|Year : 2015 | Volume
| Issue : 3 | Page : 197-200
Tinnitus: A hospital-based retrospective study
Hanifa Akhtar Laskar1, Neizekhotuo Brian Shunyu1, Jayanta Medhi1, Md Jamil2, Collete Nongsiej1, Eusebia Khyriem1
1 Department of Otorhinolaryngology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, Meghalaya, India
2 Department of General Medicine, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, Meghalaya, India
|Date of Web Publication||17-Jul-2015|
Hanifa Akhtar Laskar
Department of Otorhinolaryngology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong - 793 018, Meghalaya
Source of Support: None, Conflict of Interest: None
Aims and Objectives: To find out age, sex, laterality distribution of patients with tinnitus, to investigate the type and characteristics of associated hearing loss and to find different etiology causing tinnitus. Materials and Methods: Retrospective hospital-based study. Data collected for 154 patients who attended tinnitus clinic of Department of ENT of our institute during the year 2013. Patients with incomplete data were excluded from the study. Results: Among 154 patients included for study, 73 were male and 81 were female. The highest percentage of patients were in the middle age group of 41-50 years (27.9%) followed by 31-40 years (18.83%) and 51-60 years (16.2%) with decreasing number of patients in both younger and elderly age group. Conclusion: Tinnitus can affect any age group but its prevalence increases with age without any gender predilection. Left ear involvement is slightly more common among unilateral tinnitus. Sensorineural hearing loss is most common factor associated but in one-sixth of the cases no cause has been found for tinnitus.
Keywords: Hearing loss, Sensorineural hearing loss, Tinnitus
|How to cite this article:|
Laskar HA, Shunyu NB, Medhi J, Jamil M, Nongsiej C, Khyriem E. Tinnitus: A hospital-based retrospective study. Indian J Otol 2015;21:197-200
| Introduction|| |
Tinnitus which is defined as the conscious perception of an auditory sensation in the absence of a corresponding external stimulus,  is a common ear symptom encountered by otorhinolaryngologists. But in spite of much progress has been made, it remains a clinical and scientific enigma. It can be subjective when it is audible only to the patient and objective when heard by observer also. It can be perceived unilaterally or bilaterally and can be intermittent or constant. In general, sensation of tinnitus is described as ringing, roaring, and hissing.
The underlying causes of tinnitus are multifactorial and though it is related to ear, in many cases systemic diseases are found to be associated. In some cases, no cause has been found even after thorough investigations. Hearing loss is one of the most common risk factors for tinnitus and it is commonly of sensorineural type that can be due to ageing, noise exposure or sudden sensorineural hearing loss (SNHL). , Other risk factors associated are middle ear disease, Meniere's disease, vestibular schwannoma, trauma, systemic illness.  In spite of being a common otological problem that can cause various somatic and psychological problems, very few studies were done among the Indian population that is available in the literature. Thus, the present study was conducted among the Indian population with following aims and objectives:
- To find out age, sex, laterality distribution of patients with tinnitus
- To investigate the type and characteristics of associated hearing loss
- To find different etiology causing tinnitus.
| Materials and Methods|| |
The present study is a retrospective study in which data were collected for 154 consecutive patients, who attended the Department of ENT of Tertiary Care Centre of North Eastern region of India for tinnitus in the year 2013. The study is approved by Institution Ethical Committee.
The data were collected from the departmental audiological record book. Information was collected about the patient's tinnitus, hearing impairment, vertigo, systemic illness, and risk factors like noise trauma, drug history, and road traffic accident (RTA). Audiological test, magnetic resonance imaging (MRI) brain reports along with other relevant medical reports were examined.
The parameters which were included for analysis of data are: Age, sex, laterality of tinnitus (unilateral/bilateral), duration of tinnitus (<1 month, 1 month to 1 year, more than 1 year), hearing status (normal/hearing loss), pure tone audiogram (within normal limit, conductive hearing loss, SNHL, mixed loss), special tests (tone decay test, short increment sensitivity index).
Pure tone audiogram was performed in all patients to determine audiometric thresholds at the frequency range of 0.25 to 8 kHz and divided into minimal, mild, moderate, moderately severe, severe, profound hearing loss as per guidelines by American Speech-Language-hearing Association. 
For analysis of data, patients were divided into nine groups as per age in years: Up to 10, 11 to 20, 21 to 30, 31 to 40, 41 to 50, 51 to 60, 61 to 70, 71 to 80, and 81 to 90.
