Walsh & Hoyt: Papilledema

Papilledema is defined in this text as optic disc swelling associated with and caused by increased ICP. Intracranial tumors may produce increased ICP by several mechanisms: (a) the total amount of intracranial tissue may be increased by the tumor; (b) intracranial tissue volume may be increased by focal or diffuse cerebral edema surrounding the tumor; (c) the tumor may block the flow of cerebrospinal fluid (CSF) either within the ventricular system, creating obstructive (noncommunicating) hydrocephalus, or within the arachnoid granulations, producing nonobstructive (communicating) hydrocephalus; (d) the tumor may compromise cerebral venous outflow, thereby reducing absorption of CSF; and (e) the tumor may manufacture CSF at a rate that precludes adequate absorption for maintenance of normal ICP.