| 11. |
- Prodanovic, Srdan, et al.
(författare)
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Consequences of Mastoidectomy on Bone Conducted Sound Based on Simulations in a Whole Human Head
- 2020
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Ingår i: Otology and Neurotology. - : LIPPINCOTT WILLIAMS & WILKINS. - 1531-7129 .- 1537-4505. ; 41:9, s. E1158-E1166
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Tidskriftsartikel (refereegranskat)abstract
- Hypothesis: The aim of this study is to investigate how a mastoidectomy surgery affects bone conduction (BC) sound transmission using a whole head finite element model. Background: Air conduction (AC) and BC hearing thresholds are normally used to evaluate the effect of an ear surgery. It is then assumed that the BC hearing thresholds are unaffected by the surgery. Moreover, BC hearing aids are used in cases of unilateral or conductive hearing loss in heads that have undergone a mastoidectomy surgery. Given the invasiveness of the surgery, the BC hearing sensitivity may be altered by the surgery itself. Methods: Two types of mastoid surgery, canal wall up and canal wall down, with and without obliteration, were simulated in a whole head finite element model for BC stimulation, the LiUHead. The evaluations were conducted for two different methods of applying the BC sound, at the skin surface (B71 transducer) and directly at the bone (BC hearing aid). Results: The results showed that a mastoidectomy surgery increased the cochlear vibration responses with BC stimulation. The increase was less than 5 dB, except for a canal wall down surgery which gave an increase of up to 8 dB at frequencies close to 10 kHz. The increase was greater at the ipsilateral cochlea compared with the contralateral cochlea. Conclusion: A mastoidectomy surgery increases the vibration at both cochleae for BC stimulation and the increase generally improved with frequency. Obliteration of the surgical cavity does not influence BC sound transmission.
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| 12. |
- Rönnblom, Anton, et al.
(författare)
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A New, Promising Experimental Ossicular Prosthesis : A Human Temporal Bone Study With Laser Doppler Vibrometry
- 2020
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Ingår i: Otology and Neurotology. - : Lippincott Williams & Wilkins. - 1531-7129 .- 1537-4505. ; 41:4, s. 537-544
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We compared the sound transmission using different types of total ossicular replacement prostheses (TORP); we then studied the performance of a new TORP that we designed inspired by the columella, the single ossicle found in birds.Methods: Stapedial vibrations were measured on nine freshly frozen human temporal bones with laser Doppler vibrometry. We then compared the performances of eight common TORP positions or designs as well as the new silver prototype of bird-type prosthesis, designed also according to our digital holography patterns of the human tympanic membrane (TM).Results: The TORPs placed in lateral contact with both the TM and the malleus handle outperformed, at most frequencies, those placed only in contact with the TM.The new bird-type prosthesis performed equally well or better than all other prostheses.Conclusion: If the malleus handle can be retained when placing a TORP, the best sound transmission can be achieved by placing the TORP in contact with both the distal part of the malleus handle and the TM. The good performance of our bird-type prosthesis suggests that there is still room for future improvement of prosthesis design to further optimize hearing outcomes after surgery.
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| 13. |
- Rönnblom, Anton, et al.
(författare)
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Forces Required for Isolated Malleus Shaft Fractures
- 2021
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Ingår i: Otology and Neurotology. - : Wolters Kluwer. - 1531-7129 .- 1537-4505. ; 42:10, s. 1515-1520
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND HYPOTHESIS: Isolated malleus shaft fractures are rare cases. A commonly reported cause is a finger pulled out from a wet outer ear canal after a shower or bath. The objective was to investigate experimentally the mechanism and forces needed to establish an isolated malleus shaft fracture.METHODS: Ten fresh-frozen human temporal bones were adapted to allow visual inspection of the structures involved while negative pressure trauma was applied. Thirty malleus bones were broken and the required forces were measured. Measurements from 60 adult test subjects were used to create mathematical and physical models to calculate and measure the forces necessary for generating trauma. To calculate the maximum muscle force developed by the tensor tympani muscle, the muscle area and fiber type composition were determined.RESULTS: The temporal bone experiments showed that applied negative pressure in a wet ear canal could not fracture the malleus shaft with only passive counterforce from supporting structures, although the forces exceeded what was required for a malleus shaft fracture. When adding calculated counteracting forces from the tensor tympani muscles, which consisted of 87% type II fibers, we estimate that a sufficient force is generated to cause a malleus fracture.CONCLUSION: The combination of a negative pressure created by a finger pulling outward in a wet ear canal and a simultaneous counteracting reflexive force by the tensor tympani muscle were found to be sufficient to cause an isolated malleus fracture with an intact tympanic membrane.
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| 14. |
- Siegbahn, Malin, et al.
