Neuroscience · Year 2 · from Neuroscience
Case 3: Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)
Patient Presentation
Demographics: 28-year-old female
Chief Complaint: Daily headaches and "vision going gray" for 3 weeks
History of Present Illness: The patient reports daily throbbing headaches for the past 3 weeks, worse in the morning and when bending over. She has noticed episodes where her vision "grays out" for a few seconds when standing up or straining. She hears a "whooshing" sound in her right ear that pulses with her heartbeat. She has also had intermittent double vision when looking to the side. Her weight is 118 kg (BMI 42). She started a new oral contraceptive 2 months ago. She denies history of similar symptoms.
Physical Examination:
- Vital signs: BP 126/78, HR 72, T 36.9C
- General: Obese female in no acute distress
- Neurological:
- Mental status: Alert, oriented, normal cognition
- Cranial nerves:
- Visual acuity: 20/20 OU
- Visual fields: Enlarged blind spots bilaterally on confrontation
- Fundoscopy: Bilateral papilledema with blurred disc margins, venous engorgement, and loss of spontaneous venous pulsations
- Bilateral sixth nerve palsies with limited abduction
- Other cranial nerves normal
- Motor/Sensory/Reflexes: Normal
- Gait: Normal
Workup:
- MRI brain with MRV: No mass lesion; flattening of posterior sclera bilaterally; partially empty sella; tortuous optic nerve sheaths; patent venous sinuses
- Lumbar puncture: Opening pressure 350 mm H2O (markedly elevated; normal <200); CSF composition completely normal (protein 22, glucose 65, no cells)
- Visual field testing: Enlarged blind spots bilaterally; early peripheral constriction
- Optical coherence tomography (OCT): Increased retinal nerve fiber layer thickness consistent with papilledema
Diagnosis: Idiopathic intracranial hypertension (IIH)
Treatment:
- Acetazolamide 500 mg twice daily, titrated to 1000 mg twice daily
- Discontinuation of oral contraceptive
- Referral to weight management/bariatric surgery consultation
- Serial visual field testing and OCT monitoring
- Therapeutic lumbar puncture performed during diagnostic LP (30 mL removed)
Clinical Course: After 2 weeks of treatment, the patient reported significant headache improvement. At 1-month follow-up, papilledema had improved, and visual fields showed reduced blind spot enlargement. She lost 8 kg with dietary changes. At 6-month follow-up, she had lost 25 kg total, papilledema had resolved, and acetazolamide was being tapered with plan for eventual discontinuation.
Clinical Pearl: IIH classically affects obese women of childbearing age. The transient visual obscurations are concerning and indicate optic nerve compromise from elevated pressure. Untreated, IIH can lead to permanent vision loss from optic nerve damage. The key diagnostic criteria are elevated ICP (>250 mm H2O), normal CSF composition, and no structural cause on imaging. MRI signs include empty sella, flattened posterior globes, and tortuous optic nerves. Weight loss is the most effective long-term treatment.
Clinical Image
Image Description: Axial CT scan demonstrating hydrocephalus with marked dilation of the lateral ventricles. The temporal horns are prominently enlarged, the frontal horns are ballooned, and periventricular hypodensity may be visible representing transependymal CSF flow. The Evans ratio (ratio of maximum width of frontal horns to maximum internal skull diameter) can be calculated to quantify ventriculomegaly.
Attribution: Image from Radiopaedia (https://radiopaedia.org/), Creative Commons Attribution-NonCommercial-ShareAlike 3.0 license.