top of page

BackTable / ENT / Article

LPR Diagnosis: Laryngoscopy, Stroboscopy & pH Impedance

Author Taylor Spurgeon-Hess covers LPR Diagnosis: Laryngoscopy, Stroboscopy & pH Impedance on BackTable ENT

Taylor Spurgeon-Hess • Sep 19, 2023 • 32 hits

Laryngopharyngeal reflux (LPR) diagnosis often hinges on the proficient application and interpretation of tools like laryngoscopy, stroboscopy, and pH impedance probe monitoring. The utilization of laryngoscopy, particularly its variants such as distal chip or flexible fiber optic, provides foundational insights. Stroboscopy's significance emerges chiefly in chronic cough cases, though its routine use is debated. On the other hand, pH impedance probe monitoring, despite its invasive nature, offers a comprehensive view of reflux events, separating upper from distal issues. Otolaryngologist, Dr. Inna Husain, shares her expertise regarding the various tools that can aid in LPR diagnosis.

This article features excerpts from the BackTable ENT Podcast. We’ve provided the highlight reel in this article, and you can listen to the full podcast below.

The BackTable ENT Brief

• LPR diagnosis often requires a comprehensive approach, but basic nasal laryngoscopy suffices for many initial LPR evaluations.

• Stroboscopy is particularly useful when LPR patients are presenting with chronic cough and potential glottic insufficiency.

• The presence of mucus on vocal folds or pseudosulcus may not always be definitive of LPR.

• The pH impedance probe is a valuable diagnostic tool, but it is an uncomfortable experience for patients. It offers around 24-hour continuous recording of reflux data and distinguishes between acidic and non-acidic reflux events.

• Ensuring both proper placement in the post-cricoid region and capture of nasopharynx and esophagus activities is key to gaining information on reflux episodes and symptom correlations.

• Temporal delays might blur direct correlations between reflux events and symptoms.

LPR Diagnosis: Laryngoscopy, Stroboscopy & pH Impedance

Table of Contents

(1) The Role of Laryngoscopy & Stroboscopy in LPR Diagnosis

(2) LPR Diagnosis with pH Impedance Probe Monitoring

(3) Interpreting pH Impedance Probe Results in LPR Diagnosis

The Role of Laryngoscopy & Stroboscopy in LPR Diagnosis

The precise role of laryngoscopic examinations in the context of laryngopharyngeal reflux (LPR) is central to its accurate diagnosis and subsequent treatment. Dr. Inna Husain underscores that, despite the merits of stroboscopy, it is not routinely required for initial LPR assessments. In many cases, a basic nasal laryngoscopy, whether distal chip or flexible fiber optic, is adequate. The applicability of stroboscopy becomes particularly pronounced when evaluating patients with chronic cough, especially among older individuals where glottic insufficiency is a concern. However, it's crucial to understand that certain laryngoscopic findings, such as mucus on vocal folds or pseudosulcus, might be responses to other symptoms like chronic throat clearing or coughing, rather than being definitive of LPR. As such, the onus is on a thorough clinical evaluation to distinguish between the symptom and its potential cause.

[Dr. Ashley Agan]
With your scope exam, is stroboscopy ever-- does that ever add anything or really you just need to look down there and make sure you're not seeing anything bad?

[Dr. Inna Husain]
Yes. As a laryngologist I love my stroboscopy, so I'm like a poster child, I have it on my hoodie, that sort of thing, but the reality of this for most patients as initial stroboscopy is not realistic. Like to say that, "Oh, you need to strobe everyone." Let's be a little bit realistic here. No, primarily nasal laryngoscopy distal chip ideally, but even flexible fiber optic is fine for initial diagnosis. I add stroboscopy into my practice when there's things such as, for example, chronic cough and especially if the patient is older, so I'm really looking for that glottic insufficiency.

If the primary complaint is something like hoarseness, then, of course, I want to add s stroboscopy if they're coming to see me, but for a lot of these, for example, globus and stuff as an initial scope, I think realistically just a plain nasal laryngoscopy is good.

[Dr. Ashley Agan]
The findings that we talked about that you listed, they are, would you say pretty non-specific? Like could be caused by other things too or?

[Dr. Inna Husain]
100%, yes. That's the reason why I don't like saying that this scope proves you have LPR, because if your patient's coming in and they're like, "I've been throat clearing for two years." Well, of course, they're going to have mucus on their vocal folds. It's the chicken and the egg, like which one came first, so the act of throat clearing itself will produce mucus. The act of chronically coughing will cause pseudosulcus and irritation at the vocal fold level. A lot of these things can be the result of the symptom itself as opposed to causing the symptom.

[Dr. Ashley Agan]
Yes, that pseudosulcus, sometimes I see it in patients that don't have any [chuckles] complaint of their throat too, and I'm like, "Huh well, that's there, yes."