(författare)
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Asymmetry in Cortical Thickness of the Heschl's Gyrus in Unilateral Ear Canal Atresia
- 2024
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Ingår i: Otology and Neurotology. - : Ovid Technologies (Wolters Kluwer Health). - 1531-7129 .- 1537-4505. ; 45:4, s. 342-350
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Tidskriftsartikel (refereegranskat)abstract
- Hypothesis Unilateral congenital conductive hearing impairment in ear canal atresia leads to atrophy of the gray matter of the contralateral primary auditory cortex or changes in asymmetry pattern if left untreated in childhood. Background Unilateral ear canal atresia with associated severe conductive hearing loss results in deteriorated sound localization and difficulties in understanding of speech in a noisy environment. Cortical atrophy in the Heschl's gyrus has been reported in acquired sensorineural hearing loss but has not been studied in unilateral conductive hearing loss. Methods We obtained T1w and T2w FLAIR MRI data from 17 subjects with unilateral congenital ear canal atresia and 17 matched controls. Gray matter volume and thickness were measured in the Heschl's gyrus using Freesurfer. Results In unilateral congenital ear canal atresia, Heschl's gyrus exhibited cortical thickness asymmetry (right thicker than left, corrected p = 0.0012, mean difference 0.25 mm), while controls had symmetric findings. Gray matter volume and total thickness did not differ from controls with normal hearing. Conclusion We observed cortical thickness asymmetry in congenital unilateral ear canal atresia but no evidence of contralateral cortex atrophy. Further research is needed to understand the implications of this asymmetry on central auditory processing deficits.
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| 15. |
- Verrecchia, Luca, 1971, et al.
(författare)
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The Validation of a Simultaneous Ocular and Cervical VEMP Recording Protocol to Unilateral AC Stimuli
- 2023
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Ingår i: Otology and Neurotology. - 1531-7129 .- 1537-4505. ; 44:10, s. e739-e746
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: A simultaneous recording of cervical and ocular vestibular evoked myogenic potential (sVEMP) to unilateral air-conducted (AC) stimulation reduces the test time and halves the sound load. MATERIALS AND METHODS: The sVEMP has been compared with the conventional sequential unilateral AC cervical and ocular VEMP in a consecutive cohort of 120 subjects attending the vestibular laboratory. The stimulus was a 500-Hz 6-ms tone burst, at 130 dB peSPL for sequential recordings but at 125 dB for the added sVEMP, for cumulative sound load containment. Amplitudes, latencies, and amplitude asymmetry ratios (ARs) were the parameters included in analysis. RESULTS: Relevant results were as follows: 1) significantly lower amplitudes in sVEMP versus VEMP (ocular recordings, median = 2.90 [IQR = 0-4.98] vs. 4.15 [1.73-8.98] μV, p < 0.001; cervical, 0.84 [0.30-1.69] vs. 1.36 [0.60-2.30], p < 0.001; electromyography scaled values); 2) 10% lower response rate at cervical recordings and 11% at ocular recordings in sVEMP, particularly in older subjects; 3) significant correlations between cervical amplitudes ( rs = 0.88, p < 0.001), ocular amplitudes ( rs = 0.71, p < 0.001), peak latencies ( rs = 0.36-0.67, p < 0.001), and ARs (ocular, rs = 0.56; cervical, rs = 68, p < 0.001); and 4) good agreement in pathological AR detection (cervical recordings, Cohen's κ = 0.649, p < 0.001; ocular, κ = 0.589, p < 0.001). DISCUSSION: AC sVEMP showed good correlation/agreement with sequential AC VEMP. Test time containment and halved sound load are clinical adds in sVEMP, opening to its use as laboratory standard. However, AC sVEMP presented reduced amplitudes and response rates, secondary to the reduced AC stimulation used in this study to allow checking of the null responses and the pathological ARs at AC sVEMP with conventional AC VEMP.
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| 16. |
- Westerberg, Johanna, 1971-, et al.
