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Inner Ear Injuries

(Including Perilymph Fistula Injuries)

Inner Ear Anatomy

The inner ear is comprised of two main sections; the vestibular system and the cochlear system. The vestibular system is involved in balance, while the cochlea is involved in hearing.

The anatomy of the inner ear is dominated by large fluid-filled spaces. The inner ear consists of a complex series of tubes, running through the temporal bone of the skull. The bony tubes (sometimes called the bony labyrinth) are filled with a fluid called perilymph. Within this bony labyrinth is a second series of tubes made out of delicate cellular structures (called the membranous labyrinth). The fluid inside these membranous structures is called endolymph, The different spaces of both the perilymphatic and endolymphatic compartments are interconnected by a series of ducts.

Inner Ear Injury

An important feature of the endolymphatic space is that it is completely bounded by tissues and there are normally no ducts or open connections between perilymph and endolymph.  These fluids are retained by the round and oval windows at the front wall of the inner ear.

The existence of the many ducts connecting different parts of the inner ear has led to the idea that the cochlear fluids are flowing through the ear. However, unlike other body fluids, such as saliva or lachrymal fluid (tears), the fluids of the inner ear are not secreted and resorbed in volume. This is a widespread misconception, based on old studies that used poor experimental techniques. Studies performed over the past decade have shown that neither endolymph nor perilymph “flow” along their respective compartments in the normal cochlea. Maintenance of the chemical composition of both fluids is dominated by ion transport processes which are localized in each region.

Inner Ear Injuries – Effects of Trauma

In general terms, a perilymph fistula is an abnormal connection between the inner ear fluid spaces and the middle ear air spaces resulting in the leakage of perilymphatic fluid into the middle ear.  Perilymph fistulas can be classified into four broad categories: iatrogenic, traumatic, spontaneous, and congenital. Symptoms of perilymph fistula are variable and include sensorineural hearing loss, vertigo, dysequilibrium, unsteadiness, motion intolerance, and aural fullness. Many patients also have noise sensitivity (hyperacusis), tinnitus, memory loss, confusion, visual sensitivity and fatigue.  Due to the several overlapping symptoms between perilymph fistula and Post Concussion Syndrome, a consultation with a neurologist, and then either a neuropsychologist or a neuro-otologist or both, may prove helpful in differentiating the conditions.  While advocates of both conditions believe their particular favorite is the cause of many of the similar symptoms, both camps seem to ignore that you could very well have both after trauma.  A full evaluation of both conditions will help determine the truth.  Left untreated, these symptoms can be very dangerous. Some very good doctors who can also work with perilymph fistula injuries using conservative methods.

Inner Ear Membrane Breaks

Simmons in 1968 first postulated that sensorineural hearing loss could result from intracochlear membrane breaks. In 1971 Goodhill stated that the labyrinth is hydrostatically loaded with intimate relations to hydrodynamic forces in the carotid arterial system, intracranial venous-sinus systems and the CSF pressure gradients in the subarachnoid space. He proposed that the membranous labyrinth could be ruptured by an explosive route via the external auditory canal and eustachian tube and concluded that membrane ruptures could occur throughout the membranous labyrinth with both acoustic and/or vestibular system sequelae.

Simmons later expounded on his original theory and proposed the “double membrane break theory” in the development of sensorineural hearing loss. In this theory he postulated that the second membrane break was the result of a pressure gradient created by the first break.  He went on to note that profound sensorineural hearing loss resulted from the mixing of perilymph and endolymph, and that healing of intracochlear breaks halts the mixing of fluid. With this healing of the round and oval windows, the widespread hearing loss disappears resulting in hearing loss at the specific site where local tissue damage occurred along the membrane.

Clinically, the rupture of the oval or round window allows for the spilling of the inner ear fluid into the inner ear, where it either remains to irritate the patient, or goes down the Eustacian tube causing an itching sensation in the throat.  The desire to clean one’s ears frequently, the sensation of water in the ear when there could be none, and an itchy throat signaled by the patient’s regular throat noises (made in an attempt to “scratch” the itching sensation caused by the leak of fluid into the throat) are warning signs that you need to look for inner ear damage.

The force created from an impact such as an auto accident (even a low speed car crash) is more than sufficient to cause a tear in either the oval or round window.

What few people know, or consider, is that the inner ear is connected to the subarachnoid space by the cochlear aqueduct.  If the round window or oval window of the inner ear is perforated due to trauma, then perilymph escapes, driven by the hydrostatic pressure of Cerebral Spinal Fluid. The escaping perilymph and endolymph is replaced by CSF entering the cochlea through the cochlear aqueduct. In this condition a longitudinal flow will exist between the cochlear aqueduct and the site of the perforation. The chemical composition of perilymph will be disturbed because the perilymph will continually be “washed out” and replaced by CSF. This condition is what is technically known as a perilymphatic fistula.

This will also result in lower than normal CSF fluid levels in the brain and spinal cord.  The most common repercussion of this is a low grade headache, but it can certainly become more serious than this.  Practitioners of some chiropractic techniques would suggest that proper CSF flow and volume is crucial to proper nervous system function.  The leak from the inner ear may be holding you back from chiropractic success with your patient.

