Intracranial arachnoid cyst (Review of 20 cases)

ntroduction: The purpose of this study is to evaluate the distribution, clinical features, and treatment modalities of arachnoid cyst in our department. The study was carried out between April 1, 1996 and October 1, 2006 in the neurosurgery department, Ghaem hospital, Mashhad University of Medical Sciences. Twenty patients with arachnoid cyst underwent surgery between April 1, 1996 until October 1, 2006, consisting of 12 males and 8 females aged 5 to 68 years (mean age 32.4 years). Twelve patients underwent surgery and one patient underwent endoscopic fenestration, and cystoperitoneal shunting (medium pressure) was performed in 7 patients. All patients were followed for minimum of 6 months after surgery. During the study period, 20 patients were investigated. The cysts location was the middle cranial fossa in 12 patients (60%), suprasellar region in 1 patient (5%), the cerebral convexity in 1 patient (5%), posterior cranial fossa in 2 patients (10%), cerebellopontine angle in 3 patients (15%), and quadrigeminal cisterns in 1 patient (5%). All cysts had clearly unilateral distribution, 12 (60%) were located on the left side and 8 (40%) on the right side. The most common symptoms on presentation were epileptic seizures (46%), increased intracranial pressure (34%), visual impairment (5%), headache (10%), and cerebellar signs (5%). Arachnoid cysts have a strong predilection for the middle cranial fossa which may be explained by a meningeal mal-development theory. We also conclude that the major indication for surgery in patients with arachnoid cyst is the presence of intractable seizures, increased intracranial pressure, and compression of nervous tissues. Headache is not a surgical indication on its own.