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.

Read More

Man Files $15 million Lawsuit Against NYC Citi Bike Claiming Smell Loss From Bike Crash

Image by Pharos of Wikipedia

In 2013, a man rented a bicycle from New York City's Citi Bike program. Apparently while riding this rental bike, the front wheel struck a wheelstop installed near a bicycle docking station which the man did not notice, flipping him resulting in head trauma. This head trauma resulted in permanent smell and taste loss. [link]

The wheelstop is meant to prevent cars from from backing into bike stations, but the lawsuit alleges "no cones or colored warnings to alert a bicyclist of its existence... constituted a trap for the unwary."

Regardless of the legal merits of the case, how does head trauma like this cause smell and taste loss?

The smell nerve is located right between the eyes and is analogous to the roots of a plant where the plant is the nerve next to the brain and the roots are the nerve endings that go through the skull bone (cribiform plate) and into the nose where "smell" is detected (the yellow in pic below). With significant head trauma, the brain suddenly moves and "bounces" around in the skull when struck. When this happens, the delicate smell nerve endings which are going through the bone "tear" when the brain moves relative to the bone.

With such nerve damage, smell can be permanently lost. With complete smell loss, taste can be adversely affected given so much of flavor is attributable to smell. As such, the man can technically probably still taste (salt, sweet, sour, bitter, etc), but not smell.

BTW... Did you know that the tongue taste map we all learn in school is incorrect?


Source:
Conn. man files $15 million lawsuit against NYC, Citi Bike, claiming nerve damage from bike crash. Daily News 2/27/14

Read More

Malpractice Lawsuit for Nerve Damage Sustained After Neck Cyst Excision

Earlier this month, a malpractice lawsuit resulted in a $4 million dollar award to the patient plaintiff who suffered permanent nerve damage after a family practice physician excised a cyst from the neck. [link]

Briefly, the patient visited the family physician in July 2009 for a lump in his left neck. The family physician recommended that the mass be surgically excised which was subsequently performed by the same family physician (not a surgeon) in the office. After the procedure, the patient experienced a weakened left arm and shoulder and had difficulty picking things up with that arm or moving the arm more than 90 degrees. Subsequent evaluation by an orthopedic surgeon and neurosurgeon determined that the spinal accessary nerve was cut at the time of the neck mass excision.

So what probably happened?

The spinal accessory nerve (also known as cranial nerve XI), is a major nerve that comes off the spinal cord and supplies motor function to the shoulder and arm (red arrow below pointing to the nerve which is yellow).

Image Modified from Wikipedia

I suspect that in this case, the mass was located in the same area denoted by the red arrow above. Now assuming that media and court documents were correct that it was truly a cyst that was excised, the cyst must have laid right below the skin, but on top of the nerve.

Careless excision of the cyst would have resulted in this nerve being cut especially during dissection on the mass's deepest aspect, especially if the physician did not hug the mass during dissection. Using an analogy, good surgical technique is like peeling an orange without puncturing the yummy orange underneath. Poor surgical technique would be peeling the rind and taking bits of the edible orange as well... or leaving some nasty rind on the fleshy orange itself.

Often, novice surgeons take large cuts around a mass with the tip of the scissor or scalpel extending beyond visualization. Also, thick layers of tissues are cut rather than thin transparent amounts. Furthermore, when a mass is grasped and pulled, anatomic structures like a nerve can get pulled out of its usual location along with the mass which can lead to unintentional damage. 

As such, experienced surgeons know when to cut big (no important structures are around) and when to cut in tiny microscopic degrees (important nerves and blood vessels are around).

The neck has a large number of important blood vessels and nerves in a highly compacted area making surgery in this part of the body potentially fraught with peril. However, there are certain "safe" areas where no significant important nerves or blood vessels are found. Such a "safe" zone from a nerve perspective is right under the chin extending down over the voicebox. Of course, there are other important structures located in this area that could get damaged even if nerves aren't a concern.

Source:
Montco jury awards Hatboro man $4M for nerve damage. Phillyburbs 8/27/13

Read More

Bruce Jenner of the Kardashians with Hearing Loss Brain Tumor Scare

Image by jla0379 from Wikipedia

This past weekend, fans of the TV show Keeping Up with the Kardashians found out that Bruce Jenner had what most likely was an asymmetric nerve hearing loss in his high frequencies when he had a hearing test done that lead to a brain tumor scare.

What this means is that his ability to hear was much worse in one ear compared with the other... and it was due to nerve damage rather than earwax or fluid in the ears.

