Cigarette- and snus-modified association between unprotected exposure to noise from hunting rifle caliber weapons and high frequency hearing loss. A cross-sectional study among swedish hunters.

AIM: To investigate in this cross-sectional study among Swedish hunters if tobacco use modifies the previously observed association, expressed as prevalence ratio (PR), between unprotected exposure to impulse noise from hunting rifle caliber (HRC) weapons and high-frequency hearing impairment (HFHI). SETTINGS AND DESIGN: A nationwide cross-sectional epidemiologic study was conducted among Swedish sport hunters in 2012. MATERIALS AND METHODS: The study was Internet-based and consisted of a questionnaire and an Internet-based audiometry test. RESULTS: In all, 202 hunters completed a questionnaire regarding the hearing test. Associations were modeled using Poisson regression. Current, daily use of tobacco was reported by 61 hunters (19 used cigarettes, 47 moist snuff, and 5 both). Tobacco users tended to be younger, fire more shots with HRC weapons, and report more hunting days. Their adjusted PR (1-6 unprotected HRC shots versus 0) was 3.2 (1.4-6.7), P < 0.01. Among the nonusers of tobacco, the corresponding PR was 1.3 (0.9-1.8), P = 0.18. P value for the interaction was 0.01. The importance of ear protection could not be quantified among hunters with HRC weapons because our data suggested that the HFHI outcome had led to changes in the use of such protection. Among hunters using weapons with less sound energy, however, no or sporadic use of hearing protection was linked to a 60% higher prevalence of HFHI, relative to habitual use. CONCLUSION: Tobacco use modifies the association between exposure to unprotected impulse noise from HRC weapons and the probability of having HFHI among susceptible hunters. The mechanisms remain to be clarified, but because the effect modification was apparent also among the users of smokeless tobacco, combustion products may not be critical for this effect.

High-frequency hearing, tinnitus, and patient satisfaction with stapedotomy: A randomized prospective study.

Otosclerosis is a common disorder that leads to conductive hearing loss. Most patients with otosclerosis also have tinnitus, and surgical treatment is known to improve hearing as well as tinnitus. Some patients however experience worsening of tinnitus after the operation, but there are no known factors that allow surgeons to predict who will be at risk. In this prospective observational study on 133 patients undergoing stapedotomy, we show that postoperative air conduction thresholds at very high stimulus frequencies predict improvement of tinnitus, as assessed with proportional odds logistic regression models. Young patients were significantly more likely to experience reduction of tinnitus and patients whose tinnitus became better were also more satisfied with the outcome of the operation. These findings have practical importance for patients and their surgeons. Young patients can be advised that surgery is likely to be beneficial for their tinnitus, but a less positive message should be conveyed to older patients.

A randomised, double blind trial of N-Acetylcysteine for hearing protection during stapes surgery.

BACKGROUND: Otosclerosis is a disorder that impairs middle ear function, leading to conductive hearing loss. Surgical treatment results in large improvement of hearing at low sound frequencies, but high-frequency hearing often suffers. A likely reason for this is that inner ear sensory cells are damaged by surgical trauma and loud sounds generated during the operation. Animal studies have shown that antioxidants such as N-Acetylcysteine can protect the inner ear from noise, surgical trauma, and some ototoxic substances, but it is not known if this works in humans. This trial was performed to determine whether antioxidants improve surgical results at high frequencies. METHODS: We performed a randomized, double-blind and placebo-controlled parallel group clinical trial at three Swedish university clinics. Using block-stratified randomization, 156 adult patients undergoing stapedotomy were assigned to intravenous N-Acetylcysteine (150 mg/kg body weight) or matching placebo (1:1 ratio), starting one hour before surgery. The primary outcome was the hearing threshold at 6 and 8 kHz; secondary outcomes included the severity of tinnitus and vertigo. FINDINGS: One year after surgery, high-frequency hearing had improved 2.7 ± 3.8 dB in the placebo group (67 patients analysed) and 2.4 ± 3.7 dB in the treated group (72 patients; means ± 95% confidence interval, p = 0.54; linear mixed model). Surgery improved tinnitus, but there was no significant intergroup difference. Post-operative balance disturbance was common but improved during the first year, without significant difference between groups. Four patients receiving N-Acetylcysteine experienced mild side effects such as nausea and vomiting. CONCLUSIONS: N-Acetylcysteine has no effect on hearing thresholds, tinnitus, or balance disturbance after stapedotomy. TRIAL REGISTRATION: ClinicalTrials.gov NCT00525551.

Structural tympanic membrane changes in secretory otitis media and cholesteatoma.

