SSHL- Diagnosis and Management

Sudden Sensorineural Hearing Loss- A Single Case Study

Guided by Mr. Jabir PMPresented by Reem Noushad & Fathima Shahanas

Sudden Sensorineural Hearing Loss

First described by Dr. De Kleyn in 1944, sudden sensorineural hearing loss (SSHL or SSNHL), commonly known as sudden deafness, occurs as an unexplained, rapid loss of hearing—usually in one ear—either at once or over several days. It should be considered a medical emergency as delaying diagnosis and treatment may render the treatment less effective or ineffective.

According to National Institute on Deafness and other Communication Disorders (NIDCD) the criteria for SSNHL is

" Subjective sensation of hearing impairment in one or both ears developing within 72 hours and a decrease in hearing of more than or equal to 30 decibels, on 3 consecutive frequencies in comparison to normal ear on audiometry"

Statistics

• 1500 cases reported per year worldwide
• 4000 cases per year in the US
• According to Sunil Mathews (2020) the estimated annual incidence of SSNHL in India is 5 to 30 cases per 100,000 population

• Highest incidence in 50-60 year olds
• Lowest incidence in 20-30 year olds

• Men and women have equal distribution
• Less that 5% is bilateral
• A specific cause present only in about 10% of patients
• Limited Indian data available
• Actual incidence may be higher since many patients recover spontaneously

Etiology

Only 10 to 15 percent of the cases diagnosed as SSHL have an identifiable cause. Most cases are classified as idiopathic, also called sudden idiopathic hearing loss (SIHL) and idiopathic sudden sensorineural hearing loss (ISSHL or ISSNHL). The majority of evidence points to some type of inflammation in the inner ear as the most common cause of SSNHL.

• Viral and infectious
• Autoimmune
• Labyrinthine membrane rupture
• Vascular
• Neurologic
• Neoplastic

AUTOIMMUNE

• Autoimmune Inner Ear Disease

• Lupus erythematosus
• Cogan's syndrome

TRAUMATIC

VIRAL AND INFECTIOUS

• Temporal bone fracture
• Inner ear concussion
• Otological surgery
• Surgical complication of non-otologic surgery

• Mumps
• HIV

• Syphilis
• Rubella

• Herpes virus

DRUGS

NEOPLASTIC

• Acoustic Neuroma
• Leukemia

• Metastasis to the internal auditory canal

Ototoxic drugs like diuretics, cisplatin, non steroidal anti inflammatory drugs and antibiotics like aminoglycosides

VASCULAR

Vascular ischemia of the inner ear or cranial nerve VIII (CN8) which can result from microcirculationand lack of red blood cells or their deformity

In a meta-analysis of 23 studies of SSNHL, the most frequent causes identified were infectious (13%) followed by otologic (5%), traumatic (4%), vascular or hematologic (3%), neoplastic (2%), and other (2%) (Chau et al., 2010).

CLINICAL SIGNS AND SYMPTOMS

Most commonly seen:

Sudden onset of hearing loss, unilateral deafness

Vertigo, indicating an associated peripheral vestibular dysfuncion in about 30% of people. Nausea/vomiting is seen associated with vertigo.

High pitched tinnitus ocurs in abuot 80% of patients.

A feeling of aural fullness in about 80% of patients

Muffled conversation sounds

OTHER SYMPTOMS INCLUDE

Feelings of anxiety

Viral upper respiratory tract infection

Difficulty heaaring high pitched sounds

Trouble following group conversation

CLINICAL DIAGNOSIS

THOROUGH HISTORY AND PHYSICAL EXAM

• Sudden sensorineural hearing loss is considered to be a true otologic emergency, given the observation that there is less recovery of hearing when treatment is delayed.
• The primary goal is to rule out any treatable causes.

CIRCUMSTANCES SURROUNDING THE HEARING LOSS

ASSOCIATED SYMPTOMS

TUNING FORK TESTS

AUDIOLOGICAL TEST AND FINDINGS

Should indicate SNHL greater than 30 dB over three continuous frequenciees. SRT and SIS correlate with PTA obtained.

