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Characterization of tinnitus in Nigeria
Auris Nasus Larynx 40 (2013) 356–360
Contents lists available at SciVerse ScienceDirect
Auris Nasus Larynx journal homepage: www.elsevier.com/locate/anl
Characterization of tinnitus in Nigeria Olusola Ayodele Sogebi * Department of Surgery, College of Health Sciences, Olabisi Onabanjo University, Sagamu, Nigeria
A R T I C L E I N F O
A B S T R A C T
Article history: Received 15 July 2012 Accepted 19 November 2012 Available online 11 December 2012
Objective: This study aimed to characterize tinnitus in middle aged and elderly out-patients attending a specialized clinic in a developing country. Methods: A cross sectional study of patients attending the ear, nose and throat (ENT) clinic of Olabisi Onabanjo University Teaching Hospital, OOUTH Sagamu, Nigeria. Data was collected with the use of a structured questionnaire. Data collected included socio demographics, medical history including experience of tinnitus, PTAs, BMI and BP. Data was analyzed using SPSS version 17.0. Results: 79 patients had complaints of tinnitus thus making a crude prevalence of 14.5%, the prevalence increased steadily along the age groups. 51.9% of patients experienced tinnitus for a short period. 53.2% of the patients had symptoms referable to only one ear, while 54.4% had discrete as opposed to multiple types of tinnitus. Occurrence of intermittent symptoms was experienced by 75.9% of the patients and 70.9% were non-pulsatile in nature. Tinnitus was significantly associated with abnormal audiographic pattern, global increased hearing thresholds, high tone hearing loss, vertigo, hypertension and obesity. Conclusion: Tinnitus character was majorly short term, unilateral, discrete, intermittent, and nonpulsatile in nature, and it is associated with otological, audiological, anthropometric and cardiovascular anomalies. The characteristics of tinnitus in Nigerian patients were similar to those described in developed countries, but the major risk factors for tinnitus except hearing impairment, may be different from the latter. ß 2012 Elsevier Ireland Ltd. All rights reserved.
Keywords: Tinnitus Association Prevalence Characteristics Adults Nigerians
1. Introduction Tinnitus – an auditory sensation without the presence of an external acoustic stimulus [1] is a common otologic and audiological symptom that family physicians, Otolaryngologists and Neurologists are often confronted with. Almost all adults have experienced some form of tinnitus, mostly transient in nature, at some moments during their life, and it tends to be more prevalent with advancing age [2]. The prevalence of chronic tinnitus has been estimated to be between 6 and 20% in general adult population [3], and increase up to 33% among the elderly [4]. This sensation often occurs as part of symptoms complex of certain diseases like Meniere’s disease and Presbycusis, it can be associated with hypertension [5] and certain forms of metabolic derangement [6], and sometimes it occurs alone as idiopathic. The consequences of unrelenting tinnitus are especially grave among the elderly population in whom it manifests with insomnia, inadequate and unrefreshing sleep, social isolation, depression, and generally reduced quality of life. Several treatment modalities including use of medications, tinnitus maskers, hearing aids [7]
* Correspondence address: Department of Surgery, OACHS, Olabisi Onabanjo University, Sagamu, Nigeria. Tel.: +234 802 3262 034. E-mail address: [email protected]. 0385-8146/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.anl.2012.11.003
and other rehabilitation techniques had been deployed to control tinnitus. However the efficacy of most interventions for tinnitus remains to be demonstrated conclusively [8]. Preventive strategies of tinnitus have also not achieved much result because of its inadequate characterization, coupled with complex and multiple aetiopathogenesis. Hence isolated measures by psycho-acoustic methods are not satisfactory [9]. Characterization of tinnitus remains an important issue in otoneurological practice but more especially in resource poor countries with limited diagnostic and therapeutic facilities. This study therefore aimed to characterize tinnitus in middle aged and elderly out-patients attending a specialized clinic in a developing country. This will enable us to define the burden, the types, and associations which will assist in planning remedial health programme for this group of patients. 2. Patients and methods This was a cross sectional study of patients attending the ear, nose and throat (ENT) clinic of Olabisi Onabanjo University Teaching Hospital, OOUTH Sagamu, Nigeria. Consecutive adult and elderly patients attending the clinics were approached for recruitment into the study after being informed about the general purpose, the aims and objectives of the study. Voluntary participation and maintenance of confidentiality were emphasized
O.A. Sogebi / Auris Nasus Larynx 40 (2013) 356–360
following which consenting patients were included in the study. Subjects who did not consent, patients with wax impaction, patients with active ear infections like otitis externa or media and those on hearing aids were excluded from the study. The study protocol was approved by the Health Research and Ethics committee (HREC) of OOUTH. Data was collected with the use of a structured questionnaire. The information obtained included the socio demographic parameters of the patients, experience of tinnitus, its duration, laterality, form, frequency of occurrence, nature and other associated symptoms. The past medical, the social histories were taken and clinical diagnoses relating to the otological symptoms were also noted. Otoscopy was done on all the patients to check the status of the ear and especially the tympanic membranes. Pure tone audiometries were done for all the patients by the same audiologist using a calibrated diagnostic audiometer GSI 67, Kaplan. Patients were divided into two groups based on the symptom experience of tinnitus (absent or present). The weights and heights were measured by using the surgifriend medicals scale (Surgifriend Medicals, England) and the body mass index (BMI) calculated as weight in kg/height in m2. The information was entered into a spread sheet and analyzed using SPSS version 17.0. The data is presented in descriptive forms as tables. Discrete variables were compared using the Chi square test while continuous variables were compared using the student t-test. Statistical significance was set at p < 0.05. Data of patients who were not sure whether they had tinnitus or not and of those with incomplete information (especially PTA) were excluded from the analysis. 3. Results A total of five hundred and forty three (543) middle aged and elderly patients were seen in the ENT clinic at the period of study (July 2007–June 2011) out of which one hundred and twenty seven (127) patients participated fully (had complete data for analysis) in the study, 59.8% of which were males. Over three quarter (78.7%) of the subjects were in the age group between 61 and 80 years (mean SD, 69.6 8.9 years), while 70.9% were married. Slightly over half (52.8%) of the subjects had secondary school education with 40.9% being semi-skilled and 40.2% were Professionals. Seventy-nine patients had complaints of tinnitus thus making a crude prevalence of 14.5%. A detail of the sociodemographic characteristics of the patients is shown in Table 1. Among the patients that had complaints of tinnitus, the prevalence increased steadily along the age groups until above 80 years, while median duration of symptoms was 13 months which was used as the dividing line into short and long duration. Thus patients with symptoms 13 months were regarded as short duration while those over 13 months were treated as long duration. About half (51.9%) of patients experienced tinnitus for a short period, 53.2% of the patients had symptoms referable to only one ear, while 54.4% had discrete as opposed to multiple types of tinnitus. Occurrence of intermittent symptoms was experienced by three quarters (75.9%) of the patients and most (70.9%) were non-pulsatile in nature. Although there were no associated clinical etiologies found in 21.5% of the patients, 43.0% were associated with presbycusis and 15.2% were associated with hypertension; see Table 2. Table 3 is a comparison of the clinical characteristics of patients with and without tinnitus. Tinnitus was significantly associated with symptoms of vertigo, history of hypertension (defined as use of hypertensive or BP > 140/90 mmHg in at least two consecutive clinic attendance), obesity (BMI > 30.0), reported hearing loss by patients and observed hearing loss (obtained from the pure tone average of air conduction thresholds, of the better ear).
