papilledema

papilledema Swelling of the head of the optic nerve, a sign of increased pressure within the skull. The optic nerve head is the area where the optic nerve (the nerve that carries information from the retina to the brain) enters the eyeball. Papilledema is diagnosed through use of an ophthalmoscope. The optic nerve head is abnormally elevated in papilledema, almost always in both eyes. The causes of papilledema include swelling of the brain (as from encephalitis or trauma), tumors and other lesions that occupy space within the skull, increased production of cerebrospinal fluid (CSF), decreased resorption of CSF (due to meningitis, venous sinus thrombosis, or subarachnoid hemorrhage), obstruction of the ventricular system within the brain, hydrocephalus, craniosynostosis (premature closure of the sutures of the skull), and pseudotumor cerebri (increased pressure within the brain in the absence of a tumor). When papilledema is found, the patient requires immediate further evaluation and, if needed, intervention. Also known as a choked disk. See also brain cancer; cerebrospinal fluid; craniosynostosis; encephalitis; hydrocephalus; meningitis; pseudotumor cerebri; ventricle, cerebral.