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sudden sensorineural hearing loss ( ssnhl ) is generally defined as a threshold reduction of 30 db in at least three contiguous audiometric frequencies . all ages and both sexes
are affected , with peak ages ranging between 30 and 60 years ( 1 ) .
tinnitus is usually present in ssnhl ( > 90% ) and vertigo is frequent either spontaneously or as isolated positional vertigo ( 2,3 ) .
a maximum of 3265% of cases of ssnhl may recover spontaneously ( 4,5 ) , although clinical experience indicates that even this recovery rate may be an overestimation .
the prognosis for recovery is dependent on a number of factors , including patient age , presence of vertigo at onset , degree of hearing loss , audiometric configuration , and time between onset of hearing loss and treatment ( 68 ) . because the etiology of ssnhl is usually unknown ,
the most commonly used treatment has been corticosteroids ( systemic and/or intratympanic ) . a large array of other treatments such as antivirals , antibiotics , diuretics , vasodilators , osmotic agents , plasma expanders , anticoagulants , mineral supplements , and hyperbaric oxygen or carbon dioxide rich gases , among others ,
a retrospective analysis of patient records from 2010 to 2013 was carried out .  
 aims and objectives 
  the primary objective of the study was to evaluate the various prognostic factors associated with the outcome of ssnhl .
the factors considered were age , sex , duration of hearing loss at presentation , associated tinnitus , vertigo , and presence of various co - morbid factors such as diabetes and hypertension .
the present study was undertaken in the department of ear , nose and throat ( ent ) and head and neck surgery at our institute .
subjects included in the study were suffering from idiopathic sudden - onset unilateral or bilateral sensorineural hearing loss . only one subject was less than 10 years of age ( 8 years ) .
she was excluded from the study as she was not cooperative in the hearing assessment .
patients suffering from known causative factors such as trauma or ototoxicity were exclded from the study .
detailed otolaryngological history including hearing impairment , ear discharge , vertigo , tinnitus , aural fullness , and presence of upper respiratory infection was taken .
any history of trauma , straining , diving , flying , and intense noise exposure was noted .
past medical history of other diseases associated with sudden hearing loss was obtained , such as diabetes , autoimmune disorders , malignancies , neurologic conditions ( multiple sclerosis ) , or hypercoagulable states .
an ent examination was performed in all subjects to examine the state of the tympanic membrane .
tuning fork tests were carried out in all cases at frequencies of 256 hz , 512 hz , and 1024 hz .
this was followed by pure tone audiometry assessment at the time of presentation and subsequently on days 3,7,10 and after 1 month of treatment using a madsen orbiter 922 v2 audiometer in a sound - treated double - room set up .  
air conduction and bone conduction thresholds were tested and plotted by the same audiologist for a particular patient .
narrow band masking was used whenever required.serial testing was conducted to note the progression or resolution of the hearing loss and response to treatment .
the final outcome of disease was decided on the basis of the audiometric evaluation performed after 1 month .
patient intervention 
   evaluation and management of sudden hearing loss should be considered medically urgent , if not an emergency . in our study , after initial audiometry subjects were admitted to a ward .
routine hematological investigations ( i.e. , hemogram , serum urea , creatinine , blood sugar and electrocardio- gram ) were performed in all patients .
the following treatment was initiated : 1 . intravenous steroids ( dexamethasone ) at a dosage of 8 mg thrice a day for 10 days followed by oral steroids ( deflazacort ) in tapering doses started at an ~1 mg / kg body weight and tapered at an interval of 35 days for another 21 days .
the oral steroid was administered as a single dose after meals with a cover of oral antacid .
( in the experience of the author , giving a prolonged dose of steroids helps in treating subclinical or persistent histopathological edema ) .
2 . oral diuretics in the form of acetazolamide ( 250 mg twice a day ) for a total period of one month .