357
Table 1 Socio demographic characteristics of the patients. Variable Age group 41–50 51–60 61–70 71–80 81 Mean SD Sex Male Female Marital status Married Others Level of education No formal education Primary school Secondary school Post secondary Occupational group Unskilled Semi-skilled Skilled/professional Status of patient Tinnitus absent Tinnitus present
n
%
3 13 48 52 11 69.6 8.9
2.4 10.2 37.8 40.9 8.7
76 51
59.8 40.2
90 37
70.9 29.1
3 29 67 28
2.4 22.8 52.8 22.0
24 52 51
18.9 40.9 40.2
48 79
37.8 62.2
Further exploration of the relationship between tinnitus and other parameters of the audiograms in Table 4 revealed tinnitus was significantly associated with abnormal audiographic pattern (i.e. any deviation from symmetrical audiograms with pure tone average PTAv < 25 dB at both air and bone conduction thresholds, which should be at par with less than 5 dB gap between them). Tinnitus was also significantly associated with global increased hearing thresholds (obtained from PTAv over frequencies 0.5– 8.0 kHz, and high tone preponderant hearing loss at frequencies of 4.0–8.0 kHz).
Table 2 Characteristics of tinnitus in 79 patients. Variable Age group 41–50 51–60 61–70 71–80 81 Duration Short Long Laterality Unilateral Bilateral Form Discrete Multiple Occurrence Intermittent Continuous Nature Non pulsatile Pulsatile Associated clinical etiology Presbycusis Hypertension Noise exposure Meniere’s disease Ototoxic medication Sickle cell disease Unknown
Frequency
%
3 10 26 35 5
3.8 12.7 32.9 44.3 6.3
41 38
51.9 48.1
42 37
53.2 46.8
43 36
54.4 45.6
60 19
75.9 24.1
56 23
70.9 29.1
34 12 8 2 5 1 17
43.0 15.2 10.1 2.5 6.3 1.7 21.5
O.A. Sogebi / Auris Nasus Larynx 40 (2013) 356–360
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Table 3 Comparison of the clinical characteristics of patients with and without tinnitus. Variable
Tinnitus absent n = 48 (%)
Tinnitus present n = 79 (%)
p
Agea (mean) Sex (female) Marital status (married) Level of education (up to secondary education) Occupational class (professional) Reported hearing loss Observed hearing loss Ear blockage Vertigo Autophony Otalgia Previous otorrhoea Alcohol consumption Smoking Noise exposure Previous head injury Hypertension Diabetes Osteoarthritis Sickle cell disease Prolonged medication Ototoxic drugs Obesity
70.7 39.6 68.8 83.3
68.8 40.5 72.2 74.4
0.256 0.918 0.683 0.684
33.3 27.1 29.2 29.2 8.3 47.9 14.6 25.0 18.8 8.3 35.4 6.3 8.3 18.8 18.8 2.1 27.1 22.9 6.3
44.3 57.0 78.5 20.3 24.1 40.5 19.0 20.3 14.0 16.5 34.2 13.9 51.9 22.8 22.8 6.3 39.2 34.2 21.5
0.403 0.001* <0.001* 0.255 0.019* 0.414 0.521 0.534 0.433 0.179 0.887 0.165 <0.001* 0.588 0.588 0.274 0.159 0.174 0.024*
Note: All parameters except age were compared using Chi square test. a Statistic is Student t-test. * Statistically significant.
4. Discussion This study revealed a high prevalence of tinnitus as a major complain among the middle aged and elderly patients attending the ENT Clinic of OOUTH, Sagamu, Nigeria. Most of the patients experienced unilateral, short term, intermittent, discrete and nonpulsatile forms of tinnitus. Occurrence of tinnitus was significantly associated with experience of vertigo, both reported and observed hearing losses, abnormalities in pure tone audiograms, as well as hypertension and obesity. Although this is a hospital based study in a specialized clinic, the high crude prevalence of 14.5% underscores the importance of this symptom. By extension this prevalence may give a reflection of what obtains in the community. The prevalence increased steadily with increasing age until after the eighth decade because there were fewer patients, possibly from natural processes of death, immobility and inability to attend hospital. Some authors agreed that the prevalence of tinnitus increased with age [10], particularly above the age of 50 [11,12]. In this age group different studies reported prevalence between 7.6% and 20.1% [5,11,13], within which the prevalence in this study falls. However there was no significant association between age and tinnitus in this study.
