Review Question - QID 105021

This patient with morbid obesity and daily headaches with associated nausea and tinnitus likely has idiopathic intracranial hypertension (IIH). If left untreated, patients are at risk of blindness.

Idiopathic intracranial hypertension (previously referred to as pseudotumor cerebri) is a possible cause of headache. While not fully understood, the pathophysiology is thought to be related to overproduction or impaired absorption of cerebrospinal fluid. Classically, affected patients are obese women in the third to fourth decade of life. Other associated risk factors include steroid use, tetracycline use, and vitamin A excess (among other medications). Patients typically present with daily headaches that are often worse in the morning. Headaches are frequently accompanied by nausea and a "pulsatile" tinnitus. Evaluation of suspected IIH should begin with MRI of the brain to exclude mass occupying lesions. It could be reasonable to perform an MR venogram in some patients to exclude dural venous sinus thrombosis. Lumbar puncture will often demonstrate an opening pressure > 250 cm H2O. Conservative management consists of weight loss. Acetazolamide (a carbonic anhydrase inhibitor) decreases the production of cerebrospinal fluid and is often utilized in the management of IIH. Untreated IIH may result in vision loss due to prolonged pressure on the optic nerves. For those patients refractory to typical management, optic nerve sheath fenestration may be performed to decrease the risk of visual loss.

Raoof et. al review the diagnosis and management of idiopathic intracranial hypertension. They discuss the risk of vision loss and recommend options for management.

Incorrect Answers
Answer 2: Dementia is associated with normal pressure hydrocephalus which presents with whacky (confusion), wet (urinary incontinence), and wobbly (gait instability).

Answer 3: Pontine demyelination is associated with rapid correction of hyponatremia due to osmotic fluid shifts. It presents with the locked in syndrome.

Answer 4: Urinary incontinence is associated with normal pressure hydrocephalus but not commonly with IIH.

Answer 5: Stroke may result in the development of elevated intracranial pressure due to bleeding or obstruction of cerebrospinal fluid flow. However, untreated IIH is not associated with an increased risk of stroke.

Bullet Summary:
Idiopathic intracranial hypertension presents with daily headaches (most commonly in obese patients) and increases the risk for the development of blindness if untreated.