Vertigo and Hearing Symptoms in Pilots and other Airline Workers.
Timothy C. Hain, M.D.
Last updated: April 3, 2023
Vertigo in pilots as well as other people who work at heights (i.e. iron workers), or who are responsible for many people's welfare (i.e. Bus drivers), is usually considered differently than the general population. Both the workers as well as the licensing agencies are understandably more cautious about these individuals working, or returning to work, after vestibular injury. The generic term for this in the airline industry is "spatial disorientation" (Gillingham, 1992).
According to Martin-Saint Laurent et al (1990) incapacitation of pilots was due to vertigo in 1/10 instances. Other causes included cardiac disorders, seizures, and various other conditions. Wang and Xue (1994) reported that considering inner ear conditions reponsible for permanent grounding, the most common were "barotitis media, followed by hearing loss, Meniere's disease, motion sickness, and vertigo".
The health care workers taking care of persons in these occupations are generally placed in between, and have to mediate between the worker's desire to return to their occupation, the assessment of risk depending on the cause of vertigo and objective evidence, and the regulating authorities.
This can result in odd situations where the best treatment for migraine associated vertigo might be an antidepressant or anticonvulsant, but the pilot will refuse as their licensing authority often uses medication as the critical variable in assessing return to work.
Pilots in particular are highly paid, generally enjoy their occupations, and are eager to return to work. They are presumably slower to report a potentially disabling condition, and sometimes may be inclined to report fewer symptoms for a given amount of objective inner ear damage, than others.
Airline attendants, especially those who have achieved senior status, are also commonly reluctant to report symptoms. This is because senior flight attendants are often allowed assignments that include considerable opportunity for exotic locales.
Airline tarmac workers are exposed to loud noise and are generally not as enamored with their occupations as the foregoing groups.
In the following we will discuss the impact of specific diagnoses on these occupations.
Acoustic neuromas are slow growing tumors of the nerve between the inner ear and brain. Pons et al (2010) reported that fitness to fly decisions " were based on several factors: minimally disturbed audition, i.e., less than a 35-dB hearing loss with a good speech discrimination score; good balance, i.e., no reported difficulties; no spontaneous nystagmus recorded on videonystagmography (VNG); no postural deviation; and a normal head-shaking test."
Our take on this is that acoustic neuromas are rarely a source of acute vertigo, and that they should be treated similarly as patients with vestibular neuritis. (see below). We are dubious that a head-shaking test should be used as a screen. We would expect that well functioning and well compensated pilots, might still have head-shaking or vibration induced nystagmus. As clinical medicine improves, our technology to develop vestibular lesions has become more sensitive.
Benign Paroxysmal Positional Vertigo
Sen et al (2007) reported on a single case of a pilot who was successfuly treated, and returned to flying. We think this is reasonable --
Kirschen et al (2012) argued that physicians were ethically obligated to report BPPV to the Federal Aviation Administration, even if the patient requested confidentiality.
Our position is that once the BPPV is successfully treated, it should be allowed for pilots to fly and commercial drivers to drive.
On the other hand, we do not think that iron workers or firemen should be working "in the air" with BPPV. For iron workers, safety issues are severe, and we are dubious that they should return to working a heights.
We see no major issues with flight attendants having BPPV flying or not, as they do not endanger others.
Perilymph fistulae (PLF) are rare and controversial disorders of the inner ear, mainly seen in Scuba divers and individuals with barotrauma such pilots and airline attendants. Their symptoms are similar to individuals with SCD, in that both can cause vertigo from pressure fluctuations.
Tingly and MacDougall (1977) reported on two aircrew members, and suggested that "careful attention be paid to the ears of pilots recovered from what would otherwise appear to be a mysterious accident". This is very vague.
Groth et al (1984) proposed to use pressure chambers to simulate pressure fluctuations. This might pick up both PLF, SCD, as well as simply "alternobaric vertigo" related to dizziness from unequal pressures between the ear.
Our position on this is that pilots/airline workers should be able to fly with a PLF as long as a ventilation tube can be maintained in the ear in question, or a surgical repair has been performed successfully.
Meniere's disease is diagnosed on the basis of hearing loss, tinnitus, fullness, and episodic vertigo. While hearing symptoms generally do not impact a pilot's ability to fly, vertigo can. As Meniere's can be mild, with an impact similar to having the flu from time to time, it can also be severe and disabling due to recurrent vertigo.
