00:00
Alright, Takayasu's first. So, Takayasu's, as we've discussed, is a large vessel vasculitis
and by being a large vessel vasculitis that means it's affecting things like the aorta and other
major vessels like the brachiocephalic, the carotids, et cetera. 80%-90% of patients with
Takayasu's are women typically between the ages of 10 and 40. Classically, it's associated with
folks of Asian ancestry. On the one hand, our patient does meet the demographics, she is a woman,
she is between the right age, and we aren't explicitly told where she's from so certainly this is
a likely scenario for her. Takayasu's, unlike something like polyarteritis nodosa, can have a
really indolent course over months even years before you start to make a diagnosis. It's
going to present with constitutional symptoms which again can be fairly indolent. You may
have limb claudication or cyanosis which, as you might imagine, would be problems with disease
of the right and left subclavian or lightheadedness due to disease of the carotids. Abdominal
pain, nausea, vomiting, that will be in particular if the abdominal aorta is involved where the
mesenteric vessels are coming off. Hypertension if there is renal artery involvement or arthralgias
which it's hard to make sense of why those occur but they do occur in about 50% of patients.
01:25
On physical exam, you're going to be looking for weak pulses particularly discrepantly weak
pulses, one side worse than the other, likewise having discrepant blood pressures. It's reassuring
that our patient has the same blood pressure on both sides. You might also be looking for an
aortic insufficiency murmur which would suggest involvement of the aortic root and you should
also palpate and auscultate for bruits over the carotids, perhaps over the aorta, the renal
arteries, et cetera. This diagnosis is going to be made by magnetic resonance arteriography of
the arterial tree. I mean you can imagine, biopsy of the aorta very impractical. That being said,
for post-mortem specimens they found that there is infiltration with cytotoxic lymphocyte into
those large vessels; the subclavian, the aorta, the carotid, brachiocephalic. And on imaging,
you're going to see narrowing or occlusion and aneurismal dilatation of these vessels. What we
can see in our image here on the right is significant narrowing with beaded aneurismal dilatation
of the left subclavian. This diagnosis, just like some of the other vasculitides, will be treated
with corticosteroids. Of course if you got a significant large vessel involved that's otherwise
progressing rapidly, you may need to consult your cardiothoracic surgeon and have angioplasty or
bypass. Alright, now let's move on to giant cell arteritis. While a large vessel vasculitis, giant
cell arteritis, that can affect the very same vessels as Takayasu's, most of the symptoms of
giant cell arteritis come from involvement of smaller cranial branches of the internal and external
carotid arteries. Otherwise, it's histopathologically indistinguishable from Takayasu's. It is in
fact the most common systemic vasculitis so when you're thinking about epidemiology this is
the one you're most likely to see over the course of your career. It has a rising incidence after
age 50. So that should already raise some flags for the case that we're talking about now
though there is a 3:1 female predominance. Patients with giant cell arteritis tend to have a
fairly subacute course over weeks to perhaps months and they're going to present with constitutional
symptoms, weakness, malaise, perhaps low grade fevers, headache, jaw claudication, and vision loss.
03:48
Of course the vision loss can be from ischemic optic neuropathy typically due to occlusion of
the posterior ciliary artery. This is a branch of the ophthalmic artery. The posterior ciliary
artery is feeding the optic nerve. So that's the thing that we're most concerned about would
be acute vision loss. It's also important to mention here that many patients with giant cell
arteritis, about 50% in fact, will have associated or concomitant symptoms of polymyalgia rheumatica
and those are folks who have inflammation and pain with shoulder girdle and the hip girdle, one
of the rheumatologic diseases that we associated with this condition. About 10% of folks with
just polymyalgia rheumatica will manifest with giant cell arteritis as well. On physical exam,
you're really going to look for tenderness over the temporal arteries. You're not going to be
able to appreciate tenderness over the ophthalmic artery so that's why you really have to do
the things that are available to us. Along the same lines, the temporal artery biopsy is performed
because that's the only affected artery that's actually accessible. If you were to perform imaging,
you could use an ultrasound which would potentially show luminal narrowing, some intimal
thickening on the ultrasound. Depicted here on the right, you can see significant luminal narrowing.
05:07
You can barely make up the lumen of this temporal artery at all. There is a lot of infiltration of
the inside of that vessel. Here, you can actually see the multinucleated giant cells that earn
the disease its name, shown at the green arrow. And finally, treatment, again you're going to
use corticosteroids just like we would for Takayasu's arteritis. Alright, well, the age issue
clearly takes out giant cell arteritis and our patient doesn't really seem to fit with any of this
large vessel involvement either. So, we can take Takayasu's and giant cell arteritis off of our
list. Alright, let's take a look at cryoglobulinemic vasculitis.