Detection of Coalescent Acute Mastoiditis on MRI in Comparison with CT.

PURPOSE: Current imaging standard for acute mastoiditis (AM) is contrast-enhanced computed tomography (CT), revealing inflammation-induced bone destruction, whereas magnetic resonance imaging (MRI) outperforms CT in detecting intracranial infection. Our aim was to compare the diagnostic performance of MRI with CT in detecting coalescent AM and see to which extent MRI alone would suffice to diagnose or rule out this condition. METHODS: The MR images of 32 patients with AM were retrospectively analyzed. Bone destruction was evaluated from T2 turbo spin echo (TSE) and T1 Gd magnetization-prepared rapid acquisition with gradient echo (MPRAGE) images. Intramastoid enhancement and diffusion restriction were evaluated subjectively and intramastoid apparent diffusion coefficient (ADC) values were measured. The MRI findings were compared with contrast-enhanced CT findings of the same patients within 48 h of the MR scan. RESULTS: Depending on the anatomical subsite, MRI detected definite bone defects with a sensitivity of 100% and a specificity of 54-82%. Exception was the inner cortical table where sensitivity was only 14% and specificity was 76%. Sensitivity for general coalescent mastoiditis remained 100% due to multiple coexisting lesions. The absence of intense enhancement and non-restricted diffusion had a high negative predictive value for coalescent mastoiditis: an intramastoid ADC above 1.2â€¯× 10-3 mm2/s excluded coalescent mastoiditis with a negative predictive value of 92%. CONCLUSION: The MRI did not miss coalescent mastoiditis but was inferior to CT in direct estimation of bone defects. When enhancement and diffusion characteristics are also considered, MRI enables dividing patients into low, intermediate and high-risk categories with respect to coalescent mastoiditis, where only the intermediate risk group is likely to benefit from additional CT.

Peritonsillar infiltration of lidocaine with adrenaline is associated with increased risk of secondary post-tonsillectomy haemorrhage.

OBJECTIVES: In order to evaluate the safety of tonsillectomy among children, we retrospectively studied the incidence of post-operative complications, adverse events and their association with peri-operative medication. METHODS: Data were collected from the medical records of 691 patients aged 1-16 years, including details of post-operative complications (any unplanned contact with the hospital), analgesics, dexamethasone, 5-HT3 antagonists, local anaesthetic and haemostatic agents. RESULTS: Recovery was complicated in 13.6 per cent of patients, of whom 8.4 per cent were re-admitted to the ward. The most common complication was post-tonsillectomy haemorrhage, experienced by 7.1 per cent of patients. Re-operation under general anaesthesia (for grade III post-tonsillectomy haemorrhage) was required by 4.2 per cent of patients. Peritonsillar infiltration of lidocaine with adrenaline increased the risk of post-tonsillectomy haemorrhage (odds ratio = 4.1; 95 per cent confidence interval = 2.1 to 8.3). CONCLUSION: Every seventh paediatric patient experienced a complicated recovery after tonsillectomy, caused by post-tonsillectomy haemorrhage in most cases. Local peritonsillar infiltration of lidocaine with adrenaline was associated with an increased risk of post-tonsillectomy haemorrhage.

A New Classification System is Helpful in Diagnosing Intracranial Complications of Acute Mastoiditis in CT.

PURPOSE: To assess the usefulness of the new computed tomography (CT) classification criteria proposed by Horowitz et al. and their effect on inter-observer agreement when estimating intracranial complications of acute mastoiditis. METHODS: In this study 53 contrast-enhanced CT scans of patients with acute mastoiditis were each retrospectively reviewed by two radiologists, using two different assessment criteria for intracranial complications. According to the new criteria, intracranial CT findings in the perisinuous area were graded into four classes (I normal, II linear halo, III nodular halo ≤4 mm thick and IV nodular halo >4 mm thick), where classes III and IV indicate a high risk for epidural abscesses. Inter-reader agreement was estimated by weighted kappa analysis for both methods. RESULTS: With the old method, epidural abscesses were suspected in six and venous sinus thrombosis in five patients. With the new method, high-risk perisinuous lesions (classes III or IV) were detected in 11 patients, and sinus thrombosis outside the perisinuous area in 3 patients. All epidural abscesses were in the perisinuous area. Of the patients four, in whom intracranial pathology was not suspected with the old method, fell into the high-risk group (class III) according to the new method. All class IV lesions were also determined to be pathological with the old method. The inter-observer agreement (weighted kappa) rose from 0.21 (old method) to 0.80 (new method) when assessing epidural abscesses and from 0.44 (old method) to 0.85 (new method) when assessing sinus thrombosis. CONCLUSION: The new assessment method raised the inter-observer agreement for detection of intracranial acute mastoiditis complications, namely epidural abscesses and venous sinus thrombosis.