(författare)
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JAK/STAT Dysregulation With SOCS1 Overexpression in Acquired Cholesteatoma-Adjacent Mucosa
- 2021
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Ingår i: Otology and Neurotology. - : Lippincott Williams & Wilkins. - 1531-7129 .- 1537-4505. ; 42:1, s. e94-e100
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Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCE: Surgery remains the gold standard in cholesteatoma treatment. However, the rate of recurrence is significant and the development of new nonsurgical treatment alternatives is warranted. One of the possible molecular pathways to target is the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway.OBJECTIVE: To investigate the JAK/STAT pathway in the middle ear mucosa in patients with acquired cholesteatoma compared with middle ear mucosa from healthy controls.DESIGN: Case-control study.SETTING: Linköping University Hospital, Sweden, and Karolinska Institutet, Stockholm, Sweden. Sampling period: February 2011 to December 2016.PARTICIPANTS: Middle ear mucosa from 26 patients with acquired cholesteatoma undergoing tympanoplasty and mastoidectomy, and 27 healthy controls undergoing translabyrinthine surgery for vestibular schwannoma or cochlear implantation was investigated.MAIN OUTCOMES/MEASURES: The expression of Interleukin-7 receptor alpha, JAK1, JAK2, JAK3, STAT5A, STAT5B, and suppressor of cytokine signaling-1 (SOCS1) were quantified using quantitative polymerase chain reaction. In addition, expression level of cyclin D2, transforming growth factor beta 1, thymic stromal lymphopoietin, CD3, and CD19 was evaluated.RESULTS: In cholesteatoma-adjacent mucosa, SOCS1 was significantly upregulated (p= 0.0003) compared with healthy controls, whereas STAT5B was significantly downregulated (p = 0.0006). The expression of JAK1, JAK2, JAK3, and STAT5A did not differ significantly between groups.CONCLUSIONS AND RELEVANCE: To the best of our knowledge, this is the first article reporting dysregulation of the JAK/STAT pathway in cholesteatoma-adjacent mucosa. The main finding is that important players of the aforementioned pathway are significantly altered, namely SOCS1 is upregulated and STAT5B is downregulated compared with healthy controls.
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| 17. |
- Westerberg, Johanna, et al.
(författare)
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Nitric Oxide Is Locally Produced in the Human Middle Ear and Is Reduced by Acquired Cholesteatoma
- 2022
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Ingår i: Otology and Neurotology. - : LIPPINCOTT WILLIAMS & WILKINS. - 1531-7129 .- 1537-4505. ; 43:2, s. E198-E204
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To find out if nitric oxide (NO) can be locally produced in the middle ear and if chronic otitis media (COM) and acquired cholesteatoma affect the production. Design: Case-control study. Setting: Two tertiary-referral hospitals. Patients: Gaseous NO from 11 patients with unilateral perforations or grommet openings was measured with chemiluminescence. Middle ear mucosa from 48 patients with COM and 26 patients with cholesteatoma was investigated. Main Outcome Measures: Detection of NO. Expression of nitric oxide synthase (NOS) mRNA, in mucosa from COM, cholesteatoma and healthy controls, quantified using polymerase chain reaction. Results: The gaseous NO from ears with a unilateral tympanic membrane perforation or a grommet was higher (9 +/- 3 ppb, n = 11) than among the controls (4 +/- 1 ppb, n = 11, p = 0.04). Lower levels of eNOS (2.64 +/- 0.86 mol/100,000 mol ACTB) were detected in the pooled samples from the COM group (n = 48), compared with the control group (140.48 +/- 92 mol/100,000 mol ACTB, n = 45, p = 0.010). In the cholesteatoma group (n = 26), a lower expression of nNOS (5.78 x 10(-6) +/- 1.13 x 10(-6) Delta Ct) was found in comparison with the controls (1.23 x 10(-4) +/- 3.18 x 10(-5) Delta Ct, n = 15, p = 0.011). Conclusions: NO is likely a natural and permanent part of the gas mixture in the human middle ear. The presence of NOS enzymes in the middle ear mucosa indicates an ongoing NO production and the reduction of NOS in ears with cholesteatoma, and pooled samples from ears with COM, suggest a role for locally produced NO in middle ear disease.
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| 18. |
- Bergius, Elin, et al.
(författare)
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Benefit of Higher Maximum Force Output in Bone Anchored Hearing Systems: A Crossover Study.
- 2021
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Ingår i: Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. - 1537-4505. ; 42:10, s. 1451-1459
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Tidskriftsartikel (refereegranskat)abstract
- To investigate how higher maximum force output (MFO) in bone anchored hearing systems (BAHS) affects perceived benefit and the subjective experience of sound as well as hearing outcomes in subjects with mixed hearing loss.Prospective single-center, randomized crossover design (A-B-A) with within-subject control design.The study included 19 experienced BAHS users with mixed hearing loss in the fitting range of a standard BAHS.The study evaluated two sound processors with differing MFOs and sizes-Device A: standard sound processor with a lower MFO and Device B: superpower sound processor with a higher MFO.Speech recognition in noise at different signal to noise ratios, aided thresholds, and questionnaires.Speech recognition test showed significant improvements using Device B compared with Device A at both 78dB SPL (mean difference: 9%) and 75dB SPL (mean difference: 12%) (p<0.05). Moreover, speech, spatial and qualities of hearing scale (SSQ12-C) showed a significantly greater perceived benefit with Device B concerning spatial abilities (mean: 0.5-0.6) (p<0.05). At the conclusion of the study, 58% of participants chose to keep Device A for further use. The main reasons for this were the size of the sound processor and a more comfortable sound experience.A BAHS sound processor with a higher MFO leads to improved speech-in-noise performance in loud/noisy listening situations and is perceived as significantly better to process spatial information in daily listening situations. However, the relation between cosmetics and performance is not straightforward, and several factors seem to affect the selection process of BAHS.
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