Whenever there is this type of nerve hearing discrepancy between the right and left ears, there is concern for the possibility of a benign brain growth called an acoustic neuroma. As this tumor gets larger, it compresses the hearing nerve causing progressive hearing loss on just one side.

Whenever a significant difference in nerve hearing is found on a hearing test, an MRI scan of the internal auditory canal is performed to look for this or other related tumor. Statistically, there is only a 5-10% risk of an acoustic neuroma with the presence of an asymmetric nerve hearing loss.

Fortunately for Bruce Jenner, no tumor was found and hearing aid placement was pursued.

Now, is it absolutely necessary that an MRI be performed? No, though it is the BEST test to further evaluate.

Alternatively, one can perform serial hearing tests every 6-12 months to monitor for any progressive hearing loss... and if present, than pursue an MRI scan.

One can also get a specialized test called an auditory brainstem response (ABR) which measures how quickly a sound gets transmitted to the brain. If a tumor is present, the signal is delayed whereas if no tumor is compressing the hearing nerve, the signal reaches the brain at a normal speed.

Of course, if the ABR comes back abnormal, than an MRI scan would be recommended as the next step.

Read more about asymmetric hearing loss.

Source:
‘KUWTK’ Recap: Bruce Jenner Might Have A Brain Tumor. Charter 6/24/13

BRUCE JENNER FEARS BRAIN TUMOR IN HEARING LOSS WOES—WATCH THE NEW KARDASHIANS CLIP. E Online 6/20/13.

Read More

New Video on Thyroid Surgery and Its Complications

A new video has been created regarding how the thyroid gland is removed along with potential complications that may occur with this surgical procedure.

This video creation was a collaborative effort between myself and Dr. Henson, the general surgeon who performed the actual operation portrayed in the video. Assistance by Robin Earl and the surgical staff at Fauquier Hospital were invaluable as well.

Read more about the surgery here or watch the video!

Read More

Stroke vs Non-Stroke Facial Paralysis

Image by Patrick Lynch from Wikipedia

A recent blog post about a ER doctor who was found negligent for not pursuing a stroke workup for an isolated facial paralysis did bring up an interesting medical phenomenon about what differentiates a facial paralysis due to stroke vs facial paralysis due to facial nerve inflammation.

To begin, the facial nerve innervates the entire half of the face. The nerve itself exits from the skull behind the ear and sends finger-like branches to all the muscles of the face (nerve is yellow).

So if something happens to the nerve, the entire face including forehead, around the eye, cheek, and lip would become paralyzed.

HOWEVER, if a stroke occurs that knocks out the part of the brain that governs facial movement on just one side, the patient will have facial paralysis only on the lower half of the face. The forehead on both sides will still move just fine!

Why is that?

At the brain level, the facial nerve branch that governs forehead movement is innervated by BOTH sides of the brain. However, the facial nerve branches for the remainder (lower part) of the face is innervated by only ONE side of the brain.

As such, if complete facial paralysis including forehead is present, it is NOT due to a stroke or any other brain problem. This condition is called Bell's Palsy.

If the forehead moves fine, but the rest of the face is paralyzed on one side, than it may be due to a stroke or some other brain-level problem. Of course, with a stroke, one would see not only facial paralysis with forehead sparing, but also paralysis involving other parts of the body (which makes it obvious).

Image by Patrick Lynch from Wikipedia

Take a look at the picture to the left illustrating the facial nerve branches. Nerve branches in solid yellow or orange come from either the right or left side of the brain. Nerve branches in yellow/orange hashes come from both sides of the brain.

Read More

The Facial Triangle of Danger (Even Death)

Image by SpooSpa from Wikipedia

If you draw a line between the eyebrow to the corners of the lip, a triangle is created which delimits a region esoterically known as the "danger triangle".

Why is this region considered dangerous?

It's because infections within this region can lead to infections of the brain (rarely). Why? The blood supply within this triangular area communicates with the cavernous sinus found at the bottom of the brain. This anatomic structure is a major source of venous drainage of the brain.

If the cavernous sinus gets inflamed/infected due to a rip-roaring pimple of the upper lip, it could lead to multiple facial abnormalities due to injury of the numerous cranial nerves that go through it including:

• Inability to move the eyeballs (CN3, 4, 6)
• Numbness, pain of the skin over the forehead and cheeks (CNV1, V2)
• Loss of pupillary constriction (CN3)
• Visual loss/changes (CN1)

The cavernous sinus could also become thrombosed.

Cavernous Sinus shown by red arrow. Taken from Sonoworld.

