Case 6

A 27-year-old with a headache

Q1

A 27 yo obese female presents with a 2 week history of HA, and resent onset of decreased vision.

What additional history do you want to obtain?

Q2

On examination, you find an obese young woman with no focal neurological deficits. Her confrontational visual fields are intact. Visual acuity is 20/20 OU, extraocular muscles are intact, tonometry 12 OD, 10 OS. Fundoscopy reveals papilledema.

What is your differential diagnosis? Pick your top five choices.

Q3

Your differential diagnosis for this patient is pseudotumor cerebri, intracranial space occupying lesion, encephalitis, meningitis, hydrocephalus, and dural sinus thrombosis.

What is the next appropriate step in the workup of this patient?

Summary

Pseudotumor cerebri (now known as idiopathic intracranial HTN) is an unexplained increased intracerebral pressure. It occurs most commonly in obese young women, and is associated with the use of several medications including glucocorticoids, Vitamin A derivatives (including Acutane), tetracycline, doxycycline, monocycline, the OCP, lithium, isoniazid, and azathioprine.

The most common presenting symptoms include headache in 92% of patients and visual disturbances, which may include transient visual obscurations, photopsias, and diplopia which is most commonly due to CN VI involvement. Visual loss is a late complication of prolonged or extremely high elevation of ICP, and may be permanent depending on the duration of elevated IPC. Visual acuity is usually preserved until late in the disease course, so a visual field deficit is the most sensitive test for visual loss.

It is always important to rule out other more serious causes of increased ICP including intracranial tumor, hemorrhage, hydrocephalus, encephalitis, meningitis, and cerebral venous sinus thrombosis (in patients with thrombophilia). MRI/MRV is diagnostic modality of choice. A diagnostic LP would show elevated opening pressure often >200 mm HT. CSF should be normal in analysis for cells/organisms.

Treatment is aimed at lowering the ICP. Commonly used drugs are acetazolamide and loop diuretics, and of course discontinue any offending meds. Weight loss often helps and pseudotumor cerebri may be an indication for medically managed weight loss including gastric bypass. If the patient is not getting better, consider serial LPs, or surgical procedures such as CSF shunting or optic nerve fenestration.