Comparison of MR imaging findings in paediatric and adult patients with acute mastoiditis and incidental intramastoid bright signal on T2-weighted images.

OBJECTIVES: To compare MR imaging features in patients with incidental mastoid T2-hyperintensity with those of clinical acute mastoiditis, to ascertain characteristic differences between them. METHODS: MR images of 35 adult and paediatric patients with clinical acute mastoiditis and 34 consecutive age-matched controls without relevant middle ear pathology and with incidental T2-hyperintensity that covered ≥ 50 % of the mastoid were retrospectively analysed with regard to signal, diffusion, and enhancement characteristics, and presence of complications. RESULTS: Incidental mastoid T2-hyperintensity that covered ≥ 50 % of the mastoid volume was found in 4.6 % of reviewed MR scans (n = 2341), and associated significantly (p < 0.05) less with the involvement of the tympanic cavity (38 % vs. 74 %) and mastoid antrum (56 % vs. 80 %), hypointense-to-CSF signal intensity on T2 FSE (6 % vs. 86 %), intramastoid diffusion restriction (0 % vs. 62 %), intense intramastoid enhancement (0 % vs. 51 %), periosteal enhancement (3 % vs. 69 %), perimastoid dural enhancement 3 % vs. 43 %), bone destruction (0 % vs 49 %), intratemporal abscess or cholesteatoma (0 % vs. 24 %), labyrinth involvement (0 % vs. 14 %), and extracranial abscesses (0 % vs. 20 %). CONCLUSION: Hypointense-to-CSF signal intensity on T2WI, restricted diffusion, intense intramastoid enhancement among other MR imaging characteristics favoured an acute mastoiditis diagnosis over clinically non-relevant incidental mastoid pathology. KEY POINTS: • Intramastoid T2-hyperintensity alone is not a reliable sign for acute mastoiditis. • In acute mastoiditis, intramastoid T2-weighted signal intensity is usually hypointense to CSF. • Diffusion restriction and intense intramastoid enhancement are absent in incidental mastoid effusion. • An ADC value ≥ 1.72 × 10 (-3) mm (2) /s contradicts the AM diagnosis.

MR imaging features of acute mastoiditis and their clinical relevance.

BACKGROUND AND PURPOSE: MR imaging is often used for detecting intracranial complications of acute mastoiditis, whereas the intratemporal appearance of mastoiditis has been overlooked. The aim of this study was to assess the imaging features caused by acute mastoiditis in MR imaging and their clinical relevance. MATERIALS AND METHODS: Medical records and MR imaging findings of 31 patients with acute mastoiditis (21 adults, 10 children) were analyzed retrospectively. The degree of opacification in the temporal bone, signal and enhancement characteristics, bone destruction, and the presence of complications were correlated with clinical history and outcome data, with pediatric and adult patients compared. RESULTS: Most patients had ≥50% of the tympanic cavity and 100% of the mastoid antrum and air cells opacified. Compared with CSF, they also showed intramastoid signal changes in T1 spin-echo, T2 TSE, CISS, and DWI sequences; and intramastoid, outer periosteal, and perimastoid dural enhancement. The most common complications in MR imaging were intratemporal abscess (23%), subperiosteal abscess (19%), and labyrinth involvement (16%). Children had a significantly higher prevalence of total opacification of the tympanic cavity (80% versus 19%) and mastoid air cells (90% versus 21%), intense intramastoid enhancement (90% versus 33%), outer cortical bone destruction (70% versus 10%), subperiosteal abscess (50% versus 5%), and perimastoid meningeal enhancement (80% versus 33%). CONCLUSIONS: Acute mastoiditis causes several intra- and extratemporal changes on MR imaging. Total opacification of the tympanic cavity and the mastoid, intense intramastoid enhancement, perimastoid dural enhancement, bone erosion, and extracranial complications are more frequent in children.

Hearing aid compliance in the elderly.