5 . a broad spectrum antibiotic ( usually co - amoxiclav , at a dose of 3040 mg / kg in three divided doses ) intravenously for seven days . 6 .
subjects who did not recover hearing were followed - up for further investigations in the form of magnetic resonance imaging ( mri ) brain scans and further investigations to rule out any associated lesion in the cerebellopontine angle area or otherwise .
the average hearing loss of subjects at the time of presentation was 100 db hl ( air conduction ) , ranging from 78110 db hl .
out of the 40 subjects , 25 ( 62.5% ) experienced recovery within a period of 1 month .
the average audiometries of these subjects at the time of recovery was 38 db hl ( air conduction ) .
of these 25 subjects , only four recovered partially , having a persistent , moderate hearing loss of around 5560 db hl .
the remainder of the 21 subjects recovered completely , reaching a hearing threshold comparable to normal person .
approximately 32.5% ( 13 ) of the subjects presented within 24 hours of onset of the hearing loss ( table .
1 ) .   various prognostic factors affecting the outcome of patients presenting with sudden sensorineural hearing loss of these
all three of these subjects had an associated history of co - morbid factors such as diabetes and hypertension .
fifty - five percent ( 22 ) of subjects had an associated history of tinnitus ; while 12.5% ( five ) had vertigo and 10% ( four ) had an associated upper respiratory tract infection ( table .
more than 85% ( six out of seven ) of diabetic subjects did not recover .
unexplained left side predominance was seen in our subjects ( 67.5% had left - sided hearing loss , 27.5% had right - sided , and 5% bilateral ) , like most previous studies ( 10 ) .
hearing is one of our most important senses and its sudden loss can be frightening and frustrating for the subject as well as the physician .
the recovery rate in our study ( 62.5% ) correlated well with the previous studies ( 3265% ) ( 4,5 ) .
the aim of our study was to correlate the presence of these factors with the recovery and cure rates of ssnhl .
many previous studies have found that the subjects seen earlier after onset of hearing loss show greater improvement , reflecting either the benefit of early treatment or the natural recovery rate ( 10 ) .
suggested that if therapy with one or more treatment types was started within 1 month of sudden hearing loss , there was a ~50% rate of improvement vs. ~25% if started later than 1 month .
the amount of improvement seen on sequential audiograms may reflect the position of the subject on his / her own spontaneous improvement curve ( 7 ) .
the presence of vestibular symptoms has been considered as a poor prognostic indicator in earlier studies ( 11 ) , but no such indication was obtained through our study , possibly because of the small sample size .
viral infections , vascular compromise , autoimmune processes , and labyrinthine membrane ruptures have been proposed as possible etiologies of ssnhl ( 12 ) . in our study ,
subjects presenting with diabetes had a significantly lower rate of recovery ( only 14.3% compared with an overall recovery rate of 62.5% ) .
it has been postulated that diabetes is associated with microangiopathic injury , hence a vascular event and a possible etiological factor for ssnhl .
similarly , in our study it was seen that none of the subjects with an associated history of hypertension recovered . according to several reports ,
advanced age , hypertension , diabetes , and hyperlipidemia are poor prognostic factors , suggesting that microvascular dysfunction in the cochlea gives rise to poor outcomes ( 13 ) .
we found the prognosis for ssnhl to be improved in subjects who presented early and with tinnitus .
the outcome was poor in subjects presenting late , and having associated diabetes or hypertension .
introduction : sudden sensorineural hearing loss ( ssnhl ) is a frightening and frustrating symptom for the patient as well as the physician . 
 prognosis is affected by multiple factors including duration of hearing loss , presence of associated vertigo and tinnitus , and co - morbidities such as hypertension and diabetes . 
 materials and methods : forty subjects presenting to our department with features of sudden hearing loss were included in the study . detailed otological history and examination , serial audiometric findings and course of disease were studied . 
 results : subjects presenting late ( in older age ) , having associated vertigo , hypertension and diabetes had a significantly lower rate of recovery . 
 conclusion : only 6065% of patients experiencing ssnhl recover within a period of 1 month ; this rate is further affected by presence of multiple prognostic indicators .