TTS and PTS - Discordant or Concordant Twins?

The reduction in sensitivity level of ear on exposure to noise, described as shift in threshold of hearing can be temporary or permanent. This reduction shows high individual variation and occurs more on exposure to sounds  in the range of 2-6KHz. Temporary threshold shift (TTS)  and Permanent threshold shift (PTS) represent the most common hearing effect of acute and chronic high level acoustic stimulation (Quaranta et al, 1998). 

The interesting aspects concern the definition of duration of hearing loss (for TTS) and whether there is any relationship between the two entities. 

TTS is commonly defined as "rise in auditory threshold during short exposure to noise which normally disappears in 24 hours but may last as long as a week"

The fact is post exposure improvement of threshold following such exposure may continue for 30 days or longer and there may not be return to preexposure threshold level (I.e PTS may occur). 

The exact issue is there is no consensus as to how short or long one waits before pronouncing TTS a PTS. The exact point at which a TTS becomes a PTS is very difficult to identify.  Age, exposure duration, exposure to other ototoxicity factors, intensity of the impact noise are other factors determine PTS. 

The second issue is whether outcome of TTS studies can be grafted wholesale into prevention of PTS. 

For ethical reasons, studies on PTS focused on animals, while human studies concentrate on creating temporary hearing losses (TTS). Typically the latter assumes that PTS must always be preceded by TTS. This has been shown not be strictly true. TTS is simply not a predictor of PTS, and we do not currently have good predictor of TTS. 

The underlying molecular mechanisms are different for TTS (glutamate accumulation and tectorial membrane tip disconnection) and PTS (cell death related to apoptosis or necrosis). So TTS may not tell us much about PTS. 

Further Reading

1. Marshall Chasin. What does TTS tell us about PTS?  Available at hearing health matters.org/hear the music/2012/what-does-tts-tell-us-about-pts/ 
2. Scand Audiol Suppl 1998;48:75-86 
3. Otol Neurotol. 2016 Sep;37(8):e263-70. 

Focusing On A Third of The Story

Hearing loss is an invisible disability and like other disabilities often command the interest and attention of philanthropist and NGOs. The interesting aspect is the do-gooders always have genuine interest in helping out but are often unsure where to start. 

Take for example the Telco that desires to assist with hearing loss. In developing countries, the common approach  is to focus on hearing aids distribution. Most do it by getting hearing aids dispensers to assemble hearing impaired in the community and in the presence of TVs and the press, proceed to 'screen' and administer hearing aids in few cases. 

There is often no follow up to determine who benefits and who does not after such photo-shoots. Some even hand out hearing aids without ear moulds or ear inserts. 

Now the facts is hearing aids only benefit a third of the hearing impaired (arguably a quarter) and focusing solely on these is neglecting the remaining 3/4 - those who require middle ear surgery, those who require Cochlear implants, and those that cannot be helped by any currently known measures and likely to require educational and occupational rehabilitation. 

So while we appreciate efforts geared towards assisting the hearing impaired in our communities by donating hearing aids, please be mindful that there are countless others who would not benefit  from hearing aids and equally require assistance. As such please note you are only focusing on a third of the hearing loss story. 

Cat-Roommate Analogy for Tinnitus in Cases Coming for Ear Surgery

Tinnitus - the sensation of sound/noise in the ear or head is an age old symptom that continues to perplex sufferers and researchers alike. The interest in tinnitus stems not only from the fact that it is an annoyance to sufferers, but that there are as many types of tinnitus as there are theories about its origin. 

Tinnitus could be subjective (audible only to the sufferer) or objective (can be heard by the clinician as well as the sufferer), high or low pitch, regular or irregular noise, persistent or pulsatile and could result from organic and non-organic causes. Interestingly the noise could result from diseases affecting the external ear (ear wax, foreign body, growth, etc), the middle ear (plethora of these) as well as the inner ear (Meniere's disease, Vestibular schwanoma, etc) as well as diseases of the Eustachian tube, central nervous system and systemic diseases. 