Those patients with incomplete data and information were excluded from the study.
| Results and Observations|| |
In the present study, data were collected for 154 patients who attended tinnitus clinic during year 2013. Total number of male and female patients were 73 (47%) and 81 (53%) respectively. Male:female ratio was 0.9:1. Profile of patients with tinnitus is shown in [Table 1]. In present study, most common age group affected belongs to 41-50 years followed by 31-40 years in both gender. Number of patients who complained of tinnitus without hearing loss and tinnitus with hearing loss were 81 (52.59%) and 73 (47.4%), respectively. In 50% of patients, tinnitus was experienced bilaterally and among patients having unilateral tinnitus, it was more on left side (27.2%) compared to right (22.7%). Hearing evaluation was done by audiometry in all patients and the audiometric findings are shown in [Table 2]. Hearing sensitivity was found to be within normal limit in 43 (27.9%) patients and hearing loss was identified as conductive, SNHL and mixed type in 12 (7.79%), 92 (59.7%) and 7 (4.54%) number of patients, respectively.
Of 43 (27.9%) patients with hearing sensitivity within normal limit, 15 patients demonstrated dip in audiogram at 8 K and 4 K in 11 and 4 cases, respectively. In this group of patients, tinnitus was present bilaterally and unilaterally in 31 (72%) and 12 (28%), respectively. Of 92 tinnitus patients having SNHL positive tone decay was found in 12 cases, of which 5 cases had unilateral SNHL and 7 cases had bilateral SNHL. MRI brain was done in all these cases of which 2 cases were diagnosed as acoustic neuroma and in 10 patients MRI brain was found to be normal.
The causes associated with tinnitus are shown in [Table 3]. But cause of tinnitus could not be found in 24 (15.58%) patients.
|Table 3: Causes/factors associated with tinnitus in different categories of patients|
Click here to view
| Discussion|| |
Tinnitus is one of the health issues of concern for otorhinolaryngologists. The term tinnitus is derived from Latin word "tinnire," meaning to ring.  Tinnitus affects individuals of all age strata and most commonly affects individuals of age group 40 to 70 years.  In our study, highest number of patients belonged to age group 41-50 years. Slight female predominance was found in our study. This is similar with findings of Nondahl et al.  who reported a higher number of tinnitus among females. But few studies have reported male predominance. ,,
Tinnitus may be perceived unilaterally or bilaterally. In our study, tinnitus was experienced bilaterally in 50% of patients, similar to findings of Coles.  Left side predominance was found in cases of unilateral tinnitus similar to findings of some other studies. , But study by Alberti  found no significant difference between two ears.
As tinnitus is a symptom, not a disease, many authors have described several underlying risk factors. Among all, hearing loss is a well-recognized risk factor of tinnitus. ,, In our study, hearing loss was present in 72% of patients and in majority (59.7%), it was SNHL type of hearing loss. Our findings on type of hearing loss in tinnitus patients are similar with other studies which also mentioned SNHL type as commonest in patients of tinnitus with hearing loss. , The high percentage of SNHL in tinnitus patients is explained by theory that tinnitus results from reduction of effective functioning of the auditory afferent system. 
Presbycusis is most common cause of SNHL with tinnitus in our study. The other causes of SNHL were sudden SNHL (5.84%), noise-induced (3.89%), Meniere's disease (1.94%), cochlear otosclerosis (1.29%), post road traffic accident (1.29%) and systemic diseases like hypertension, diabetes, and hypothyroidism. Causes of SNHL in tinnitus patients in our study match with findings of other investigators. ,
Magnetic resonance imaging was done in all cases of unilateral SNHL and in SNHL with positive tone decay. Out of five cases of unilateral SNHL with positive tone decay, two patients were diagnosed as acoustic neuroma (1.29%).
Tinnitus with conductive hearing loss was found in 7.79% of patients and causes were Eustachian tube More Details dysfunction (5.19%), chronic suppurative otitis media (0.64%), otosclerosis (0.64%), Post-tympanoplasty (0.64%), and traumatic tympanic membrane perforation (0.64%). Our finding does not match with study by Shrestha et al.  which mentioned chronic otitis media as cause of tinnitus in 22.4% of patients.
Audiological assessment was done by pure tone audiometer. In patients of tinnitus with conductive hearing loss, degree of loss was mild and moderate in 66.6% and 16.6%, respectively. Degree of hearing loss in tinnitus with SNHL was mild, moderate, and asymmetric in 30%, 23%, and 24%, respectively. In our study, majority of tinnitus patients with hearing loss had mild loss (32.43%) followed by moderate loss (23.42%), moderately severe loss (12.61%), severe loss (5.4%), profound loss (1.8%). Our result does not match with findings of study by Dias and Cordeiro  that found higher prevalence of tinnitus among patients with higher degree of hearing loss.
