1. 2015 Otolaryngology Update
Chuck Reese
CAPT MC USN

2. Hearing Loss
Tinnitus and Hearing loss are the two most common disability claims in the military.
Together, DoD and the VA spend more than $4 Billion a year on evaluation, treatment and disability payments related to tinnitus and hearing loss.

3. Hearing Loss
Although the financial burden and the potential for mission impact are significant, the effect on quality of life and an individual’s diminished ability to “connect” with family and friends is perhaps even more significant.

4. Hearing Loss Two basic types of hearing loss: Sensorineural Conductive
Combination of sensorineural and conductive is referred to as Mixed Loss

5. Hearing Loss Other less common types of hearing loss are: Somatoform
Malingering
Central

6. What is sound?
Sound is a physical force that results in alternating movements of the molecules of air (or whatever medium is exposed to the sound).
Measured in cycles per second, or Hertz (HZ)
Sound is produced when there is a source of vibration such as tuning forks, vocal cords, jet engines, that transmit those vibrations into the air. The vibrations can also be transmitted into water or metal. The speed of sound travels fastest in solid objects and slowest in air. At high altitudes, where there are fewer molecules of air to transmit the vibrations, the speed of sound is slower.
When sound energy is transmitted in the air, the air molecules are alternately compressed and pulled apart in areas of alternating compression and rarefaction. If there are two sources of sound with the same degree of loudness and frequency that are next to each other, the overlapping areas of compression will result in what is referred to as “constructive interference” and the loudness will increase (by 3 dB-we’ll do the math later). If these same two sounds are located half a wavelength apart, one in front of the other, then if you are in the right location, the areas of compression will overlap the areas of rarefaction and they will cancel each other and there will be no sound heard. This phenomenon is the principle for sound cancellation headphones.

7. dB Source
Jet Engine, Gun Shot
Car Horn
Pneumatic Drill Subway Noisy Restaurant Busy Street Conversation Average Home Quiet Office Whisper Threshold of Hearing

8. Tympano-Cochlear schematic
There is a specific frequency distribution within the cochlea. The cochlea is arranged so that it responds to high frequency sounds with the first part of the cochlea and gradually lower frequencies sounds out to the tip of the cochlea. Because all sound energy (high frequency or low frequency) enters the cochlea through the oval window, it is this first part of the cochlea that wears out first. Therefore a noise induced hearing loss is a high frequency phenomenon. Typically there is a “notch” at 4000 Hz where the hearing is the worst. The hearing levels will drop off at 4000 Hz and then rise in the high frequencies.
With continued noise exposure more frequencies are affected and the hearing loss can spread into the speech frequencies (500 Hz to 2000 Hz) in which case the individual will become more aware of the loss and may require hearing aids. As we get older there is a tendency for us to develop a high frequency hearing loss- presbycusis. If an individual has a pre-existing noise induced hearing loss, the changes of presbycusis will be additive on top of that.
From Ear Diseases, Deafness and Dizziness; V Goodhill, 1979, Harper and Row, Publishers

9. Classic noise-induced notch at
4 kHz
A typical noise induced hearing loss with a notch at 4000 Hz. This individual has excellent speech reception thresholds since the speech frequencies are not involved ( Hz). Word recognition is also excellent at 100%. Tympanometry is Type A, or normal.

10. Scanning E.M., Outer Hair Cells of Cochlea,
I. Hunter-Duvar, in Schuknecht, 2nd Edition Pathology of the Ear
Electron micrograph of normal outer hair cells.

