There are individual differences in the degree of CSP; whereas some have complete closure of the cavum, others present with a small degree (4–6 mm wide, in the coronal plane) of incomplete closure.[4] The most common type of CSP is noncommunicating; that is, it does not connect to the brain's ventricular system. Because of this lack of communication, the previous use of the term "fifth ventricle" is no longer used, and the fifth ventricle is the name often used for the terminal ventricle.