BACKGROUND: Otitis media may predispose for retraction pathologic abnormality later in life. A weakening of the collagen fiber bundles in the lamina propria of the tympanic membrane (TM) is a prerequisite for the formation of a retraction pocket. Various collagen types have different tensile strength. The collagen-type distribution in the TM during otitis media and cholesteatoma has not been reported before. MATERIALS AND METHODS: The collagen contents of TM biopsies from child patients with longstanding secretory otitis media without retraction pockets were compared with pars tensa cholesteatomas using immunohistochemical staining for collagen Types I to IV. The histology was also investigated using transmission electron microscopy. RESULTS: The outer epithelium was in some biopsies thickened with evidence of edema. The biopsies showed an intact lamina propria with positive immunohistochemical staining for collagen Types I to III and showed normal collagen fiber bundles on electron microscopy. The outer epithelium of the cholesteatomas showed marked thickness variations and signs of edema. There was a presence of normal collagen fiber bundles in smaller parts of all cholesteatomas, positive for collagen Types I to II. In other parts, only scattered collagen fibers were found. CONCLUSION: Tympanic membrane biopsies from patients with longstanding secretory otitis media may show a thickening of the outer epithelium. Collagen Types I to III are present in the lamina propria, and no ultrastructural changes of the collagen fiber bundles are observed. Collagen is found in cholesteatomas in the remnants of the lamina propria, with positive staining for collagen Types I and II, whereas Type III seems to be lacking.

The use of radiology in middle ear and temporal bone surgery.

A nationwide survey was performed in Sweden regarding the way that practicing otosurgeons utilize radiological imaging before and after performing surgery of the middle ear and temporal bone. Sixty-six surgeons from 30 different otorhinolaryngology departments participated in the study. These represented all hospitals in Sweden where ear surgery is performed to some degree. A questionnaire was designed consisting of 18 questions that were assigned to 4 different groups. Questions in group 1 assessed the general conditions regarding imaging services in the local hospital. Questions in group 2 illuminated the level of tuition and competence development when it comes to judging radiological examinations. Group 3 questions mirrored the clinical routines when ordering various specific investigations. In group 4, the questions were aimed at describing which type of information the surgeons wanted to obtain from the imaging investigations. The answers gave a good picture of how Swedish otosurgeons use the services offered by their local radiological departments. One of the conclusions is that, although there is consensus regarding certain types of examinations in specific conditions, there is a great variation in how surgeons utilize radiological imaging in many of the most common clinical conditions. It is obvious that the routines regarding the use of radiology in conjunction with ear surgery vary from place to place and also between different surgeons. Whether a consensus can be reached in the future regarding this issue remains to be seen.

Collagen type distribution in the healthy human tympanic membrane.

BACKGROUND: A weakening of the collagen fibers of the lamina propria of the tympanic membrane is a prerequisite for the formation of a retraction pocket. The various collagen types differ in tensile strength. The distribution of the different collagen types in the lamina propria of the healthy human tympanic membrane has not been reported before. METHODS: Immunohistochemical staining for collagen Types I, II, III, and IV in healthy human tympanic membranes harvested during translabyrinthine surgery for acoustic neuroma. The staining was semiquantified using light microscopy. RESULTS: Collagen Type II was the most abundant collagen of the lamina propria. When subdividing the staining between the 2 fiber layers of the lamina propria, it was observed that the inner layer was enriched with Type III relative to Type II, as reflected in staining patterns. In the outer radial fiber layer of the lamina propria, staining for collagen Type II was predominant.The fibrous annulus could be subdivided into an inner and an outer portion by immunohistochemistry. The inner portion stained strongest for collagen Type II and to a lesser extent for Type I. The outer portion stained strongest for collagen Type III and Type I. CONCLUSION: The differences in distribution of collagen types in the different fiber layers of the lamina propria suggest that the lattice of connective tissue supporting the tympanic membrane is not uniform. Understanding the differences in collagen type distribution and in the physical properties of the individual collagen types themselves may contribute to a comprehensive model of retraction pocket pathogenesis.

Hypoglossal schwannoma-successful reinnervation and functional recovery of the tongue following tumour removal and nerve grafting.

OBJECTIVE: Hypoglossal nerve schwannomas are rare tumours that usually cause ipsilateral hypoglossal palsy. This report describes such lesions in two patients and suggests nerve grafting as part of the treatment regimen. METHOD: Two patients with intra- and extra-dural hypoglossal schwannomas respectively were treated by direct surgery via a postero-lateral approach to the posterior fossa, hypoglossal canal and carotid sheath. Following tumour removal, sural nerve grafting was used to reconstruct the nerves. Unexpectedly, muscle bulk and motor function returned within 6 months in both patients. CONCLUSION: Nerve grafting was highly successful in achieving functional recovery following surgery for hypoglossal nerve schwannomas.

