Benign Enlargement of the Subarachnoid Space

• Etiology: due to immature + inefficient arachnoid villi, causing temporary communicating hydrocephalus
• Imaging: subarachnoid space relatively larger in infants < 2 years old, subarachnoid vessels cross the space
• Clinical: presents with macrocephaly, resolves on its own by 2-3 years

Cases of Benign Enlargement of the Subarachnoid Space