Inner Ear Injuries’ Impact on Postural Muscles

In addition to the aforementioned problems with cognition, this condition can permanently alter the function of the postural muscles, in an attempt to recruit them to maintain balance.  The tie between whiplash injuries, equilibrium problems and posture changes was noted in a 1997 study from Italy. The study also noted that the cervical problems compounded the equilibrium problems stating “it appears reasonable to assume that cervical proprioceptive alterations play a preminent role in the genesis of whiplash-induced chronic postural instability. This would result in an attempt to vary the physiology from an ankle to a hip strategy; incomplete manifestation of this new posture would cause the feeling of instability mentioned by the patients and documented by posturography.” P. Giacomini, A. Magrini, F. Sorace. Alterazioni della strategia posturale nel “colpo di frusta” valutate mediante posturografia statica. Acta Otorhinolaryngol Ital 17 (6), 409-413, 1997.

In short, cervical subluxations and perilymph fistulas together cause significant long term postural problems, and it is unlikely that either can be properly corrected without correction of the other.  Moreover, this may explain why some patients do not “hold an adjustment.”  From a proprioceptive standpoint they are forced to alter their cervical position to remain upright.

Inner Ear Injury Neurological Effects

In mentioning this, I must also mention the substantial neurological effect this problem can cause.  Due to abnormal signals coming from the inner ear, the brain is constantly dealing with feedback to fundamental responses.  This derogates from the brain’s ability to manage with every day tasks such as memory, and cognitive function.  In a review of Maslows work in the 1950s called “The Heirarchy of Needs,” we find that the body has a hierarchal system of prioritizing body functions.  This places the basics for survival (obtaining oxygen and water) over all other functions.  When these things are satisfied it goes on to prioritize things like the ability to stay upright, digest food etc.  Things like cognitive function, coordination of distal extremities, and the ability to do one’s work or studies properly, are prioritized at a lower level.

 

The more significant repercussions of inner ear injuries, is that people can not normally place themselves in space, leaving them susceptible to falls, bumping into objects, crashing into objects while driving in a car, and drowning if disoriented while underwater.  Even more problematic though, is the potential for meningitis to spread from the inner ear during a routine upper respiratory infection.  We know that communication of bacteria through the cochlear aqueduct is possible, as it also occurs in the reverse flow with a condition called Purulent Labyrinthitis.  In Purulent Labyrinthitis CSF tainted by Menigitis flows through the cochlear aqueduct into the inner ear causing complete hearing loss, and facial paralysis.

Healing From Inner Ear Injuries

Healing of the inner ear membrane occurs one cell at a time.  If it is re-ruptured by new trauma you start over again.  Once it heals over at one cell thin, the connective tissue starts to move in.  This is vastly different from other parts of the body where collagen comes in early after an injury.  This means that collagen fibers do not lay down for approximately eight weeks of uninterrupted healing.  Once the connective tissue starts to lay down, it does not fully rehab for 12-18 months.  The minute movements constantly made by the malleus, incus and stapes provide the “cross fiber friction” to properly rehab this very small and fragile membrane.

Consider the following about perilymph fistulas:

  1. The oval window tears in the inner ear can heal 80% of the time;
  2. The best way to heal the inner ear is a conservative method which I will outline below;
  3. The best period in which to heal is the first 6-12 weeks subsequent to an injury;
  4. Unfortunately, many people are not aware to take precautions during this first 6-12 week period because either their symptoms have not yet become apparent, or they have not been correctly diagnosed;
  5. The cognitive problems which occur with this condition are due to the brain requiring its capacity normally used for cognitive processes to take over the balance mechanisms of the inner ear and battle the ongoing incorrect spatial input coming from the inner ear;
  6. The headaches associated with this condition are due to a CSF leak (referred to as perilymph fluid if it exits the ear) which causes lower than normal levels and pressure within the spinal column and cranium;
  7. This CSF leak makes patients extremely susceptible to meningitis if opportunistic infections or bacteria spread to the ear.

Precautions for Healing Following an Inner Ear Injury

As a result of the very serious problems resulting from even a low speed impact, one should take what precautions are available to help the inner ear heal.  These precautions are taken directly from Dr. Black’s patient instruction manual:

The goal of fistula precautions is to minimize any movement, pressure changes or trauma that keeps the fistula open or re-opens the fistula.

Activities that are exertional in nature may increase the pressure in your head, chest or abdomen, resulting in increased cerebrospinal fluid pressure, causing your fistula to leak or recur if it is sealed.

Sharp jerking motions (e.g. “whiplash”) or blows to the head or neck may be sufficient to cause or reopen a fistula.

Rapid air pressure changes (e.g. plane travel or travel over significant altitude) may be sufficient to alter middle ear pressure and cause fistula or re-open fistula.

