Case 14Idiopathic Intracranial Hypertension
Clinical Presentation
A 20-year-old obese woman has experienced severe headaches for several weeks, but has no ocular symptoms. The photograph depicts the fundus appearance in both eyes.
Learner Questions
- Describe the ophthalmoscopic findings.
- What is your plan for further diagnostic evaluation?
- What is the differential diagnosis?
Answer Framework
Findings
Bilateral PAPILLEDEMA: disc elevation with 360 degrees blurred margins, obscuration of disc surface vessels, peripapillary flame hemorrhages, Paton's lines (concentric retinal folds from CSF displacement), +/- cotton-wool spots. Macula and peripheral retina normal. Papilledema = disc swelling specifically from elevated ICP (not other causes of disc edema).
Diagnostic plan
Step 1: MRI brain + MRV (rule out mass lesion and venous sinus thrombosis - BEFORE LP). IIH MRI findings: empty sella, posterior globe flattening, optic nerve sheath distension, transverse sinus stenosis. Step 2: LP (lateral decubitus) - opening pressure >25 cmH₂O + NORMAL CSF analysis (cells, protein, glucose) = required. Step 3: labs - thyroid function, medication review (tetracyclines, isotretinoin, OCP, steroid withdrawal).
DDx for bilateral papilledema
IIH (diagnosis of exclusion): Intracranial mass (tumor/abscess/hematoma - CT/MRI required), Cerebral venous sinus thrombosis (OCP, hypercoagulable - MRV; can perfectly mimic IIH), Hypertensive emergency (check BP immediately!), Meningitis/encephalitis (fever, meningismus, CSF pleocytosis), Hydrocephalus (enlarged ventricles on CT/MRI).
Teaching Pearl
IIH classic: young obese woman + bilateral papilledema + LP opening pressure >25 cmH₂O + normal MRI + NORMAL CSF. Associated medications: tetracyclines (doxycycline!), isotretinoin, OCP, steroid withdrawal. Treatment: weight loss (most effective long-term), acetazolamide (IIHTT trial), ONSF or CSF shunt if vision threatened. Monitor visual fields - permanent loss in ~10% if undertreated.
Original answer transcript
Findings
Bilateral PAPILLEDEMA: disc elevation with 360 degrees blurred margins, obscuration of disc surface vessels, peripapillary flame hemorrhages, Paton's lines (concentric retinal folds from CSF displacement),
+/- cotton-wool spots. Macula and peripheral retina normal. Papilledema = disc swelling specifically from elevated ICP (not other causes of disc edema).
Diagnostic plan
Step 1: MRI brain + MRV (rule out mass lesion and venous sinus thrombosis - BEFORE LP). IIH MRI findings: empty sella, posterior globe flattening, optic nerve sheath distension, transverse sinus
stenosis. Step 2: LP (lateral decubitus) - opening pressure >25 cmH₂O + NORMAL CSF analysis (cells, protein, glucose) = required. Step 3: labs - thyroid function, medication review (tetracyclines,
isotretinoin, OCP, steroid withdrawal).
DDx for bilateral papilledema
IIH (diagnosis of exclusion): Intracranial mass (tumor/abscess/hematoma - CT/MRI required), Cerebral venous sinus thrombosis (OCP, hypercoagulable - MRV; can perfectly mimic IIH),
Hypertensive emergency (check BP immediately!), Meningitis/encephalitis (fever, meningismus, CSF pleocytosis), Hydrocephalus (enlarged ventricles on CT/MRI).
TEACHING PEARL
IIH classic: young obese woman + bilateral papilledema + LP opening pressure >25 cmH₂O + normal MRI + NORMAL CSF. Associated medications: tetracyclines
(doxycycline!), isotretinoin, OCP, steroid withdrawal. Treatment: weight loss (most effective long-term), acetazolamide (IIHTT trial), ONSF or CSF shunt if vision
threatened. Monitor visual fields - permanent loss in ~10% if undertreated.