Better to be lucky than good

[Docxter]

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Or, in other words, you might see it on CT (like we did), but the "gold standard" (if there is one) is MRI.

That is correct. In my very limited experience from a dozen or so cases of RPL that I have seen, CT was abnormal only in about 1/4th of them. I don't know the exact sensitivity of CT for PRES.

 

[ERMudPhud]

Doxter is increased OP a sign of PRL? I don't seem to remember it being so.

I assumed that with the cerebral edema you could get but may not have to have some intracranial hypertension.

I'm still curious to hear Docxter or Voxels thoughts on the radiographic findings.

I also still wonder if this isn't within the spectrum of eclampsia since it seems to have some similarities. If I had had even a trace of proteinuria might I have given her Mg and thus prevented the subsequent seizure?

 

[Apollyon]

I assumed that with the cerebral edema you could get but may not have to have some intracranial hypertension.

I'm still curious to hear Docxter or Voxels thoughts on the radiographic findings.

I also still wonder if this isn't within the spectrum of eclampsia since it seems to have some similarities. If I had had even a trace of proteinuria might I have given her Mg and thus prevented the subsequent seizure?

The case we had last week was a diabetic 36 y/o female, who is an ESRD/dialysis patient. She was nowhere near recently postpartum (I don't even know if she is nulliparous); she wasn't even my patient, and only came to my attention when she had a t/c seizure. She had presented with acute, new-onset blindness. She had already had her head scanned, and was just about to go upstairs, admitted to neuro. The neuro senior was still in the ED, and he told us about PRES, and he had a few articles with him (probably the ones you quoted above). We must have had some good luck, because her CT findings were so obvious, the intern (with 3 weeks of EM training) picked it out right away. Then, the case was presented in radiology rounds, and the rads resident was all over it.

 

[Old MD]

ERMudPhud:

Excellent post! Yeah, those are the papers. #2 is the one I was talking about that was very good ? if anyone is going to read just one paper on PRL I think that should probably be it. Regarding your thoughts about the possible connectedness of the syndromes and stuff, that?s the PhD part of your brain showing I can?t say much most of this stuff is over my head anyway, i just try and remember important ddx lol..

 

[Voxel]

Sorry, things have been really busy lately. I should have added PRES and Postpartum Cerebral Angiopathy into the differential diagnosis. Nice call Docxter.

I am curious to note the the MRI findings state that it involved the cortex and no mention was made of the white matter. I haven't seen a case of this yet, but I thought it was very common to get get white matter involvment PRL/PRES.

Reversible posterior leukoencephalopathy is thought to be a hypertensive encephalopathy, possibly by decreased autonomic innervation of brain arteries.

It is seen following immunosuppressive treatment with cyclosporine A, FK-501, tacrolimus, and cisplatin. It is also seen following acute rise in bp, preeclampsia, eclampsia.

Location is usually the posterior cerebral white matter, but can be found in other places.

Radiology findings include:

non-con CT: hypodense white matter.
MRI: T1 weighted hypointense, T2 weighted hyperintense.
Lesion can be isointense on DWI (?due to net effect of elevated diffusion coefficient from vasogenic edema and T2-shine through).
I believe it is contrast enhancing. (?) <-edited.

 

[Docxter]

I assumed that with the cerebral edema you could get but may not have to have some intracranial hypertension.

I'm still curious to hear Docxter or Voxels thoughts on the radiographic findings.

I also still wonder if this isn't within the spectrum of eclampsia since it seems to have some similarities. If I had had even a trace of proteinuria might I have given her Mg and thus prevented the subsequent seizure?

CSF fluid dynamics are pretty complex. Focal cerebral edema may or may not cause increased LP pressures. As a matter of fact, this is exactly the reason behine the different types of brain or cord herniation, i.e the presence of pressure gradients. If there is no pressure gradient, there will be no movement or herniation.

