Idiopathic Intracranial Hypertension in a 24-Year-Old Woman
Case
A 24-year-old woman presented to the ED for evaluation of a 3-week history of worsening headache and a 5-day history of increasingly blurry vision. The patient stated that she had initially contacted her primary care physician, but instead presented to the ED because he had no open appointments until the following week and recommended that she go to the ED.
The patient described her headache as a pulsating and throbbing pain over her entire head, which only mildly improved after taking over-the-counter (OTC) ibuprofen. She further noted that her headache was somewhat worse when lying down, and reported the sensation of hearing her own pulsating heartbeat in her ears.
The patient had no personal or family history of migraines, tension headaches, aneurysms, clotting disorders, bleeding disorders, or renal disease, and stated that she had never experienced this type of headache before. She denied photophobia, phonophobia, neck stiffness, fever, vomiting, cough, numbness or weakness in her extremities, or pain anywhere else in her body.
Over the past 5 days, the patient noticed her vision had become increasingly blurry. She was not on any prescription medications, stating the only medication she used was occasional OTC ibuprofen. She had no known allergy to medications and denied smoking or recreational drug use; she admitted to occasional alcohol consumption.
The patient resided with her husband, who had no similar symptoms. Physical examination showed an obese woman (height, 5 ft 6 in; weight, 195 lb; body mass index, 32 kg/m2), lying supine in apparent discomfort. Vital signs at presentation were all normal, and oxygen saturation was normal on room air.
A bedside ocular examination showed 20/100 in both eyes while using glasses; no visual field cuts or obvious central scotoma was present. The patient was alert and oriented to time and place. The neurological examination showed intact cranial nerves, 5/5 strength in all extremities, intact sensation in all extremities, no pronator drift, negative Romberg test, and a normal gait. Fundoscopic examination revealed mildly blurred medial optic discs bilaterally. The rest of the physical examination was normal.
Discussion
Pseudotumor cerebri, more commonly referred to as idiopathic intracranial hypertension (IIH), is characterized by increased intracranial pressure (ICP) with no explanatory findings on imaging studies or in cerebrospinal fluid (CSF) analysis, and may be accompanied by symptoms of chronic headache, tinnitus, papilledema and progressive vision loss caused by optic nerve damage.1 Though historically IIH was referred to by several other names, including “benign intracranial hypertension,” the condition is not benign—when untreated, IIH can cause chronic disabling headaches and permanent vision loss.1
Clinical Course
The clinical course of IIH is unpredictable: In some patients, vision loss occurs gradually over the course of several weeks, while in others, loss occurs over a several month period. There are also patients with IIH who do not experience any alteration or loss of vision. Furthermore, some patients will experience permanent resolution of symptoms after a single lumbar puncture (LP); others have symptom recurrence after less than 24 hours; and some patients spontaneously remit on their own with no treatment whatsoever.1-4
Etiology
In the United States, IIH is a rare cause of headache, occurring in just 1 person per 100,000 annually.1 Though 90% of IIH cases occur in obese women of childbearing age, the etiology of IIH is unknown. Lumbar puncture usually alleviates the patient’s headache, but the CSF pressure typically returns to its pre-tap levels after a few hours.4,5 Neither CSF overproduction nor insufficient CSF resorption is responsible for causing IIH. One theory on the etiology of IIH proposes its cause to be due to a congenital malformation of the venous sinuses. This theory would explain why the symptoms so closely mimic those of venous sinus thrombosis, and why some IIH patients experience relief of symptoms after placement of a venous sinus stent.2
Symptoms
As noted previously, the most common symptom of IIH is headache, which patients usually describe as pressure-like and throbbing, and often involving retro-ocular pain. One feature in over half of patients is pulse-synchronous tinnitus (ie, hearing their own heartbeat in their ears). Eye pain, photophobia, blurry vision, and nausea/vomiting are all common symptoms in IIH, but these symptoms are also present in other causes of headache. The IIH headache might be relapsing and remitting, and can last from a few hours to weeks.2-4,6