Wideband reflectance associated with otitis media in infants and children with cleft palate.

Wideband reflectance (WBR) is a method of middle-ear analysis that may provide more information and provide a more detailed look at the middle-ear system than tympanometry. WBR has the potential to improve efficiency of newborn hearing screening programs by reducing time needed to accurately diagnose middle-ear status. This prospective study compares wideband reflectance results with 226-Hz and 1000-Hz tympanometry and distortion product otoacoustic emissions in a group of infants and children with cleft lip and palate, who have not been treated with myringotomy or tubes. Results are also compared to normative data in children of similar ages using the same instrument and methods. Results demonstrate that wideband reflectance showed the highest level of agreement (88%) with DPOAE results.

Effects of using combined transpetrosal surgical approaches to treat petroclival meningiomas.

OBJECTIVE: Surgical treatment may be required for large petroclival meningiomas; however, surgery for these lesions is a major undertaking, and modern surgical approaches are still associated with considerable morbidity and recurrence rates. We analyzed our series of transpetrosally operated petroclival meningiomas to obtain detailed information regarding the surgery outcomes with respect to facial nerve effects, hearing changes, general neurological and psychosocial differences, and recurrence rates to identify opportunities for improvement. METHODS: Between 1994 and 2004, we used transpetrosal approaches to operate on 29 patients for petroclival meningiomas larger than 30 mm. All patients were analyzed in detail regarding neurological outcomes and hearing abilities after surgery. Swedish-speaking patients were contacted for a psychosocial follow-up evaluation using the short-item 36 (SF-36) form. RESULTS: After surgery, the Glasgow Outcome Score improved in 14 patients, was unchanged in 11 patients, and worsened in four patients. Facial nerve function was found to be of House-Brackmann Grade 3 or worse in six patients (including three individuals with transcochlear surgery and facial nerve rerouting). Of the 23 patients who underwent hearing-preservation surgery, serviceable hearing was preserved in 17 individuals. Nineteen Swedish patients were contacted for psychosocial evaluation. Three patients could not participate for health reasons; of the remaining 16 patients, 12 reported physical health scores that were below mean values for the general population. For patients who did not experience very serious neurological compromise, we found that unexpected painful trigeminal neuropathy and unilateral swallowing difficulties conveyed a negative influence on health. Three years after surgery, the patients reported more normalized health scores. CONCLUSION: Generally, outcomes compared well with current reports. Outcomes can be improved, however by improving patients' psychosocial support; striving to decompress, preserve, and minimize dissection of ill-defined planes of cranial nerves; and using Simpson Grade 4 gamma knife approaches when radicality is precluded. Currently, the performance of transpetrosal surgery for petroclival meningiomas is a major undertaking that significantly affects a patient's health for several years; however, the approaches that we used allowed a high degree of tumor control with relatively little neurological morbidity.

Effects of using combined transpetrosal surgical approaches to treat petroclival meningiomas.

OBJECTIVE: Surgical treatment may be required for large petroclival meningiomas; however, surgery for these lesions is a major undertaking, and modern surgical approaches are still associated with considerable morbidity and recurrence rates. We analyzed our series of transpetrosally operated petroclival meningiomas to obtain detailed information regarding the surgery outcomes with respect to facial nerve effects, hearing changes, general neurological and psychosocial differences, and recurrence rates to identify opportunities for improvement. METHODS: Between 1994 and 2004, we used transpetrosal approaches to operate on 29 patients for petroclival meningiomas larger than 30 mm. All patients were analyzed in detail regarding neurological outcomes and hearing abilities after surgery. Swedish-speaking patients were contacted for a psychosocial follow-up evaluation using the short-item 36 (SF-36) form. RESULTS: After surgery, the Glasgow Outcome Score improved in 14 patients, was unchanged in 11 patients, and worsened in four patients. Facial nerve function was found to be of House-Brackmann Grade 3 or worse in six patients (including three individuals with transcochlear surgery and facial nerve rerouting). Of the 23 patients who underwent hearing-preservation surgery, serviceable hearing was preserved in 17 individuals. Nineteen Swedish patients were contacted for psychosocial evaluation. Three patients could not participate for health reasons; of the remaining 16 patients, 12 reported physical health scores that were below mean values for the general population. For patients who did not experience very serious neurological compromise, we found that unexpected painful trigeminal neuropathy and unilateral swallowing difficulties conveyed a negative influence on health. Three years after surgery, the patients reported more normalized health scores. CONCLUSION: Generally, outcomes compared well with current reports. Outcomes can be improved, however by improving patients' psychosocial support; striving to decompress, preserve, and minimize dissection of ill-defined planes of cranial nerves; and using Simpson Grade 4 gamma knife approaches when radicality is precluded. Currently, the performance of transpetrosal surgery for petroclival meningiomas is a major undertaking that significantly affects a patient's health for several years; however, the approaches that we used allowed a high degree of tumor control with relatively little neurological morbidity.

