Volatile agents and CSF Dynamics
Isoflurane will increase the absorption of cerebrospinal fluid (CSF) and does not influence the production of CSF.
Below are a couple of references for this topic.
Miller 7th ed.p.322
Absorption of CSF is reduced by halothane and enflurane, unchanged by desflurane, and increased by isoflurane. Though probably of minimal relevance to clinical practice, a theoretical concern might be in the setting of a prolonged closed-cranium procedure in a patient with poor intracranial compliance.
Morgan/Mikhail 4th ed.p.621
Volatile anesthetics affect both formation and absorption of cerebrospinal fluid. Halothane impedes absorption of CSF but only minimally retards formation. Isoflurane, on the other hand, facilitates absorption and is therefore the only volatile agent with favorable effects of CSF dynamics.
Barash 6th ed.p.427
Isoflurane does not appear to alter cerebrospinal fluid production, but may increase, decrease, or leave unchanged the resistance to resorption depending on dose. Sevoflurane at 1 MAC depresses production up to 40%. Desflurane at 1 MAC leaves production unchanged or increased. In general, anesthetic effects on ICP via changes in CSF dynamics are clinically far less important than anesthetic effects on CBF.