Table 4 Relationship between tinnitus and audiometric parameters. Parameter of audiogram
Tinnitus absent
Tinnitus present
p
Abnormal audiogram PTAv in better eara (mean) High tone hearing loss
29.2% 28.6 50.0%
78.5% 42.6 69.6%
<0.001* 0.001* 0.027*
Note: abnormal audiogram and high tone hearing loss were analyzed with the Chi square test. a Statistic is Student t-test. * Statistically significant.
Variations in the reported prevalence of tinnitus across different studies likely resulted from different investigators having differing criteria for the definition of tinnitus [5,11]. Most elderly people have some forms of tinnitus particularly in a quiet environment which can be disturbing for some of them. With the projected increase in the number of elderly patients, tinnitus has the potential of becoming a leading problem among the elderly in the near future [10]. It therefore places a duty on clinicians and other care givers of the elderly to be conversant with the characteristics of this ailment in their locality so as to prevent or ameliorate its unpleasant and discomforting effects. The descriptive characteristics of the types of tinnitus experience of our study gave the impression that the mild and relatively innocuous forms were experienced in our patients. The nature, duration and severity of tinnitus found in this study were however similar to those described in Europe and the USA [14]. Most forms of tinnitus usually start in seemingly innocuous ways, but become progressive and unrelenting with consequent uncomfortable symptoms with time. Furthermore these seemingly innocuous forms could also produce some uncomfortable effects which include sleep disturbances, anxiety, depression and general reduction in quality of life. These consequences are more crucial when they are associated with other otological symptoms. Common otological symptoms that were significantly associated with tinnitus in this study were hearing loss and vertigo. Gopinath et al. reported that incident tinnitus was predicted by two otological risk factors, dizziness and hearing loss [7]. The differentials of this triad of symptoms will include Meniere’s disease, Presbycusis and vestibular schwannoma each of which can make life miserable for the sufferer. Unilateral Tinnitus may connote a retrocohlear or nervous disease [15] like vestibular schwannoma, however the pure tone audiograms of many of our patients with tinnitus were confirmatory of Presbycusis. While Meniere’s disease and Presbycusis affect both ears, patients may present with symptoms referable to the worse ear alone. Tinnitus was associated with other abnormalities in the audiographic findings including the shape, the hearing thresholds and high tone hearing loss. Studies have shown hearing loss as a risk factor for tinnitus [16,17] especially among elderly subjects [18]. It was even reported that tinnitus patients with normal audiograms might have restricted cochlear damage [19] or hearing loss at frequencies above 8 kHz, which is not detected by normal clinical audiometry [20]. The greater likelihood of tinnitus in hearing impaired adults may be attributable to the loss of cochlear hair cells or hair cell function that occurs in hearing loss, leading to the aberrant auditory signals that are experienced as tinnitus [21]. Tinnitus is believed to arise from alterations in the spontaneous activity of neurons in the auditory system [22]. Similarly, findings on the relationship between tinnitus and shape of audiogram suggest that the occurrence of tinnitus is promoted by a steep audiogram slope (reflected as high tone hearing loss). A steep slope leads to abrupt discontinuities in the activity along the tonotopic axis of the auditory system, which could be misinterpreted as sound [23]. Thabet [24] reported that Transient Otoacoustic Emissions (TEOAEs) were significantly abnormal in tinnitus ears compared to control ears; especially at frequencies above 2000 Hz and were more common between 4000 and 5000 Hz. This suggests that outer air cells dysfunction may be important in the generation of tinnitus. The foregoing buttresses the probability of an intimate connection in the pathogenesis of both tinnitus and hearing loss that there may be an overlap or convergence at some points. There is, in fact, a statistically significant association between high-pitched tinnitus
O.A. Sogebi / Auris Nasus Larynx 40 (2013) 356–360
and high-frequency SNHL [18] suggesting that the auditory pathway reorganization induced by hearing loss could be one of the main sources of the tinnitus sensation. Some clinicians have suggested that some of the factors that are responsible for hearing loss are also likely to have caused an associated tinnitus [25]. On the other hand, several layers of complexity of pathological mechanisms are involved in the cause and generation of tinnitus and it is rarely known what causes an individual’s tinnitus (idiopathic tinnitus) [11,26]. Three mechanisms have been proposed to underlie tinnitus namely; changes in the level of spontaneous neural activity in the central auditory system; changes in the temporal pattern of neural activity, and reorganization of tonotopic maps [1,11]. Results from study on neural activity underlying tinnitus generation indicate that in addition to the auditory system, non-auditory systems in the central nervous system may represent a neural correlate of tinnitus. The implication of these is that there is a wide variability in tinnitus and search for a single cure for tinnitus is futile. Testing of new treatments is hampered by the fact that it is not possible to distinguish between different forms of tinnitus for which different treatments may be effective [11]. This study also found an association between hypertension, obesity and tinnitus similar to other studies [5,6,12]. Arterial hypertension belongs to the most important factors of origin and persistence of tinnitus [27] resulting from generalized microangiopathic changes which also affect the cochlear arterial circulation. Similarly Kaz´mierczak and Doroszewska reported that patients suffering from unknown tinnitus, vertigo, and hearing loss were found to be significantly more overweight (on the basis of body mass index) than were the control subjects [6]. However whether this was true for patients suffering from tinnitus alone was not ascertained. It will be necessary to further research into a causal relationship between obesity and tinnitus. Incidentally weight reduction surgery was effective in relieving persistent tinnitus in