idiopathic sudden sensorineural hearing loss ( issnhl ) is one of the emergent conditions among various otologic diseases .
it is the acute onset of hearing loss of 30 db in three contiguous frequencies , which may occur instantaneously or progressively over several days ( 1 ) .
it occurs mostly unilaterally , with a bilateral occurrence in 1 - 7.1% ( 2 ) .
treatment strategy is variable , while steroids , vasodilators , and anti - viral agents are most frequently prescribed .
stahl and cohen ( 3 ) recently determined the outcome in patients with issnhl in their only hearing ear , and concluded that they may be treated the same way as those with normal contralateral ear .
however , treatment regimens other than conventional ones may have to be considered in those who do not recover
. therefore , we aimed to determine the outcome of this specific patient group and to define the timing to consider other treatment regimen such as cochlear implantation .
medical records of issnhl patients who were admitted to chonnam national university hospital , gwangju , korea , from august 1999 to june 2006 were retrospectively analyzed .
the control group consisted of 192 patients having issnhl in one ear and normal contralateral ear .
they were given prednisolone ( solu - dacortin , hanall , seoul , korea ) starting from 1 - 1.5 mg / kg / day and tapered for next 12 days .
mgso4 ( 4 g / day ) , dextran 40-dex ( 10 ml / kg in 5% dextrose ) and carbogen inhalation were also given for 7 days with prednisolone .
complete blood cell counting , routine serum chemistry , immunologic markers , viral markers , temporal magnetic resonance imaging or computed tomography were taken .
if the patient did not recover until the day of discharge , he / she was then given intratympanic steroid injection once a week for 3 weeks .
the intratympanic injection was started with local anesthesia by placing cotton pledget soaked with xylocaine ( 10% lidocaine , 10 mg / dose ; astrazeneca , tx , usa ) at the tympanic membrane .
after 15 min , the cotton pledget was removed , and 0.3 - 0.4 ml dexamethasone ( 5 mg / ml ) solution was injected by puncturing the anterosuperior aspect of tympanic membrane with 25-gauge spinal needle .
patients ' age , sex , underlying diseases , the degree of hearing loss , and the presence of dizziness or tinnitus were reviewed .
the duration from the attack of issnhl to the first hospital visit , recovery rate , duration until the recovery , and follow - up period after discharge were compared between the groups . the degree of hearing loss was defined as mild ( 26 - 40 db ) , moderate ( 41 - 55 db ) , moderate - severe ( 56 - 70 db ) , severe ( 71 - 90 db ) , and profound ( 91 db or worse ) using the mean level of 3 frequencies ( 500 , 1,000 , 2,000 hz ) .
the patients were divided into two groups according to the degree of hearing loss : one group included mild , moderate and moderate - severe losses , and the other severe and profound losses .
the recovery rate was determined by siegel 's criteria ( 2 ) : complete , partial , and slight recovery , and no improvement . in those who could not recover and
finally received cochlear implantation , the ability of sound perception and the time elapsed to recover the communication were also determined .
the ability of sound perception was examined using category auditory performances ( cap ) scores ( 4 ) : 0 , no awareness of environmental sounds ; 1 , awareness of environmental sounds ; 2 , response to speech sounds ; 3 , identification of environmental sounds ; 4 , discrimination speech sounds ; 5 , understand common phrases , no lip - reading ; 6 , understand conversation , no lip - reading ; 7 , use of telephone with known speaker .
the statistics included chi - squared test for the analysis of demographic parameters , and independent sample t - test for the duration or recovery rates .
medical records of issnhl patients who were admitted to chonnam national university hospital , gwangju , korea , from august 1999 to june 2006 were retrospectively analyzed .
the control group consisted of 192 patients having issnhl in one ear and normal contralateral ear .
they were given prednisolone ( solu - dacortin , hanall , seoul , korea ) starting from 1 - 1.5 mg / kg / day and tapered for next 12 days .
mgso4 ( 4 g / day ) , dextran 40-dex ( 10 ml / kg in 5% dextrose ) and carbogen inhalation were also given for 7 days with prednisolone .
complete blood cell counting , routine serum chemistry , immunologic markers , viral markers , temporal magnetic resonance imaging or computed tomography were taken .
