Idiopathic Intracranial Hypertension (IIH) - The Basics

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AKA Pseudotumor Cerebri

Simply speaking, Idiopathic Intracranial Hypertension (IIH) (sometimes called Pseudotumor Cerebri isn't a headache disorder, but it can cause headaches and trigger Migraines. IIH is a condition in which the body either produces too much cerebrospinal fluid or doesn't absorb it well, resulting in increased cerebrospinal fluid pressure.

Pseudotumor cerebri literally means "false brain tumor." The name pseudotumor cerebri has been used for this condition because its symptoms mimic those of brain tumors. It is officially and more accurately called Idiopathic Intracranial Hypertension (IIH). The term idiopathic is applied because it's cause is not truly known. It is likely due to high pressure caused by the buildup or poor absorption of cerebrospinal fluid in the subarachnoid space surrounding the brain, but the reason for the buildup or poor absorption are also unknown. The disorder is most common in women between the ages of 20 and 50. Being overweight seems to be a a possible contributing factor, but IIH should not be ruled out based only on body weight, age, or gender.

Symptoms of IIH:

  • headache, sometimes daily, sometimes severe, not relieved by medication

  • hearing loss

  • impaired vision or eventual blindness

  • memory problems

  • Migraine attacks with unexplained triggers

  • nausea

  • pain behind the eyes

  • pulsating intracranial noises

  • shoulder and/or neck pain

  • tinnitus

  • vomiting

Diagnosis of IIH:

The only truly definitive diagnostic tests for IIH are a lumbar puncture (LP) (spinal tap) or or by epidural or intraventricular pressure monitoring (CSF pressure monitoring). A lumbar pucture is the easier method, with the cerebrospinal fluid (CSF) pressure measured when the needle is inserted. In some patients, swelling of the optic nerve (papilledema) can be observed in a thorough eye exam. However, it is important to note that the absence of papilledema does not rule out IIH. Not all patients with IIH exhibit papilledema. When the LP is performed, it is also essential that the protein level and cell count of the fluid be tested. The presence of protein or elevated white blood cell count indicate can indicate that inflammation or infection could be causing the elevated CSF pressure. The second, more complicated method of diagnosing IIH is intraventricular pressure monitoring (CSF pressure monitoring).

Secondary Intracranial Hypertension:

While IIH is idiopathic in origin, Secondary Intracranial Hypertension always has a cause. Diagnosis of Secondary IH is the same as IIH, but Secondary IH can be traced back to causes such as other conditions or medications:

  • dural venous sinus thrombosis

  • kidney failure

  • Leukemia

  • Lupus

  • excess Vitamin A

  • growth hormone treatments

  • nasal fluticasone propionate

Treatment:

  • Medications, commonly medications with diuretic actions. (Diamox is a common choice.)

  • Discontinuing medications that can exacerbate the condition. (Includes oral contraceptives and some steroids)

  • Weight loss

  • When medications fail to control the CSF pressure, therapeutic shunting, which involves surgically inserting a draining tube from the spinal fluid space in the lower spine into the abdominal cavity, may be needed to remove excess fluid and relieve pressure.

Prognosis:

Close, repeated ophthalmologic exams are required to monitor any changes in vision. Surgery may be needed to remove pressure on the optic nerve. The disorder may cause progressive, permanent visual loss in some patients.

How does IIH relate to headaches and Migraine and their treatment? IIH can cause headaches and/or trigger Migraines. It can also keep headache and Migraine preventives from working properly.

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Medical review by John Claude Krusz, PhD, MD