Topic: Post-Covid sequelae - Hearing loss, Tinnitus & Vertigo

Speaker: Prof Dr JM Hans, Padma Shri Awardee, Director Dr Hans Centre for ENT, Hearing Care & Vertigo, New Delhi

18^th December, 2021, Saturday; 9.30am-11am

• There has been a 10-15% increase in patients suffering post-Covid sequelae of hearing loss, tinnitus, vertigo. The age variants are disturbing; now these problems are seen in persons as young as 18-20 years.
• Viruses such as rubella, rubeola (measles), mumps, VZV, CMV have a predilection for the inner ear. They directly affected any part of the inner ear like the stria vascularis, organ of Corti or nerves and indirectly they decrease immunity in the host. Covid virus behaved similarly to other respiratory viruses causing cochlear symptoms or vestibular symptoms or both.
• The most important part of the inner ear is the endolymph, which is formed inside the cochlea by the stria vascularis and is also absorbed by the stria vascularis. We do not know where the coronavirus is acting, but based on what we know about the earlier respiratory viruses, we know that they act at the stria vascularis and endolymphatic duct. 
• The most common ear conditions seen are endolymphatic hydrops/Meniere’s disease, labyrinthitis, vestibular migraine and benign paroxysmal positional vertigo (BPPV).
• The first symptoms are fullness pain, deep seated vague burning sensation. The disease has to be picked up at this initial stage. Once the disease is established i.e., when the endolymphatic duct is totally occluded, the condition becomes irreversible.
• Vestibular migraine can be in the vestibular nuclei. The precipitating factor is either endolymphatic (hence called the Migraine Meniere’s syndrome) or working for long hours on the computer or using the mobile phone. 
• BPPV is now known to be in any canal, multiple canals, it could be bilateral. Hence, the maneuvering exercises also vary. There are 15 types of BPPV and there are about 15 types of maneuvering exercises. So, it is very important to pinpoint where exactly the BPPV is.
• The virus directly damages the intracochlear structure and induces inflammatory response leading to formation of debris inside the inner ear, which block the drainage of endolymphatic system causing hydrops. It also causes immunosuppression leading to increased susceptibility to bacterial infections.
• In post-Covid stress, the plasma levels of stress-related hormones such as anti-diuretic and catecholamine are raised. They alter the inner ear fluid dynamics and may cause endolymphatic hydrops. Disease may worsen the emotional state, which in turn may worsen the symptom perception.
• Predisposing factors are genetic, autoimmune state, ototoxic drugs and hormonal imbalance.
• Many of them had underlying allergies, which made them vulnerable after exposure to the Covid virus. People on aspirin were more predisposed to develop endolymphatic hydrops.
• High estrogen levels cause sluggishness of blood flow in stria vascularis, which changes the fluid balance of the inner ear leading to endolymphatic hydrops. Low estrogen may weaken the otoconia and produce symptoms such as BPPV.
• The three major symptoms of Meniere’s disease are episodic vertigo, fluctuating hearing loss, roaring tinnitus. But the blocked ear, which is the initial symptom is the most important. Most blocked ear are treated as eustachian catarrh. If tympanic membrane and impedance are normal, this should raise suspicion of endolymphatic hydrops. 
• Causes are genetic, vascular (stress-induced vasoconstriction), viral infection, allergic/autoimmune, environmental (increased salt and water intake). Secondary endolymphatic hydrops may occur following trauma, otitis media, otosclerosis, internal auditory canal (IAC) lesions or mass. Asians are more prone to this disease than their western counterparts.
• Etiopathogenesis is the formation or excretion of the endolymph. Radial flow where the endolymph is formed and absorbed in the stria vascularis and longitudinal flow where the endolymph is formed in the stria vascularis and absorbed in the endolymphatic duct. Debris are entangled in the endolymphatic duct, which is narrowed by mastoid hypocellularity. Other factors are hypodeveloped Trautman’s triangle and anterior displacement of lateral sinus. 
• Meniere’s disease has to be diagnosed at the prodromic stage, where the patients come with vague symptoms like fullness in the head etc. In stage 1a (fluctuating stage), there is fluctuating hearing loss and roaring tinnitus. This is followed by the disabling stage (stage 1b), where destruction is evident. The hearing loss further deteriorates each time there is an attack. In stage 2, the disease is stable, there is no vertigo but the disease might recur after few years. This latent period keeps on decreasing. The third stage is the contralateral ear stage. 