morbidly obese patients with associated pseudotumor cerebri syndrome [28]. Studies have reported tinnitus as a manifestation of otoneurological complications of diabetes [29] with emphases that disturbances of glucose metabolism may be responsible for inner ear diseases [6]. However it was also observed that diabetics appear to have more significant vestibular system changes compared to the auditory system [30]. No significant association was found between tinnitus and diabetes in this study. Also no association was found with history of previous ear diseases, noise exposure and head injuries which are among the prominent risk factors of tinnitus reported in literature from developed countries [2,10,11,31]. In this study, the symptoms that suggested previous ear diseases (ear blockage, autophony, otalgia, otorrhoea) were comparable in both subjects with and without tinnitus possibly due to their common occurrences in the environment. A similar trend was noted in history of exposure to noise and previous head injuries. However we might have studied patients with minor head injuries due to inadvertent elimination of those with major head injuries consequent upon limited medical facilities hampering treatment and survival of such patients in our environment. It is obvious that ear diseases, noise exposure and previous head injuries may not be risk factors for tinnitus in Nigeria. The small sample size of this study is perceived as a limitation and further characterization will be needed with a community based controlled, longitudinal study. This will allow better clarification to ascertain if there is a causal relationship
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between the significant factors and tinnitus in our environment and the direction of causality. The inability to analyze the loudness of tinnitus due to lack of necessary equipment is also admitted a limitation, as effects may be related to the magnitude of tinnitus. In conclusion, the crude prevalence of tinnitus among Nigerian adult ENT patients was 14.5% and tinnitus was associated with vertigo, hearing losses, abnormalities in pure tone audiograms, hypertension and obesity. While the characteristics of tinnitus in Nigerian patients were similar to those described in developed countries, the major risk factors for tinnitus except hearing impairment, may be different from the latter. Conflict of interest I hereby declare no conflict of interest. Acknowledgement I wish to acknowledge Dr. Rufus Akinyemi for going through this manuscript and his advice toward its final preparation. References [1] Lanting CP, de Kleine E, van Dijk P. Neural activity underlying tinnitus generation: results from PET and fMRI. Hear Res 2009;255:1–13. [2] Nondahl DM, Cruickshanks KJ, Wiley TL, Klein BE, Klein R, Chappell R, et al. The ten-year incidence of tinnitus among older adults. Int J Audiol 2010;49:580–5. [3] Lockwood AH, Wack DS, Burkard RF, Coad ML, Reyes SA, Arnold SA, et al. The functional anatomy of gaze-evoked tinnitus and sustained lateral gaze. Neurology 2001;56:472–80. [4] Seidmann MD, Jacobson GP. Update on tinnitus. Otolaryngol Clin North Am 1996;29:455–65. [5] Fujii K, Nagata C, Nakamura K, Kawachi T, Takatsuka N, Oba S, et al. Prevalence of tinnitus in community-dwelling Japanese adults. J Epidemiol 2011;21:299– 304. [6] Kaz´mierczak H, Doroszewska G. Metabolic disorders in vertigo, tinnitus, and hearing loss. Int Tinnitus J 2001;7:54–8. [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. [8] Hoare DJ, Kowalkowski VL, Kang S, Hall DA. Systematic review and metaanalyses of randomized controlled trials examining tinnitus management. Laryngoscope 2011;121:1555–64. [9] Figueiredo RR, Rates MA, Azevedo AA, Oliveira PM, Navarro PBA. Correlation analysis of hearing thresholds, validated questionnaires and psychoacoustic measurements in tinnitus patients. Braz J Otorhinolaryngol 2010;76:522–6. [10] Xu X, Bu X, Zhou L, Xing G, Liu C, Wang D. An epidemiologic study of tinnitus in a population in Jiangsu Province, China. J Am Acad Audiol 2011;22:578–85. [11] Moller AR. Tinnitus: presence and future. Prog Brain Res 2007;166:3–16. [12] Shargorodsky J, Curhan GC, Farwell WR. Prevalence and characteristics of tinnitus among US adults. Am J Med 2010;123:711–8. [13] Michikawa T, Nishiwaki Y, Kikuchi Y, Saito H, Mizutari K, Okamoto M, et al. Prevalence and factors associated with tinnitus: a community-based study of Japanese elders. J Epidemiol 2010;20:271–6. [14] Hall DA, La´inez MJ, Newman CW, Sanchez TG, Egler M, Tennigkeit F, et al. Treatment options for subjective tinnitus: self reports from a sample of general practitioners and ENT physicians within Europe and the USA. BMC Health Serv Res 2011;11:302. [15] Ferreira LM, Ju´nior AN, Mendes EP. Characterization of tinnitus in the elderly and its possible related disorders. Braz J Otorhinolaryngol 2009;75:249–55. [16] Sindhusake D, Golding M, Newall P, Rubin G, Jakobsen K, Mitchell P. Risk factors for tinnitus in a population of older adults: the Blue Mountains Hearing Study. Ear Hear 2003;24:501–7. [17] Sindhusake D, Golding M, Wigney D, Newal P, Jakobsen K, Mitchell P. Factors predicting severity of tinnitus: a population-based assessment. J Am Acad Audiol 2004;15:269–80. [18] 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. ˜ a A. Psychoacoustic [19] Weisz N, Hartmann T, Dohrmann K, Schlee N, Noren evidence for deafferentiation in tinnitus subjects with normal audiograms. In: Dauman R, Bouscau-Faur F, editors. Proceedings of the VIIIth international tinnitus seminar. 2005. p. 76.
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[20] Roberts LE, Moffat G, Bosnyak DJ. Residual inhibition functions in relation to tinnitus spectra and auditory threshold shifts. Acta Otolaryngol Suppl 2006;556:27–33. [21] Hazell JW, Jastreboff PJ, Tinnitus I. Auditory mechanisms: a model for tinnitus and hearing impairment. J Otolaryngol 1990;19:1–5. [22] Eggermont JJ. Central tinnitus. Auris Nasus Larynx 2003;3:7–12. [23] Ko¨nig O, Schaette R, Kempter R, Gross M. Course of hearing loss and occurrence of tinnitus. Hear Res 2006;221:59–64. [24] Thabet EM. Evaluation of tinnitus patients with normal hearing sensitivity using TEOAEs and TEN test. Auris Nasus Larynx 2009;36:633–6. [25] Henry JA, Dennis KC, Schechter MA. General review of tinnitus: prevalence, mechanisms, effects, and management. J Speech Lang Hear Res 2005;48:1204–35. [26] Gabr TA, El-Hay MA, Badawy A. Electrophysiological and psychological studies in tinnitus. Auris Nasus Larynx 2011;38:678–83.
