Question: Please tell me something about post-traumatic dizziness and in particular, perilymphatic fistulas. What treatments are there for dizziness after TBI?
Answer: Brain Injury Source, Volume 2, Issue 4, Ask the Doctor
by Nathan Zasler, MD, FAAPM&R, FAADEP, CIME
Clinicians often diagnose "post traumatic dizziness: without looking much further than that in attempt to identify the underlying etiology of the subjective complaint of dizziness. All dizziness has a cause. Elucidating the cause and stipulating a specific rather than general diagnosis allows for appropriate and timely treatment to be rendered, thereby optimizing functional outcome. It is important to differentiate symptoms of dizziness based in subjective sensations. Specifically, dizziness may be any of the following: pre-syncope (near fainting/lightheadedness), disequilibrium (unsteadiness/wooziness), vertigo, motion sickness and psychogenic.
There are various etiologies of post traumatic dizziness. Perilymphatic fistulas (PLFs), which can occur following trauma of various types is only one potential etiology and its frequency following trauma has been highly debated (e.g., some clinicians feel it is very common, whereas others feel it is quite uncommon). Readers should note that brain injury is not necessary for development of a PLF.
Perilymphatic Fistula
Post traumatic PLFs may present as a result of rupture of the oval and less commonly the round window with subsequent dehiscence between the inner ear and middle ear resulting in inappropriate stimulation of labyrinthine receptors. Symptoms may include vertigo, fluctuating hearing loss (usually a late complication), tinnitus (ringing in the ears) and chronic low-grade nausea. Other associated conditions include endolymphatic hydrops (Meniere’s disease), cervical myodystonia (abnormal muscle tone) and persistent or exertional headache. These types of patients and others with vestibular disorders may often complain of non-specific imbalance problems that are worse than those experienced when turning suddenly. Other complaints include disequilibrium with perceptually complex external stimuli. Specifically, these individuals report feeling uncomfortable in crowds, when driving down tree lined streets and when traveling on an escalator.
It is quite interesting that patients with perilymphatic fistulas, as well as vestibular disorders, in general, often become agoraphobic (develop a fear of being among crowd) and have a relatively high incidence of anxiety related disorders, including panic attacks. The aforementioned phenomena has been studied to some extent and makes sense relative to the fact that visual stimulation associated with a perceptually stimulating environment has the propensity to make one become avoidant of such stimuli if one has a vestibular disorder of any magnitude. Given that such stimuli cause the patient to feel uncomfortable, it is not unexpected that such secondary psychological disorders may develop.
Some clinicians have speculated that post traumatic perilymphatic fistula symptoms stimulate visual compensation for labyrinthine dysfunction subsequently causing disorientation in visually complex situations. Additionally, some have noted problems with higher cognition and language. All these problems are presumed to have a perceptual basis, related not to brain injury per se, but attempted sensory accommodation to aberrant sensory input as a result of the perilymphatic fistula. I think this point is quite important in that I have seen many cases, both clinically as well as forensically, where patients are labeled as brain injured when they in fact only have a vestibular disorder causing an array of somatic, cognitive and behavioral symptoms that were incorrectly apportioned to brain injury. The diagnoses of traumatic brain injury and perilymphatic fistula are not mutually exclusive and must be treated for each accordingly.
The definitive diagnostic test for perilymphatic fistulas remained somewhat controversial. There has been recent literature looking at the use of the fistula test that questions its utility as a definitive measure of PLF presence. Bedside clinical findings are generally not particularly sensitive to this condition including the Hallpike or Nylen-Barany maneuver, Tragus test and/or Hennebert’s test, among others. Certain software programs have been designed to provide a "fistula test" during posturographic assessment; again in the field of neuro-otology and vestibular rehabilitation relative to its level of specificity and sensitivity.
New techniques including transtympanic electrocochleography have been used pre-operatively, as well as post-operatively to evaluate for perilymphatic fistulas. Many clinicians believe that the definitive diagnosis can only be made at the time of surgery. Based on the inspection, however, many clinicians will tell you even at that point that it is still difficult at times to make a definitive diagnosis. Newer techniques utilizing analysis of fluid harvested at the time of surgical inspection with analysis for beta II transferring via immunoblotting assay have been used to assist in definitively making the diagnosis. This substance is only found in cerebral spinal fluid and inner ear perilymph and is absent from serum and other body fluids.
Generally, post traumatic PLF heal spontaneously. Treatment of non-resolving OPLF involved surgical patching of the leak if bed rest is ineffective. Surgery is also indicated if there is a sudden hearing loss without improvement and/or continued symptoms beyond one month from a presumptive PLF.
Other Causes of Dizziness
Other causes of dizziness following trauma include inner ear dysfunction due to a variety of different conditions aside from perilymphatic fistula including post traumatic endolymphatic hydrops (so-called Meniere’s disease), benign paroxysmal positional vertigo (also referred to as BPPV) and labyrinthine concussion. Vestibular nerve damage with disruption of 8th cranial nerve function. Not uncommonly associated with temporal bone fractures, is another etiology of post traumatic dizziness. Direct injury of the brain stem or vestibulocerebellar connections can also result in so-called central vertigo. This is a very challenging problem with a very guarded prognosis for improvement.
A common (at least in this author’s opinion), yet still somewhat controversial etiology of dizziness is so-called cervical vertigo associated with whiplash injuries. This type of dizziness is related to perturbations in information received from joint position receptors (so-called proprioreceptors) in the neck that feed into the vestibular system.
Psychological conditions can also result in complaints of dizziness including anxiety disorders, depression, panic disorders and certain somatoform disorders. Certainly, dizziness can also be embellished and/or malingered. One should not forget dizziness due to such things as over-medication or medication-related side effects.
A relatively uncommon cause of dizziness following trauma can also be seen with what has been termed ictal vertigo, associated with post traumatic epilepsy. This has also been referred to as "tornado" epilepsy. This primarily occurs in simple partial seizures that usually evolve into complex partial seizures or generalized seizures with loss of consciousness.
From a treatment standpoint, regardless of the etiology of the condition, there is generally always something that can be offered to the patient with post traumatic dizziness to ameliorate their symptoms and associated balance dysfunction. Of the aforementioned conditions, central vertigo due to brainstem injury is the most challenging to treat. Options for treatment may include various medications, balance retraining, vestibular habituation therapies, otolithic repositioning maneuvers, myofascial pain management and surgical strategies depending on the etiology of the dizziness.
References
Delaroche O, Bodoure P, Lippert E & Sagniez M: Perilymph detection by beta II – Transferring Immunoblotting. Application to the Diagnosis of Perilymphatic Fistula. Clin Chim Acta. 254:1, 93-104, 1996.
Fitzgerald DC: Head trauma: Hearing loss and dizziness. J Trauma. 40:3, 488-496, 1996.
Sass K, Densert B & Magnusson M: Transtympanic electrocochleography in the assessment of perilymphatic fistulas. Audiol Neuro-Otol. 2:6, 391-402, 1997.
Tusa RJ & Brown SB: Neuro-otologic trauma and dizziness. In: Head Injury and Post Concussive Syndrome. M Rizzo & D Tranel (Eds). New York: Vertual Livingston. Pgs. 177-200, 1996.
Zasler ND: Neuromedical diagnosis and management of post-concussive disorders. In: Medical Rehabilitation of Traumatic Brain Injury. L Horn & N Zasler (Eds). Philadelphia: Hanley & Belfus, Inc., 1996.