• The disease is most damaging in the first year. symptoms are blocked ear/deep seated ear pain/burning sensation, Tulio phenomenon (dizziness when there is loud sound), hyperacusis (irritation to the sound - one of the cardinal symptoms of endolymphatic hydrops). Once tinnitus, vertigo and hearing loss occur, this means that the destruction has already started and the disease is becoming less reversible.
• Diagnosis is based mostly on history. Audiometry shows flat curve in 60%, rising curve in 17% (low frequency hearing loss) and falling curve in 12% (high frequency hearing loss). Electrophysiological tests include Short Increment Sensitivity Index (SISI), Electrocochleography (EcocG), Vestibular Evoked Myogenic Potential (VEMP). If EcocG /VEMP is positive, it is a sure case of endolymphatic hydrops. However, a complete vestibular assessment is essential to rule out associated conditions such as BPPV, vestibular migraine.
• In BPPV, the otoliths could be in the canal called canalithiasis or in the cupula called cupulolithiasis. They are most commonly in the posterior canal but lateral or anterior canals may also be involved. There are about 15 types of BPPV, including multicanal BPPV. And there are different repositioning exercises. The Dix Hallpike Test is to be done to pinpoint the otoliths and by which exercise they can be repositioned into the utricle so that they become ineffective. 
• Other tests include thyroid function tests, vitamin B12 and D3, P-ANCA/C-ANCA, skin prick allergy tests, hormonal assay, HRCT (temporal bone) and MRI (IAC)
• Earlier surgical treatment was stressed upon, but this is not the case now. Management involves Meniett’s device, psychotherapy and drugs including intratympanic instillation.
• The drugs include betahistine, piracetam, diuretics (acetazolamide) and steroids. Give all four together to treat endolymphatic hydrops, then the results are very good. Betahistine increases cochlear/vestibular and cerebral blood flow; diuretics reduce formation of endolymph; piracetam reduces erythrocytes adhesion, hinders vasospasm and improves microcirculation.
• Intratympanic steroid increases vascularity, reduces inflammation in the labyrinth, restores normal functioning of stria, regulates inner ear de novo protein synthesis and improves excretion via longitudinal flow.
• If post-Covid acute tinnitus is not treated properly, it becomes chronic, which cannot be treated by intratympanic steroids. The phantom noise has to be treated by tinnitus matching and masking.
• Tinnitus can be matched from 50Hz to 13,500 Hz with One Hz steps.  Advanced audiometers can match till 16-18,000 but with only 500 Hz. Tinnitus masking app can be downloaded on mobile, which has 250 environmental and 250 filtered musical masking tracks. 
• Acute tinnitus which is due to the distension of the endolymphatic system and stretching of the neural element inside, can be very well treated by diuretics and intratympanic steroid.
• Medications have to be stopped as early as possible after tapering the dose and start vestibular rehabilitation.
• Cervical spondylosis is no more a cause of vestibular vertigo. It causes vertebrobasilar insufficiency and pain. The vertebrobasilar insufficiency may cause vertigo, which has a very characteristic feature that there is blurring of vision for few seconds and then it becomes alright. In vestibular vertigo, there is no blurring of vision or sinking sensation. Cervical spasm is secondary to the vertigo. The straightening of the cervical spine is due to the spasm of the muscles.

Participants

Member National Medical Associations

Dr Yeh Woei Chong, Singapore, Chair CMAAO 

Dr Alvin Yee-Shing Chan, Hong Kong, Treasurer, CMAAO

Dr Marthanda Pillai, India Member World Medical Council, Advisor CMAAO

Dr Wasiq Qazi, Pakistan, President-elect CMAAO

Dr Angelique Coetzee, South Africa

Dr Akhtar Hussain, South Africa

Dr Salma Kundi, Pakistan

Dr Ashraf Nizami, Pakistan

Dr Qaiser Sajjad, Pakistan 

Dr Md Jamaluddin Chowdhury, Bangladesh 

Dr Debora Cavalcanti, Brazil

Invitees

Prof Dr JM Hans, New Delhi

Dr Monica Vasudev, USA

Dr Eng Chang Ng

Dr Ng Hwee Hin

Dr Nisha Jacob

Dr Yeo Khoonhui

Dr Patricia La’Brooyi

Dr Gaurav Chaturvedy

Dr Xinhuo Peter Liao

Dr LC Lim

Dr Ashok Gupta, India

Dr Hwee Yee Lai

Dr S Sharma, Editor IJCP Group

Moderator

Mr Saurabh Aggarwal