Brain & Nervous System Headaches Causes & Risk Factors Causes and Treatment of Idiopathic Intracranial Hypertension (IIH) A Rare Cause of Headache in Young Females By Colleen Doherty, MD Updated on April 19, 2024 Medically reviewed by Brigid Dwyer, MD Fact checked by Nick Blackmer Print Table of Contents View All Table of Contents Symptoms Causes Diagnosis Treatment Idiopathic intracranial hypertension (IIH) is a condition mainly affecting females that causes increased pressure around the brain and symptoms like headache and vision changes. If left untreated, permanent vision loss and blindness are possible. IIH is a condition of unknown origin that mostly affects females in their childbearing years. Obesity also plays a part. Certain medications can reduce the intracranial pressure, but surgery may be needed to avoid permanent vision loss. This article describes the symptoms and causes of idiopathic intracranial hypertension, including how this rare cause of headaches is diagnosed and treated. Vladimir Vladimirov / Getty Images What Are Symptoms of Idiopathic Intracranial Hypertension? Headache with vision changes are classic signs of IIH. On close inspection of the eye, your healthcare provider will detect papilledema, the swelling of the optic nerve caused by increased pressure in the brain. IIH was once called pseudotumor cerebri (“false brain tumor”) because it mimics symptoms of a brain tumor. These include symptoms like: Headache felt mainly behind the eyes Pulsatile tinnitus (ringing in the ears that pulsates with your heartbeat) Brief episodes of vision loss Pain with eye movement Poor peripheral (side) vision Scotoma (blind spots) Photopsia (flashing or sparkling lights) Diplopia (double vision) Severe cases of IIH can place extreme pressure on an optic nerve, causing unilateral (one-sided) or bilateral (two-sided) vision loss or blindness. What an IIH Headache Feels Like IIH headaches can vary but often mimic a migraine, causing severe, throbbing pain. On occasion, the pain may be steady and aching like a tension headache. In both cases, there would be notable pain behind the eyes. What Causes Idiopathic Intracranial Hypertension? IIH is a rare condition affecting one of every 100,000 people annually. Females are at much greater risk, accounting for more than 90% of cases. “Idiopathic” means of unknown origin. As such, IIH is a condition that occurs for no apparent reason. There are several hypotheses about why IIH suddenly occurs: Dysregulation of cerebrospinal fluid (CSF), due either to overproduction or reduced reabsorption A sudden increase in the volume of blood or brain tissues The temporary obstruction of the veins that drain blood from the brain Being overweight or having obesity also increases the risk. Research suggests that women 20 to 44 years of age who are 20% over their ideal weight have 19 times the risk of the general population. It’s not clear why females are affected more by weight than males are. How Idiopathic Intracranial Hypertension Is Diagnosed In addition to a severe headache with intermittent vision loss, IIH is recognized by the development of papilledema in one or both eyes during an ophthalmoscopic exam. A lumbar puncture (“spinal tap”) would likely be ordered to extract a sample of cerebrospinal fluid (CSF) and measure the pressure inside your skull. A pressure greater than 250 mmH2O is diagnostic for intracranial hypertension. Thereafter, the diagnosis is exclusionary. What this means is that all other causes of your symptoms must be excluded before IIH can be confidently diagnosed. This may involve an extensive battery of tests, including blood tests, brain scans, and a lab analysis of CSF. Among some of the conditions excluded in the differential diagnosis are: Cerebral venous thrombosis (blood clot in the brain) Brain tumor (both benign and malignant) Obstructive hydrocephalus (“water on the brain”) Subarachnoid hemorrhage (a type of brain bleed) Malignant hypertension (dangerously high blood pressure) How Idiopathic Intracranial Hypertension Is Treated The treatment of IIH typically involves a neurologist and ophthalmologist. The primary goals are to relieve symptoms and prevent vision loss. There are several treatments commonly used for this: Acetazolamide: This prescription drug can quickly reduce CSF production by the choroid plexus of the brain.Serial lumbar puncture: The diagnostic procedure can also be used to relieve intracranial pressure by removing small amounts of CSF a little at a time.Analgesics: These include over-the-counter drugs like Tylenol (acetaminophen) and Advil (ibuprofen) and prescription drugs like Topamax (topiramate) to ease headache pain.Transverse sinus stenting: This is the placement of a metal tube into a part of the skull to drain fluids and relieve pressure.Cerebrospinal fluid (CSF) shunting: This surgery creates a conduit from the brain to another part of the body, usually the abdominal cavity, to drain excess CSF.Optic nerve sheath fenestration (also called optic nerve sheath decompression): With this surgery, the connective tissue surrounding the optic nerve is cut to relieve pressure. Summary Idiopathic intracranial hypertension is a condition of unknown origin that causes increased pressure in the brain, causing severe headaches, transient vision loss, and other symptoms. If not treated appropriately, permanent vision loss can ensue. IIH involves a diagnosis of exclusion in which all other causes of your symptoms are excluded. Treatment involves medications and procedures (such as a spinal tap) to relieve intracranial pressure and prevent potentially irreversible damage to the optic nerve. 8 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Keskın AO, İdıman F, Kaya D, Bırcan B. Idiopathic intracranial hypertension: etiological factors, clinical features, and prognosis. Noro Psikiyatr Ars. 2018;57(1):23-26. doi:10.5152/npa.2017.12558 Toscano S, Lo Fermo S, Reggio E, Chisari CG, Patti F, Zappia M. An update on idiopathic intracranial hypertension in adults: a look at pathophysiology, diagnostic approach and management. J Neurol. 2021;268(9):3249-3268. doi:10.1007/s00415-020-09943-9 Chen BS, Britton JOT. Expanding the clinical spectrum of idiopathic intracranial hypertension. Curr Opin Neurol. 2023;36(1):43-50. doi:10.1097/WCO.0000000000001131 Mollan SP, Davies B, Silver NC, et al. Idiopathic intracranial hypertension: consensus guidelines on management. J Neurol Neurosurg Psychiatry. 2018;89(10):1088-1100. doi:10.1136/jnnp-2017-317440 Wakerley BR, Mollan SP, Sinclair AJ. Idiopathic intracranial hypertension: update on diagnosis and management. Clin Med (Lond). 2020;20(4):384-388. doi:10.7861/clinmed.2020-0232 UpToDate: Idiopathic intracranial hypertension (pseudotumor cerebri): prognosis and treatment. Friedman DI, Quiros PA, Subramanian PS, et al. Headache in idiopathic intracranial hypertension: findings from the Idiopathic Intracranial Hypertension Treatment Trial. Headache. 2017;57(8):1195-1205. doi:10.1111/head.13153 Souza MNP, Costa BAL, Santos FRDR, Fortini I. Update on idiopathic intracranial hypertension management. Arq Neuropsiquiatr. 2022;80(5 Suppl 1):227-231. doi:10.1590/0004-282X-ANP-2022-S110 Additional Reading National Institute of Neurological Disorders and Stroke. Pseudotumor cerebri. Obi EE, Lakhani BK, Burns J, & Sampath R. Optic nerve sheath fenestration for idiopathic intracranial hypertension: a seven year review of visual outcomes in a tertiary centre. Clin Neurol Neurosurg. 2015;137:94-101. doi:10.1016/j.clineuro.2015.05.020 By Colleen Doherty, MD Dr. Doherty is a board-certified internist and writer living with multiple sclerosis. She is based in Chicago. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? 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