From there, the infection can spread to the rest of the brain and potentially can even lead to death if not treated promptly and aggressively.

Of course, tiny infections like a small pimple or a small laceration due to biting a lip is not going to cause problems.

However, rapidly progressive major infections of the skin with abscess formation do need to be treated cautiously.  Typically, such patients are hospitalized on IV antibiotics until definite and significant improvement can be seen at which time patients can be discharged home on oral antibiotics.

At which point a "minor" infection becomes "major" requiring hospitalization is a judgement call.

Read More

Speech Impediment to Great Singing on American Idol

During January 2013 auditions of Season 12 of American Idol, there was Lazaro Arbos who has a terrible stutter when he talks, but sings beautifully. A week later, we encountered Micah Johnson who also suffers from a speech impediment, but rather than a stutter, it was due to "nerve damage" sustained during a tonsillectomy. (Watch videos below)

With stuttering, the problem mainly lies at the brain level. The brain coordinates how a person uses all of their throat muscles to create speech. Talking and language is mainly a LEFT-brain activity (or more precisely, the dominant hemisphere). Singing is mainly a RIGHT-brain activity and as such, uses different pathways than talking. It's also the same reason why patients who have suffered from a stroke may not be able to talk at all, but can sing their words out.

Now, in the case for Micah Johnson, it is reported that his speech impediment was due to "nerve damage" from tonsil removal surgery. As such, his speech impediment is NOT at the brain level (also known as central), but peripheral. Peripheral nerve injury is much more difficult to correct and requires extensive practice (speech therapy) in order to create brand new pathways at the brain level to help it "adapt" and compensate for the loss of function from the nerve injury. The analogy would be walking with a limp to compensate for a leg injury.

However, in Micah's case, it is a bit difficult to explain why he talks with an impediment, but sings wonderfully. It is not a matter of activating previously established brain pathways as what happens with stuttering.

With a tonsillectomy, there is a mouth gag placed to move the tongue out of the way. Typically, this surgery takes about 15 minutes to perform on average. Per Micah, his tonsillectomy took 90 minutes or almost 6 times longer than normal.

I hypothesize that the mouth gag over that time duration slowly crushed the nerve innervating the tongue (cranial nerve 12) causing it to not move as well leading to his speech difficulties. This complication is EXTREMELY rare and if it occurs, almost always temporary. This situation is analogous to a "dead" arm when sleeping on it for too long... but recovering normal function after a few minutes.

Unfortunately in Micah's case, it seems to never have recovered fully.

The puzzling issue for me is how is it that he is able to sing, but not talk well? Peripheral nerve injuries would affect ANY activity involving the affected muscle. For example, if the nerve to a leg muscle is cut, that muscle will not work well whether running or walking. The ability to sing, but not talk well due to a peripheral nerve injury is akin to stating that one can only limp when walking, but can run fantastic.

Anyone have any ideas what may be going on with Micah's amazing singing?

Just as an FYI, another rare complication of tonsillectomy that may lead to speech problems is velopharyngeal insufficiency leading to a hyper-nasal sounding speech. In this situation, there is no nerve damage present. Rather, it is an anatomic problem whereby the soft palate does not 'lift" completely to close off the nasal passage from the mouth. This problem can be surgically fixed.

In any case, best of luck to both men!

Read More

Parkinson's Disease Diagnosed by Salivary Gland Biopsy

Taken from Wikipedia

Currently, diagnosing Parkinson's Disease (a degenerative neurological disorder) is hard, usually a clinical exam and assessment of symptoms by a neurologist with at best about an 80% accuracy rate. There is no "test" per se that can diagnose Parkinson's Disease... until possibly now.

According to a study released in advance of its presentation at the annual meeting of the American Academy of Neurology, which will be held from March 16 to 23 in San Diego, Mayo Clinic researchers have determined a submandibular gland biopsy can offer 82% certainty whether a living patient has Parkinson's Disease or not. What is so special about this particular gland located under the jawline?

In patients with Parkinson's Disease, an uniquely abnormal protein called alpha-synuclein protein can be found.

In order to "biopsy" the submandibular gland which produces saliva, it does require a head and neck surgeon given the gland's location under the jawline. Beyond the usual risks of bleeding and infection present with any type of surgery, additional risks with this biopsy include:

• Permanent lip paralysis as the nerve that goes to the lower lip is located right over this gland.
• Permanent tongue paralysis as the nerve that moves the tongue is located right under this gland.
• Permanent numbness of the mouth floor as the nerve that provides sensation in this location is also located right under the gland.

