The Audiometric Assessment of the Effectiveness of Surgical Treatment of Otosclerosis Depending on the Preoperative Incidence of Carhart's Notch.

Objective: The presence of Carhart's notch at 2000 Hz in otosclerosis links the changed bone conduction for this frequency with the otosclerotic process occurring in the oval window. The aim of this study is to perform an audiometric assessment of the effectiveness of surgical treatment of otosclerosis depending on the incidence of Carhart's notch. Methods: The analysis included 116 patients treated surgically for the first time due to otosclerosis. Patients were divided into 4 groups depending on the occurrence of Carhart's notch, determined by pure-tone audiometry (PTA) before the surgery and 36 months afterward. The mean value of bone conduction thresholds was calculated for 500 Hz, 1000 Hz, 2000 Hz, and 3000 Hz in the groups in which the Cahart's notch was observed. This value of bone conduction (BC) was a reference point for further analysis in patients who had no preoperative or postoperative Carhart's notch. Results: The analysis indicated that Cahart's notch in preoperative PTA is a statistically significant improvement factor for average BC. It was found that over a longer observation period, the presence of Carhart's notch has adverse effects on the size of the postoperative air-bone gap, and consequently on hearing improvement after surgical treatment. A comparison between patients from the two groups without preoperative Carhart's notch found that no beneficial effects of the surgery on speech comprehension were observed regarding high-level sensorineural hearing loss (SNHL). Conclusions: (1) In a long-term observation post-stapedotomy, average BC values were found to improve. Nevertheless, the improvement is less evident in patients with preoperative Carhart's notch. (2) Disappearance of Cahart's notch after surgical treatment of otosclerosis is a good prognosis of improvement in speech audiometry. (3) Deep SNHL in the absence of Carhart's notch in PTA constitutes a bad prognostic factor for improvement in speech audiometry in patients qualified for surgical treatment of otosclerosis.

Carhart Notch-A Prognostic Factor in Surgery for Otosclerosis.

OBJECTIVE: Otosclerosis is an underlying disease of the bony labyrinth. This disorder, occurring only within the area of a person's temporal bone, is characterized by a progressive hearing loss and tinnitus. MATERIAL AND METHODS: The study looked for the answer to the question of whether the presence or absence of Carhart notch in the presurgical tonal audiogram affects the final outcome of the otosclerosis surgery. RESULTS: The analysis included 140 patients operated on for the first time due to otosclerosis between 2010 and 2016. The study group consisted of 107 women aged from 19 to 62 (average age: 40.33) and 33 men aged 27 to 59 (average age: 38.23). Analysis showed a statistically better result of stapedotomy in patients without the notch than in the same procedure in patients with the notch present. The opposite situation occurred in the case of stapedectomy. CONCLUSION: (1) The presence of a refraction of the bone conduction curve with a depth of 10 to 20 dB at a frequency of 2000 Hz (the so-called Carhart notch) in the presurgical tonal audiogram is an unfavorable prognostic factor in relation to closing the cochlear reserve and improving bone conduction after the stapedotomy. (2) Regardless of the presence or absence of Carhart notch in the presurgical tonal audiogram, stapedotomy is the procedure with the highest efficiency in the treatment of otosclerosis.

Impact of surgery in otosclerosis on the non-operated ear.

Backgrounds Otosclerosis is an underlying disease of the bony labyrinth. The hearing loss is most often of conductive nature, in some cases the involvement of the bony part of the cochlea results in mixed hearing loss. Aims: The aim of the analysis was to answer the question whether a surgery on one of the ears affects the state of the other ear in the course of otosclerosis. Methods The analysis included 140 patients hospitalized and operated on between 2010 - 2016. Only patients who had not had a surgical operation within the middle ear due to otosclerosis prior to the study were included in it. An audiological assessment was performed with the use of pure tone threshold audiometry taking into account. Results In the group of patients with no Carhart's notch, the mean threshold of bone conduction was statistically lower than before the procedure for the frequencies of 500, 1000 Hz and statistically equal for the frequency of 2000 Hz. The same analysis in the group of patients with Carhart's notch present in the pre-surgical tonal audiogram of the non-operated ear showed a statistically significant lower value of the post-surgical threshold bone conduction value. Conclusion It was confirmed the possibility of improving the hearing of the non-operated ear after the stapedotomy of the opposite ear, in the author's own studies by an average of 5 dB in the low-frequency range.

