|Year : 2012 | Volume
| Issue : 2 | Page : 65-68
Analysis of sensorineural hearing loss in chronic suppurative otitis media with and without cholesteatoma
Rohit Sharma, Vinit K Sharma
Department of ENT and HNS, SRMS Institute of Medical Sciences, Ram Murti Puram, Bareilly (UP), India
|Date of Web Publication||6-Sep-2012|
Associate Professor, Department of ENT and HNS, SRMS Institute of Medical Sciences, Ram Murti Puram, Bareilly (UP) 243202
Source of Support: None, Conflict of Interest: None
Background: Chronic suppurative otitis media (CSOM) still remains a major cause of conductive hearing loss in our country. On contrary a few patients also display an added sensorineural component. Materials and Methods: Hundred patients with unilateral CSOM undergoing ear surgery at our department were included in the study. The affected ears formed the 'CSOM group' and the normal ears formed the 'Control group'. Detailed otologic history, clinical, surgical, and audiometric findings were recorded and analyzed. Results: It was inferred that though CSOM is associated with sensorineural (SN) loss in small majority of patients only. No co-relation was established between the duration of discharge and SN loss. Conclusions: Though, greater SN loss was seen in patients of CSOM with cholesteatoma but it was not statistically significant. It can be further studied that whether an early surgery in CSOM can prevent SN loss or not.
Keywords: Chronic suppurative otitis media, Conductive hearing loss, Sensorineural hearing loss
|How to cite this article:|
Sharma R, Sharma VK. Analysis of sensorineural hearing loss in chronic suppurative otitis media with and without cholesteatoma. Indian J Otol 2012;18:65-8
|How to cite this URL:|
Sharma R, Sharma VK. Analysis of sensorineural hearing loss in chronic suppurative otitis media with and without cholesteatoma. Indian J Otol [serial online] 2012 [cited 2020 Feb 19];18:65-8. Available from: http://www.indianjotol.org/text.asp?2012/18/2/65/100699
| Introduction|| |
Chronic suppurative otitis media (CSOM) is a common ENT problem and still remains the commonest cause of hearing impairment which can be prevented / treated.
Conventionally, hearing loss described in CSOM is air bone gap i.e. a conductive hearing loss. But, it has been observed that some patients displayed an added sensorineural component to their conductive hearing loss.
Azevedo et al. in their study found that in the ear with CSOM, the frequency of SNHL was 13%. It is likely that SNHL associated with CSOM is higher in populations of lower socioeconomic status. This may be corroborated by hypothesis that there is a difficulty to access treatment with antibiotics, inadequate follow up and poor hygiene and education in the lower socioeconomic group. 
Papastavros and Verlejides in their study of 66 cases of CSOM observed the presence of SNHL as a reversible and a permanent component, where permanent component was present in whole range of tested frequencies and reversible component was present in the higher frequencies. 
Paparella et al. in their research found that the toxins cross the round window membrane and cause irreversible cochlear hair cell loss mostly affecting the basal turn of the cochlea. 
On reviewing the literature, it was evident that the issue of SNHL in CSOM with or without cholesteatoma still remains a matter of debate. Even the patients who have a definite raised bone conduction (BC) threshold do not have any symptoms of labyrinthitis. Thus, 100 patients suffering from unilateral CSOM with chosen criteria were selected. Otologic history and examination, and audiometry findings were recorded and analyzed statistically.
| Materials and Methods|| |
The primary objective of this study was to evaluate the incidence and degree of sensorineural hearing loss in CSOM and also to find the correlation between S.N. hearing loss (if any) with the age of the patients, duration of the disease and the surgical findings observed.
The present study was undertaken in the Department of ENT and Head/Neck Surgery, at our institute. The study group included the patients those were operated in the institute for CSOM.
The patients had to meet the following criteria to become eligible for the study. The patients had to be suffering from unilateral CSOM with normal contralateral ear. The normal ear was used as a control to cancel out the confounding factors such as presbycusis, noise induced or congenital hearing losses etc. The subjects between 10 and 50 years of age were included in the study. The children below 10 years were excluded as they were expected to be unco-operative for accurate testing. Also above 50 years, there is a possibility of an element of presbycusis. Subjects with a history suggestive of systemic diseases like diabetes, meningoencephalitis, head injury, familial hearing loss, prolonged noise exposure, previous otologic surgeries were excluded from the study.
Detailed otolaryngologic history including hearing impairment, ear discharge, vertigo, tinnitus etc., was taken. Extensive ENT examination was done in all subjects to look for status of otorrhea, site and size of perforation, ossicular disruption and presence of cholesteatoma. Tuning fork tests (Rinne's, Weber's and Absolute BC test) were carried out in all the cases. Pure tone audiometry (PTA) was done in all subjects using an Elkon Audiometer in a partially sound attenuated room. Air conduction and BC thresholds were tested and plotted by a trained audiologist. Narrow band masking was used whenever appropriate. The surgical findings of all the patients were observed and documented. Special observation regarding presence or absence of cholesteatoma and ossicular chain status was made. All these findings were documented as per the study Performa.
| Results|| |
The age of the subjects included in the study ranged from 12-50 years with a mean of 24.6 years, 36% being males and 64% females. There was no significant difference in the left or right ear.
Around 52% ears had history of discharge for less than 2 years whereas only 8% ears had history of discharge for more than 5 years.