[27] Gaspar L, Jurcova D, Ocadlik I, Makovnik M, Hlinstakova S, Bendzala M, et al. The importance of ambulatory blood pressure monitoring (ABPM) in patients with tinnitus. Bratisl Lek Listy 2011;112:63–6. [28] Michaelides EM, Sismanis A, Sugerman HJ, Felton III WL. Pulsatile tinnitus in patients with morbid obesity: the effectiveness of weight reduction surgery. Am J Otol 2000;21:682–5. [29] Lasisi AO, Nwaorgu OGB, Bella AF. Cochleovestibular complications of diabetes mellitus in Ibadan, Nigeria. Int Congr Ser 2003;1240:1325–8. [30] Klagenberg KF, Zeigelboim BS, Jurkiewicz AL, Martins-Bassetto J. Vestibulocochlear manifestations in patients with type I diabetes mellitus. Braz J Otorhinolaryngol 2007;73:353–8. [31] Nondahl DM, Cruickshanks KJ, Huang GH, Klein BE, Klein R, Javier Nieto F, et al. Tinnitus and its risk factors in the Beaver Dam offspring study. Int J Audiol 2011;50:313–20.
Contents lists available at SciVerse ScienceDirect
Auris Nasus Larynx journal homepage: www.elsevier.com/locate/anl
Characterization of tinnitus in Nigeria Olusola Ayodele Sogebi * Department of Surgery, College of Health Sciences, Olabisi Onabanjo University, Sagamu, Nigeria
A R T I C L E I N F O
A B S T R A C T
Article history: Received 15 July 2012 Accepted 19 November 2012 Available online 11 December 2012
Objective: This study aimed to characterize tinnitus in middle aged and elderly out-patients attending a specialized clinic in a developing country. Methods: A cross sectional study of patients attending the ear, nose and throat (ENT) clinic of Olabisi Onabanjo University Teaching Hospital, OOUTH Sagamu, Nigeria. Data was collected with the use of a structured questionnaire. Data collected included socio demographics, medical history including experience of tinnitus, PTAs, BMI and BP. Data was analyzed using SPSS version 17.0. Results: 79 patients had complaints of tinnitus thus making a crude prevalence of 14.5%, the prevalence increased steadily along the age groups. 51.9% of patients experienced tinnitus for a short period. 53.2% of the patients had symptoms referable to only one ear, while 54.4% had discrete as opposed to multiple types of tinnitus. Occurrence of intermittent symptoms was experienced by 75.9% of the patients and 70.9% were non-pulsatile in nature. Tinnitus was significantly associated with abnormal audiographic pattern, global increased hearing thresholds, high tone hearing loss, vertigo, hypertension and obesity. Conclusion: Tinnitus character was majorly short term, unilateral, discrete, intermittent, and nonpulsatile in nature, and it is associated with otological, audiological, anthropometric and cardiovascular anomalies. The characteristics of tinnitus in Nigerian patients were similar to those described in developed countries, but the major risk factors for tinnitus except hearing impairment, may be different from the latter. ß 2012 Elsevier Ireland Ltd. All rights reserved.
Keywords: Tinnitus Association Prevalence Characteristics Adults Nigerians
1. Introduction Tinnitus – an auditory sensation without the presence of an external acoustic stimulus [1] is a common otologic and audiological symptom that family physicians, Otolaryngologists and Neurologists are often confronted with. Almost all adults have experienced some form of tinnitus, mostly transient in nature, at some moments during their life, and it tends to be more prevalent with advancing age [2]. The prevalence of chronic tinnitus has been estimated to be between 6 and 20% in general adult population [3], and increase up to 33% among the elderly [4]. This sensation often occurs as part of symptoms complex of certain diseases like Meniere’s disease and Presbycusis, it can be associated with hypertension [5] and certain forms of metabolic derangement [6], and sometimes it occurs alone as idiopathic. The consequences of unrelenting tinnitus are especially grave among the elderly population in whom it manifests with insomnia, inadequate and unrefreshing sleep, social isolation, depression, and generally reduced quality of life. Several treatment modalities including use of medications, tinnitus maskers, hearing aids [7]
* Correspondence address: Department of Surgery, OACHS, Olabisi Onabanjo University, Sagamu, Nigeria. Tel.: +234 802 3262 034. E-mail address: [email protected]. 0385-8146/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.anl.2012.11.003
and other rehabilitation techniques had been deployed to control tinnitus. However the efficacy of most interventions for tinnitus remains to be demonstrated conclusively [8]. Preventive strategies of tinnitus have also not achieved much result because of its inadequate characterization, coupled with complex and multiple aetiopathogenesis. Hence isolated measures by psycho-acoustic methods are not satisfactory [9]. Characterization of tinnitus remains an important issue in otoneurological practice but more especially in resource poor countries with limited diagnostic and therapeutic facilities. This study therefore aimed to characterize tinnitus in middle aged and elderly out-patients attending a specialized clinic in a developing country. This will enable us to define the burden, the types, and associations which will assist in planning remedial health programme for this group of patients. 2. Patients and methods This was a cross sectional study of patients attending the ear, nose and throat (ENT) clinic of Olabisi Onabanjo University Teaching Hospital, OOUTH Sagamu, Nigeria. Consecutive adult and elderly patients attending the clinics were approached for recruitment into the study after being informed about the general purpose, the aims and objectives of the study. Voluntary participation and maintenance of confidentiality were emphasized
O.A. Sogebi / Auris Nasus Larynx 40 (2013) 356–360
