Dr. Shivashankar’s Case Commentaries (Part 2)

Ediitor’s Note: This is part 2 of Case Commentaries by Dr. Shivashankar. Part 1 focused on a case of unusual conductive hearing loss and a Case of Landau Kleffner Syndrome.

 

Case C: An unpardonable error due to lack of in-depth knowledge about the spectrum of hearing difficulties an individual can have

This is the story of a girl aged 16 years. She had recently completed high school (Grade 10). She was examined at an ‘X’ place for her hearing impairment when she was 16 years of age (April’1999). She was diagnosed as having bilateral conductive hearing loss based on a basic audiology evaluation that comprised of pure tone audiometry and a detailed ENT evaluation. She was subjected to stapedectomy in the right ear, following which hearing worsened to profound deafness.  Her parents took her for a second opinion for her hearing problems wherein she was suspected to have either Wernicke’s aphasia or a bilateral profound hearing loss. She was referred to NIMHANS for further evaluations. Yes! This was a case that required differential diagnosis. Needless to say, it excited me. Remember I am talking about a case I saw way back in 1999.

My favourite first step was to start with case history. Parents reported that she presented with difficulty in hearing in competing noise/ noisy environment. They observed this ever since their daughter was 6 years old. I noticed this difficulty soon after we began the interview. It was a hot summer day. The ceiling fan was running adding to the ambient noise. My office was amidst a busy neurology out-patient clinic. Noises from the hallway included people talking to each other, a baby crying, and a father yelling at his naughty pre-schooler. As I probed further, parents told me that their daughter started to complain a lot more about inability to hear in middle school. She often did not understand instructions that the teacher gave her. I had ruled out Wernicke’s aphasia. Yet, I decided to ask her to read – I was checking reading comprehension. She was able to read just fine. Without spending more time on the Wernicke’s diagnosis, I started to think about the second potential diagnosis – bilateral profound hearing loss. How could it be as simple as profound hearing loss when the most glaring problem was difficulty in perceiving speech in noise? I decided to evaluate this young lady. At this juncture, I was clear about the path ahead – she needed an evaluation to see if her auditory nerve function was intact (see Table-3). This was not evaluated in any of the previous consultations in places outside of our center (NIMANS).

 

Table 3. Audiological findings

Tests Right ear Left ear
PTA 101.67 dB HL 43.33 dB HL
AFA 97.14 dB HL 46.43 dB HL
SAL 105 dB HL 45 dB HL
ABR Could not be evaluated No peaks
CM Present
DPOAE Absent Present

 

PTA: Pure tone average of 500, 1k & 2k Hz; AFA: All frequency average from 250-8000Hz; SAL: Speech Awareness Level; CM: Cochlear Microphonic; DPOAE: Distortion product otoacoustic emissions 

 

Based on a series of evaluations (Table 3) a diagnosis of Primary Auditory Neuropathy (PAN), now designated as Auditory Neuropathy Spectrum Disorder (ANSD,) was made for the left ear. Extrapolating based on PAN in the left ear, I strongly feel that all along it was PAN and stapedectomy was a gross error of judgement. Further, Computerized Tomography (CT) – brain, did not show space occupying lesion(s), PAN was the diagnosis of choice.

Points to note:

  • Again, a detail case history that includes onset and progression is most crucial to plan steps ahead and to arrive at a diagnosis
  • Differentiating hearing acuity from hearing speech during case history may be more than enough to give us an idea of the expected results and diagnosis

 

Case D: Importance of mentoring and training the next generation

I firmly believe that one of our duties as mentors is to train our students to become future leaders. Training must not only be academic and clinical, but also include grooming. Training need not always be classroom based; it can be more hands-on where students learn by mere observation. Clinical discussions as far as possible must include students. Here I highlight a case which one my former students (Pradeep Yuvaraj, PY – an Asst. Prof now at NIMHANS), successfully cracked. A case that required detailed history taking and needed thinking out-of-the-box – two qualities I encourage my students to hone from the first day of their training program.

A lady aged 62 years handed over a report from an otolaryngologist. She was diagnosed to have a vocal nodule. After thorough evaluation, she was advised voice rest and vocal hygiene since the nodules were small. As predicted she recovered. After 3 months she came back with similar complaints without significant history. She was again advised voice rest following which she recovered in a couple of weeks. Her 3rd Visit with similar complaints made us confused. We knew this was challenging.  PY set out to find the reason for her recurrent occurrence of vocal nodules. She persistently refused any vocal abuse. PY took a more detailed history than what he took during his first interaction. One point in the interview that caught PY’s attention was the husband’s age. He was 70 years old. PY wondered if there was a link here. As a reader I am sure you will wonder what the husband’s age has to do with the wife’s nodules. Well! there was a connection. PY insisted he met the husband in the clinic. Within a few minutes PY had picked up that the husband was hard of hearing. Soon the husband’s hearing evaluation was conducted. He had bilateral moderate to severe sloping sensorineural hearing loss . PY explained the audiological findings to the couple as well as the potential link between the husband’s hearing loss and the wife’s persistent vocal nodules. The lady had gradually adapted to speaking to her husband in a loud voice to accommodate his hearing loss. The vocal abuse was more so, since most of the communication was with the television (TV) turned on. The TV volume was high since the husband had to hear inspite of his hearing loss. PY counselled the husband to use hearing aids and emphasized  that  it would not only benefit him, but potentially help resolving his wife’s vocal nodules and contribute to overall quality of life. As expected, the wife did not present with vocal nodules during follow-up evaluations.

 

Key learning

  • Importance of mentoring
  • To be a good future leader you have to be student, be observant, be willing to learn
  • Think out-of-the box.

 

Concluding remarks:

I believe essential pre-requisites a clinician must  possess are – ears that listen, a mind that analyses, a heart that is filled with compassion, an ability to learn from others and from your own previous experiences. Sophisticated equipment, tests and tools come next. I am a big fan of mnemonics. Atleast, that is how I have taught myself. So, here is one for you. ABCDE of audiology practice for clinicians –

A-Always elicit proper and clear history

B-Beware of confounding factors

CConduct appropriate tests

D– Diagnosis is an art – take time

E-Effective Communication is the corner stone of clinical care

 

I hope you have found these cases interesting. I will be happy to answer queries you may have about these cases. I would love to hear your feedback and your experiences. Though I have retired from my teaching position, I continue to keep my enthusiasm and love for audiology alive, by re-visiting old cases, listening to webinars, seeing patients, interacting with my students and  not to forget, staying in touch with readers like you. I thank my former doctoral student, Shoba S. Meera, Ph.D., now as Asst. professor at NIMHANS, for helping me draft this note.

 

 

Nagarajarao Shivashankar, Ph.D.
Former Professor and Head,
Department of Speech Pathology and Audiology &
Former Associate  Dean, Division of Neurosciences
National Institute of Mental Health and Neurosciences (NIMHANS)
Bangalore, India.
e-mail: n.shivu54@gmail.com 

About Pathways

Pathways is both a column that covers topics related to CAPD and Neuroaudiology and a society for people interested in central auditory disorders that regularly meets to discuss these issues.

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