CBL: Pseudotumor Cerebri (Idiopathic Intracranial Hypertension)

Learning Objectives

• Distinguish symptoms of pseudotumor cerebri (IIH) from migraine and tension headache.
• Recognize that elevated CSF opening pressure is required for diagnosis.
• Review treatment strategies including acetazolamide and CSF shunting procedures.

Vignette

VP is a 22-year-old woman with two ER visits for a progressive, diffuse aching headache affecting both sides of the head. She is not photophobic but reports blurred vision; optometrist lens adjustments were unhelpful. Appetite is decreased without nausea/vomiting. Onset was gradual with no trauma. Positional change does not affect symptoms; OTC analgesics were ineffective.

Medications: Combined estrogen/progesterone for menstrual regulation; otherwise none. Allergies: None. PMH: None. FH: Maternal aunt with migraine. SH: Nonsmoker; preschool care provider; ~2 glasses of wine/week. ROS: No fever, dysphagia, hearing change, chest pain, cough, arthralgia, bleeding/rash, mood or menstrual changes; vision blurred, no diplopia.

Examination

BP 133/82, HR 80, T 98.5°F; BMI 30. Uncomfortable but alert with good eye contact. Heart sounds normal. Pupils equal/reactive; fundi with bilateral blurred optic discs consistent with papilledema; retinas otherwise normal. Cognition and language intact. EOMI without diplopia/nystagmus. Facial sensation and hearing normal. Facial expression, palate, SCM, and tongue movements normal. Normal strength, reflexes, plantar responses downgoing. Sensation intact; coordination normal; gait slow but steady.

Diffuse headache + blurred vision + papilledema with otherwise nonfocal exam raises concern for intracranial hypertension and supports suspected pseudotumor cerebri.

Localization & Neuroanatomy

Pseudotumor cerebri (IIH) reflects elevated intracranial pressure in the absence of mass lesion, hemorrhage, or infection. Historically, raised pressure suggested a space-occupying process; modern CT/MRI exclude these causes, leaving intracranial hypertension as a diagnosis of exclusion when clinical features and CSF pressure support it.

Diagnosis

Diagnostic criteria include compatible history/exam (e.g., papilledema), normal brain imaging (CT/MRI) without secondary cause, and elevated CSF opening pressure on lumbar puncture. Imaging is commonly obtained prior to LP in practice. Symptomatic relief may follow LP due to transient CSF removal, but the effect is short-lived and repeated LPs are not recommended as therapy.

Treatment

Medical therapy with acetazolamide or furosemide can reduce CSF pressure via alterations in fluid balance and CSF dynamics. In vision-threatening or refractory cases, surgical options include optic nerve sheath fenestration and ventriculoperitoneal (VP) shunting to divert CSF.

Teaching Points

• Headache phenotype differs from migraine/tension and often accompanies visual complaints.
• Papilledema plus elevated CSF opening pressure with normal imaging supports the diagnosis.
• LP may provide transient symptom relief but is not maintenance therapy.
• First-line therapy is acetazolamide; surgery (fenestration or VP shunt) is reserved for refractory or vision-threatening disease.

References

1. Module adapted from provided teaching text on pseudotumor cerebri (idiopathic intracranial hypertension), highlighting diagnostic criteria and treatment options.