Theories put forward to explain tinnitus focused on peripheral mechanisms (discordant damage to outer and inner hair cells, imbalance of afferent and efferent hair cells of the auditory pathway, etc), brain stem anomalies (inferior colliculus and dorsal cochlear nucleus hyperactivity / disinhibition, etc), and the cerebral cortex(auditory cortex / amygdala hyperactivities, etc) and other non-auditory mechanisms for generation of tinnitus. 

To tinnitus sufferer, the simple worry is 'Am I going crazy or is something terribly wrong with me or my head'?

To the clinician, the worry is 'Is this tinnitus of organic or non-organic source'? 'Is it of central or peripheral origins'? 'Is it associated with hearing loss'?

Now the interesting aspect is, with this plethora of possible etiologies, patients with tinnitus and middle ear diseases (like cholesteatoma and chronic suppurative otitis media) coming for ear surgeries (Tympanomastoidectomy, tympanoplasty) often ask the most interesting question: 'Will this noise disappear after my ear surgery'? 

After a decade of middle ear surgery, I finally found the most interesting analogy as response to that scary question. It goes like this:

Imagine there are 3 of us living in a house - you (patient), myself (the clinician) and a cat. Now imagine the 2 of us were seated in the living room and a noise was headed continuously from the bedroom, with the cat nowhere in site! 

The interesting initial  assumption  is "it is that stupid cat'. 

Now there is only the one way to verify that assumption: Go into the bedroom and look for the cat. Now, this is where it gets so interesting, finding a cat in the room does not CONFIRM it is the source of the sound/noise. What the modern scientific medicine taught is that we remove the cat from the room, close the door and go back to the living room to listen again. It is the absence of the noise/sound after that, that CONFIRMS 'It is the cat'. Persistence of the sound after that means we need to look for other source(s) of the sound. 

This "Cat Roommate" analogy has assisted me in putting succinctly the reality regarding expectations from middle ear surgery in patients with background tinnitus. Perhaps you may find it useful for your cases too. 

Further Reading

1. Theories of generation and management of tinnitus. https://www.mayo.edu/mayo-edu-docs/mayo-clinic-audiology-conference-documents/handouts-new-theories-on-the-generation-and-management-of-tinnitus.pdf 

2. Tinnitus- Current neuroscience research and theories. http://www.hearingloss.org/sites/default/files/docs/LeaverAM_.pdf 

Dizziness: Probe before You Treat

From personal experience of running a dedicated vertigo clinic for a decade now, it appears that when people experience dizziness for the first time, the experience is so terrifying that they are often short of vocabulary to describe the sensation they feel. This lack of clarity in symptom description often mislead inexperienced physicians into the wrong treatment. 

Generally, the presenting complaint is always "I am feeling dizzy". Now the issue is this can mean several things to several people:

Feeling like blackout / lightheaded which may direct physician towards the cardiovascular system

Feeling like drunk while walking which may direct physician to the neurological system

Feeling as if the whole world is spinning or as if the subject is spinning which directs physician to the vestibular system

Feeling like seeing double which may direct clinician to the ophthalmology 

And so on. 

So when confronted with the dizzy patient, the challenge confronting clinician is what does the client mean by "I am feeling dizzy"

The interesting thing in ORL is that dizziness as a symptom, in most countries where English is a second language, is regarded as a block symptom which should not be accepted without probing for the details. It is similar to saying "I have catarrh" which can be taken to mean either 'I have stuffy nose', or 'I have blocked nose' or 'I have runny nose'

The interesting aspect is most GPs have little interest, training and understanding in diagnosis and management of the dizzy patient, but would nevertheless have commenced patients with dizziness on medications before referral to ORL surgeons. 

It would be nice for GP clinicians to make sure they're on the same page with patients presenting with dizziness before commencement of treatment. 

