CASE REPORT Idiopathic Intracranial Hypertension in a 24-Year-Old Woman Aaron Heckelman, MD; Tony Zitek, MD A 24-year-old woman presented with a history of severe headache and blurry vision. Case Over the past 5 days, the patient no- A 24-year-old woman presented to the ED ticed her vision had become increasingly for evaluation of a 3-week history of wors- blurry. She was not on any prescription ening headache and a 5-day history of in- creasingly blurry vision. The patient stated that she had initially contacted her prima- ry care physician, but instead presented to the ED because he had no open appoint- ments until the following week and recom- mended that she go to the ED. The patient described her headache as a pulsating and throbbing pain over her en- tire head, which only mildly improved af- ter taking over-the-counter (OTC) ibupro- fen. 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 photopho- bia, phonophobia, neck stiffness, fever, vomiting, cough, numbness or weakness in her extremities, or pain anywhere else in her body. © Image Point Fr/ChaNaWiT/LeksusTuss/Shutterstock Dr Heckelman is a postgraduate year 3 resident, department of emergency medicine, University Medical Center, Las Vegas, Nevada; he is affiliated with the University of Nevada School of Medicine. Dr Zitek is an assistant research director and assistant professor, department of emergency medicine, University of Nevada School of Medicine, Las Vegas. Authors’ Disclosure Statement: The authors report no actual or potential conflict of interest in relation to this article. DOI: 10.12788/emed.2017.0012 www.emed-journal.com FEBRUARY 2017 I EMERGENCY MEDICINE 77 IDIOPATHIC INTRACRANIAL HYPERTENSION blurred medial optic discs bilaterally. The Table. Differential Diagnosis for Increased rest of the physical examination was normal. Opening Pressure on Lumbar Puncture Discussion Meningitis/encephalitis Pseudotumor cerebri, more commonly re- ferred to as idiopathic intracranial hyper- Cerebral edema tension (IIH), is characterized by increased Intracranial mass lesion intracranial pressure (ICP) with no explan- atory findings on imaging studies or in ce- Subarachnoid hemorrhage rebrospinal fluid (CSF) analysis, and may be accompanied by symptoms of chronic Venous sinus thrombosis headache, tinnitus, papilledema and pro- gressive vision loss caused by optic nerve Pseudotumor cerebri damage.1 Though historically IIH was re- Guillain-Barré syndrome ferred to by several other names, including “benign intracranial hypertension,” the Jugular vein compression condition is not benign—when untreated, (from neck mass or postsurgical scarring) IIH can cause chronic disabling headaches and permanent vision loss.1 Meningeal carcinomatosis Choroid plexus tumor Clinical Course (causes overproduction of cerebrospinal fluid) The clinical course of IIH is unpredictable: In some patients, vision loss occurs gradu- ally over the course of several weeks, while in others, loss occurs over a several month medications, stating the only medication period. There are also patients with IIH she used was occasional OTC ibuprofen. who do not experience any alteration or She had no known allergy to medications loss of vision. Furthermore, some patients and denied smoking or recreational drug will experience permanent resolution of use; she admitted to occasional alcohol symptoms after a single lumbar puncture consumption. (LP); others have symptom recurrence af- The patient resided with her husband, ter less than 24 hours; and some patients who had no similar symptoms. Physical spontaneously remit on their own with no examination showed an obese woman treatment whatsoever.1-4 (height, 5 ft 6 in; weight, 195 lb; body mass index, 32 kg/m2), lying supine in appar- Etiology ent discomfort. Vital signs at presentation In the United States, IIH is a rare cause of were all normal, and oxygen saturation headache, occurring in just 1 person per was normal on room air. 100,000 annually.1 Though 90% of IIH A bedside ocular examination showed cases occur in obese women of childbear- 20/100 in both eyes while using glasses; no ing age, the etiology of IIH is unknown. visual field cuts or obvious central scotoma Lumbar puncture usually alleviates the was present. The patient was alert and ori- patient’s headache, but the CSF pressure ented to time and place. The neurological typically returns to its pre-tap levels after examination showed intact cranial nerves, a few hours.4,5 Neither CSF overproduc- 5/5 strength in all extremities, intact sen- tion nor insufficient CSF resorption is re- sation in all extremities, no pronator drift, sponsible for causing IIH. One theory on negative Romberg test, and a normal gait. the etiology of IIH proposes its cause to be Fundoscopic examination revealed mildly due to a congenital malformation