The Hearing Journal's August issue
By Gordon Glantz
The Hearing Journal’s salary survey looks into current trends and pressing issues affecting the career satisfaction and advancement of today’s audiology professionals, including the gender pay gap, mentorship in the industry, among others. Read more.
By Sharon Van Hyfte, AuD, CCC-A
The tried-and-true externship guidelines observed by Purdue University’s AuD program highlight the importance of preparations, research, and continuous communication to the success of an externship program. Read more.
By Hamid R. Djalilian, MD, and Autefeh Sajjadi, MS
A 65-year-old man who had a gunshot wound to the face 20 years ago presents with a right postauricular mass and complete facial paralysis on the right. What’s the diagnosis? Read more.
By Dennis Colucci, AuD, MA, FAAA
Studies have shown that cannabis has medicinal benefits for some major health disorders like multiple sclerosis and Alzheimer’s, but its effects on those with hearing loss and tinnitus, good and bad, remain unclear. Read more.
By Brittney Sprouse AuD, and Michelle Ketcham Gozdecki AuD
Children diagnosed with cancer are at risk for decreased quality of life due to ototoxic effects like hearing loss and its impact of hearing loss on speech and language and school reintegration. How can audiologists contribute to developing a multidisciplinary approach to help these patients? Read more.
By Alexis Guerra
Researchers at Harvard Medical School and Boston Children's Hospital developed an optimized gene-editing system to recover the hearing of mice with genetic hearing loss. “The most surprising aspect was that it worked so well, giving almost undetectable cutting of inappropriate genes,” said study co-senior investigator David Corey, PhD. Read more.
ONLINE EXCLUSIVE: BONUS VIDEOS
WATCH accompanying patient videos online to improve your diagnosis of this month's Clinical Consultation Case.
Are You Compensated Fairly? Salary Survey Results Revealed No abstract available |
| Vibroacoustic Disease: More Than a Hearing Problem In the late 1990s, I was working with some professional audio sound technicians, and had the opportunity to experience the sound system for a major concert prior to the show. When they turned on the sound system, it took me only seconds to yell out, “Turn it off, it hurts!” The sound didn't only hurt my ears but my whole body. That's when I first realized that high-intensity/low-frequency (HI/LF) sound vibration could be dangerous to one's overall health.
At the time, I was in the U.S. Army Reserve and the Medical Service Corps, where I served as a clinical psychologist, a general hospital commanding officer, and a special projects officer, among others. Earlier in my military career, I was also a combat engineer, where I experienced loud explosions (blast waves) and weapons that emitted HI/LF vibrations. These experiences motivated me to look into the effects of HI/LF sound on the human body, particularly vibroacoustic disease (VAD). Fortunately for me, I discovered that medical specialists in Europe had already done research in this area. As early as 1956, Professor Eugenia Andreeva-Galanina developed a classification of hand-arm vibration-induced pathology, followed by more medical research (Aviat Space Environ Med. 1999 Mar;70[3 Pt 2]:A32-9). The article that made the strongest impact on me was “The Vibroacoustic Disease—An Emerging Pathology” by N.A.A. Branco Castelo and Lopez E. Rodriguez (Aviat Space Environ Med. 1999; 70[3, Suppl]:A1-6).
In 2001, an occupational physician in the U.S. Navy who attended the Civilian Combat Stress Conference, which I founded and directed, asked me if I had an idea why even experienced sailors would walk off the deck or in front of jet engine intakes while working on aircraft carriers. Noting my previous research, I told him that when a person feels sound waves from HI/LF vibrations, every cell in his or her body is being damaged. When this happens, the body automatically dumps adrenaline and endorphins into the blood stream in an effort to survive (AKA fight-or-flight response to injury). This, in turn, causes disorientation, confusion, and an overall lack of awareness, which can result in accidents. This is similar to the classic tale of an Olympic marathon runner who, after running over 26 miles with a massive amount of endorphins in his system, gets confused and runs the wrong way at the finish line.