[Dr. Inna Husain]
Right. We see it in our elderly patients too with the idea being that it's probably somewhat compensatory for some of the [unintelligible 00:23:21] changes that are happening. If you treat every pseudosulcus with the PPI which unfortunately probably does happen in some places, you're doing an injustice to patients.

Listen to the Full Podcast

Laryngopharyngeal Reflux with Dr. Inna Husain on the BackTable ENT Podcast)
Ep 83 Laryngopharyngeal Reflux with Dr. Inna Husain
00:00 / 01:04

Earn CME

BackTable CMEfy button

Stay Up To Date



Sign Up:

LPR Diagnosis with pH Impedance Probe Monitoring

Laryngopharyngeal reflux diagnosis has always been a challenge, and many patients consult numerous general ENTs before seeking an LPR specialist's insights. Dr. Inna Husain underscores the importance of pH impedance probe placement in diagnosing LPR. Though the process of catheter placement is uncomfortable, it remains invaluable in assessing reflux episodes and their correlation to patient symptoms. Positioned strategically in the post-cricoid region, the catheter helps capture a complete picture of the esophagus, enabling clinicians to discern upper from distal issues. Moreover, a collaborative approach with GI colleagues becomes essential when traditional GERD symptoms are suspected or when the focus is on broader upper symptoms like globus.

[Dr. Ashley Agan]
Right now for your patients who are like, "Look, I've been to 10 ENTs, and I've tried all the therapies, and now I'm coming to see you because you're the expert and let's do this pH probe monitoring thing." Let's get into that. What's that conversation go like? What does it entail as far as putting that in? What happens with that?

[Dr. Inna Husain]
Being a laryngologist when I first started in practice, I was like, "I need to be able to offer something different." Because if I'm just offering what everyone else is offering, how is this a sub-specialty kind of visit? I started actually doing my own pH impedance probe placement just to be able to offer that to patients, so that's what we talk about. We say basically, "This is really the only diagnostic tool we currently have. It's not perfect by any means, but it's what we have." Generally, what we do is I actually place the catheter. I have a nurse place [unintelligible 00:41:05] with an NG tube, and then I scope through the other side and just watch the placement of it so I can see that it's being placed with the probes at the post-cricoid region. Yes, it's uncomfortable. I tell patients it's going to feel weird having something in your throat. Most patients do not enjoy the whole experience, but by the time again that they're coming to see me, they're really bothered by these symptoms, they need some more information so we offer it. They usually come back the next day, and then we're able to review the recording and look for episodes of reflux and if it correlates to the symptoms that they're having.

[Dr. Ashley Agan]
Okay. That catheter, that probe when it's placed, is the tip of it just beyond the upper esophageal sphincter or does it go all the way down?

[Dr. Inna Husain]
Yes, so I actually use the GI one. There are some on the market, for example, that just sit in the nasopharynx. For me, I felt if I was going to do it, I want to know what's happening in the esophagus as well. Because if we see a lot of distal issues, I need to get my GI colleagues involved. If we want, we can talk a little bit about how we interact with GI with all of these as well. I decided if I was going to do it, I wanted to do the full probe.

[Dr. Ashley Agan]
Got you, and is there a marker on the probe that let's you know?

[Dr. Inna Husain]
There is.

[Dr. Ashley Agan]
That's how you know the depth, basically?

[Dr. Inna Husain]
Yes, so two ways. When GI does it, they obviously don't scope in the office and so they can use a pressure gauge to mark when they're at the lower sphincter. For ENT scoping is so routine for us that I usually just scope to see where the upper marker is.

[Dr. Ashley Agan]
Okay. Is there any reason to do either esophagoscopy in the OR, or transnasal esophagoscopy in the office? Does that ever give you any additional information that you need?

[Dr. Inna Husain]
Yes. There's definitely patients where that is recommended, and I think a lot of that has to do with the symptoms of it. If any traditional GERD symptoms, any concerning symptoms, for sure, I get my GIs involved incredibly early in this process. Even maybe the first visit based on the symptoms. For some of these very upper symptoms, if it's more globus probably and we're not getting anywhere, we would include an esophagoscopy in that workup. It's tricky when we're talking about things like dysphagia because usually, we end up doing some imaging early on for that as well even if we think it's due to LPR. Definitely work hand in hand with the GI component here.

Interpreting pH Impedance Probe Results in LPR Diagnosis

Interpreting the pH impedance probe's results is an intricate process. Once the catheter is in place, it continuously records data for around 24 hours, offering a deep dive into a patient's reflux events. A highlight of this tool is its ability to differentiate between acidic and non-acidic reflux events, painting a more detailed picture of the reflux scenario. While a direct correlation between reflux events and symptoms might not always be evident due to potential temporal delays, any event type can provide valuable insights. Especially in LPR, where throat symptoms might not mirror those of heartburn, this differentiation and correlation become pivotal. Finally, the treatment approach is tailored based on the information derived, guiding clinicians on whether to opt for acid-suppressing medication or consider alternative treatments like alginate suspension.