The Audiology of Otosclerosis.

Diagnostic audiologic procedures for otosclerosis are effective tools in identifying this condition. Audiometric data usually demonstrate a conductive hearing loss at the early stages of otosclerosis. Modern middle ear analysis procedures are becoming more popular in the better diagnosis of otosclerosis. In clinical practice, cochlear otosclerosis can also be observed. Audiologic rehabilitation of otosclerosis includes fitting of hearing aids and implantable hearing devices. Current hearing technology enables patients who do not pursue surgical correction to function well and significantly improve their communication and quality of life. Otosclerosis may also be associated with annoying tinnitus, and tinnitus management is important in the rehabilitation process.

Middle-ear and inner-ear contribution to bone conduction in chinchilla: The development of Carhart's notch.

While the cochlea is considered the primary site of the auditory response to bone conduction (BC) stimulation, the paths by which vibratory energy applied to the skull (or other structures) reaches the inner ear are a matter of continued investigation. We present acoustical measurements of sound in the inner ear that separate out the components of BC stimulation that excite the inner ear via ossicular motion (compression of the walls of the ear canal or ossicular inertia) from the components that act directly on the cochlea (cochlear compression or inertia, and extra-cochlear 'third-window' pathways). The results are consistent with our earlier suggestion that the inner-ear mechanisms play a large role in bone-conduction stimulation in the chinchilla at all frequencies. However, the data also suggest the pathways that conduct vibration to the inner ear via ossicular-motion make a significant contribution to the response to BC stimulation in the 1-3 kHz range, such that interruption of these path leads to a 5 dB reduction in total stimulation in that frequency range. The mid-frequency reduction produced by ossicular manipulations is similar to the 'Carhart's notch' phenomenon observed in otology and audiology clinics in cases of human ossicular disorders. We also present data consistent with much of the ossicular-conducted sound in chinchilla depending on occlusion of the ear canal.

Pure-tone audiometry in otosclerosis: insufficient evidence for the diagnostic value of the Carhart notch.

OBJECTIVE: To evaluate whether the Carhart notch on pure-tone audiometry is reliable as a diagnostic test for predicting otosclerosis in patients with conductive hearing loss. Data Sources PubMed, Embase, the Cochrane Library, CINAHL, and Scopus. METHODS: A systematic search was conducted. Studies reporting original study data were included. After assessment of directness of evidence and risk of bias of the selected articles, the prevalences and the positive and negative predictive values were extracted. RESULTS: A total of 1402 unique studies was retrieved. Three of these satisfied the eligibility criteria. One study provided direct evidence, while all studies carried moderate to high risk of bias. One study with moderate directness of evidence and high risk of bias was not further analyzed. In a study with a high directness of evidence, a high risk of bias, and a low prevalence of otosclerosis (8%) in patients with conductive hearing loss, the presence of a Carhart notch at 2000 Hz increased the risk of otosclerosis with 33%. In a second study with moderate directness of evidence, moderate risk of bias, and a high prevalence of otosclerosis (72%) in patients with a surgically confirmed congenital ossicular anomaly or otosclerosis, the presence of a Carhart notch at 2000 Hz increased the risk of otosclerosis with 2%. CONCLUSION AND RECOMMENDATION: Although there is insufficient high-quality evidence regarding the diagnostic value of the Carhart notch, it seems it is a useful hint for the presence of otosclerosis, but it cannot be used to confirm a diagnosis of otosclerosis.