As a military veteran, I am concerned that when soldiers return from combat, VAD is rarely diagnosed and most often overlooked as PTSD. For example, I had a patient who had many classic symptoms of VAD but was diagnosed with PTSD. He was inappropriately given brain-altering drugs with black box warnings for many years before he finally realized he needed to stop the medications.
Patients with hearing loss from exposure to HI/LF sounds should also be evaluated for VAD. I saw a patient with 20 body system problems, which no one realized were from VAD until I explained what occurred when he was handling a machine eight hours a day for eight years. His symptoms were in line with those described by Castelo and Rodriguez (Aviat Space Environ Med. 1999; 70[3, Suppl]:A1-6).
High-intensity, low-frequency sounds not only produce auditory and vestibular symptoms, but may also impact the overall status and functions of neurological, muscular, or even cardiovascular systems. The impact of high-intensity, low-frequency sounds is underappreciated. The diagnosis and treatment of their associated symptoms need to be improved.
Thoughts on something you read here? Write to us at HJ@wolterskluwer.com
REFERENCES
1. Castelo Branco NA. The clinical stages of vibroacoustic disease. Aviat Space Environ Med. 1999 Mar;70(3 Pt 2):A32-9.
2. Castelo Branco NAA, Rodriguez Lopez E. The vibroacoustic disease-An emerging pathology. Aviat Space Environ Med 1999; 70(3, Suppl):A1-6.
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Early Mechanical Hearing Devices No abstract available |
Advantages of Deep Learning for ECoG-based Speech Recognition No abstract available |
Audiological Management of Pediatric Oncology Patients No abstract available |
State-by-State Trends in School-Age Hearing Screening No abstract available |
AuD Externships: Building, Managing Successful Experiences No abstract available |
Gene-editing Tool Saves the Hearing of Beethoven Mice No abstract available |
| Audiologists Key in Survivorship Care No abstract available |
Symptom: Postauricular Mass
A 65-year-old man came in for a consultation for a right postauricular mass. The mass had been growing and caused problems each time he wore glasses. The patient also had complete facial paralysis on the right side. No drainage from the ear or mass was found. The mass was mildly fluctuant but not completely fluid-filled. It appeared to be fixed to the underlying tissues. Audiometry showed profound hearing loss on the right side. The patient had a gunshot wound to the face 20 years ago. A picture of the mass is on the right.
The first issue that needed to be clarified was whether this mass was a new development or a possible complication from the patient's old gunshot injury. Gunshots carry a substantial amount of kinetic energy due to the very high speed of the projectile. Generally, the entrance wound of a gunshot can be very small, and measures approximately the diameter of the projectile caliber or smaller, depending on tissue elasticity. However, the tissue area damaged below the skin is substantially larger than the caliber size. The formula of kinetic energy (KE = ½mv2) determines the amount of energy transferred to the tissues by a bullet. Increasing the velocity of the bullet by 100 percent (doubling it) will increase the energy by 300 percent (four times). Therefore, a long rifle will cause substantially more damage than a handgun, even if the caliber of the bullet is the same due to the rifle bullet's higher velocity. A military-type rifle will inflict even greater damage.
Tissue damage can occur a significant distance away from the bullet path when the bullet's kinetic energy produces a shock wave. As the bullet passes through the tissue, it can create a shock wave that measures much larger than its diameter, creating a cavitary effect that damages the tissues around the bullet's path. After the temporary cavity around the bullet path collapses, a permanent cavity wider than the size of the bullet may persist.
Gunshot wounds to the temporal bone and skull (which can eventually reach the temporal bone) are unique in that the otic capsule bone is very hard, causing the bullet to shatter after it makes contact with the temporal bone's hard surfaces. Each shattered piece of the bullet then scatters within the skull and damages the structures within and around its path (Figs. 2-5). A unique feature of gunshot wounds that traverse the temporal bone is the close proximity of the neurovascular structures. Damage to the carotid artery is possible when the gunshot traverses the temporal bone. The initial workup of a patient with a gunshot wound to the face or temporal bone includes a CT of the brain and CT angiography to evaluate the carotid and vertebral systems.