Also, there are questions that need to be answered before this test is available more widely including:

How early in the Parkinson's Disease will this protein accumulate in the submandibular gland? If there is an "accumulation" time period, when is the best time to do the biopsy than?

Does the biopsy require a bloc of tissue or can a needle biopsy be sufficient (thereby reducing some of the surgical risks)?

Will insurance pay for this procedure?

Also, when is the paper going to be published regarding these results and can others replicate these findings? Here's the presentation abstract...

Source:
New saliva gland test may better diagnose patients with Parkinson's. FoxNews 1/11/13

Salivary Gland Biopsy as a Diagnostic Test for Parkinson's Disease. AAN 65th Annual Meeting Abstract

Read More

Breathing or Voice... You Can Only Have One...

Sounds like a choice taken out of a morbid horror movie...

"You can ONLY have one... Your voice or your breath..."

The victim than loses one or the other after making a choice getting either the tongue or head cut off with a knife.

But patients with vocal cord paralysis on both sides are essentially faced with this very question.

Normally, the vocal cords (TVC in picture below) found in the voicebox move to accommodate talking or breathing.

When the vocal cords are apart, breathing occurs allowing air to pass unimpeded between the vocal cords and down into the lungs. However, with talking, the vocal cords come together tightly and vibrate creating voice. Watch a movie.

However, when both vocal cords become paralyzed, they neither move apart to help with breathing nor come together to assist with talking. Indeed, the voice and breathing BOTH stink.

It is in just this situation that the choice of breathing or voice becomes important because a patient can not have both. Improving one will sacrifice the other.

To explain this connection of voice and breathing further, normally, when the vocal cords are both moving fine, the voice is at 100% and breathing is at 100%. However, with bilateral paralysis, the voice and breathing are now linked to each other and collectively can not exceed 100%. As such, a patient with new onset bilateral vocal cord paralysis may start with a 40% of normal vocal quality and 60% of normal breathing ability for a total of 100%.

Using this scenario as a starting point where vocal quality is at 40% and breathing is at 60% of normal...

If a patient chooses to improve the vocal quality from 40% to 100% (an improvement of 60%), then breathing WILL correspondingly decrease 60% down to 0%... and potentially die given the ability to breathe is lost. Why? Because the vocal cords can be surgically forced together to allow for voice... but given the vocal cords are paralyzed, they can not move back apart to allow for breathing.


If a patient chooses to improve breathing quality from 60% to 100% (an improvement of 40%),  then the vocal quality WILL correspondingly decrease 40% down to 0%... and lose the ability to talk. Why? Because the vocal cords can be surgically forced apart to allow for breathing... but given the vocal cords are paralyzed, they can not move back together to allow for vocal cord vibration.


The total percentage of vocal and breathing quality can never be more than 100%. If a patient wants the best possibly voice and breathing, than a compromise would be to increase the vocal quality 10% from 40% to 50%, but understanding that this 10% improvement in vocal quality WILL mean a corresponding 10% decrease in breathing ability from 60% to 50%. This 10% change means that in the end, the voice and breathing would both end up at 50% of normal.

In most cases of bilateral vocal cord paralysis, it is the reduced breathing and shortness of breath that bothers people the most. The voice isn't good, but when given the choice, most people choose to try and improve their breathing ability understanding their voice may further deteriorate.

To read more about such treatment options, click here.

Read More

What is Asymmetric Nerve Hearing Loss

Given my last blog article regarding an ENT who got sued for not doing an MRI after audiogram showing an asymmetric hearing loss, the question that should be on everybody's mind is what IS asymmetric nerve hearing loss on a hearing test?

I am sad to report that there is no clear consensus on what is asymmetric nerve hearing loss.

First of all, at its most basic definition, asymmetric nerve hearing loss is when hearing is worse in one ear when compared with the opposite ear due to nerve damage.

Technically, hearing should decrease equally on both sides over time, but when one side gets worse faster than the other, it can cause concern because:

1) A tumor can be pressing against the nerve causing it to slowly fail faster than the other ear's nerve which is not compressed.
2) There is a loud noise history with asymmetric exposure to the ears. One example is hunting with a rifle where the left ear would repetitively get noise-induced damage from the gunshot in a right-handed shooter.
3) Bad luck

The conflict is at what point is an asymmetry considered significant enough to warrant a workup which may include an MRI scan of the head and/or auditory brainstem response (ABR)? Also, for a given patient history, a physician/patient may elect to recheck hearing bi-annually to monitor for asymmetric progression rather than pursue workup immediately (further studies being pursued only if asymmetry progresses over time).

