Interactive Transcript
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This is the type of case where even the
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scalp view is actually pretty helpful.
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We see that this is a relatively large
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individual with a lot of subcutaneous tissue.
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So this is the substrate for which we would expect
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to see a patient who has idiopathic intracranial
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hypertension, usually high body mass index.
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Here is the CT scan with contrast in this individual
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who was complaining of headaches and visual blurring.
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And the finding that is most evident here is the
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empty sella, large empty sella with CSF density
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on the contrast-enhanced CT scan.
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You look at the optic nerve sheath complexes.
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They are not dramatically enlarged.
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I would probably pass them.
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And we're not seeing papilledema.
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We also do not see any other lesions in the brain.
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We would look at Meckel's cave region.
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A little bit plump here on the left side.
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Not traumatic.
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A little bit of remodeling of the bone,
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not traumatic.
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This patient was sent for MR venography for the
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potential for idiopathic intracranial hypertension.
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And so, you may see quite a bit of patients like
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this where CT venograms are being performed.
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Remember, with CT venogram, you do have to alter the
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timing of the bolus and the CT scanning after the bolus
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to adjust for a venographic
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image, not an angiographic image.
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So, the clinician might write,
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IIH, Pseudotumor Cerebri, CTA.
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You have to notify the technologist or
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make sure the technologist is aware that
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the issue here is not the arterial phase,
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but in doing it in the venous phase,
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so we can look for venous sinus stenosis.
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So let's look at the venogram that was performed.
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In this case, I'm going to be
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showing you the reconstructed images.
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So here we have the right transverse sinus, here
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we have the left transverse sinus, and off the
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bat, some of you would look at the left transverse
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sinus and say, wow, that's pretty narrow.
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And that could be the issue in this patient.
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Actually, the abnormal sinus is the right side.
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This left side is narrow throughout its course
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and doesn't show any evidence of a focal stenosis.
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Therefore, this left side is actually just the normal
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hypoplastic left transverse sinus that I talked about
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as being a normal variant from right-to-left asymmetry.
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If we look on the right side, however, we see that there
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is a focal area where there is narrowing of the sinus.
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Here's a relatively normal-sized sinus, and then we
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lose the sinus right through this portion right here.
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And that is the area of sinus stenosis,
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which may be implicated in pseudotumor cerebri.
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In these patients, often, uh, they will be treated
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medically first, either symptomatically for their
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headache, or they will be given, uh, Diamox as
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one of the, uh, one of the drugs that is utilized for
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pseudotumor cerebri to decrease the CSF pressure.
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Um, if that resolves the problem, they're done.
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However, if they are medically resistant,
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then there are two surgical or two
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interventional procedures that may be done.
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Number one is doing a stenting of
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that area of venous sinus stenosis
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interventionally with endovascular treatment.
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The second is, if that is not successful, or they
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don't see a gradient, but the patient is still
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potentially losing vision, they can do optic
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nerve sheath fenestration because the pressure
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that's being placed on the optic nerve is
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transmitted from the intracranial compartment.
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If you open the optic nerve sheath up,
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then that pressure is not transmitted to the optic
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nerve, and you don't get pressure ischemic optic
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neuropathy, which is thought to be the source of
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the visual loss associated with pseudotumor cerebri.
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