Vestibular schwannoma, cerebellopontine tumors, brain stem infarctions, and demyelinating disease

Rinne and Weber should indicate SNHL

Abnormal OAE findings

PTA & SA

OAE

Screening TFT

CT/MRI

Otoscopy

Immittance Audiometry

ABR

Fistula Test

To exclude cerumen impaction, middle ear effusion, infection, mass or a perforated TM

Prolonged or absent peaks. 30 dB or greater loss.

Negative fistula test

Normal tympanometric findings with reflexes absent in the affected ear

TREATMENT OPTIONS

First line of treatment depends on the causative factors.

TRAUMATIC

INFECTIOUS

AUTOIMMUNE

NEOPLASTIC

5 days of strict bed rest

Traumatic

Avoid strainig activities

The patients history will usually elicit an inciting event such as a blow to the head, sneezing, bending over, lifting a heavy object, exposure to sudden changes in barometric pressure (such as during flying or diving), or exposure to a loud noise.

6 weeks of modified physical activity

Surgical management

Infectious

Infectious SSHL are mostly attributed to viral infections that can occur due to direct viral invasion or latent virus reactivation. Treatment involves identifying the causative pathogen and following its treatment protocol.

Neoplastic

Acoustic neuromas are usually associated with gradually progressive hearing loss. However, the increasingly widespread use of CT and MRI imaging of patients has indicated that nearly 19% of patients with acoustic tumors may present with SSHL

19%

Treatment involes surgical removal of the tumor in combination with radiotherapy.

Autoimmune

• The cornerstone of therapy is corticosteroids.
• Most authors suggest using prednisone 1mg/kg for 2-4 weeks with a subsequent rapid taper for cases of complete resolution and slow taper for those with incomplete response.

Other medical treatment

The following treatment methods are adopted only if every other treatment plan proves to be futile. They may be given in conjunction to other medications.

02

01

03

low molecular weight dextrane

Oral nicotinic acid

aspirin

06

04

05

antivert, promethazine, valium

pentoxifylline therapy

carbogen therapy

To treated associated symptoms

CORTICOSTEROID THERAPY

Write a subtitle here

What are they?

Corticosteroids are synthetic drugs that are used to treat a wide variety of disorders, including asthma, arthritis, skin conditions and autoimmune diseases. The drug mimics cortisol, a hormone that's naturally produced by the adrenal glands in healthy people.

How do they work?

The most striking effect of glucocorticoids is to inhibit the expression of multiple inflammatory genes (cytokines, enzymes, receptors and adhesion molecules).

Administration

• Systemic steroids dosage- Prednisone 1mg/kg up to 60 mg for 3-5 days, tapered 10–60 mg/d for 6–14 days.
• Intratympanically dosage is about 0.3–40 mg/injection once a day or once every 2 days for 6 days to 4 weeks.

Intratympanic Administration

Equipment: Ear speculum, binocular otology microscope, a syringe with a 25-gauge spinal needle, anesthetics and steroid preparation at body temperature. Preparation: Position the patient in a comfortable position supine in a chair with their head rotated to the contralateral ear. Wax and debris in the external auditory canal may need to be removed to ensure good visualization of the entire tympanic membrane. Topical anesthetic (Xylocaine 2%/dose spray) placed on the anteroinferior quadrant of the tympanic membrane. Technique: Infused dexamethasone 1 ml injected using a 25-gauge spinal needle through the anteroinferior anesthetized region into the middle ear space until full. Myringotomy and grommet insertion done to avoid barotrauma to the round window. Following administration, the patient remains supine with injected ear up and avoids swallowing, yawning, or speaking for 20 to 30 minutes to facilitate steroid passage across the round window membrane and prevent leakage into the eustachian tube.

Intratympanic Administration

Complications of Corticosteroid Therapy

Intratympanic steroids have minimal morbidity; however, there are some potential complications or side effects that must be considered and thoroughly discussed with the patient before undergoing the procedure.The most common side effects are transient dizziness, injection site pain, and a burning sensation.Other possible complications or side effects include:

• Pain
• Ear fullness

• Vertigo (generally temporary)

• Headache

• Dizziness

• Persistent tympanic membrane perforation

• Tinnitus

• Infection

• Syncopal episode

• Tongue numbness

Effectiveness

• A systematic literature search performed by Li and Ding in 2020 concluded that moderate and high doses of CT could accelerate hearing improvement in SSHL.
• About two-thirds of patients with SSNHL will experience full or partial recovery.
• Recovery varies with severity at presentation, and those with mild hearing loss usually achieve full recovery.
• Spontaneous improvement or full recovery is rarely seen in those with severe to profound hearing loss.