OBJECTIVES: A decreasing but still substantial proportion of elderly persons with hearing aids use them only occasionally. Because the prevalence of age-related hearing loss is increasing, it is important for the hearing rehabilitation process to be effective. The aim of this study was to use a mailed questionnaire to evaluate the rate of hearing aid use and the reasons for minimal use or nonuse. METHODS: Questions about hearing aid use and associated problems were included in a survey of hearing mailed to 4,067 people in age cohorts of 70, 75, 80 and 85 years in an industrialized urban community in Finland. RESULTS: In this sample of 249 hearing aid users, 55.4% used their hearing aid daily, and 27.3% used it > 6 hours a day. The percentage of subjects who never used their hearing aid was 10.7%. Use of hearing aids tended to decline with advancing age. The most common reasons for minimal use were disturbing background noise, acoustic feedback problems, battery cost, and a lack of motivation to use the hearing aid. CONCLUSIONS: Compliance with hearing aid use by the elderly is increasing, but a significant proportion of hearing aids are still used only occasionally or never. We discuss methods to improve compliance in this patient group. Our results may be used to reexamine existing procedures for fitting hearing aids for counseling, which may increase patient compliance with hearing aids, leading to greater benefits from their use.

Cone-beam computed tomography: a new method for imaging of the temporal bone.

BACKGROUND: Clinical cone-beam computed tomography (CBCT), used in diagnostics of dental and maxillofacial radiology for almost 10 years, allows three-dimensional (3D) imaging of a focused area, with reasonable radiation dose. PURPOSE: To clarify the applicability of CBCT in imaging of the temporal bone. MATERIAL AND METHODS: We imaged cadaver temporal bones, one non-operated and five postmortem operated, with CBCT to evaluate the accuracy of this method in showing clinically important landmarks and the positions of middle-ear implants. In addition, to clarify the imaging protocols for the best possible result, we conducted a contrast-to-noise ratio (CNR) analysis by imaging a specially built phantom insert with different protocols. RESULTS: For all the temporal bones, image quality was good and of diagnostic value, and the surgical landmarks as well as positions and details of the implants could be accurately observed. Based on measurements conducted with the phantom, the best possible clarity of the images with the machine used (3D Accuitomo; Morita Co., Kyoto, Japan) was achieved with a tube voltage of 80 kVp and a current of 4 mA. CONCLUSION: Cone-beam CT is a promising new method for otologic imaging, based on its accuracy and relatively low radiation exposure per investigation.

Anti-clarin-1 AAV-delivered ribozyme induced apoptosis in the mouse cochlea.

Usher syndrome type 3 is caused by mutations in the USH3A gene, which encodes the protein clarin-1. Clarin-1 is a member of the tetraspanin superfamily (TM4SF) of transmembrane proteins, expressed in the organ of Corti and spiral ganglion cells of the mouse ear. We have examined whether the AAV-mediated anti-clarin ribozyme delivery causes apoptotic cell death in vivo in the organ of Corti. We used an AAV-2 vector delivered hammerhead ribozyme, AAV-CBA-Rz, which specifically recognizes and cleaves wild type mouse clarin-1 mRNA. Cochleae of CD-1 mice were injected either with 1mul of the AAV-CBA-Rz, or control AAV vectors containing the green fluorescent protein (GFP) marker gene (AAV-CBA-GFP). Additional controls were performed with saline only. At one-week and one-month post-injection, the animals were sacrificed and the cochleae were studied by histology and fluorescence imaging. Mice injected with AAV-CBA-GFP displayed GFP reporter expression of varying fluorescence intensity throughout the length of the cochlea in the outer and inner hair cells and stria vascularis, and to a lesser extent, in vestibular epithelial cells. GFP expression was not detectable in the spiral ganglion. The pro-apoptotic effect of AAV-CBA-delivered anti-clarin-1 ribozymes was evaluated by TUNEL-staining. We observed in the AAV-CBA-Rz, AAV-CBA-GFP and saline control groups apoptotic nuclei in the outer and inner hair cells and in the stria vascularis one week after the microinjection. The vestibular epithelium was also observed to contain apoptotic cells. No TUNEL-positive spiral ganglion neurons were detected. After one-month post-injection, the AAV-CBA-Rz-injected group had significantly more apoptotic outer and inner hair cells and cells of the stria vascularis than the AAV-CBA-GFP group. In this study, we demonstrate that AAV-CBA mediated clarin-1 ribozyme may induce apoptosis of the cochlear hair cells and cells of the stria vascularis. Surprisingly, we did not observe apoptosis in spiral ganglion cells, which should also be susceptible to clarin-1 mRNA cleavage. This result may be due to the injection technique, the promoter used, or tropism of the AAV serotype 2 viral vector. These results suggest the role of apoptosis in the progression of USH3A hearing loss warrants further evaluation.

