Arachnoid Cysts-Cause and Etiology
Arachnoid Cysts 1. Cause and Etiology Arachnoid cysts are cerebrospinal fluid (CSF)-filled sacs that occur within the arachnoid membrane , which is one of the three meningeal layers that surround the brain and spinal cord. The etiology is broadly categorized into: A. Primary (Congenital) Arachnoid Cysts · These are by far the most common type. · Result from developmental abnormalities during embryogenesis , especially between the 3rd and 4th months of gestation. · It is thought to be caused by splitting or duplication of the arachnoid membrane, leading to a CSF-filled pocket. B. Secondary (Acquired) Arachnoid Cysts · Less common. · Typically result from: o Head trauma o Infections (e.g.,...