• A recent national study, with Carey leading the work at Johns Hopkins, assigned 255 patients with sudden hearing loss to receive either oral or middle ear injection of steroids over two weeks. Their findings suggest that the two treatments have comparable outcomes, at least for patients with hearing loss less than 90 decibels. For those with very severe loss, 90 decibels or above, oral steroids proved to be a better treatment. The study, published in the Journal of the American Medical Association in 2011, showing that in most cases, injected steroids are as effective as oral steroids”.

• When surveyed, 98% of U.S. otolaryngologists reported treating idiopathic SSNHL with oral steroids; additionally, 8% of otolaryngologists reported the use of intratympanic steroids (Shemirani et al., 2009). Corticosteroids are thought to improve idiopathic SSNHL by reducing inflammation and edema in the inner ear (Merchant et al., 2008; Wei, Mubiru, & O’Leary, 2006).

Complications

• Full recovery of hearing is not a common outcome of SSHL as the time of essence when it comes to its management. Sometimes treatment is rendered ineffective and can lead to complications such as persitance of hearing loss and tinnitus.
• The resulting hearing loss may be unilateral in many cases, but the impact of the loss should not be minimized.
• In one study (Chiossoine-Kerdel et al., 2000), 86% of adults with unilateral SSNHL reported the presence of hearing handicap as measured by the Hearing Handicap Inventory of Adults (Newman et al., 1990) and 57% reported tinnitus handicap as measured by the Tinnitus Handicap Scale (Newman et al., 1996). Patients who have hearing loss may lose more hearing, as shown in a retrospective study by Stahl and Cohen (2006), who reported that 20% of their subjects developed SSNHL in their only normal-hearing ear resulting in bilateral hearing loss.
• Audiologic rehabilitation must be addressed at the time of identification of hearing loss whether the loss is unilateral or bilateral.

Audiological Management in Case of Persistence of Symptoms

Components of an audiologic rehabilitation program designed for patients experiencing SSNHL should include:1. Counseling:

• The counseling role of the audiologist is critical to the management of SSNHL (Schein & Miller, 2005).

• Time for counseling should be included at each follow-up assessment during the treatment period to address communication issues, even if there is an indication that hearing will return. Including the family and significant others in this process is critical during this phase of treating SSNHL, and the patient may need to consider individual and/or group treatments such as auditory training and speechreading as intervention options.

• Referral to support groups may assist in the patient’s adjustment to hearing loss.

Audiological Management in Case of Persistence of Symptoms

2. Amplification options such as CROS hearing instruments (Hearing aids), implantable devices (BAHA, cochlear implants)

Audiological Management in Case of Persistence of Symptoms

3. Hearing assistive technology such as FM systems and signal-alerting devices.

4. Tinnitus retraining therapy and tinnitus maskers

CASE PRESENTATION

A 20 year old female came to the ENT and Audiology department (BMH) with the complaint of sudden reduced hearing sensitivity and ringing sensation in the right ear since 1 week. Earlier the patient had undergone treatment (in Tely Health Centre)for the same two days after the onset of the above mentioned symptoms and vertigo, which included intravenous administration of corticosteroids for the duration of three days (Methyl Prednisolone 1 gm) and oral adminstration of Predmet 16 mg, Neurokind plus, Rabemac, Vertin and Mondeslor.

Initial PTA (Tely Medi Centre)

Provisional Diagnosis: Right Ear:Moderately Severe Mixed Hearing Loss Left Ear: Hearing Sensitivity Within Normal Limits

The patient vistited the department as their symptoms (ringing sensation and reduced hearing sensitivity)continued to persist even after the primary treatment.

Case History

• Reduced hearing sensitivity in the right ear since 1 week.
• Persistent high frequency tinnitus in the right ear since 1 week.
• History of vertigo 5 days ago which subsided with the initial intake of corticosteroids.
• Difficulty localizing sounds.
• Difficulty hearing in noisy situations.

• No history of exposure to noise or ototoxic drugs.
• No other significant medical or otological history as reported.