Posterior canal dehiscence syndrome caused by an apex cholesteatoma.

OBJECTIVE: To compare audio-vestibular findings caused by a dehiscence of the posterior semicircular canal with those found in the superior canal dehiscence syndrome. STUDY DESIGN: Case report. SETTING: University hospital, tertiary referral center. PATIENT: The 44-year-old woman suffered from a gradual hearing loss with pulse-synchronous tinnitus as well as sound and pressure-induced vertigo. INTERVENTION: Audio-vestibular testing and high-resolution computed tomography. MAIN OUTCOME MEASURE: The superior canal dehiscence syndrome is caused by failure of normal postnatal bone development in the middle cranial fossa leading to absence of bone at the most superior part of the superior semicircular canal. The typical features for this syndrome are sound- and pressure-induced vertigo with torsional eye movements, pulse synchronous tinnitus and apparent conductive hearing loss in spite of normal middle-ear function. We present a patient with very similar symptoms and findings who, instead, had a posterior semicircular canal dehiscence caused by an apex cholesteatoma. CONCLUSION: Patients with semicircular canal dehiscence have common auditory-vestibular features regardless of which of the two vertical semicircular canals is affected. The only obvious difference between the two is the vertical component of the sound and pressure-induced eye movements (which beats in opposite directions).

Pars flaccida displacement pattern in otitis media with effusion in the gerbil.

HYPOTHESIS: Our hypothesis is that otitis media with effusion causes stiffness loss in the pars flaccida of the tympanic membrane. This loss of stiffness may be persistent and may trigger the development of retraction pockets and cholesteatoma. BACKGROUND: Otitis media with effusion is a very common disease in childhood. It can cause minor to moderate hearing loss and delayed speech development. Otitis media with effusion is a risk factor for retraction pocket formation. METHODS: Otitis media with effusion was induced unilaterally in 15 gerbils by obstructing the eustachian tube with glue. The contralateral ears served as normal controls. As a measure of mechanical stiffness, pars flaccida peak displacement versus pressure was used. The displacement measurements were made with moire interferometry. This is a noncontacting optical technique with which the displacement of an object can be measured in real time. RESULTS: The mean peak displacement of the pars flaccida in the group with otitis media with effusion was increased threefold as compared with normal controls. This difference was statistically significant. CONCLUSION: There was a loss of mechanical stiffness in the pars flaccida caused by otitis media with effusion. This loss of stiffness may be persistent and may predispose for retraction pocket formation and cholesteatoma development.

Pars flaccida displacement pattern in purulent otitis media in the gerbil.

HYPOTHESIS: Our hypothesis is that purulent otitis media and otitis media with effusion cause stiffness loss of the tympanic membrane. This loss of stiffness may be persistent and precede the development of retraction pockets and cholesteatoma. BACKGROUND: Postinflammatory changes such as retraction pockets and cholesteatoma develop in the pars flaccida and in the pars tensa of the tympanic membrane. In our previous experimental studies, stiffness changes were shown to develop early in the pars tensa in response to purulent otitis media and otitis media with effusion. These changes are suggested to be precursors to a later development of retraction pockets and cholesteatoma. In the clinical situation, retraction pockets are often found in the pars flaccida only. The aim of the current study was thus to investigate whether stiffness changes appear also in the pars flaccida during purulent otitis media. METHODS: Streptococcus pneumoniae type 3 was injected into the middle ear to induce purulent otitis media. As a measure of pars flaccida stiffness, peak displacement versus middle ear pressure was used. The peak displacement measurements were obtained from full-field moiré; interferometry, which is a noncontacting optical technique for deformation measurements. RESULTS: Ears with purulent otitis media showed increased peak displacement of the pars flaccida at a middle ear pressure of 200 daPa, compared with normal controls. CONCLUSION: There was a decreased mechanical stiffness of the pars flaccida in acute purulent otitis media. This decreased stiffness may predispose for future retraction pocket formation and cholesteatoma development.