Guyot (1996) discussed a case involving a pilot with Meniere's disease. This case was handled by having the pilot voluntarily stop flying when having vertigo. Guyot mentions that a law stating that Pilots with Meniere's should be permanently grounded, regardeless of treatment, might be dangerous.
Treatment and diagnosis of Meniere's has improved in recent years. In particular, low-dose gentamicin treatment often eliminates significant vertigo. This converts individuals with Meniere's into a group resembling vestibular neuritis.
Many persons with Meniere's also have or at least admit to very little vertigo while they are taking their medications. This is a somewhat thorny situation that seems best managed on a case-by-case, rather than with generalizations.
Airline workers, especially "tarmac" workers, are exposed to loud noises from airplanes. Pilots and flight attendants also may be exposed less frequently to airplane noises, and also they are exposed to pressure fluctuations related to the airplane environment, as well as self-induced pressure fluctuations when they "pop" their ears. The typical pattern is of a "noise notch". Occasionally persons with noise induced hearing loss experience tinnitus, but only in tarmac workers can it become severe enough to impair their carrying out of their occupation.
The audiogram aboves shows both a gentle "noise notch" centered at 4K, as well as asymmetry in tympanometry (presumably related to a more compliant TM on the left, perhaps related to repeated self-Politizerization.
Vestibular Neuritis.
Vestibular neuritis, operationally defined as an idiopathic illness that damages the vestibular nerve, is usually a condition where there is vertigo that gradually resolves over several months, and then usually associated with a residual reduction in balance and sensitivity to head movement. It can flare up again, but this is unusual. Vestibular neuritis can be easily diagnosed with the "VHIT" test.
Shupak et al (2003) reported on their experience with 18 military pilots. This is a very thoughtful paper. They had an average of 67% reduction of caloric responses (which is rather high for this diagnosis). Many of their patients had deficits on formal testing that were not apparent at the bedside. The implication here is that specialized evalation is needed.
They recommended return to flight should require either normal rotatory chair testing, or "compensated vestibulopathy", which they defined as "no asymmetry", associated with phase lead and low gain. They also suggested that if pilots had "any abnormality on bedside testing", would mean no return to flying. This seems a little vague to us. They suggested that for the most part, Pilots returned to flying should be required to fly with a co-pilot.
These restrictions are much more severe than those that are generally advocated for tumors of the 8th nerve, and we think that they are a bit draconian. We think that pilots who have had no vertigo for a year, and who are "well compensated" on their vestibular testing (i.e. no spontaneous nystagmus), might reasonably be allowed to fly.
References:
- Gillingham, K. K. (1992). "The spatial disorientation problem in the United States Air Force." J Vestib Res 2(4): 297-306.
- Guyot, J. P. (1996). "Should a pilot suffering from Meniere's disease be grounded or lifted off to the moon?" ORL J Otorhinolaryngol Relat Spec 58(6): 304-305.
- Groth, P. and O. Tjernstrom (1984). "Pressure chamber tests for selection of aircrew." ORL J Otorhinolaryngol Relat Spec 46(5): 264-269.
- Kirschen, M. P. and J. A. Friedlander (2012). "Grounded for an ethical dilemma: disequilibrium in a commercial airline pilot." Continuum (Minneap Minn) 18(5 Neuro-otology): 1158-1162.
- Martin-Saint-Laurent, A., et al. (1990). "Clinical aspects of inflight incapacitations in commercial aviation." Aviat Space Environ Med 61(3): 256-260.
- Pons, Y., et al. (2010). "Vestibular schwannoma and fitness to fly." Aviat Space Environ Med 81(10): 961-964.
- Sen, A., et al. (2007). "Benign paroxysmal positional vertigo in an airline pilot." Aviat Space Environ Med 78(11): 1060-1063.
- Shupak, A., et al. (2003). "Vestibular neuronitis in pilots: follow-up results and implications for flight safety." Laryngoscope 113(2): 316-321.
- Tingley, D. R. and J. A. MacDougall (1977). "Joint Committee on Aviation Pathology: XVII. Round window tear in aviators." Aviat Space Environ Med 48(10): 971-975.
- Wang, E. T. and S. Y. Xue (1994). "A review of otolaryngologic aircrew disqualification in the Chinese Air Force, 1961-90." Aviat Space Environ Med 65(5): 424-427.