11. Outer Hair Cell damage from mild noise damage
Diseases of the Ear, Hawke and Jahn, 1987, Section 5.14

12. Outer Hair Cell damage from significant noise damage
Diseases of the Ear, Hawke and Jahn, 1987, Section 5.14

13. What did you say??

14. Components of Hearing Conservation Program
Noise measurements at job site
Engineering fixes if possible; otherwise, administrative controls on duration of exposure
Periodic audiograms (annual for aviation)
Hearing protection devices mandated and provided

15. Components of Hearing Conservation Program
New Reference Audiogram: Average of 10 dB shift at 2K, 3K and 4K Hz Requires repeat testing after 14 hrs in noise free environment Special reporting requirements Possible ENT consultation
Education - counseling - motivation
15 dB drop between audiograms in single frequency: may indicate a problem and member should be counseled

16. Role of the Flight Surgeon
From OPNAVINST E: “…..it is incumbent upon leadership to set the right example in their personal protective practices, to enforce compliance, and to ensure HCP receives their full support.”

17. Role of the Flight Surgeon
From OPNAVINST E: i. When an audiologist or a physician confirms the positive threshold shift is permanent, the individual shall be notified in writing within 21 days of such determination…….

18. Role of the Flight Surgeon
From OPNAVINST E: Supervisors shall be notified, in writing, that the worker has experienced a decrease in hearing.

19. Role of the Flight Surgeon
From OPNAVINST E: In accordance with subparagraph C of Reference (s), workers shall be informed, in writing, that their supervisors are notified that they have experienced a decrease in hearing.

20. Role of the Flight Surgeon
-Coordinate with division officers…. -Conduct training for all hands…. -Ensure annual refresher training…. -Consult the command industrial hygiene survey…… -Schedule personnel…. -…personnel who require hearing retests … -…ensure the certification of annual…. -Report all permanent threshold shifts… -Enter into the web-enabled safety system…

21. From OPNAVINST E:
(3) Any individual who has hearing loss in both ears in which the sum of thresholds at the frequencies of 3000, 4000 and 6000 Hz exceeds a total of 270 dB or has their reference hearing test (form DD 2215) re-established three times will not be assigned to duties involving exposure to hazardous noise until evaluated and waived by an audiologist, otologist, or occupational medicine physician. Page B4-A-8

22. Role of the Flight Surgeon
The hearing conservation program is receiving increased scrutiny. There have been several working groups over the years and it continues to be a tough nut to crack The flight surgeon’s role is critical. The AVTs and their entry of data into DOEHRS-HC is a critical component of the program. They are a crucial resource.

23. Sudden Idiopathic Sensorineural Hearing Loss
Incidence of 2-20 per 100,000 per year
30 dB threshold shift in 3 contiguous frequencies occurring within 72 hours. ~50% awaken with the loss
Idiopathic: Viral cochleitis, microvascular event, autoimmune
90% with tinnitus % with vertigo

24. Sudden Idiopathic Sensorineural Hearing Loss
Potentially a diagnostic challenge. Patients frequently report that the ear feels blocked or plugged. Clinicians convince themselves that the drum looks retracted or red or………
You MUST remember how to use tuning forks, and more importantly, you must know where one is and you must use it!!

25. Sudden Idiopathic Sensorineural Hearing Loss
Approx two thirds will have some degree of spontaneous recovery
Prognosis is generally worse for a profound loss affecting all frequencies and in the presence of vertigo
Recovery most likely if treatment is initiated within days

