Headache With Papilledema
Papilledema is bilateral optic disc swelling due to increased intracranial pressure. It is considered an emergency because intracranial pressure may rise in an exponential fashion with the potential for acute neurologic decompensation. The increased CSF pressure is transmitted to the optic nerve, resulting in stasis of axoplasmic flow causing intra-axonal edema. There may be cases of “unilateral” papilledema, but these are rare and local optic nerve conditions such as ischemic optic neuropathy and optic neuritis should be considered first.
The early funduscopic changes of papilledema include opacification or “splaying” of the peripapillary nerve fiber layer; obscuration of the retinal vessels as they cross the optic disc margin; optic disc hyperemia; optic disc telangiectasias or hemorrhages; retinal venous dilation; and loss of venous pulsations, especially if they were previously present (Figure 6a and 6b).
Papilledema causes nerve fiber layer-related visual field defects (arcuate and paracentral scotomas, nasal step defects) and typically spares central visual acuity, unless there is macular edema, macular hemorrhage, retinal/choroidal folds, or secondary ischemic optic neuropathy. The enlarged blind spots noted with papilledema are usually refractive scotomas and not necessarily related to axonal damage.
The symptoms of increased intracranial pressure include daily headache that is often worse after being supine or with Valsalva maneuver, nausea and vomiting, transient visual obscurations (TVOs), binocular diplopia due to sixth nerve palsy, and pulse-synchronous intracranial noises. The TVOs are monocular or binocular graying or darkening of vision that last for a few seconds and are often associated with postural changes.
The blood pressure should be checked in all patients presenting with bilateral optic disc swelling to exclude malignant hypertension. Although most patients with severe hypertension will show retinal hemorrhages and retinal arteriolar narrowing, there may be exceptions where bilateral optic nerve swelling is the only manifestation. The detection of papilledema warrants emergent neuroimaging, preferably MRI. If a mass lesion is detected, urgent neurosurgical consultation should be arranged (Figure 6c and 6d). If the MRI is normal, a lumbar puncture is recommended to measure the CSF opening pressure and analyze the CSF to rule out meningitis, leptomeningeal disease, and other inflammatory processes. In cases of papilledema where the MRI is normal, the CSF opening pressure is elevated, and the CSF profile is negative, the diagnosis of idiopathic intracranial hypertension (IIH/pseudotumor cerebri) is made.