Tinnitus can be present in patients with normal hearing. In our study, 27.9% patients had hearing sensitivity within normal limit. Among patients with normal hearing, 34.8% of patients demonstrated dip at 4 K and 8 K in audiogram. Our findings are identical with some studies , that mentioned pathogenesis of tinnitus in normal hearing patients with high-frequency dip may be due to disturbance in activity along tonotopic axis in auditory pathway, which is not documented in audiometrically normal thresholds. In present study, this group of patients had associated systemic diseases such as anemia, diabetes, hypertension, somatization disorder, and previous history of noise exposure.
In spite of thorough investigations, no cause of tinnitus could be established in 15.58% of our patients. But in other studies by Martines et al.  and Savastano,  percentage of unidentified etiology of tinnitus was higher and was 26% and 30.77%, respectively.
| Conclusion|| |
The present study reveals that tinnitus can affect all age groups but middle age group and above are more commonly affected without any significant gender predilection. Tinnitus can affect unilaterally or bilaterally with slight left ear predominance among patients with unilateral tinnitus. Audiometric results showed SNHL in majority with the presence of conductive and mixed hearing loss in minority of patients. But a quarter of patients had normal hearing. Most of our patients had mild to moderate degree of loss. Eustachian tube dysfunction and presbyacusis were found to be the most common cause of tinnitus in patients with conductive hearing loss and sensorineural loss, respectively. In patients with normal hearing, anemia and noise trauma was found to be a common cause of tinnitus. But even after thorough evaluation, cause of tinnitus could not be established in around one-sixth of total number of patients.
| References|| |
Baguley D, McFerran D, Hall D. Tinnitus. Lancet 2013;382:1600-7.
Gopinath B, McMahon CM, Rochtchina E, Karpa MJ, Mitchell P. Risk factors and impacts of incident tinnitus in older adults. Ann Epidemiol 2010;20:129-35.
Sindhusake D, Mitchell P, Newall P, Golding M, Rochtchina E, Rubin G. Prevalence and characteristics of tinnitus in older adults: The Blue Mountains Hearing Study. Int J Audiol 2003;42:289-94.
Clark JG. Uses and abuses of hearing loss classification. ASHA 1981;23:493-500.
Noell CA, Meyerhoff WL. Tinnitus. Diagnosis and treatment of this elusive symptom. Geriatrics 2003;58:28-34.
Nondahl DM, Cruickshanks KJ, Dalton DS, Klein BE, Klein R, Schubert CR, et al.
The impact of tinnitus on quality of life in older adults. J Am Acad Audiol 2007;18:257-66.
Johansson MS, Arlinger SD. Prevalence of hearing impairment in a population in Sweden. Int J Audiol 2003;42:18-28.
Zarenoe R, Ledin T. A cohort study of patients with tinnitus and sensorineural hearing loss in a Swedish population. Auris Nasus Larynx 2013;40:41-5.
Martines F, Bentivegna D, Martines E, Sciacca V, Martinciglio G. Characteristics of tinnitus with or without hearing loss: Clinical observations in Sicilian tinnitus patients. Auris Nasus Larynx 2010;37:685-93.
Coles RR. Epidemiology of tinnitus: (2) Demographics and clinical features. J Laryngol Otol 1984;98 Suppl 9:195-202.
Alberti PW. Tinnitus in occupational hearing loss: Nosological aspects. J Otolaryngol 1987;16:34-5.
Nondahl DM, Cruickshanks KJ, Huang GH, Klein BE, Klein R, Nieto FJ, et al.
Tinnitus and its risk factors in the Beaver Dam offspring study. Int J Audiol 2011;50:313-20.
Eggermont JJ. Central tinnitus. Auris Nasus Larynx 2003;30 Suppl: S7-12.
Nicolas-Puel C, Faulconbridge RL, Guitton M, Puel JL, Mondain M, Uziel A. Characteristics of tinnitus and etiology of associated hearing loss: A study of 123 patients. Int Tinnitus J 2002;8:37-44.
Shrestha BL, Amatya RM, Shrestha I, Pokharel M. Analysis of etiological factors of tinnitus in patients attending Kathmandu University Hospital. Indian J Otol 2012;18:196-9.
Dias A, Cordeiro R. Association between hearing loss level and degree of discomfort introduced by tinnitus in workers exposed to noise. Braz J Otorhinolaryngol 2008;74:876-83.
König O, Schaette R, Kempter R, Gross M. Course of hearing loss and occurrence of tinnitus. Hear Res 2006;221:59-64.
Savastano M. Tinnitus with or without hearing loss: Are its characteristics different? Eur Arch Otorhinolaryngol 2008;265:1295-300.
[Table 1], [Table 2], [Table 3]