Diagnostic Test for Laryngeal Sensory Neuropathy (Chronic Cough)?

Patients who suffer from a persistent chronic cough undergo a tremendous amount of testing, trials of medications, and seeing numerous specialists to try and make the cough go away. Ultimately, the cough may be found due to a rare condition called laryngeal sensory neuropathy which is treated with anti-depressant and even seizure medications. This nerve also may contribute to swallowing problems as well.

Because laryngeal sensory neuropathy is a diagnosis of exclusion, an extensive workup is required to rule out all other causes of cough including tests for reflux, reactive airway disease, allergy, etc. Given the time-consuming nature of evaluating a chronic cough, very smart researchers have been trying to develop a test that checks for laryngeal sensory neuropathy (LSN).

One such test called SELSAP (Surface Evoked Laryngeal Sensory Action Potential) is a non-invasive, surface evoked, sensory nerve function testing of the superior laryngeal nerve. Why the superior laryngeal nerve? It's because that's the nerve that is responsible for causing the sensation/urge to cough in affected patients. It's also the primary nerve that suffers from the neuropathy. [see references below]

The test basically involves placing an electrode to the side of the voicebox and another under the chin. A mild electric stimulus is than performed behind the ear.

Because this test is so new, it is unproven and unclear whether this test will ultimately provide valuable assistance in the evaluation of a patient suffering from chronic cough. Normative values have yet to be rigorously determined.

BUT... it is something that can be considered especially if the history is consistent with LSN and the SELSAP is "clearly" abnormal (HYPERfunctional). In such cases, appropriate treatment can be immediately started without going through the entire chronic cough workup first.

Of course, even though LSN treatment is started, it still behooves to still do the workup to ensure a person does not have more than one cause for persistent cough that would still need to be addressed for true cough resolution. Read more about LSN treatment failures here.

When it comes to swallowing difficulties, if SELSAP does come back abnormal (HYPOfunctional), it may suggest that there is "numbness" of the voicebox region preventing a proper swallow as the body does not "know" where the food is when it passes by leading to aspiration.

Be aware that not all places will offer such testing. Contacting a good neurologist is really one's best bet to see if they are willing to learn and perform SELSAP.

However, Dr. Kristin Williams in Warrenton, VA does perform this test.
Office Phone: 540-316-5980
384 Hospital Drive
Warrenton, VA 20186


References:
Surface-Evoked Laryngeal Sensory Action Potential Evaluation in Neurogenic Chronic Cough. Journal of Voicw, May 28, 2014.

A new noninvasive method for determination of laryngeal sensory function. Laryngoscope. 2011 Jan;121(1):158-63. doi: 10.1002/lary.21182.

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30% of Patients with Reflux will NOT Respond to Medications

Specifically, patients who are suffering with throat symptoms of reflux will often not respond to proton-pump inhibitor (PPI) medications. Such throat symptoms include throat-clearing, phlegmy throat, cough, hoarseness, and globus. Known as LPR (laryngopharyngeal reflux), a study was done measuring the pH at the throat level after 4+ weeks of twice daily PPI.

This retrospective study found that although 67.4% had symptom normalization, 32.6% of patients showed no subjective or objective treatment response. For all patients whose symptoms did not normalize, pH scores also did not normalize.  For individuals whose symptoms normalized but whose pH scores did not normalize, there was a significant decrease in upright pH score.

Based on these findings, one should NOT assume that lack of response to reflux medications indicative of reflux being an incorrect diagnosis. Further study with a pH or impedance monitoring should be performed in non-responders to help figure out what is going on.

Reference:
Effects of Proton Pump Inhibitor Therapy for Laryngopharyngeal Reflux on Posttreatment Symptoms and Hypopharyngeal pH. Otolaryngol Head Neck Surg. 2014 Mar 19. [Epub ahead of print]

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How to Describe Hoarseness?

At heart, physicians are science geeks. And when it comes to a raspy voice, one can go truly bananas in how exactly to describe how a raspy voice sounds.