Is asymmetry defined as 1 decibel difference between ears? Is it 50 decibel difference?

Even if the decibel difference is agreed upon, than over what frequencies? All of them or just a few of the frequencies?

So for the purposes of a "medically" significant asymmetric nerve hearing loss, the definition must define not only HOW big the difference in hearing loss is present between ears but also at what frequencies.

In one paper, it is 15 decibels at just 3000 Hz.

In another paper, it is 20 decibels at any two adjoining frequencies (or 15 decibels at two adjoining frequencies between 2000 and 8000 Hz).

Get this... even when criteria is defined, one study found substantial disagreement among five expert judges on what hearing tests they considered showed asymmetry.

Even insurance companies are jumping into the fray in what they considered significant enough to warrant covering the MRI scan. At one point when I ordered an MRI scan of the head for what I thought was a significant asymmetry found in one patient's hearing test, the insurance company denied the test citing "that there needed to be other neurological deficits PLUS the asymmetry seen on hearing test before MRI scan would be authorized".

I personally pursue further workup using the 20 decibel difference at two adjoining frequencies OR 30 decibel at one frequency.

Assuming medically significant asymmetric hearing loss has been defined and is present...

What are the chances of something bad going on (i.e., tumor) when an MRI scan of the head is ordered for asymmetry found on hearing test?

Less than 10% (depending on study, can be as low as 1-4%).

Given such a low positive yield on testing, why even pursue a MRI scan?

Because of defensive medicine to avoid being named in a lawsuit if the affected patient just happens to be within that 10% found to have an acoustic neuroma.

Indeed, in one study, 40% of ENTs stated medico-legal concerns factored into their decision to get an MRI scan of the head.

Read More

People DO Suffer Hearing Loss After a Loud Concert

Almost everybody at some point in their lives have attended a loud concert or loud nightclub.

Almost everybody will also recall a temporary reduction in their hearing with or without ringing afterwards for a short period of time.

This phenomenon is called temporary threshold shift (TTS) whereby the affected person has a temporary hearing loss that may last hours to days due to temporary damage of the outer hair cells of the cochlea.

If loud nose exposure happens enough times, permanent hearing loss can occur.

For some, permanent hearing loss may occur after attending numerous loud concerts whereas in other more "susceptible" individuals, it can happen after a single loud concert.

It doesn't even have to be a loud music concert. ANY loud noise exposure can do including shooting guns, listening to a portable music player like the iPod, fireworks, playing in an orchestra/band, etc.

However, loud concerts are of particular interest given how many individuals are exposed all at once and provided a unique research opportunity which was presented on May 21, 2012 at the American Otologic Society Meeting in Los Angeles.

The researchers (led by Dr. Jennifer Derebery of the House Ear Institute) essentially took hearing test before and after the concert of 29 teenagers.

72% suffered objective hearing loss after the concert though only 53% reported subjective hearing loss. 25% reported new onset tinnitus after the concert.

Of note, hearing ear plugs were offered to the study subjects, but only 3 accepted them.

Adult researchers who sat with the teenagers under investigation measured sound levels throughout the concert. During the 26 songs played during the three hour concert, sound levels ranged from 82 to 110 decibels with an average of 98.5 decibels. The mean level was greater than 100 decibels for 10 of the 26 songs.

As a reference, ear pain occurs at 125dB. Jet engine noise is at 140dB. Sustained loud noise exposure of 90-95dB can result in permanent hearing loss.

OSHA (Office of Safety and Health Administration) mandates workers to never be exposed to sound levels of 100dB for more than 2 hours per day (no more than 4 hours per day at 95dB).

Clearly something more needs to be done to protect teenagers' hearing, especially given how few accepted hearing ear plugs. A fundamental cultural shift would most likely have to occur with encouragement from not only the musicians but also parents and teachers...

OR, the music volume at concerts should be turned down... No boos please.


Reference:
Teenagers Hear Worse After Attending Concert. LiveScience 5/21/12

Read More

Head MRI and CT Scans Explained!

@ENTHouse brought to my attention a FANTASTIC website that literally identifies and goes through all anatomic structures on every slice of a CT or MRI scan of the head.

Sinus cavities, blood vessels, nerves, bone, suture lines, etc...

Wish I thought of doing it first...

It may be a bit confusing for a layperson, but if you have a copy of your CT/MRI scan and wonder where the maxillary sinus or optic nerve is located on your scan, check this website out and you probably can figure it out!

headneckbrainspine.com

Check it out!

Read More