Another unique feature of gunshot wounds to the temporal bone is the confined intracranial space and the effect of edema. Significant edema can occur in response even to a minor injury to the brain. Because of the confined space of the intracranial cavity, the edema will gradually increase the intracranial pressure and reduce the intracranial arterial blood flow. In general, three things are contained within the skull: the brain, cerebrospinal fluid, and intravascular blood. Increased fluid within the brain displaces the cerebrospinal fluid and eventually the arterial blood. This causes anoxia and herniation of the brain. Rapid action is necessary to decompress the skull and control major vascular injury. Decompression is performed with a ventriculostomy, which reduces the cerebrospinal fluid pressure. In addition, a craniectomy (removal of a portion of the skull) may be performed to allow for expansion of the brain and prevent brain herniation. To treat a vascular injury, a neurointerventional radiologist usually isolates the injury using small intravascular balloons or placing coils within the blood vessel.
As important as hearing and facial nerve functions are to human beings in general, they are of secondary importance to patients with a gunshot wound to the head. After addressing the intracranial issues and stabilizing the patient, the physician can then address the facial and hearing issues. When evaluating the facial nerve of a patient who is experiencing some tension, the physician needs to assess whether the paralysis is due to edema of the facial nerve or the bullet fragments transecting the nerve. To best evaluate the condition, a CT scan of the temporal bone and an electrical test can be performed. If the bullet fragments do not appear to be violating the facial nerve, it is most likely damaged by edema from the cavitary forces of the bullet. Evoked and unevoked electromyography (EMG) can allow the clinician to determine if the facial nerve is in continuity. Unevoked EMG, also known as electroneuronography (ENoG), is inaccurate in the first three days after injury, as the distal facial nerve will continue to be stimulable up to 72 hours even after it has been completely transacted. EMG allows the clinician to determine even if a single nerve fiber is potentially intact. If a single nerve fiber action potential is seen in the face, it means that the nerve is intact and only time is needed for recovery. If the fallopian canal is fractured, the segment of the nerve can be explored further. If bullet fragments are found within the facial nerve canal or if the facial nerve (fallopian) canal is comminuted, the physician must prepare for nerve grafting, as the nerve has likely been transacted. Usually, the nerve becomes too damaged for spontaneous regrowth due to the bullet's high velocity and force energy; thermal injury can occur in these situations. The ends of the facial nerve need to be trimmed back to normal healthy nerves to facilitate the regeneration process. If the patient is stable, it is best to perform surgery or explore the nerve early in the course since the development of granulation (healing) tissue will make it challenging to identify the nerve and the normal anatomy.
Very little can be done to restore the hearing of patients with a damaged otic capsule or cochlear nerves after a gunshot injury. Another consideration is cerebrospinal fluid leakage, which needs to be addressed immediately after the injury. This may require mastoid obliteration through the middle ear or intranasal closure of the Eustachian tube. Finally, stenosis of the canal or trapping of epithelium (skin) can lead to cholesteatoma formation.
This patient underwent a retrosigmoid craniectomy with removal of a portion of the skull. The imaging showed the dura sitting very superficially under the skin. During resection, the postauricular mass was found to be partially filled with cholesterol granuloma fluid, squamous epithelium, and keratin (dead skin). The mass involved the dura but not the intracranial cavity. Histopathologic examination showed a squamous epithelium that indicated cholesteatoma. The skin trapped in the mastoid most likely started out at the facial skin surface where the bullet entered. The bullet carried a piece of the skin into the temporal bone, which led to a cholesteatoma that grew for over 20 years and became a mass behind the ear.
BONUS ONLINE VIDEOS: VISUAL DIAGNOSIS
Read this month's Clinical Consultation case, then watch the accompanying videos from Hamid R. Djalilian, MD, to review the patient's imaging for yourself.
Watch the patient videos online at thehearingjournal.com https://journals.lww.com/thehearingjournal/Pages/collectiondetails.aspx?TopicalCollectionId=23.
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