, and hemiparesis) and large cyst size. Conclusion: Cerebrospinal fluid accumulation in the brain's arachnoid layer causes non-cancerous arachnoid cysts. Larger cysts may push on brain tissue and cause neurological difficulties. MRI may diagnose arachnoid cysts, and treatment options include cystoperitoneal shunt, craniotomy, and neuro-endoscopic fenestration, the least invasive. Cyst size and location determine therapy. In this example, endoscopic treatment reduced symptoms and consequences.