Walsh & Hoyt: Conditions Associated with Papilledema

Intracranial masses such as tumors produce increased ICP through most of the mechanisms mentioned above. They may act solely as space-occupying lesions; they may produce focal or diffuse cerebral edema, and they may block the outflowof CSF by direct compression of CSF drainage pathways or by infiltration of the arachnoid villi or the cerebral venous sinuses. Other potential mechanisms are the production of increased protein or blood products that secondarily block the arachnoid villi, and by directly producing CSF.