of the 78 EMERGENCY MEDICINE I FEBRUARY 2017 www.emed-journal.com venous sinuses. This theory would explain contrast CT and MRI can identify subtle why the symptoms so closely mimic those anatomical deformities and small lesions, of venous sinus thrombosis, and why some their absence on these studies can help es- IIH patients experience relief of symptoms tablish a diagnosis of IIH. after placement of a venous sinus stent.2 Venous Sinus Thrombosis. Venous sinus thrombosis is a rare but devastating condi- Symptoms tion that also cannot be diagnosed from a As noted previously, the most common noncontrast CT but must always be consid- symptom of IIH is headache, which pa- ered in the differential diagnosis of IIH.8-10 tients usually describe as pressure-like and Venous sinus thrombosis is characterized throbbing, and often involving retro-ocular by a clot in one of the large venous sinuses pain. One feature in over half of patients that drain blood from the brain; the clot is pulse-synchronous tinnitus (ie, hear- causes pressure to back up into the smaller ing their own heartbeat in their ears). Eye cerebral vasculature, eventually inducing pain, photophobia, blurry vision, and nau- either a hemorrhagic stroke from a stressed sea/vomiting are all common symptoms in vessel rupturing, or an ischemic stroke IIH, but these symptoms are also present from lack of blood flow to the affected area in other causes of headache. The IIH head- of the brain. This condition is even more ache might be relapsing and remitting, and rare than IIH (0.5 cases per 100,000 popu- can last from a few hours to weeks.2-4,6 lation), but it can be devastating if missed, carrying a mortality rate as high as 15% in Diagnosis some studies.11 Imaging Studies. Noncontrast computed tomography (CT) imaging studies do not Risk Factors typically demonstrate any abnormal find- Risk factors known to cause cerebral venous ings.1 Magnetic resonance imaging (MRI) clots include genetic thrombophilias, preg- studies show some inconsistent and subtle nancy or recent pregnancy, oral contracep- findings, such as flattening of the backs of tive use, inflammatory bowel disease, severe the eyeballs, empty sella, or tortuous optic dehydration, local infection/trauma, and nerves.1 substance abuse. Regardless of risk factors, Lumbar Puncture. On LP, a very high the most recent guidelines of the American opening pressure is a hallmark of IIH. An Heart Association/American Stroke Asso- opening pressure <20 cm H2O is generally ciation recommend imaging studies of the considered normal, 20 cm to 25 cm H2O is cerebral venous sinuses for any patient pre- 7 “equivocal,” and >25 cm H2O is abnormal. senting with new-onset symptoms sugges- Patients presenting with IIH commonly tive of IIH (Class 1, Level of Evidence C).11 have an opening pressure that exceeds 200 The two imaging options for evaluation of 1-3 cm H2O. Extremely high pressures, how- the cerebral venous sinuses are CT venog- ever, are not required for the diagnosis, but raphy or MR venography. Since the 2013 some elevations in opening pressure will American College of Radiology Appropri- always be present.2,5 With the exception of ateness Criteria do not indicate a preference a high opening pressure, the patient’s CSF of one modality over the other, the choice of analysis is normal. can be left to your radiologist.12 Differential Diagnosis Patient Disposition Idiopathic intracranial hypertension is es- Patients with IIH typically do not require sentially a diagnosis of exclusion, one that inpatient admission. Only about 3% of is made after exclusion of all other poten- IIH patients will have a fulminant course tial causes of increased ICP (Table). Since of rapid-onset of vision loss, but even www.emed-journal.com FEBRUARY 2017 I EMERGENCY MEDICINE 79 IDIOPATHIC INTRACRANIAL HYPERTENSION the most severe and acute cases will de- varied from 15 to 25 mL, without adverse teriorate over weeks, not hours or days.13 effects. A 1975 case series by Weisberg6 Never theless, close neurology follow-up is described safe removal of up to 30 mL of essential. If rapid and thorough outpatient CSF in pseudotumor patients—the precise neurological care is unavailable, admis- amount removed was determined by that sion is required. which was necessary to lower the CSF pressure into the normal range. In 2007, Management a case report by Aly and Lawther16 of a Not every patient with IIH experiences pregnant woman with IIH describes twice amelioration or resolution of symptoms weekly LP drainage of 30 mL. following an LP; moreover, there is no clear There is nothing in the current litera- way to differentiate patients who will ex- ture to suggest that removing 10 to 30 mL perience therapeutic effects from LP from of CSF instead of the 4 to 8 mL typically those who will not.