A 29-year-old obese woman presented with chronic headaches that were worse in the morning or while lying down. She denied nausea or other neurologic symptoms. She had no other medical problems and took no medications. On examination, she had a visual acuity of 20/20 in both eyes, bilateral papilledema (Figure 24-1), no spontaneous venous pulsations (SVPs), and no other neurologic signs. She had a brain MRI showing no mass or hydrocephalus, and elevated intracranial pressure measured by lumbar puncture. She was diagnosed with idiopathic intracranial hypertension and was followed closely for any changes in her vision. She was started on acetazolamide and assisted with a weight-loss program. Her symptoms resolved over the course of 18 months.
Papilledema from increased intracranial pressure. The optic disc is elevated and hyperemic with engorged retinal veins. The entire optic disc margin is blurred. Optic neuropathies can also have blurring of the entire disc margin, but often, only part of the disc is blurred. (Reproduced with permission from Paul D. Comeau.)
The term papilledema refers specifically to optic disc swelling related to increased intracranial pressure. When no localizing neurological signs or space-occupying lesion is present, idiopathic intracranial hypertension (IIH) is a likely cause in patients younger than age 45 years, especially obese women. Patients with IIH usually present with daily pulsatile headache with nausea and often have transient visual disturbances and/or pulsatile tinnitus. Patients often report a "whooshing" sound that they hear. Bilateral papilledema and visual field defects on a perimetry test are found in almost all patients. Elevated opening pressure on lumbar puncture is required for the diagnosis.
For IIH: Pseudotumor cerebri or benign intracranial hypertension.
0.9 per 100,000 people and 3.5 per 100,000 women in the United States.1
19 per 100,000 obese women ages 20 to 44 years.1
Prevalence may be increasing with increasing obesity.1
Mean age of diagnosis is approximately 30 years.1
ETIOLOGY AND PATHOPHYSIOLOGY
The optic disc swells because of elevated intracranial pressure from any cause. In IIH, the cerebral spinal fluid pressure is increased. The cause of this increase in unknown, but a current hypothesis implicates arterial flow in the transverse sinus due to a combination of increased arterial flow and low-grade stenosis.2
Patients with papilledema should undergo imaging, preferably MRI, followed by lumbar puncture. MRI will reveal many causes of increased intracranial pressure.
IIH is a diagnosis of exclusion ...