PROGRESSIVE BILATERAL HEARING LOSS
Timothy C. Hain, MD. •
Page last modified:
October 1, 2022
What is progressive bilateral hearing loss?
Progressive bilateral hearing loss (PBHL) is defined rather simply as the significant decline in the hearing of both ears at the same time.
PHBL comes in several different timing variants --rapid, and slow. Rapid (or subacute) over several months. Slow, over years. Autoimmune inner ear disease is an example of a subacute process. Age is an example of a slow process.
PBHL is much more common than the unilateral hearing loss. For example, nearly 100% of the population eventually develops age related bilateral hearing loss.
PBHL also is divided up by location --including "conductive" (such as due to ear wax , otosclerosis, or fluid in the middle ear), "sensorineural" (inner ear or nerve), and "central" (brainstem and above). We will leave out the conductive causes below as they are nearly all just bilateral versions of unilateral disease. There are only a few rare exceptions due to bone diseases affecting the skull such as osteogenesis imperfecta, Pagets, Engelmann's disease, or fibrous dysplasia.
What is progressive bilateral hearing loss?
A list of the most common causes of PBHL include:
- age-related hearing loss (everyone eventually gets this -- it is a slow process, over years)
- noise induced hearing loss (very frequent as well, usually another slow process)
- ototoxins (unusual, but generally over months as in aminoglycoside ototoxicity)
- Meniere's disease (about 5% of 1/2000 prevalence of Meniere's -- usually occurs in steps, one ear at a time, so not strictly meeting the definition of PBHL)
After one excludes the very common disorders above, what is left over is:
- meningitis (both bacterial and viral) including syphilis and cancer cells in spinal fluid (carcinomatosis) e.g. Ozturk et al (2014)
- autoimmune disorders such as Cogan's syndrome.
- genetic causes of progressive hearing loss (especially Connexin mutations). Aport syndrome is another one of these (due to a Collagen IV mutation), as is EYA4.
- superficial siderosis -- iron deposition, generally from a leak close to the 8th nerve, causes hearing loss over years. (Aran Yoo and Kattah, 2017; Halmagyi et al, 2022)
- low spinal fluid pressure (e.g. Sahin et al, 2015) -- this is usually from shunts.
- Chiari malformation (Dolgun et al, 2009)
- Myelodysplastic diseases such as leukemia or lymphoma. (e.g. Cherchi et al, 2006; Lee et al, 2007; Hoistad and Hain, 2003)
- Central hearing loss (exceedingly rare) are largely grouped by their location -- such as brainstem damage, or auditory cortex damage.
- Other bilateral forms of unilateral diseases than Meniere's -- bilateral labyrinthitis, or bilateral tumors (e.g. bilateral acoustic schwannomas)
- Mysterious (i.e. "idiopathic") progressive hearing loss
These are mostly processes that damage both ears or the nerves to the ears together.
How is progressive bilateral hearing loss diagnosed and treated ?
In essence, PBHL is diagnosed by documenting an ongoing decline in hearing in both ears. This
generally requires several audiograms.
Other than this, diagnosis of PBHL requires checking for a large number of individual causes, as outlined above.
Treatment of PBHL is generally specific to the cause. Cochlear implants are much more frequently used in this condition however.
Sudden bilateral hearing loss.
PBHL is not "Sudden". Sudden bilateral hearing loss is defined as hearing loss, occuring in both ears, occurring over roughly 48 hours. Sara et al (2014) reviewed "bilateral sudden sensorineural hearing loss" and found 103 reported cases in the world literature, most of which were "toxic, autoimmune, neoplastic or vascular".
Sun et al (2019) in an article written in Chinese, stated that "Si-BSSHL has a female preponderance and tends to occur in advanced age in our cohort. Compared to USSHL patients, Si-BSSHL patients have less profound hearing loss and more descending audiograms, and the proportion of patients with extremely severe deafness is relatively small. There is no significant difference in the therapeutic effect between the two groups." This is difficult to interpret in as much as the article is inaccessible to most English speakers.