Atticoantral type of CSOM was found to be in 28% of the study ears. Tubotympanic type of CSOM was seen in the remaining 72% ears. Distribution of various sizes of central perforations was observed as in [Table 1]. Also, it was observed that cholesteatoma was present in 28% ears of the CSOM group. However, ossicular chain was eroded in 20% ears of the CSOM group and in rest 80% it was intact.
As expected mean AC (air conduction) threshold in the CSOM group was significantly elevated (48.25dB) as compared to the mean AC threshold of the control group. The mean BC threshold in the control group was 12dB and in CSOM group it was observed to be 15.03dB. This difference though not large but was statistically significant (P<0.05) [Table 2].
It was observed in CSOM group that mean BC threshold did not increase with the duration of discharge, but it does appear to rise with increasing age and presence of cholesteatoma [Table 3]. However, difference in the BC threshold in the ears with or without cholesteatoma was not significant.
|Table 3: Mean bone conduction values in relation to duration of discharge, age of the patient and presence of cholesteatoma|
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[Table 4] shows means and comparisons of bone conduction thresholds at various frequencies in controls and CSOM group. Higher bone conduction thresholds were observed in the CSOM group. But the difference was statistically significant at 1KHz and 2KHz of the frequencies tested.
|Table 4: Comparisons of bone conduction thresholds at various frequencies between controls and CSOM group|
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| Discussion|| |
Conventionally, a conductive hearing loss is expected in a patient suffering from CSOM. Occasionally, elevated BC thresholds have been observed in various audiometric recordings in patients suffering from CSOM indicating a sensorineural (SN) element. On reviewing the literature results from different authors on this issue have been variable.
Our aim was to find whether there is any relation between CSOM and SN hearing loss. And if there is any, does the presence of cholesteatoma, duration of discharge or age of the patient affect the degree of SN element. Present study was done in 100 patients of unilateral CSOM. The normal ears formed the control group and 100 ears suffering from CSOM formed the CSOM group. Detailed otologic history, clinical, surgical, and audiometric findings were recorded and analyzed.
The mean difference in the preoperative BC thresholds in the normal ears (control group) and ears suffering from (CSOM group) was around 3dB. MacAndie and O'Reilly in their study observed that this difference was 5.24-9.02 across the frequency range.  Though, this was on the lower side in our study but it was statistically significant.
A number of authors have studied the BC thresholds in CSOM across various frequency ranges. Redaelli et al. stated that differences in mean BC thresholds varied from 0.6dB at 500Hz to 3.7dB at 4KHz.  In the series by Noordzig et al. it was found that these values were small. They were -0.5dB at 500Hz, 0.9dB at 1KHZ, 4.4dB at 2KHz and 3.6dB at 4KHz. 
Paperella et al. came to conclusion that SN hearing loss does occur in CSOM, especially at higher frequencies.  BC thresholds were also elevated in the CSOM group in our study. The mean differences across the various frequency ranges were 2.6dB at 500 Hz, 3.4dB at 1 KHz, 4.4dB at 2 KHz and 1.8 at 4 KHz. The differences in mid frequencies i.e., 1 and 2 KHz were statistically significant but not at 500 Hz and 4 KHz.
The relationship between duration of discharge and mean BC thresholds in CSOM group was assessed. BC thresholds did not show any rise when ears with different ranges of duration of discharge were analyzed. In a similar assessment, de Azavedo et al. did not find any significant difference in the BC thresholds in patients having prolonged history of ear discharge.  In contrast, Handa et al. found that the relative SN loss varied significantly with the duration of disease. 
Papp et al. in their study concluded that BC threshold shift was more accentuated as the age increased.  In our series, there was a gradual elevation of BC thresholds from 13.40dB in 10-20 years age group to 19.16dB in 40-50 years age group.
With regards to the association of cholesteatoma and SN loss in patients with CSOM different studies have produced variable results. Most of the researches reviewed in literature did not show a significant correlation. , Though, our BC thresholds were higher in CSOM group having cholesteatoma but they were not statistically significant, in consistency with above studies. However, there are certain other authors who have shown a significant correlation. 
Paperella et al. showed in an extensive experimental research, this association between SN hearing loss and CSOM. They emphasized the deleterious consequences of chronic otorrhea for the inner ear.  In a study of breakdown of round window membrane permeability Engel et al proposed that damage to the round window membrane by potent pore-forming cytolysins (pneumolysin and streptolysin O) lead to leakage of ions from the perilymph. Ionic disequilibrium and passage of toxic macromoleculesto the cochlea could contribute to disturbances of the inner ear function. 
Thus, detailed statistical analysis of our study along with the review of available literature on the subject, it is hereby inferred that CSOM can cause variable degree of SN hearing loss. Moreover, if definitive treatment is done earlier, a greater number of patients presenting with mixed losses may be prevented. This is important in view of the fact that National programme prevention and control of deafness is already underway in India.
| Conclusions|| |
In the analysis of sensorineural hearing loss in CSOM with and without cholesteatoma, the following conclusions were drawn. Chronic otitis media appears to be associated with sensorineural hearing loss, but the degree of SNHL is small in majority of patients. The degree of SNHL did not bear any correlation with the duration of discharge. Greater SN loss is present in the ears suffering from CSOM with cholesteatoma, but it is not significant. Although, we have concluded that there is an association of CSOM with SN loss, still a study with a large sample size is needed to evaluate the role of cholesteatoma. It can be further studied that whether an early surgery in CSOM can prevent an added SN loss or not.
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[Table 1], [Table 2], [Table 3], [Table 4]