Idiopathic Intracranial Hypertension
NORD gratefully acknowledges Bradley K. Farris, MD, Professor, Department of Ophthalmology, Adjunct Professor, Department of Neurology & Neurosurgery, University of Oklahoma School of Medicine; and Mark Robinson, MD, Neuro-Ophthalmology Fellow, Department of Neurology & Neurosurgery, University of Oklahoma School of Medicine, for assistance in the preparation of this report.
Synonyms of Idiopathic Intracranial Hypertension
benign intracranial hypertension
- pseudotumor cerebri
Subdivisions of Idiopathic Intracranial Hypertension
Intracranial Hypertension (IH) is characterized by increased pressure inside the skull. Intracranial means inside the skull and hypertension means high fluid pressure. Intracranial hypertension means that the pressure of the fluid that surrounds the brain (cerebrospinal fluid or CSF) is too high. Elevated CSF pressure can cause two problems, severe headache and visual loss. If the elevated CSF pressure remains untreated, permanent visual loss or blindness may result.
Pseudotumor cerebri and benign intracranial hypertension are both former names for IH, which are now considered inaccurate. These names do not adequately describe the disorder and downplay the seriousness of IH. There are two categories of IH: primary intracranial hypertension and secondary intracranial hypertension.
Primary intracranial hypertension, now known as idiopathic intracranial hypertension (IIH), occurs without known cause. This form most often occurs in young, overweight, females in their reproductive years (ages 20-45).
Secondary intracranial hypertension has an identifiable, causative agent, including drugs
(such as tetracycline, lithium, Vitamin A-derived oral acne medications or excessive ingestion of Vitamin A, and oral or intrathecal steroids, growth hormone treatments), sleep apnea and certain systemic diseases such as lupus, leukemia, kidney failure (uremia), meningitis and dural venous sinus thrombosis. There is an association of IH and Chiari type I malformation. Many other causes have been suggested in the medical literature but have not yet been confirmed as true causes. It is critical in these patients to rule out an intracranial space occupying mass by neuro-imaging (CT or MRI).
Although many factors are known to trigger the disease, the mechanism by which IH occurs, in either primary or secondary forms, is not known. In many cases, either type of IH may be chronic.
Idiopathic Intracranial Hypertension Resources
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