Investigations

Otoscopic Examination (ENT Findings)

• Auditory Canal: Unobstructed in both ears.
• TM: Gray in color, translucent and in neutral position in both ears.

• Malleus lies in oblique position behind the upper part of drum in both ears.
• TM mobile with air inflation in both ears.

Impression: Bilateral intact external auditory canal and TM.

Done on 01.03.2021

Puretone Audiometry

Provisional Diagnosis: Right Ear: Moderately Severe Sensorineural Hearing Loss Left Ear: Hearing Sensitivity Within Normal Limits

Immittance Audiometry

Tympanometry

Impression: Bilateral 'A' type tympanogram

REFLEXOMETRY - IPSILATERAL

Impression: RE: Ipsilateral reflexes absent. LE: Ipsilateral reflexes present.

Conclusion: Bilateral no indication of middle ear pathology

Auditory Brainstem Response

Threshold Estimation: Stimulus used: Clicks (19.3/s, Rarefaction polarity) Right Ear: AEPs are elicited till 70 dB nHL (Morphology of wave- Good, Wave consistency and reproducibility: Good) Left Ear: AEPs are elicited up to 30 dB nHL (Morphology of wave- Good, Wave consistency and reproducibility: Good)

Provisional Diagnosis: Right Ear : Moderately Severe Hearing Loss. Left Ear : Hearing sensitivity within normal limits.

Recommendations:

• ENT Review
• Medical Management

*Counseling done

ABR Waveform

ENT Review

• Diagnosed as right sudden onset moderately severe sensorineural hearing loss
• Treatment suggested: Intratympanic steroid injection.

Treatment

• Patient admitted for procedure two days after initial evaluation (03.03.2021).
• Right intratympanic steroid injection performed under local anesthesia.
• Local anesthesia done with xylocaine 2% - anteroinferior qudrant.
• Infused dexamethasone 1 ml injected using a 25-gauge spinal needle through the anteroinferior anesthetized region.

• Myringotomy and grommet insertion in the posteroinferior qudrant.
• Supine position maintained for 30 minutes after administration.

Medications given after the procedure:

• Ampoxin-500 mg
• Stemetil 5 mg
• Emeset 4 mg

Recommendations:

• Soft diet
• Keep ear dry
• Follow up after two days

Follow up PTA after the procedure

06.03.2021

RIGHT EAR: Mild High Frequency Sensorineural Hearing Loss (Greater loss above 4 KHz) LEFT EAR: Hearing Sensitivity Within Normal Limits

Recommendations from the audiologist following the procedure

• Avoid exposure to loud sounds
• Avoid prolonged exposure to sounds
• Regular audiometric testing to monitor hearing levels
• Immediate medical consultation in case of any pain, discharge, aural fullness or reduced hearing.

Hearing Sensitivity in Subsequent PTA

29.03.2021

29.04.2021

12.03.2021

29.09.2021

14.03.2022

10.06.2021

Final PTA

14.03.2022

RIGHT EAR: Hearing Sensitivity Within Normal Limits Except at 8 KHz LEFT EAR: Hearing Sensitivity Within Normal Limits

PTA as a function of time

Initially the PTA was found to be 62 dB indicating Moderately Severe loss in the right ear. Immediately following the administration of ITS, the PTA came down to 27 dB indicating Mild loss. In the subsequent hearing evaluations, hearing improved evidently, reaching normal level (7 dB HL) 9 days after the procedure. Though normal PTA was obtained, the loss at 8 KHz continued to persist. The patient was instructed by the doctor to have follow up hearing evaluation every 6 months.

Audiological Recommendations

• Avoid exposure to loud sounds
• Avoid prolonged exposure to sounds
• Regular audiometric testing to monitor hearing levels
• Immediate medical consultation in case of any pain, discharge, aural fullness or reduced hearing.
• Avoid ototoxic drugs
• Report incidence of SSHL in any future medical consultations

TEAM INVOLVED

Radiologist

Other healthcare workers

ENT Consultant

Audiologist

Psychologist

Session Open For Discussion

Take Home Message

SSHL is a condition that occurs overnight and can leave the patient confused and distressed. Early diagnosis is key for its appropriate management and should be treated as a medical emergency. Misdiagnosis or late diagnosis results in poor prognosis and can leave the patient with a permanent hearing loss.

Thanks!