following which consenting patients were included in the study. Subjects who did not consent, patients with wax impaction, patients with active ear infections like otitis externa or media and those on hearing aids were excluded from the study. The study protocol was approved by the Health Research and Ethics committee (HREC) of OOUTH. Data was collected with the use of a structured questionnaire. The information obtained included the socio demographic parameters of the patients, experience of tinnitus, its duration, laterality, form, frequency of occurrence, nature and other associated symptoms. The past medical, the social histories were taken and clinical diagnoses relating to the otological symptoms were also noted. Otoscopy was done on all the patients to check the status of the ear and especially the tympanic membranes. Pure tone audiometries were done for all the patients by the same audiologist using a calibrated diagnostic audiometer GSI 67, Kaplan. Patients were divided into two groups based on the symptom experience of tinnitus (absent or present). The weights and heights were measured by using the surgifriend medicals scale (Surgifriend Medicals, England) and the body mass index (BMI) calculated as weight in kg/height in m2. The information was entered into a spread sheet and analyzed using SPSS version 17.0. The data is presented in descriptive forms as tables. Discrete variables were compared using the Chi square test while continuous variables were compared using the student t-test. Statistical significance was set at p < 0.05. Data of patients who were not sure whether they had tinnitus or not and of those with incomplete information (especially PTA) were excluded from the analysis. 3. Results A total of five hundred and forty three (543) middle aged and elderly patients were seen in the ENT clinic at the period of study (July 2007–June 2011) out of which one hundred and twenty seven (127) patients participated fully (had complete data for analysis) in the study, 59.8% of which were males. Over three quarter (78.7%) of the subjects were in the age group between 61 and 80 years (mean SD, 69.6 8.9 years), while 70.9% were married. Slightly over half (52.8%) of the subjects had secondary school education with 40.9% being semi-skilled and 40.2% were Professionals. Seventy-nine patients had complaints of tinnitus thus making a crude prevalence of 14.5%. A detail of the sociodemographic characteristics of the patients is shown in Table 1. Among the patients that had complaints of tinnitus, the prevalence increased steadily along the age groups until above 80 years, while median duration of symptoms was 13 months which was used as the dividing line into short and long duration. Thus patients with symptoms 13 months were regarded as short duration while those over 13 months were treated as long duration. About half (51.9%) of patients experienced tinnitus for a short period, 53.2% of the patients had symptoms referable to only one ear, while 54.4% had discrete as opposed to multiple types of tinnitus. Occurrence of intermittent symptoms was experienced by three quarters (75.9%) of the patients and most (70.9%) were non-pulsatile in nature. Although there were no associated clinical etiologies found in 21.5% of the patients, 43.0% were associated with presbycusis and 15.2% were associated with hypertension; see Table 2. Table 3 is a comparison of the clinical characteristics of patients with and without tinnitus. Tinnitus was significantly associated with symptoms of vertigo, history of hypertension (defined as use of hypertensive or BP > 140/90 mmHg in at least two consecutive clinic attendance), obesity (BMI > 30.0), reported hearing loss by patients and observed hearing loss (obtained from the pure tone average of air conduction thresholds, of the better ear).
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Table 1 Socio demographic characteristics of the patients. Variable Age group 41–50 51–60 61–70 71–80 81 Mean SD Sex Male Female Marital status Married Others Level of education No formal education Primary school Secondary school Post secondary Occupational group Unskilled Semi-skilled Skilled/professional Status of patient Tinnitus absent Tinnitus present
n
%
3 13 48 52 11 69.6 8.9
2.4 10.2 37.8 40.9 8.7
76 51
59.8 40.2
90 37
70.9 29.1
3 29 67 28
2.4 22.8 52.8 22.0
24 52 51
18.9 40.9 40.2
48 79
37.8 62.2
Further exploration of the relationship between tinnitus and other parameters of the audiograms in Table 4 revealed tinnitus was significantly associated with abnormal audiographic pattern (i.e. any deviation from symmetrical audiograms with pure tone average PTAv < 25 dB at both air and bone conduction thresholds, which should be at par with less than 5 dB gap between them). Tinnitus was also significantly associated with global increased hearing thresholds (obtained from PTAv over frequencies 0.5– 8.0 kHz, and high tone preponderant hearing loss at frequencies of 4.0–8.0 kHz).
Table 2 Characteristics of tinnitus in 79 patients. Variable Age group 41–50 51–60 61–70 71–80 81 Duration Short Long Laterality Unilateral Bilateral Form Discrete Multiple Occurrence Intermittent Continuous Nature Non pulsatile Pulsatile Associated clinical etiology Presbycusis Hypertension Noise exposure Meniere’s disease Ototoxic medication Sickle cell disease Unknown
Frequency
%
3 10 26 35 5
3.8 12.7 32.9 44.3 6.3
41 38
51.9 48.1
42 37
53.2 46.8
43 36
54.4 45.6
60 19
75.9 24.1
56 23
70.9 29.1
34 12 8 2 5 1 17
43.0 15.2 10.1 2.5 6.3 1.7 21.5
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Table 3 Comparison of the clinical characteristics of patients with and without tinnitus. Variable
Tinnitus absent n = 48 (%)
Tinnitus present n = 79 (%)
p
Agea (mean) Sex (female) Marital status (married) Level of education (up to secondary education) Occupational class (professional) Reported hearing loss Observed hearing loss Ear blockage Vertigo Autophony Otalgia Previous otorrhoea Alcohol consumption Smoking Noise exposure Previous head injury Hypertension Diabetes Osteoarthritis Sickle cell disease Prolonged medication Ototoxic drugs Obesity
70.7 39.6 68.8 83.3
68.8 40.5 72.2 74.4
0.256 0.918 0.683 0.684
33.3 27.1 29.2 29.2 8.3 47.9 14.6 25.0 18.8 8.3 35.4 6.3 8.3 18.8 18.8 2.1 27.1 22.9 6.3
44.3 57.0 78.5 20.3 24.1 40.5 19.0 20.3 14.0 16.5 34.2 13.9 51.9 22.8 22.8 6.3 39.2 34.2 21.5
0.403 0.001* <0.001* 0.255 0.019* 0.414 0.521 0.534 0.433 0.179 0.887 0.165 <0.001* 0.588 0.588 0.274 0.159 0.174 0.024*
Note: All parameters except age were compared using Chi square test. a Statistic is Student t-test. * Statistically significant.