26. Sudden Idiopathic Sensorineural Hearing Loss
Clinical Practice Guideline from AAO-HNSF Otolaryngol Head Neck Surg Mar; 146(3 Suppl):S Delineate SNHL from Conductive loss. -Recommendation for offering treatment with oral glucocorticoids -Recommendation for consideration of trans- tympanic steroids for treatment failures -Recommend against treating with antivirals. -Recommend consideration of hyperbaric oxygen. -Obtain MRI of IACs to evaluate for retrocochlear lesions
From UptoDate:
With recognition of the equivocal efficacy of treatment, guidelines from the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) suggest that patients with SSNHL be offered treatment with oral glucocorticoids, with the greatest likelihood of some response if started promptly after diagnosis, and within two weeks [3]. Patients should be advised of the risks and benefits of glucocorticoid treatment. The recommended dose for prednisone is 1 mg/kg/day (to 60 mg maximum) given as a single dose for 10 to 14 days. Some have advised that treatment be extended another 10 days if a partial response is found at the end of the initial course [32]. Dosing regimens for intratympanic glucocorticoids vary between studies, but include dexamethasone 10 to 24 mg/mL or methylprednisolone 30 to 40 mg/mL; dosing frequency ranges from continuous infusion [33] to a few times a day through a pressure-equalizing tube to several days consecutively or once weekly. Intratympanic administration is typically managed by an otolaryngologist. Transient side effects associated with intratympanic dexamethasone included otalgia, dizziness, and ear fullness. Antiviral agents — Although HSV-I may be an important etiology for SSNHL, randomized trials have found no superiority of treatment with antiviral medication plus glucocorticoids compared with glucocorticoids alone [39-42]. However, these studies were small and associated with some flaws and, therefore, definitive conclusions cannot be made.
Guidelines from the AAO-HNS suggest not treating with antivirals, citing the lack of evidence for efficacy and some risk of medication side effects (nausea, vomiting, dizziness) [3]. A systematic analysis of randomized trials evaluating antiviral agents for SSNHL noted no difference in response rates for groups that used antivirals or not, but also no difference in serious adverse effects between groups [43]. The review concluded that larger trials, with a uniform definition of SSNHL, are needed to draw definitive conclusions on the effectiveness of antivirals for this condition. In the absence of larger trials of antivirals, we typically treat SSNHL of unknown origin with a 7- to 10-day course of an anti-HSV antiviral such as valacyclovir 1 g three times daily or famciclovir 500 mg three times daily, in addition to high-dose prednisone.

27. Unrecognized sudden SNHL nine days after symptom onset and treatment with ear drops, motrin and augmentin.
This patient woke up on 29 September with "unbearable left ear pain," tinnitus, and significant hearing loss in the left ear. In the emergency room he was apparently diagnosed with otitis externa, because they put him on Ciprodex eardrops. The next day he was seen by a primary care doctor who thought the eardrum looked red and that there was fluid in the middle ear. He added Augmentin and Motrin and told the patient to followup in 2 days. The patient also mentioned that he was having intermittent vertigo in addition to the hearing loss and tinnitus. 5 days later the patient was seen for his annual audiogram (his birthday is in October) and the audiology technician made arrangements for him to see ENT and get a formal audiogram which was done on 8 October. Earlier in the day on 8 October he was seen by another primary care doctor who thought the eardrum looked retracted and told the patient that his hearing would probably improve when his upper respiratory symptoms resolved. From the way that note is written, it sounds as though this doctor considered telling the patient not to bother with the ENT evaluation since the vertigo was intermittent and she thought that the hearing would improve with time. At no time in any of these evaluations was a tuning fork used.
On 8 October formal audiometry demonstrated a profound hearing loss in the left ear with normal tympanometry. Otolaryngology saw the patient and gave him a transtympanic dose of Decadron and started him on a prednisone taper. The tympanic membrane was "normal in appearance with normal mobility." A. Weber tuning fork was only heard in the right ear. Rhinne testing was also only heard in the right ear. There was no perception of sound in the left ear with tuning fork testing.
Over a two-week period the patient received a total of 3 doses of Decadron through the tympanic membrane and on an audiogram from 5 December has hearing levels of approximately 70 dB, indicating some recovery, but clearly exceeding standards and at this point a waiver to return to flight duties as an aircrewman will not be considered. He is being fitted with a hearing aid for the left ear.

28. Sudden SNHL. Results after treatment with aggressive prednisone taper and three transtympanic injections of decadron that started 9 days after onset due to delay in Dx.

29. “I woke up this morning and could not hear in my left ear.”

30. Audiogram three weeks later after aggressive oral steroid taper.

31. Sudden Idiopathic Sensorineural Hearing Loss
Not everyone will have this good of a response, but you have to start with the correct diagnosis.
Simple use of tuning forks will work for you.
If in doubt, get a formal audiogram!

32. Finally, don’t forget to ignore the light reflex!!

33. Finally, don’t forget to ignore the light reflex!!

34. Questions?