Imamura et al (2005) discussed sudden bilateral low tone hearing loss, and stated "Our review indicated that 9.0% (162 of 1803) ALHL patients were bilaterally affected, possibly indicating that AIHL includes a larger number of bilateral cases than currently assumed, if the opposite side were given a especially detailed clinical interview. "
Sudden bilateral hearing loss (SBHL) is related to the more common condition of "sudden hearing loss", or SHL, which generally is defined as being confined to one ear. Perhaps "SUHL" would be a better name than SHL. Sudden bilateral hearing loss occurs 20 times less commonly than sudden hearing loss in one ear (Oh et al, 2007). According to Chen and Young (2016), the prognosis is very poor for sudden bilateral hearing loss with a very high mortaility rate (44%) in 16 patients over 5 years.
- Aran Yoo, B. S. and J. C. Kattah (2017). "Superficial siderosis syndrome with progressive hearing loss and bilateral vestibular failure, 51 years after a neurosurgical procedure: diagnostic value of combined MRI and video head impulse test." J Neurol 264(2): 391-393.
- Chen, Y. H. and Y. H. Young (2016). "Bilateral simultaneous sudden sensorineural hearing loss." J Neurol Sci 362: 139-143.
- Cherchi, M., et al. (2006). "Gradual hearing loss with bilateral labyrinthine hemorrhage in chronic myelogenous leukemia." Neurology 67(1): 177-178.
- Dolgun, H., et al. (2009). "Chiari Type I malformation presenting with bilateral hearing loss." J Clin Neurosci 16(9): 1228-1230.
- Halmagyi GM, Parker GD, Chen L, Welgampola MS, Watson JDG, Barnett MH, Todd MJ, El-Wahsh S, Rose V, Stoodley MA, Brennan JW. Progressive loss of hearing and balance in superficial siderosis due to occult spinal dural defects. Eur Arch Otorhinolaryngol. 2022 Jul 16. doi: 10.1007/s00405-022-07523-3. Epub ahead of print. PMID: 35841407.
- Hoistad, D. L. and T. C. Hain (2003). "Central hearing loss with a bilateral inferior colliculus lesion." Audiol Neurootol 8(2): 111-113.
- Imamura S, Honda H, Miyata M, Mizukoshi A, Masuyama K. [Bilaterality in acute low-tone sensorineural hearing loss]. Nihon Jibiinkoka Gakkai Kaiho. 2005 Mar;108(3):214-21. Japanese. doi: 10.3950/jibiinkoka.108.214. PMID: 15828287.
- Kishimoto, I., Yamazaki, H., Naito, Y., Shinohara, S., Fujiwara, K., Kikuchi, M., . . . Harada, H. (2014). Clinical features of rapidly progressive bilateral sensorineural hearing loss. Acta Otolaryngol, 134(1), 58-65. doi: 10.3109/00016489.2013.831993
- Lee, S. H. and P. H. Wiernik (2007). "Adult T-cell leukemia/lymphoma presenting with bilateral hearing loss: a case report." Med Oncol 24(1): 109-113.
- Oh, J. H., et al. (2007). "Bilateral versus unilateral sudden sensorineural hearing loss." Otolaryngol Head Neck Surg 136(1): 87-91.
- Ozturk, M., et al. (2014). "Bilateral sudden sensorineural hearing loss caused by leptomeningeal carcinomatosis: case report and review." Kulak Burun Bogaz Ihtis Derg 24(5): 287-291.
- Sahin, C., et al. (2015). "Sudden bilateral hearing loss after spinal anaesthesia." J Laryngol Otol 129(4): 395-397.
- Sun CL, Guo DN, Shen J, Du XD. [A clinical analysis of 27 cases of simultaneous bilateral sudden sensorineural hearing loss]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2019 Dec;33(12):1134-1137. Chinese. doi: 10.13201/j.issn.1001-1781.2019.12.005. PMID: 31914259. [article is in Chinese]
- Sara, S. A., et al. (2014). "Bilateral sudden sensorineural hearing loss: review." J Laryngol Otol 128 Suppl 1: S8-15.
- Wang Y, Xiong W, Sun X, Liu W, Fan Z, Wang H, Wang M. Characteristics and prognosis analysis of bilateral sudden sensorineural hearing loss: A retrospective case-control study. Clin Otolaryngol. 2022 Sep 10. doi: 10.1111/coa.13981. Epub ahead of print. PMID: 36087103. [This paper suggests that BSHL is related to homocysteine levels. We find this very dubious].