For the layperson, when asked to describe a hoarse voice, one often gets imprecise answers to a question most feel ridiculous... I often get a blank look with an answer that goes something like "You know... raspy... it's not clear." Unfortunately, such a description is inadequate. Even when using more descriptors like deeper/higher than normal, onset delays, pitch breaks, breathy, click, tight, etc, more information is needed.

There are 2 fundamental ways to more precisely convey the characteristics of how a raspy voice sounds and to document change (better/worse) over time.

Method #1 - Perceptual Tests

Developed by Dr. Robert Bastian, I personal prefer this method as it is more intuitive and replicable by anybody including the patient.

1) Maximum Phonation Time (MPT) - How many seconds can a single note be sustained for with a single breath? This test provides a rough measure of lung capacity and how "breathy" a voice is. The more breathy a voice is, the lower the MPT.
2) Pitch Range - What is the lowest and highest note a person can say/sing (I use a piano keyboard). Provides information on how much vocal cord swelling and length is present (the more swollen the vocal cords are, the deeper the pitch just like a violin string). I also typically like the patient to glide up and down from their lowest and highest note as it provides some additional information on neurological/muscular control of their voice depending on how smoothly it is performed.
3) Swell Tests - Essentially, the test involves singing a song (I use Happy Birthday) very quietly an octave higher than your normal pitch. If onset delays or pitch breaks are heard, does suggest the presence of a small bump (nodule, cyst, polyp, etc) on the vocal cords.

One can also add documentation of yell, cough, throat-clearing, and speaking voice.

Method #2 - Objective Tests

This type of testing can only be performed with the help of instruments and provides "numbers" that can be documented. It is more difficult to "hear" the voice looking at just these numbers, but does provide a more rigorous way to actually "measure" the voice quality. There are now even iPhone apps that can obtain such data.

The basic measures include:
1) Shimmer - Measures how much variation in loudness is present. Think of a volume knob being turned up and down slightly. Normal is less than 3%.
2) Jitter - Measures how much variation in pitch is present. Think of going up and down on the equalizer slightly. Normal is less than 1%.
3) MPT is also measured.
4) Fundamental frequency (f0) - Measure of how high/low a person's voice sounds (pitch).

One can go crazy and also add intensity, glottal noise, ratio, tremor, spectrum, EGG-pitch, EGG-intensity, EGG-jitter, EGG-shimmer, EGG-noise, CQ, CQ perturbation, CI, CI perturbation, opening rate, etc.

Regardless of the method, with this type of information, the actual degree and characterization of the vocal quality can be measured, documented, and tracked over time. Also, when communicating with other health professionals, such measures provide for an efficient and understandable way to describe a patent's voice with a colleague.

Of course, from the patent's perspective, they "just want to sound better," but this is how professionals do it.

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Accurate Hearing Testing Using an iPhone

There is an iPhone app called "EarTrumpet" that apparently can provide accurate hearing testing... almost as good as a professionally administered test (conventional audiometry) and certainly as good (if not better) than medical-quality automated testing machines (ie Otogram).

Created with the assistance of the ENT department at the University of California, Irvine...

According to one study, this iPhone application provided results as good as one administered by an audiologist:

• 96% of the threshold values when obtained in a sound booth
• 94% of the threshold values when testing was done in just a "quiet" room

When accuracy was defined as "within 10 dB of the corresponding threshold value obtained using conventional audiometry."

Given how accurately the iPhone application performs, it may potentially be a very helpful screening tool to evaluate patients with ear/hearing complaints. If the testing comes back normal hearing (between 0-20db at ALL frequencies), than the patient probably hears just fine.

However, if there's any hearing loss detected, it is advised to seek professional opinion because there  are weaknesses to this program and further testing WILL be necessary.