4. Discussion This study revealed a high prevalence of tinnitus as a major complain among the middle aged and elderly patients attending the ENT Clinic of OOUTH, Sagamu, Nigeria. Most of the patients experienced unilateral, short term, intermittent, discrete and nonpulsatile forms of tinnitus. Occurrence of tinnitus was significantly associated with experience of vertigo, both reported and observed hearing losses, abnormalities in pure tone audiograms, as well as hypertension and obesity. Although this is a hospital based study in a specialized clinic, the high crude prevalence of 14.5% underscores the importance of this symptom. By extension this prevalence may give a reflection of what obtains in the community. The prevalence increased steadily with increasing age until after the eighth decade because there were fewer patients, possibly from natural processes of death, immobility and inability to attend hospital. Some authors agreed that the prevalence of tinnitus increased with age [10], particularly above the age of 50 [11,12]. In this age group different studies reported prevalence between 7.6% and 20.1% [5,11,13], within which the prevalence in this study falls. However there was no significant association between age and tinnitus in this study.
Table 4 Relationship between tinnitus and audiometric parameters. Parameter of audiogram
Tinnitus absent
Tinnitus present
p
Abnormal audiogram PTAv in better eara (mean) High tone hearing loss
29.2% 28.6 50.0%
78.5% 42.6 69.6%
<0.001* 0.001* 0.027*
Note: abnormal audiogram and high tone hearing loss were analyzed with the Chi square test. a Statistic is Student t-test. * Statistically significant.
Variations in the reported prevalence of tinnitus across different studies likely resulted from different investigators having differing criteria for the definition of tinnitus [5,11]. Most elderly people have some forms of tinnitus particularly in a quiet environment which can be disturbing for some of them. With the projected increase in the number of elderly patients, tinnitus has the potential of becoming a leading problem among the elderly in the near future [10]. It therefore places a duty on clinicians and other care givers of the elderly to be conversant with the characteristics of this ailment in their locality so as to prevent or ameliorate its unpleasant and discomforting effects. The descriptive characteristics of the types of tinnitus experience of our study gave the impression that the mild and relatively innocuous forms were experienced in our patients. The nature, duration and severity of tinnitus found in this study were however similar to those described in Europe and the USA [14]. Most forms of tinnitus usually start in seemingly innocuous ways, but become progressive and unrelenting with consequent uncomfortable symptoms with time. Furthermore these seemingly innocuous forms could also produce some uncomfortable effects which include sleep disturbances, anxiety, depression and general reduction in quality of life. These consequences are more crucial when they are associated with other otological symptoms. Common otological symptoms that were significantly associated with tinnitus in this study were hearing loss and vertigo. Gopinath et al. reported that incident tinnitus was predicted by two otological risk factors, dizziness and hearing loss [7]. The differentials of this triad of symptoms will include Meniere’s disease, Presbycusis and vestibular schwannoma each of which can make life miserable for the sufferer. Unilateral Tinnitus may connote a retrocohlear or nervous disease [15] like vestibular schwannoma, however the pure tone audiograms of many of our patients with tinnitus were confirmatory of Presbycusis. While Meniere’s disease and Presbycusis affect both ears, patients may present with symptoms referable to the worse ear alone. Tinnitus was associated with other abnormalities in the audiographic findings including the shape, the hearing thresholds and high tone hearing loss. Studies have shown hearing loss as a risk factor for tinnitus [16,17] especially among elderly subjects [18]. It was even reported that tinnitus patients with normal audiograms might have restricted cochlear damage [19] or hearing loss at frequencies above 8 kHz, which is not detected by normal clinical audiometry [20]. The greater likelihood of tinnitus in hearing impaired adults may be attributable to the loss of cochlear hair cells or hair cell function that occurs in hearing loss, leading to the aberrant auditory signals that are experienced as tinnitus [21]. Tinnitus is believed to arise from alterations in the spontaneous activity of neurons in the auditory system [22]. Similarly, findings on the relationship between tinnitus and shape of audiogram suggest that the occurrence of tinnitus is promoted by a steep audiogram slope (reflected as high tone hearing loss). A steep slope leads to abrupt discontinuities in the activity along the tonotopic axis of the auditory system, which could be misinterpreted as sound [23]. Thabet [24] reported that Transient Otoacoustic Emissions (TEOAEs) were significantly abnormal in tinnitus ears compared to control ears; especially at frequencies above 2000 Hz and were more common between 4000 and 5000 Hz. This suggests that outer air cells dysfunction may be important in the generation of tinnitus. The foregoing buttresses the probability of an intimate connection in the pathogenesis of both tinnitus and hearing loss that there may be an overlap or convergence at some points. There is, in fact, a statistically significant association between high-pitched tinnitus
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and high-frequency SNHL [18] suggesting that the auditory pathway reorganization induced by hearing loss could be one of the main sources of the tinnitus sensation. Some clinicians have suggested that some of the factors that are responsible for hearing loss are also likely to have caused an associated tinnitus [25]. On the other hand, several layers of complexity of pathological mechanisms are involved in the cause and generation of tinnitus and it is rarely known what causes an individual’s tinnitus (idiopathic tinnitus) [11,26]. Three mechanisms have been proposed to underlie tinnitus namely; changes in the level of spontaneous neural activity in the central auditory system; changes in the temporal pattern of neural activity, and reorganization of tonotopic maps [1,11]. Results from study on neural activity underlying tinnitus generation indicate that in addition to the auditory system, non-auditory systems in the central nervous system may represent a neural correlate of tinnitus. The implication of these is that there is a wide