[Dr. Ashley Agan]
Let's talk about interpreting those results. You get the catheter, everything in place, and I assume it's hooked up to some sort of monitoring device, so they just clip that on their belt, or their shirt, or something?

[Dr. Inna Husain]
Yes, it's like a little messenger bag purse type of thing that they have that's continuously recording, and then patients have the ability to press buttons based on symptoms. There's a button for-- You can program it for three symptoms that they might be having, so they could press when they have a symptom. Then they can also press a button when they're starting a meal, [unintelligible 00:44:09], that sort of thing.

For about 24 hours, it's continuously recording. Patients come in the next day, the nurse is able to just remove the catheter. Just make sure it's still taped in place and that it didn't shift, and then we take the recording. There's programs that come with it, which will plot out the pH and then timestamp it for symptoms. The program is really helpful because it does all of that plotting for you, and then you can look at how many reflux events the patient have. We have some normative data from GI, which again is primarily based on distal esophageal reflux events that we do have some for the pharynx.

The tricky part about where this gets to not being a perfect test is the idea that like, what if there is no correlation but you see reflux events. For GI, for GERD, they consider that negative if there's no correlation. With ENT or laryngology, we're a little bit softer on that because we do know that there's a neurosensory network. I usually look for any sort of events. The correlation part I'm not as concerned about because if people are having LPR events, yes, an hour later they could have throat clearing. There's a little bit of a temporal delay in throat symptoms as compared to heartburn, so I'm looking really for any type of reflux events. If there's correlation, fantastic, but often, there just isn't that exact correlation.

[Dr. Ashley Agan]
Does it break it up between acidic and non-acidic events?

[Dr. Inna Husain]
It does. That's why I like the pH impedance probe because I tell patients, "Tell me about your lower esophagus and upper." They'll tell me if it's acidic or not, and then it tells me if there's any correlation, so it does provide a lot of information. Again, the alternative would be an empiric trial. It provides a lot more information than us just looking with the scope.

[Dr. Ashley Agan]
Then what do you do with that information? Once you have established that a patient is having reflux events whether acidic or non-acidic, does your treatment look similar to what your empiric treatment was going to look like, or is it different?

[Dr. Inna Husain]
Definitely. If I see a lot of abnormal amount of acid, then I know this patient should be in an acid-suppressing medication. If we see a lot of non-acid reflux, then I usually talk to them about the alginate suspension. For both of these if we're seeing a lot of reflux and it encourages patients, I'm like, "Listen, there's a lot of dysmotility or something happening here contributing to this reflux." By the time that they come for the testing, most of these patients have already tried the diet behavior. They're very strict about it. If you're still having a lot of dysmotility, then we probably need to add further testing in that way with regards to motility testing, need to get our GI colleagues involved, and I even refer some patients for reflux surgery if we see it there.

Podcast Contributors

Dr. Inna Husain discusses Laryngopharyngeal Reflux on the BackTable 83 Podcast

Dr. Inna Husain

Dr. Inna Husain is the medical director of laryngology with the CCNI Network and Community Hospital in Munster, Indiana.

Dr. Ashley Agan discusses Laryngopharyngeal Reflux on the BackTable 83 Podcast

Dr. Ashley Agan

Dr. Ashley Agan is a practicing ENT and assistant professor at UT Southwestern Medical Center in Dallas, TX.

Cite This Podcast

BackTable, LLC (Producer). (2023, January 3). Ep. 83 – Laryngopharyngeal Reflux [Audio podcast]. Retrieved from

Disclaimer: The Materials available on are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.



Laryngopharyngeal Reflux with Dr. Inna Husain on the BackTable ENT Podcast)
RefluxRaft: A New Option Beyond Conventional Therapy with Dr. Spencer Payne on the BackTable ENT Podcast)
Lifestyle Medicine in Otolaryngology with Dr. Jessica Lee on the BackTable ENT Podcast)


The Role of Alginates in the Contemporary Management of Reflux

The Role of Alginates in the Contemporary Management of Reflux

Laryngopharyngeal Reflux (LPR) Treatment

Laryngopharyngeal Reflux (LPR) Treatment

Laryngopharyngeal Reflux (LPR): Symptoms, Subtypes & Patient Presentation

Laryngopharyngeal Reflux (LPR): Symptoms, Subtypes & Patient Presentation


Learn about Laryngology on BackTable ENT

Get in touch!

We want to hear from you. Let us know if you’re interested in partnering with BackTable as a Podcast guest, a sponsor, or as a member of the BackTable Team.

Select which show(s) you would like to subscribe to:

Thanks! Message sent.

bottom of page