• It ONLY performs air conduction testing. Given the lack of bone conduction testing, pure nerve testing is not possible, especially when hearing loss is detected. For example, the iPhone application will not be able to test hearing loss due to earwax/fluid versus actual nerve hearing loss.
• Speech audiometry is not present. Only pure tone audiometry. Speech audiometry provides information regarding how well spoken words are understood... one can potentially "hear" a beep at a specific frequency just fine, but still mishear a spoken word which is composed of many different sound frequencies.
• As it pertains to this research study, while there was excellent agreement in masked threshold values between the iPhone app and conventional audiometry, the sample size was limited. Masking is especially important when significant asymmetric hearing loss is present.

There may also be potential bias with the research. The developer of the EarTrumpet iPhone app, Allen Foulad, is also the lead researcher of the paper. It would be worthwhile to have other independent labs reproduce and verify the findings.

However, I applaud Dr. Foulad for his work in this area as well as entrepreneurial spirit!

You can download his app here.

As a bonus, this iPhone application can also act as a personal sound amplifier. It can enhance environmental sounds via earphones attached to the iPhone.


Reference:
Automated Audiometry Using Apple iOS-Based Application Technology. Otolaryngol Head Neck Surg. 2013 Aug 20. [Epub ahead of print]

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At Home Allergy Testing

Recently, a new at-home allergy test can be found on store shelves throughout the United States as well as Amazon.com. It is called "MyAllergyTest" produced by ImmuneTech Corporation and it is FDA approved. The way it works is that you place a few drops of blood into the collection kit which is than mailed to a lab in a pre-paid, pre-addressed envelope.

Results are than obtained via internet or by certified mail in about one week.

What's tested? Only ten things (IgE only):

• Timothy Grass
• Bermuda Grass
• Mountain Cedar
• Short Ragweed
• Alternaria Mold
• Cat Dander
• Mite pternoyssinus
• Egg White
• Wheat
• Milk

As such, if testing comes back normal, it does not mean you do not have allergies... It just means that you do not have allergies to these 10 things only... You could be allergic to other non-tested substances.

A report is produced listing what you are allergic to and how badly:

How accurate is the testing? Apparently, it is comparable to Pharmacia CAP system (specific IgE FEIA).

In terms of actual numbers, the test has a sensitivity 88%, specificity 94%, and accuracy 91%.



Source:
FDA.gov

Company Website

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Kim Kardashian Gets Allergy Testing

Celebrity Kim Kardashian of Keeping up with the Kardashians reality TV show underwent allergy testing with Dr. Mirmelli. Allergy testing was accomplished via skin prick (our office performs allergy testing by blood draw instead called immunocap).

She apparently was allergic to her pet cat...

Kim apparently decided to let her pet cat Mercy go... a decision in contrast to what most cat-allergic people do.

Watch the video.

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Hearing Aid Styles and Colors - There Are Many!

It is not uncommon that a patient with hearing loss interested in hearing aids mistakenly believe there's only TWO hearing aid styles.

The kind that goes in the ear and the kind that goes behind the ear.

Although that is true, there are more different variations of both types that catches many people by surprise.

Image taken from NIH

There also seems to be a generational gap in what style is preferred by patients.

"Older" folks in their 60's or older prefer the styles that go in the ear, mostly because of the stigma associated with hearing loss and use of a hearing aid that reinforces and reminds them of their age. Also, because they remember the large skin-toned BTE that used to be the only option.

The "younger" generation typically prefer the min-BTE that go behind the ear. It probably helps that so many people use wireless bluetooth earpieces almost like a status symbol.

Beyond where hearing aids go, they now come in different colors and patterns for further personalization! Skin-tone is no longer the only color option.

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New Video on Newborn Hearing Testing

Given how often we see newborns in need of hearing testing, we have produced a video showing how the two main types of non-verbal hearing tests are performed today: Auditory Brainstem Response (ABR) and Otoacoustic Emission (OAE).

Given newborns can not communicate whether they can hear or not, such hearing tests depend on the ability to detect nerve signals transmitting sound information from the ear all the way to the brain. This type of test is much like an EKG which can detect the electrical activity of the heart.

Watch the video to see how ABR and OAE hearing testing works in infants (as well as adults)!

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