if the patient did not recover until the day of discharge , he / she was then given intratympanic steroid injection once a week for 3 weeks .
the intratympanic injection was started with local anesthesia by placing cotton pledget soaked with xylocaine ( 10% lidocaine , 10 mg / dose ; astrazeneca , tx , usa ) at the tympanic membrane .
after 15 min , the cotton pledget was removed , and 0.3 - 0.4 ml dexamethasone ( 5 mg / ml ) solution was injected by puncturing the anterosuperior aspect of tympanic membrane with 25-gauge spinal needle .
patients ' age , sex , underlying diseases , the degree of hearing loss , and the presence of dizziness or tinnitus were reviewed . the duration from the attack of issnhl to the first hospital visit
, recovery rate , duration until the recovery , and follow - up period after discharge were compared between the groups .
the degree of hearing loss was defined as mild ( 26 - 40 db ) , moderate ( 41 - 55 db ) , moderate - severe ( 56 - 70 db ) , severe ( 71 - 90 db ) , and profound ( 91 db or worse ) using the mean level of 3 frequencies ( 500 , 1,000 , 2,000 hz ) .
the patients were divided into two groups according to the degree of hearing loss : one group included mild , moderate and moderate - severe losses , and the other severe and profound losses .
the recovery rate was determined by siegel 's criteria ( 2 ) : complete , partial , and slight recovery , and no improvement . in those who could not recover and
finally received cochlear implantation , the ability of sound perception and the time elapsed to recover the communication were also determined .
the ability of sound perception was examined using category auditory performances ( cap ) scores ( 4 ) : 0 , no awareness of environmental sounds ; 1 , awareness of environmental sounds ; 2 , response to speech sounds ; 3 , identification of environmental sounds ; 4 , discrimination speech sounds ; 5 , understand common phrases , no lip - reading ; 6 , understand conversation , no lip - reading ; 7 , use of telephone with known speaker .
the statistics included chi - squared test for the analysis of demographic parameters , and independent sample t - test for the duration or recovery rates .
patients ' age was 47.815.8 yr in the study group , and 51.015.3 yr in the control .
underlying diseases included mostly diabetes mellitus and hypertension , and associated symptoms were dizziness and tinnitus ; with no significant differences between the groups .
there were no significant differences of the initial degree of hearing loss between the groups ( table 1 ) . among the 25 patients in the study group , 14 patients ( 56% )
did not recover the hearing at the time of discharge , 4 of which ( 29% ) received the intratympanic injection of steroids . in the control
, 59% did not recover the hearing at the time of discharge , 24% of which received the intratympanic injection .
the underlying entities of deafness on contralateral ear in the study group were issnhl in 4 , chronic otitis media in 7 , enlarged vestibular aqueduct syndrome in 2 , acoustic schwannoma in 1 , acoustic trauma in 1 , temporal bone fracture in 1 , and unknown in 8 .
table 2 shows the time elapsed from the attack of issnhl to the hospital visit . in the study group
, it was 5.1 days in those showing less than moderate - severe degree , and 3.0 days in those showing severe or profound degree . in the control group ,
it was 7.3 days in those showing less than moderate - severe degree , and 4.5 days in those showing severe or profound degree ( p>0.05 ) .
the total follow - up period was longer in the study group than in the control . in the study group , it was 269.4 days in those having smaller than moderate - severe degree and 329.8 days in those having severe or profound degree . in the control group , it was 62.7 days in those having less than moderate - severe degree and 89.7 days in those having severe or profound degree .
the recovery rate was quite similar between the groups : 64.0% in the study group and 62.5% in the control group ( p>0.05 ) . in the study group , according to siegel 's criteria , 3 were completely recovered ( 12% ) , 6 partially recovered ( 24% ) , 7 slightly recovered ( 28% ) , and 9 were not ( 36% ) . in the control group , there were 43 showing complete recovery ( 22% ) , 36 showing partial recovery ( 19% ) , 41 showing slight recovery ( 21% ) , and 72 showing no recovery ( 38% ) . the recovery rate of those who had issnhl worse than severe degree was 52.9% in the study group and 58.0% in the control group , being not significantly different between the groups .