So when next you're experiencing dizziness, make sure you explicitly describe your symptom to your GP and that he understood these, before accepting treatments offered. 

Why Buying OTC ‘Hearing Aids’ Might be Bad for You and Yours

Significant Hearing loss is known to affect about 5 per cent of people world wide, and the prevalence is believed to be higher in some countries that others. Data from the hearing loss clinic (that I run for the past 10 years) revealed that out of every 10 people diagnosed with hearing loss, 4/10 will require hearing aids, 2/10 will require ear surgery, 3/10 will require cochlear implants, and the remaining 1/10 cannot be helped and will require  vocational training. 

Of the 4/10 that require hearing aids, only 1 to 2 can afford it. This is where it gets more interesting. With the currently available technology, Hearing aids are fast becoming valuable ‘consumer electronics’ objects. Like cars. Like iPad. You can get different models and make that make a whole world of difference beyond merely amplifying sound. A pair of these digital and programmable devices cost between $2,000 and $6,000. 

These high-tech, costlier devices provide best amplification and their fittings often require 2 important processes: hearing measurements (called audiometry) and hearing aids impression taking. The impression is taken to ensure perfect fit into the ear canal, since hearing aids without a perfect fit may result in leakages, described as acoustic feedbacks, manifesting as annoyance noise perceived while the hearing aids are being used. The effect of this is tendency of the wearer to become non-user. 

Now it is on the issue of cost and time to fitting (it takes between 2 - 4 weeks between the impression taking and hearing aids fitting in most developing countries where hearing aids are not manufactured) that a new market niche is being created. This ‘instant hearing aids’ providers utilize silicon ear pieces of variable diameter coupled to cheap sound amplifiers to provide cheap, instant, pick and pay ‘hearing aids’.

This is similar to picking prescription lenses from a supermarket / shopping mall when you have mild refractive error. Now the debate is whether these amplification devices should be classified as “hearing aids”. 

According to Yee, Chan & McPherson (2015), Hearing aids sold directly to consumers in retail stores or through the internet, without individual prescription by audiological professionals are termed over-the-counter devices. These amplifiers cost between $300 to $500, provide low frequency amplifications (and this explains why they are not good for your old grannies’ age-related hearing loss) and for others with significant hearing loss beyond the low frequency range, and are not FDA approved! 

The interesting thing about these hearing amps market is they are currently incorporating interesting hearing aids features like directional microphones, and bluetooth connection to smart phones!

In developing countries like Nigeria, these hearing amps are being distributed and marketed as ‘low cost hearing aids’ to appeal to indigent majority who cannot afford FDA approved devices. The truth is OTC ‘hearing aids’ provide sound amplification for people with mild-moderate hearing loss. They are ‘one-size-fits-all’ devices, unlike prescription hearing aids which are programmed to address the user’s specific hearing impairment. 

When next you handed your granny a ‘pick and pay’ “hearing aids”, try to follow up and see why granny dislikes wearing his/her hearing aids. 

Further Readings:

1. Anne Eisenberg. Just Don’t Call Them Hearing Aids. New York Times. Available online at http://www.nytimes.com/2014/03/23/technology/just-dont-call-them-hearing-aids.html?_r=0 . Accessed 11/11/2015
2. Yee Z, Chan T, McPherson B. Oveer-the-counter Hearing Aids: A Lost Decade For Change. BioMed Research International Volume 2015 (2015), Article ID 827463, 15 pages http://dx.doi.org/10.1155/2015/827463

Strange Postoperative Behaviors in ORL

It is not uncommon for post operative patients to manifest strange behaviors. This is often noted as complications of medications, anesthesia or the pre morbid condition the patient had prior to surgery. Post operative confusion and agitated behaviors commonly seen in the elderly, for example, have been attributed to several factors. 

In the past 10 years, I have experienced 2 cases of young adult females demonstrating what I considered weird post operative behaviors outside the realm of psychosis. 