variability in tinnitus and search for a single cure for tinnitus is futile. Testing of new treatments is hampered by the fact that it is not possible to distinguish between different forms of tinnitus for which different treatments may be effective [11]. This study also found an association between hypertension, obesity and tinnitus similar to other studies [5,6,12]. Arterial hypertension belongs to the most important factors of origin and persistence of tinnitus [27] resulting from generalized microangiopathic changes which also affect the cochlear arterial circulation. Similarly Kaz´mierczak and Doroszewska reported that patients suffering from unknown tinnitus, vertigo, and hearing loss were found to be significantly more overweight (on the basis of body mass index) than were the control subjects [6]. However whether this was true for patients suffering from tinnitus alone was not ascertained. It will be necessary to further research into a causal relationship between obesity and tinnitus. Incidentally weight reduction surgery was effective in relieving persistent tinnitus in morbidly obese patients with associated pseudotumor cerebri syndrome [28]. Studies have reported tinnitus as a manifestation of otoneurological complications of diabetes [29] with emphases that disturbances of glucose metabolism may be responsible for inner ear diseases [6]. However it was also observed that diabetics appear to have more significant vestibular system changes compared to the auditory system [30]. No significant association was found between tinnitus and diabetes in this study. Also no association was found with history of previous ear diseases, noise exposure and head injuries which are among the prominent risk factors of tinnitus reported in literature from developed countries [2,10,11,31]. In this study, the symptoms that suggested previous ear diseases (ear blockage, autophony, otalgia, otorrhoea) were comparable in both subjects with and without tinnitus possibly due to their common occurrences in the environment. A similar trend was noted in history of exposure to noise and previous head injuries. However we might have studied patients with minor head injuries due to inadvertent elimination of those with major head injuries consequent upon limited medical facilities hampering treatment and survival of such patients in our environment. It is obvious that ear diseases, noise exposure and previous head injuries may not be risk factors for tinnitus in Nigeria. The small sample size of this study is perceived as a limitation and further characterization will be needed with a community based controlled, longitudinal study. This will allow better clarification to ascertain if there is a causal relationship
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between the significant factors and tinnitus in our environment and the direction of causality. The inability to analyze the loudness of tinnitus due to lack of necessary equipment is also admitted a limitation, as effects may be related to the magnitude of tinnitus. In conclusion, the crude prevalence of tinnitus among Nigerian adult ENT patients was 14.5% and tinnitus was associated with vertigo, hearing losses, abnormalities in pure tone audiograms, hypertension and obesity. While the characteristics of tinnitus in Nigerian patients were similar to those described in developed countries, the major risk factors for tinnitus except hearing impairment, may be different from the latter. Conflict of interest I hereby declare no conflict of interest. Acknowledgement I wish to acknowledge Dr. Rufus Akinyemi for going through this manuscript and his advice toward its final preparation. References [1] Lanting CP, de Kleine E, van Dijk P. Neural activity underlying tinnitus generation: results from PET and fMRI. Hear Res 2009;255:1–13. [2] Nondahl DM, Cruickshanks KJ, Wiley TL, Klein BE, Klein R, Chappell R, et al. The ten-year incidence of tinnitus among older adults. Int J Audiol 2010;49:580–5. [3] Lockwood AH, Wack DS, Burkard RF, Coad ML, Reyes SA, Arnold SA, et al. The functional anatomy of gaze-evoked tinnitus and sustained lateral gaze. Neurology 2001;56:472–80. [4] Seidmann MD, Jacobson GP. Update on tinnitus. Otolaryngol Clin North Am 1996;29:455–65. [5] Fujii K, Nagata C, Nakamura K, Kawachi T, Takatsuka N, Oba S, et al. Prevalence of tinnitus in community-dwelling Japanese adults. J Epidemiol 2011;21:299– 304. [6] Kaz´mierczak H, Doroszewska G. Metabolic disorders in vertigo, tinnitus, and hearing loss. Int Tinnitus J 2001;7:54–8. [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. [8] Hoare DJ, Kowalkowski VL, Kang S, Hall DA. Systematic review and metaanalyses of randomized controlled trials examining tinnitus management. Laryngoscope 2011;121:1555–64. [9] Figueiredo RR, Rates MA, Azevedo AA, Oliveira PM, Navarro PBA. Correlation analysis of hearing thresholds, validated questionnaires and psychoacoustic measurements in tinnitus patients. Braz J Otorhinolaryngol 2010;76:522–6. [10] Xu X, Bu X, Zhou L, Xing G, Liu C, Wang D. An epidemiologic study of tinnitus in a population in Jiangsu Province, China. J Am Acad Audiol 2011;22:578–85. [11] Moller AR. Tinnitus: presence and future. Prog Brain Res 2007;166:3–16. [12] Shargorodsky J, Curhan GC, Farwell WR. Prevalence and characteristics of tinnitus among US adults. Am J Med 2010;123:711–8. [13] Michikawa T, Nishiwaki Y, Kikuchi Y, Saito H, Mizutari K, Okamoto M, et al. Prevalence and factors associated with tinnitus: a community-based study of Japanese elders. J Epidemiol 2010;20:271–6. [14] Hall DA, La´inez MJ, Newman CW, Sanchez TG, Egler M, Tennigkeit F, et al. Treatment options for subjective tinnitus: self reports from a sample of general practitioners and ENT physicians within Europe and the USA. BMC Health Serv Res 2011;11:302. [15] Ferreira LM, Ju´nior AN, Mendes EP. Characterization of tinnitus in the elderly and its possible related disorders. Braz J Otorhinolaryngol 2009;75:249–55. [16] Sindhusake D, Golding M, Newall P, Rubin G, Jakobsen K, Mitchell P. Risk factors for tinnitus in a population of older adults: the Blue Mountains Hearing Study. Ear Hear 2003;24:501–7. [17] Sindhusake D, Golding M, Wigney D, Newal P, Jakobsen K, Mitchell P. Factors predicting severity of tinnitus: a population-based assessment. J Am Acad Audiol 2004;15:269–80. [18] 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. ˜ a A. Psychoacoustic [19] Weisz N, Hartmann T, Dohrmann K, Schlee N, Noren evidence for deafferentiation in tinnitus subjects with normal audiograms. In: Dauman R, Bouscau-Faur F, editors. Proceedings of the VIIIth international tinnitus seminar. 2005. p. 76.
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