Osteosclerosis represents a primary disease having characteristics of impaired metabolism in the bony labyrinth of the ears. It usually starts with softening of the osseus tissues followed by secondary pathological sclerosis. The disease generally includes the anterior niche of the oval window that induces the stapes to be fixed. Osteosclerosis is a common reason for the conductive hearing loss with tympanic membrane being intact.¹

Sensorineural hearing loss can also be seen when otosclerotic foci develop within the cochlea. The diagnosis for the osteosclerosis includes literal and detailed assessment including the imaging, hearing tests, and medical history. It is vital to distinguish osteosclerosis from other conditions which still remains a challenge to diagnose.²

Surgery can ultimately help in the definitive diagnosis of osteosclerosis and is an effective management strategy for improvement in the hearing. Also, preoperative assessment and diagnosis of the surgical indication are usually vital. Osteosclerosis is commonly seen in India, South America, North America, Middle East, and European regions.³

Osteosclerosis is highly prevalent in India. However, existing literature data is scarce concerning clinical features and audio logical characteristics of subjects with osteosclerosis in Indian context. The present study was aimed to analyze the clinical features and audiological characteristics of subjects with osteosclerosis in India aimed to improve diagnosis and determine surgery to reduce incidence.

The present retrospective study was aimed to analyze the clinical features and audiological characteristics of subjects with osteosclerosis in India aimed to improve diagnosis and determine surgery to reduce incidence. The study was done at Department of ENT, GMERS Medical College, Vadnagar, Gujrat. Verbal and written informed consent were taken from all the subjects before study participation. The study assessed 160 ears in 96 subjects that underwent surgery for osteosclerosis at the Institute within the defined study period. All the subjects were assessed for various signs and symptoms of osteosclerosis and were recorded in a preformed proforma designed for the study. The mean age of the study subjects was 38.39±12.32 years and in the range of 11-56 years. There were 72 females and 24 males in the study. All the cases were confirmed using surgery and underwent laser-assisted stapedotomy. In all the subjects, a comprehensive clinical history was recorded along with physical assessment, audiological testing, and imaging studies in all the included study subjects. In all the subjects, preoperative audiograms were done one week before the surgery. All the audiometric tests were done by audiologist expert in the field using an audiometer. The distribution of Carhart notch was done at varying frequencies. Carhart notch was considered as an impairment in the BC of ≥7.5 dB above the higher and lower adjacent frequencies. The data gathered were assessed statistically using the chi-square test, Fisher’s exact test, Mann Whitney U test, and SPSS (Statistical Package for the Social Sciences) software version 24.0 (IBM Corp., Armonk. NY, USA) using ANOVA, chi-square test, and student's t-test. The significance level was considered at a p-value of <0.05.

The present retrospective study was aimed to analyze the clinical features and audiological characteristics of subjects with osteosclerosis in India aimed to improve diagnosis and determine surgery to reduce incidence. The study assessed 160 ears in 96 subjects that underwent surgery for osteosclerosis at the Institute within the defined study period. All the subjects were assessed for various signs and symptoms of osteosclerosis and were recorded in a preformed proforma designed for the study.

It was seen that for the clinical features of osteosclerosis in the 160 ears assessed in the study, there thrice females compared to males in the study depicting a female predominance. Also, there were higher number of middle-aged subjects with the mean age of 36 years. In the 160 ears from 96 subjects, there were 64 bilateral onset, whereas, there were 32 ears with unilateral onset. The bilateral involvement was seen in 66.66% of the subjects (Table 1).

The study results showed that tinnitus was seen in 89% of the study subjects where ear fullness was seen in only 10% of the study subjects. In 2.5% study subjects, Willis paracusis was noted. Schwarz sign was absent in all the study subjects, and negative Gelle test was seen in 99% of the study subjects. Decrease in the bone density and increase in the stapes density in the vestibular window area was seen in 20% of the study subjects. Also, 20% subjects exhibited tympanogram of type As.

For pure tone audiometry in the study subjects from 160 ears, the mean AC (air conduction threshold) was in the range of 49 to 60 db HL, whereas, BC (bone conduction) was mean in the range of 22 to 36 dB HL. With increase in the test frequency, the AC gradually decreased and slightly increased at 8kHz. On the contrary, BC increased gradually with increase in the test frequency and decreased at 4 kHz. In the present study, 31% subjects had no Carhart notch and Carhart notch at 2kHz and 1kHz was seen in 64% and 5% study subjects respectively. The notch presence showed no correlation with hearing threshold (Table 2).

Table 1: Clinical manifestation in study ears with osteosclerosis

Table 2: PTA in 160 ears with sclerosis in study subjects

Table 3: Distribution of Carhart notch in study subjects

The present study assessed 160 ears in 96 subjects that underwent surgery for osteosclerosis at the Institute within the defined study period. All the subjects were assessed for various signs and symptoms of osteosclerosis and were recorded in a preformed proforma designed for the study. The design of the present study was comparable to the previous studies of Kan T et al5 in 2020 and Genç A et al6 in 2007 where study design comparable to the present study were also adopted by the authors in their studies.

The study results showed that for the clinical features of osteosclerosis in the 160 ears assessed in the study, there thrice females compared to males in the study depicting a female predominance. Also, there were higher number of middle-aged subjects with the mean age of 36 years. In the 160 ears from 96 subjects, there were 64 bilateral onset, whereas, there were 32 ears with unilateral onset. The bilateral involvement was seen in 66.66% of the subjects. These findings correlated with the results of Wiatr A et al7 in 2021 and Bonnafous S et al8 in 2022 where results for clinical features of osteosclerosis reported by the authors were comparable to the present study.

It was seen that tinnitus was seen in 89% of the study subjects where ear fullness was seen in only 10% of the study subjects. In 2.5% study subjects, Willis paracusis was noted. Schwarz sign was absent in all the study subjects, and negative Gelle test was seen in 99% of the study subjects. Decrease in the bone density and increase in the stapes density in the vestibular window area was seen in 20% of the study subjects. Also, 20% subjects exhibited tympanogram of type As. These results were consistent with the findings of Lamblin P et al9 in 2021 and Skarzynski PH et al10 in 2019 where tinnitus and various signs comparable to the present study were also reported by the authors in their study subjects.

Concerning pure tone audiometry in the study subjects from 160 ears, the mean AC (air conduction threshold) was in the range of 49 to 60 db HL, whereas, BC (bone conduction) was mean in the range of 22 to 36 dB HL. With increase in the test frequency, the AC gradually decreased and slightly increased at 8kHz. On the contrary, BC increased gradually with increase in the test frequency and decreased at 4 kHz. In the present study, 31% subjects had no Carhart notch and Carhart notch at 2kHz and 1kHz was seen in 64% and 5% study subjects respectively. The notch presence showed no correlation with hearing threshold. These findings were in agreement with the results of Batson L et al11 in 2017 and Stenfelt S12 in 2015 where pure tone audiometry results reported by the authors were comparable to the results of the present study.

Within its limitations, the present study concludes that

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