  1.  Keep your head above the level of your heart at all times.
  2. When reclining, keep your head elevated 30 to 45 degrees. You must NOT lie flat.
  3. When moving up in bed, bend your knees and arms, then push gently with your feet and hands. To sit up roll to one side, move your legs over the side of the bed and use your hands and arms to slowly push yourself up.
  4. When not in bed you may recline on a couch, sit in a well padded easy chair or sit in a high-backed chair to rest your head. Again, your head must be elevated at 30 to 45 degrees AT ALL TIMES.
  5. Eat a well balanced diet and drink plenty of fluids (six to eight 8 oz glasses per day).

Inner Ear Injury Fistula Dos and Dont’s

The following is a list of specific “dos and don’ts”. Keep in mind that these are only a few examples. We cannot list each and every activity that might violate fistula precautions. You must use your common sense to decide whether or not a situation or activity is appropriate for you.

  • Do not lift anything over five pounds (unless otherwise instructed by your doctor).
  • Do not bend over or squat down.
  • Do not strain or bear down-avoid constipation.
  • Do not blow your nose. Nasal secretions should be “sniffed” gently back into the throat and spit out.
  • When you cough or sneeze, do so as gently as possible with your mouth wide open. Do not hold your nose and blow to “pop” your ears.
  • No housework or yard work.
  • Do not blow up balloons or bubble gum.
  • Do not sing or yell loudly.
  • Do not use straws or waterbottles that create suction in your ear.
  • Do not try to open tightly sealed jars.
  • Be careful when putting on shoes and socks. Do not bend over and do not tug hard on them.
  • It is best to avoid wearing any kind of boots, as tugging them on and off will cause too much pressure in your head.
  • Avoid strenuous activity and sexual relations (unless otherwise instructed by your physician). Do not throw things, cast a fishing line, etc.
  • It is preferable that you not go higher than five floors on an elevator.
  • Avoid altitudes greater than 500 feet (in Portland this applies to Skyline, Burnside, Barnes Rd., Council Crest, Sylvan Hill, Mt. Scott, Taylor’s Ferry, Sunnyside, etc.).
  • Do not travel by plane for at least one year following fistula closure, and never travel by plane if you have a cold (upper respiratory infection).”

While this list can be seemingly impossible for some people, there are patients who will be able to comply.

Inner Ear Conservative Care and Surgical Intervention

While some doctors complain that taking eight weeks off to lay in bed and let the inner ear heal is ridiculous and not possible for any modern human being, the injury does have an 80% chance of healing under such conditions which would prevent the necessity for surgery for 80% of the patients who have this injury.  That is a success rate for a conservative treatment which we could only pray existed for other serious conditions.  So, for those who could possibly do this, and do have a confirmed perilymph fistula, it would be worth the time.

In cases where the ear does not heal with the above protocol, there is the option of surgery.  There are several large studies reporting the results of surgical treatment of perilymphatic fistulas. The percentage of patients with fistulas found surgically ranges from 24% to 93%. Vestibular symptoms had the best response to surgical treatment, with 60% to 90% of cases improving. Hearing loss responded much less favorably except in fluctuating or progressive sensorineural hearing loss in which case surgery would often stabilize or slightly improve the hearing. Postoperative management consists of bed rest, head elevation and no straining for the first 5 days, followed by 4 to 6 weeks of light, non-strenuous activity.

Endolymph Hydrops (is it the same as Meniere’s Syndrome)?

Another inner ear injury is called an Endolymph Hydrops.  This condition can be caused by traumatic damage to the “hair cells” in the vestibular areas of the inner ear.  Insurance defense doctors will sometimes testify that an injured person would have to have a massive head blow (like a baseball bat to the head) in order to sustain an inner ear injury.  Contrary to what the insurance doctors will say, hundreds of medical research papers confirm that inner ear injuries are caused by less severe head trauma, including trauma caused by motor vehicle collisions.

Insurance doctors will also say that the symptoms of an inner ear injury will be immediate.  This is their testimony despite a recent check of medline on “delayed onset endolymph hydrops”  showing that there are over 500 articles on delayed onset endolymph hydrops after trauma.

The other misleading testimony that insurance doctors will provide is that traumatic Meniere’s is very rare.  They will claim that Endolymph Hydrops and Meniere’s are the exact same condition.  What they fail to honestly disclose, is that there are “primary” and “secondary” types of Endolymph Hydrops.  Primary Endolymph Hydrops is called Meniere’s Syndrome.  By definition, primary endolymph hydrops or Meniere’s is non-traumatic because the cause is unknown.  But secondary endolymph hydrops is known to be caused by trauma, including trauma from a motor vehicle collision.  So, when an insurance defense doctor testifies that an injured person cannot have a traumatic Meniere’s Syndrome (while equating that with all types of Endolymph Hydrops), it is misleading because they are intentionally failing to disclose to the judge, jury or arbitrators that Meniere’s is only one type of endolymph hydrops.  Unless the lawyer understands this distinction and makes it very clear to the judge, jury or arbitrators, you can and likely will, lose your traumatic inner ear injury case.

Inner Ear Injury Lawyer

If you need a traumatic inner ear injury lawyer, call today for a free consultation at 503.227.1233  or Toll Free at 866.843.3476. Our Portland based firm handle personal injury matters throughout Oregon and Washington.