As for the MRI report for your patient, was this the exact report or did you summarized it for sakes of posting? The reason I'm asking is because there some atypical things about it. The report states that the areas of FLAIR abnormality and also (?) areas of restricted diffusion on the DWI and ADC were limited to the posterior frontal cortex and posterior parietal/occiptal cortex. If by cortex, they mean the gray matter is exclusively involved without any white matter abnormality, then this is pretty atypical for PRES. The presence of restricted diffusion in the gray matter only in what probably sounds to be a borderzone (watershed) distribution, suggests laminar necrosis, which could be to due focal hemodynamic changes, which in turn can be the result of cerebral angiopathy.

 

[roja]

Excellent posts!

 

[Mollaret]

...If by cortex, they mean the gray matter is exclusively involved without any white matter abnormality, then this is pretty atypical for PRES...

RPLS is a frequently encountered clinical and radiologic entity. Despite the "leuko" component this condition may involve the cortex in additon to the white matter. For RPLS to only involve the cortex would draw into question the diagnosis. However, involvement of the cortex is not in itself that unusual. I have seen this occur in both patients with immunosuppressant associated RPLS, as well as with the hypertensive form.

Perhaps, it is more atypical that this patient did not appear encephalopathic as is more commonly seen. The etiology for this patient's presentation may be related to her hypertension. BP 160/110 is a profound elevation in a patient 7 days post-partum. We usually see hypertensive associated RPLS in adult non-pregnant patients with SBP >220. This BP elevation in a 7 days post-partum patient would be similarly high. Rarely would a post-partum patient with essentially clinically isolated HA present with an MRI which suggests RPLS. Severe cerebral vasoconstriction in the distal vascular bed is the pathophysiologic correlate. Local, but reversible small vessel ischemia may be postulated to occur.

Laminar necrosis occurs in the context of a separate clinical entity and would be doubtful in this case. I do not believe that is what the radiologist was describing.

Interesting case. We also see alot of RPLS at my institution.

 

[Docxter]

I'll let Docxter post the PM he sent me which helped define the difference between Postpartum Cerebral Angiopathy and PRES for me.

Ok, here's the message I had sent you:

RPL or the newer name, PRES, refers to a distinct clinico-radiological syndrome which has many many causes. It was initially thought to be only seen in eclampsia-preeclampsia or malignant/accelerated hypertension, but a lot of causes have been described, including various drugs and chemotherapy regimens, lupus, AND postpartum angiopathy/vasculitis, etc. There are some caveats, however. Postpartum angiopathy often presents with a PRES picture, but it may not, hence the confusion that sometimes arises. It may just present with infarcts and/or intracerebral hemorrhage. The cerebral angiogram can be negative in a low but significant percentage and some cases are only diagnosed by brain biopsy. Some believe that PRES is by definition, reversible, but a postpartum angiopathy patient presenting with a PRES clinico-radiologic syndrome may sustain irreversible damage.

The other caveat is that PRES (or RPL) is not necessarily limited to the posterior brain, i.e. occipitoparietal, and often involves other areas of the brain such as the temporal and frontal lobes, pons, and cerebellum and is not limited to white matter. Hence, another source for confusion.

Actually, I have seen only one case of postpartum angiopathy, (in contrast to dozens of other cases of PRES) and the patient bled while I was doing her arteriogram, which needed to be evacuated neurosurgically after she almost coded and I had to intubate her in the CT scanner.

As for your patient, without having seen her MRI or knowing the results of the angiogram, I think she has presented with a PRES syndrome which may or may not be due to postpartum cerebral angiopathy. If she doesn't have or doesn't develop infarcts and if the angio is negative and if the MRI and clinical changes resolve over the next few hours/days (patients get better faster clinically than their MRI changes get back to normal), then she just has a PRES without postpartum angiopathy. If she has a positive angio (which will only be suggestive of postpartum angiopathy because the smae angio picture can be seen in lupus, primary CNS vasculitis, etc.) or develops infarcts, then she has probably presented with a PRES-like picture due to cerebral angiopathy.

Another thing. You said edema was seen on MRI. Was it vasogenic edema or cytotoxic edema on the MR? This is a critical question. Pure PRES causes vasogenic edema only. Only if you have an almost irreversible damage, such as that caused by an infarct, e.g. secondary to vasculopathy, will you see cytotoxic edema.

