NeuroOp Guru: Should lumbar puncture be required to diagnose every patient with idiopathic intracranial hypertension?

Andy Lee, MD: Hello, and welcome again to another edition of the NeuroOp Guru. I'm here with my good friend, Elizabeth Fortin. Hi, Elizabeth.

Elizabeth Fortin, MD: Hi.

Lee: And today we're going to be talking about should lumbar puncture be required to diagnose every patient with Idiopathic Intracranial hypertension. So what do you think, Elizabeth, should we do a lumbar puncture?

Fortin: You know, I think the conclusion of this, this article is very interesting. We don't know for sure that we need to do it for every single patient. I think you have to be very, very cautious in patients in whom you decide not to do a lumbar puncture. Ideally, I think you would get in every patient. And the reason is simple, you want to confirm the diagnosis first. So it's a diagnostic criteria to get an opening pressure that's elevated for patients with increased intracranial pressure, ah, and you need to rule out also secondary causes of increased intracranial pressure. So in order to do that, and be 100% sure, you need to have the CSF analysis for your patient.

Lee: I don't think there's any issue on people who are atypical, thin people, elderly patients, men … the issue for me is in a typical demographic, obese young female. And as you can see here, in the comment section, written by Dr. Margolin that no red flag symptoms systemically well and had adequate imaging, does that person need a lumbar puncture?

Fortin: Yeah, that's where it gets tricky. Because I think if that person is evaluated by an experienced neuro ophthalmologist and is going to have follow ups with this practitioner, then it could be safe to just treat the pieces patient as an IE patient and make sure that things evolve the way we expect them to evolve. Now, I'd be very, very trigger happy if there's any change in the situation and vision loss, any symptoms that persist despite treatment to obtain the lumbar puncture afterwards. But it's true that probably some subset of these patients with all the criteria that have been named by Dr. Margolin there, could be potentially treated without the lumbar puncture. But I think we really need to make sure that we, we assess these patients properly, and that we rule out secondary causes. And we can do that in clinic and with radiologic findings most of the time, but you need to make sure you do take a very, very good history, and that patients didn't don't have any atypical symptoms, and also that you look at your MRI very carefully, and you obtain also an MRV, to make sure that you don't have a sinus thrombosis, I think that's one of the main secondary causes that you need to eliminate before calling a patient with otter H.

Lee: So the way this comes to me is when the patient refuses to have the spine, I'd be my number one cause for having no Spinal Tap. Do you tell patients? Look, I can't take care of you if you don't have the Spinal Tap? Or do you let them have no LP?

Fortin: I do let them honestly and I think, you know, I tried to emphasize my point that the ideal scenario is to obtain the LP with explaining the rationale behind it, like we just discussed. But of course, if the patient is very reluctant, especially if they fit the typical demographics and symptoms and MRI findings, then I'll probably make sure that I have a really good follow up and treat them as, as I age patients. What about you?

Lee: I do the same. My second most common scenario is that they tried to do it and they couldn't get it. And then the patient doesn't like it because they were stuck. So many times do you let that person not have a lumbar puncture? Do you force them to have a fluoroscopic LP.

Fortin: I tried to have a copy. But again, I don't force my patients if, if I feel like I'm pretty confident about the diagnosis, although you know, we want to call this probable IH as opposed to definite Ah, but I'm mostly comfortable. Again, if they fit the right demographics and symptoms and MRI findings.

Lee: My third most common scenario is if they're on aspirin, or some sort of anti-platelet or anti-coagulation, and my neurologist won't do it on any of those agents, do you say “look, you got to stop this medicine and have a lumbar puncture?” Do you let that person have no LP?

Fortin: I think you know, it's all the same approach. I think even for that patient. You know, ideally, if you're able to do it safely, depending on the reason why they're on these medicines in the first place. Ideally, you stop the medicine if you have the agreement of their neurologist or other practitioner who prescribe the medicine and you obtain the LP. But again, you have to make sure you're safe and doing that. So I don't do that myself. I want to make sure that the physician who or prescribe the medicine is in agreement. What about you?

Lee: Same. And do you document anything different if they don't have an LP on their chart?

Fortin: I will call them probable IH. I think it's important to keep that level of suspicion that we've never fully made a definite diagnosis and also to keep in mind that if there's anything atypical, you might want to go back to your diagnosis and do some more workup for these patients, or you want to be careful. We've all seen cases of, it's rare, but it does happen of patients with spinal cord tumors or leptomeningeal disease. Now, it is brought up in this in this study, most commonly, these patients will have some sort of atypical features, whether it's their age, the gender, whether it's, you know, symptoms like nausea, vomiting, so you really want to get a good history. But despite all these being negative, we've all been surprised once or twice in our career with a patient that had alternative diagnoses. And I think we have to keep an open mind if things don't evolve the way we think they should.

Lee: So I think should lumbar puncture be required for it? Ah, yes. No. Yes, they're atypical in any way. No, because some people just can't have it or refuse or whatever. And maybe you can get away with it. But with caution, yes. No, maybe. Anything else you want to tell our audience today, Elizabeth?

Fortin: No, I think that sums it up. Very well. And

Lee: That concludes another edition of the NeuroOp Guru. We'll see you guys next week.

Fortin: See you next week.