Case 1: Dateline 2007. A young adult female presented with features of inactive CSOM and persistent annoying ipsilateral tinnitus. Clinical and audiometric analysis showed moderate conductive hearing loss and a 75% pas tensa perforation. The handle of malleus was eroded. So a type 3 tympanoplasty was planned and carried out. Now as was explained to her pre operative, her follow up would entail review on day 3, day 7(for removal of sutures) and day 10(for first graft inspection).  However following discharge home on day 3, she absconded (with aural packs in situ!) only to re-appear on day 20 post op complaining of persistent tinnitus and requesting for referral to 'go abroad' for further care. Examination revealed the aural packs were already removed (by who?). Apparently she had travelled 800 km (Abuja to Lagos) to go and consult another facility where she claimed the sutures and packs were removed!!! Apparently she also had attempted securing entry visa to the particular country to meet with her 'fiancé' and failed prior to coming for surgery, and was planning to use the surgery and the report as a means of authenticating her visa claim. Lesson learned: do not carry out tympanoplasty on anyone whose main worry for coming to surgery is tinnitus

Case 2: Dateline 2014. A young female with left parotid tumor of 8 months duration was referred by her sister to a private facility for review and surgery. Clinical examination showed a firm, smooth, non-tender left tail-of-parotid tumor measuring 4x5 cm, with limited mobility, no skin involvement and intact facial nerve. She had no palpable neck nodes associated. Prior to referral she had FNAC with inconclusive cytology report. U.S. Scan confirmed tail of parotid lesion. She was clinically diagnosed as Pleomorphic adenoma. She has superficial Parotidectomy and as was the practice at that setting, she was handed the specimen for onward transfer to Histopathology at nearby facility. Her follow up after was tied to her collecting and presenting the histology report. However she absconded and represented 4 months later with a pea-size mobile nodular swelling inferior to site of previous surgery, and hyperpigmented overlying skin. Apparently she had gone to collect her histology report, read it and referred herself for oncology treatment. She already had chemo-radiation and only noticed the nodular swelling after completion of therapy, all without the knowledge of the primary surgeon!!! A repeat biopsy with neck dissection was suggested. She again absconded, went to a third facility where the excision of nodular swelling was done. She presented again to the primary surgeon 12 months after with cutaneous involvement. At this stage, all that the primary surgeon could do was referral for palliative oncology care. 

It is, up to the present, perplexing why such bizzare postoperative behaviors could  manifested in otherwise sane, young and educated women. 

Observe the nodular swelling just inferior to hyperpigmented (post XRT) skin area. This was at second presentation after initial default to postop visit. 

Further Reading

1.  Post operative confusion - Guide to management. https://mpatkin.org/surgery_clinical/post_op_confusion.htm

2. Confused about postoperative confusion. 

http://www.jhartfound.org/blog/confused-about-post-operative-confusion/ 

Acceptance and Rejection of Academic Papers in ORL

This past weekend has been one of emotional roller-coaster for me. Of the 3 papers from the studies I was involved in, I got notification of 1 acceptance and 1 rejection. That in itself is no big issue: acceptance and rejection is commonplace in the life of an academic. There are several reasons a paper get rejected (see http://www.deakin.edu.au/__data/assets/pdf_file/0011/269831/reasons_papers_rejected-_24.08.pdf )

It hurts because the reason for rejection is preventable human errors. In an attempt to rush a paper to publication because of the excitement of 'discovery' by the author(s), certain details get overlooked. And the reviewer is often not forgiving of such 'silly inconsistencies' in a scientific paper ( I know because aside from being an author, I've been a reviewer to several journals). So the author is left to lonely whisper of 'I can't believe I could be so stupid' while accepting the decision of the editor. Plagiarism is a serious offence in academics and there is no way the poor editor can discern honest but stupid mistake of a paper's authors from the former. The only times I've cried as an adult were times when my papers get rejected!!  But then, the author picks the gauntlet from his raw data and starts all over again.