the time duration until recovery was 17.6 days in the study group and 11.0 days in the control group , the difference being not statistically significant ( p>0.05 ) . in both groups ,
recovery patterns were similar and the recovery was achieved mostly within 1 - 2 weeks after the initiation of the treatment ( fig .
all the recovery was achieved before 12 weeks ( 3 months ) , with only one patient recovering after that time ( 116 days ) . among 8 of those who did not recover in the study group and ended with total deafness in both ears , 6 patients underwent cochlear implantation .
most of the patients reached cap score 5 within 2 - 3 months and could communicate without visual help ( table 3 ) . and about in an year they could talk on the telephone with a familial speaker ( cap score 7 ) .
note that the duration to reach cap score 7 were longest in patients who received their cochlear implantation latest after sudden deaf attack ( patient # 1 & # 2 in table 3 ) .
issnhl occurring in the only hearing ear is a quite important issue because it can cause a sudden blockade of entire verbal communication . however , very few studies have documented its outcomes .
the prognostic factors include age , treatment fastness , degree of hearing loss , and presence of dizziness ( 5 ) .
although it was not the main aim of our study , we also observed that the degree of hearing loss was an important factor of the recovery .
the hearing recovery following the treatment was similar between these two groups : 64.0% of recovery in the study group and 62.5% in the control group .
we could see that conventional treatment strategy also worked with issnhl patients on their only hearing ear since demographic properties , recovery rate and recovery pattern ( fig .
it is suggested that patients with issnhl in their only hearing ear may be treated the same way as issnhl patients with normal opposite hearing ear .
the follow - up duration in the study group was far longer than in the control group .
it is likely that the patients with the only hearing ear would more eagerly seek a professional consult
. they may be more nervous and worried about their outcomes , even in those who have mild or moderate degree hearing loss .
the recovery was achieved mostly within 1 - 2 weeks after the start of treatments .
the longest duration caused for recovery was 90 days in the study group and 116 days in the control group .
most of the patients in both groups achieved recovery within 3 months and the recovery curve showed a plateau after that time ( fig .
1 ) . among 8 patients who did not show hearing recovery in the study group , 6 patients underwent cochlear implantation .
one of the postoperative performance prognostic factors of cochlear implantation is the duration of deafness ( 6 ) .
although there may be some environmental or genetic differences , the time needed for the patient to communicate verbally without visual help was longest in patients who got their implantation after 2 - 3 yr from issnhl attack ( table 3 ) .
most of the patients could communicate without visual help within 2 - 3 months ( cap score 5 ) . and finally they could hear and talk on the telephone with an known speaker about in an year .
similar as in previous reports , we could see that the duration of deaf is an important prognostic factor in cochlear implantation of sudden deafened only hearing ear patients . for those who do not attain a hearing recovery from issnhl in the only hearing ear ,
it may not be proper just to wait and hope for a recovery . because for more the duration of deafness occurs , the poorer result of cochlear implantation might happen .
an active treatment such as cochlear implantation may be considered as early as 3 months in order to return the patient to daily verbal communication .
 the present study was undertaken to learn the outcome of patients with idiopathic sudden sensorineural hearing loss ( issnhl ) in their only hearing ear . 
 timing to conduct a cochlear implantation was also determined in those who did not recover the hearing . 
 the study group comprised 25 patients who confronted issnhl in their only hearing ear . 
 a total of 192 patients , who had issnhl in one ear and had normal contralateral ear , served as the control . 
 demographically there were no significant differences between the groups . 
 the recovery rate was similar between the groups : 64.0% in the experimental and 62.5% in the control group . 
 the duration until the recovery of issnhl in the only hearing ear was 5 - 90 days ( average 17.6 days ) . in the experimental group 
 , 8 patients did not recover from issnhl , and underwent cochlear implantation in 6 with satisfactory results . 
 these results suggest that the same treatment is applicable for patients with issnhl regardless of whether their contralateral ear is deaf or normal . for those who do not recover from issnhl in their only hearing ear , culminating in bilateral deafness 
 , we may consider further definitive treatment including cochlear implantation as early as 3 months after initiating the treatment of issnhl . 
INTRODUCTION
MATERIALS AND METHODS
Patients
Study parameters
Statistical analysis
RESULTS
DISCUSSION