A 22-year-old woman presented to our office complaining of headaches that started 6 weeks earlier. Initially the headache was throbbing, nonpositional, infrequent, and intermittent, lasting 15 to 45 minutes, often starting in the neck and migrating towards the right frontotemporal region. During the week prior to presentation, the headaches became daily and constant, with brief periods of relief after the patient took ibuprofen 400 mg 4 times a day as needed. The patient reported associated nausea, a sensation of pressure changes in the ears, and intermittent dimming of vision in the right eye (sometimes independent of headache). The patient denied photophobia and phonophobia. Her only medication was an oral contraceptive pill (OCP). She had no prior history of headaches.
Physical examination showed a blood pressure of 148/66 mm Hg, body mass index of 44.38, muscle tenderness in the neck and upper back, and no focal neurological findings. Funduscopic examination was unsuccessful. A working diagnosis of atypical migraine was made, but because of unilateral visual disturbance the patient was referred to Ophthalmology for further evaluation. The following day, ophthalmological consultation found bilateral papilledema and the patient was admitted to our hospitalist service via the Emergency Department. She subsequently was referred to inpatient Neurology.
Magnetic resonance imaging (MRI) of the brain and orbits with and without contrast was unremarkable. Magnetic resonance venography (MRV) with contrast of the brain showed possible stenosis at the junction of the transverse and sigmoid sinuses but no mass lesion nor venous sinus thrombosis. Lumbar puncture (LP) revealed an opening pressure of 650 mm H20 (reference range, 60–250 mm H2O).1 A diagnosis of idiopathic intracranial hypertension (IIH) was made.
IIH, previously known as pseudotumor cerebri and benign intracranial hypertension, is defined by signs and symptoms of elevated intracranial pressure (ICP) without obvious cause on neuroimaging (TABLE 12-5). It is well documented that IIH is consequential and can result in vision loss and intractable chronic headaches.5,6 Older terms such as pseudotumor cerebri and benign intracranial hypertension are therefore no longer recommended because they are considered misleading and not reflective of the severity of potential injury caused by the condition3,4,6 IIH is considered a diagnosis of exclusion requiring certain criteria to be met (TABLE 22). Although the etiology of IIH is unclear, associations have been made between IIH and various medications and conditions2-5,7 (TABLE 33,5).
Classically, IIH affects women who are obese and of childbearing age, but studies have shown that this condition also can affect men and children—albeit less frequently.3,5-7 The incidence of IIH in the general population is between 0.03 to 2.36/100,000 people per year, but in women, the incidence is 0.65 to 4.65/100,000 per year.6 Furthermore, females who are obese have an incidence of 2.7 to 19.3/100,000 per year.6
Headache is the most common symptom of IIH. Unfortunately, the differential diagnosis of headache is vast; thus, a careful history is needed to narrow the field3,5-7 (TABLE 42). Associated symptoms of transient visual changes, pulsatile tinnitus, neck and back pain, nausea, vomiting, photo/phonophobia, and findings of abducens nerve palsy or papilledema—while nonspecific— should raise suspicion for elevated ICP and IIH, especially in women who are obese.2-8 Once IIH is suspected, an urgent diagnosis and treatment is necessary to prevent permanent vision loss.3,4,6
Headache with findings of papilledema warrants neuroimaging, preferably with MRI, to rule out intracranial mass and hydrocephalus.1,2,5 MRV also is recommended to assess for intracranial venous thrombosis, an alternate cause for papilledema and increased ICP.1,2,4,5
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