 

[Seaglass]

Thanks to this thread I will remember PRES for the rest of my life.

 

[ERMudPhud]

The MRI report was slightly edited but I don't think I took out anything that would have changed the description. In no case did they make grey/white matter distinctions. They did not specifically say that the cortex was exclusively involved but tended to use language like, "primarily involving the posterior frontal cortex" and things like that. For whatever reason the rads general impression was that this fit better with PPCA than with PRES but I can't say for sure why. Sorry I can't post the primary images. You have to also realize that early Saturday morning at the community hospital you get whoever from the RADs group got stuck with that call. I love my radiologists, they do a great job, and I couldn't live without them but at that hour you might have the U/S guru reading your brain MRI and not the neurorads guru.

P.S. Where do you want your stuffed zebra sent 😀

 

[MustafaMond]

Radiology findings include:

non-con CT: hypodense white matter.
MRI: T1 weighted hypointense, T2 weighted hyperintense.
Lesion can be isointense on DWI (?due to net effect of elevated diffusion coefficient from vasogenic edema and T2-shine through).
I not believe it is contrast enhancing.

Great post, voxel.

http://www.ijri.org/articles/archives/2002-12-3/neuroradiology_321.htm

 

[anonymousEM]

great case! So, how did you treat her? Anything those of us who don't have access to MR without an Act of Congress should be looking for?

 

[mrmed]

You mentioned siezures...does she have any cafe au lait spots?

 

[neurodoc]

I'd say the most likely diagnosis is post "LP" headache.

 

[ERMudPhud]

I'd say the most likely diagnosis is post "LP" headache.

With T/C seizures and the previously mentioned MRI changes?

great case! So, how did you treat her? Anything those of us who don't have access to MR without an Act of Congress should be looking for?

With the radiologist saying she thought postpartum cerebral angiopathy was more likely than PRES we spent some time talking to various neurologists around town. We only found one who had seen a case before and none of the OB's we talked to recalled seeing a case. Then the neurologists, the intensivist, and the ED docs all spent a while on Pubmed and Up-to-Date reading what we could. It seemed like all we found was case reports. A few were treated with steroids (probably because the angiogram resembles CNS vasculitis) and got better. A few were treated with CCB's and got better. Most got no treatment and got better. A few stroked, or bled, or died. Our neurologist chose watchful waiting (or benign neglect depending on your point of view) We didn't give Mg since we couldn't really show evidence of eclampsia and the literature didn't support a connection. We didn't lower her BP since it came down to <130/80 with pain meds. She spent a few days in the hospital until her headache was gone and didn't bleed or stroke. She never got an angiogram. She still has an abnormal eeg but will is symptom free and will f/u with neuro this week.

I trained at a place that took an act of god to get an MRI (we had to transport to another hospital) but I think it is important to know the indications for one and how to sell it to the radiologist. Make sure you've done everything else that needs to be done and be able to tell them clearly what you are looking for and why you are worried about it. Site literature if you have to. Now I can order an MRI anytime I want but I still discuss it with the radiologist. They can give you a lot of insite into what is appropriate and what isn't plus they can give better directions to the tech if they know what they are looking for. As I said before I still have about >80% of my MRI's with significant emergent pathology. My CT rate isn't even close to that good

P.S. I relooked at the rads report. Although she never denies involvement of any white matter. Three times she says lesions primarily involve the cortex so I think that may be why PPCA was first on the rads differential and PRES was second.


😉

 

[Sessamoid]

With T/C seizures and the previously mentioned MRI changes?

I think that was a joke, dude.

 

[Apollyon]

Bump for a GREAT thread. A new generation of EM docs needs to know about this. I, for one, will never forget the case I saw.

 

[Doctor Bob]

Bump for a GREAT thread.

Hehe.... interesting how timely things can be. I'm on my neuro month right now and we have a lady on our service now with PRES. Her causal agent seems to be the prograf she's taking for her recent kidney transplant.