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?

[accordion clicktoclose=true tag=p]

[accordion-item title=”Describe your headache. (click to show/hide)”]

It’s kind of all over. It’s worst in the morning when I wake up and gets better over the course of the day. I’m almost afraid to go to sleep because I know I’ll wake up with the headache.

[/accordion-item]

[accordion-item title=”What do you mean by decreased vision? (click to show/hide)”]

Well, I notice that I walk into things at my side a bit more. Like, I hit my shoulder on the door jamb this morning. Also my vision is really blurry when I wake up.

[/accordion-item]

[accordion-item title=”Have you noticed any other symptoms? (click to show/hide)”]

I have been fairly nauseous recently, but I haven’t vomited…yet.

[/accordion-item]

[accordion-item title=”Has this ever happened to you before? (click to show/hide)”]

No. This is all new, and frankly a little concerning.

[/accordion-item]

[accordion-item title=”What medications are you currently taking? (click to show/hide)”]

Oh, I take Acutane for my acne, and I’m on the pill.

[/accordion-item]

[/accordion]

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.

[accordion clicktoclose=true tag=p]

[accordion-item title=”Pseudotumor cerebri (idiopathic intracranial hypertension) (click to show/hide)”]

Correct: Pseudotumor cerebri is the most likely diagnosis in this patient as she is obese, on numerous drugs that could cause pseudotumor, and has papilledema and visual disturbance.

[/accordion-item]

[accordion-item title=”Migraine headaches (click to show/hide)”]

Incorrect: Migraine headaches are usually accompanied by an aura which may cause some similar visual disturbances. However, the pattern of these headaches which are worse when lying down is more typical for increased ICP.

[/accordion-item]

[accordion-item title=”Intracranial space occupying lesion (click to show/hide)”]

Correct: The pattern of headaches suggests elevated ICP. While pseudotumor is the most likely diagnosis, it is important to rule out life threatening cases of elevated ICP such as intracranial space occupying lesions.

[/accordion-item]

[accordion-item title=”Encephalitis (click to show/hide)”]

Correct: Encephalitis is a possible cause of her headache and visual disturbance. However, we would expect to see a fever and maybe some delirium in encephalitis.

[/accordion-item]

[accordion-item title=”Tension headaches (click to show/hide)”]

Incorrect: Tension headaches usually have a band-like distribution and come on in the evenings, not in the mornings. Also the pattern of headache suggest raised ICP, which is not present in tension headaches.

[/accordion-item]

[accordion-item title=”Meningitis (click to show/hide)”]

Correct: Meningitis could cause an elevated ICP and altered sensorium including visual changes. As with encephalitis, you would expect a fever. LP will help distinguish between causes.

[/accordion-item]

[accordion-item title=”Hydrocephalus (click to show/hide)”]

Correct: This patient displays signs of increased intracranial pressure. Hydrocephalus could cause these symptoms, but is not expected in this patient with her unremarkable medical and surgical history, and her normal neurological exam.

[/accordion-item]

[accordion-item title=”Central retinal vein occlusion (click to show/hide)”]

Incorrect: Central retinal vein occlusion can present with sudden painless loss of vision and papilledema. However it does not usually cause headache. Fundoscopy would have shown the classic ‘blood and thunder’ appearance.

[/accordion-item]

[/accordion]

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?

[accordion clicktoclose=true tag=p]

[accordion-item title=”Non-contrast CT of brain (click to show/hide)”]

Incorrect: A non-contrast CT of the brain is most useful when looking for hemorrhage. It is not very useful for distinguishing between these differential diagnoses.

[/accordion-item]

[accordion-item title=”Plain MRI of brain (click to show/hide)”]

Incorrect: While a plain MRI would rule out many of these conditions, it would not rule out dural sinus thrombosis. A MRV is required.

[/accordion-item]

[accordion-item title=”MRI/MRV of brain (click to show/hide)”]

Correct: MRI/MRV is the diagnostic test of choice to rule out all the conditions on this differential list.

[/accordion-item]

[accordion-item title=”LP (click to show/hide)”]

Incorrect: LP would provide a great deal of information such as opening pressure and rule out infectious etiology, but is not recommended until brain imaging reveals no evidence of herniation.

[/accordion-item]

[/accordion]

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.