Limited cone-beam computed tomography imaging of the middle ear: a comparison with multislice helical computed tomography.

PURPOSE: To determine the applicability of cone-beam computed tomography (CBCT) in otological imaging, and to compare its accuracy with the routinely used multislice helical CT (MSCT) for imaging of the middle- and inner-ear areas. MATERIAL AND METHODS: Thirteen unoperated human cadaver temporal bones were imaged with CBCT and MSCT. Sixteen landmarks of the middle and adjacent inner ear were evaluated and compared for their conspicuity according to a modified Likert scale. Total scores and scores for subgroups including landmarks of specific clinical interest were also compared. RESULTS: No significant differences were found between the imaging techniques or subgroups when scores of individual structures were compared. While the middle ear itself was visible in all cases with CBCT, parts of the inner ear were "cut off" in four cases due to the limited field of view. For the same reason, the evaluation of the whole mastoid was not possible with CBCT. The cochlear and vestibular aqueducts were not visualized in either CT techniques. The contrast-to-noise ratio was more than 50% lower in CBCT than in MSCT, but still adequate for diagnostic task. CONCLUSION: CBCT proved to be at least as accurate as routinely used MSCT in revealing the clinically and surgically important middle-ear structures. The results show that high-quality imaging of the middle ear is possible with the current CBCT device.

Efficacy of gene transfer through the round window membrane: an in vitro model.

The viral vector-transgene soaked gelatin-sponge method has been shown to be successful in mediating transgene expression across an intact round window membrane (RWM) in mouse in vivo. However, there are many confounding factors which make it difficult to evaluate the role of the RWM in gene transfer. We have created an in vitro model to test the feasibility of gene delivery through an intact RWM. The round window including the bony niche of a CD1 mouse was removed under an operating microscope and fixed with adhesive on the base of a petri dish through which a hole had been drilled. Toluidine blue was injected into the niche containing a hyaluronic acid ester sponge against the round window membrane. The niche was closed with a fascia. A plastic tube containing PBS was fixed on the opposite side, from where the samples were collected at different time points. The concentration of toluidine blue was evaluated spectrophotometrically. An adenoviral vector containing green fluorescent protein (GFP) marker gene was injected into the niche. Samples were collected from the opposite side at different time points. The presence of the vector was studied with GFP PCR. We also modulated the permeability of the RWM by treating it with clinically applicable detergents, histamine or silver nitrate. Silver nitrate and trichloracetic acid caused destruction of the surface epithelium of the RWM as shown by light microscopy. Both toluidine blue and adenoviral vectors passed through the RWM in a time-dependent fashion. RWM cells expressed GFP after Ad-GFP treatment. The permeability of the RWM was decreased after treatment with different detergents, histamine or silver nitrate. RWM offers an atraumatic route to the inner ear. Compared with more invasive gene delivery methods, this technique represents a safer and clinically more viable route of cochlear gene delivery.

Acute complications of otitis media in adults.

OBJECTIVES: To establish the incidence, current treatment and outcome of adult patients with acute intratemporal and intracranial complications of otitis media (OM). DESIGN: A retrospective chart review with a sent questionnaire. SETTING: Tertiary referral centre, University hospital. PARTICIPANTS: Adult patients treated for acute intratemporal and intracranial complications of OM over the past 15 years (1990-2004) in the study hospital. MAIN OUTCOME MEASURES: Incidence, treatment and outcome of patients with intratemporal and intracranial complications of OM. RESULTS: Fifty patients aged 16-75 years were treated. The annual age-adjusted incidence of acute intratemporal and intracranial complications was 0.32/100 000. Forty-one (82%) of the complications were intratemporal and nine (18%) were intracranial. The ear disease behind the acute complication was acute otitis media (AOM) in 80% (40/50), chronic otitis media (COM) in 12% (6/50) and COM with cholesteatoma in 8% (4/50). Mastoiditis was complicated by subperiosteal abscess, labyrinthitis and facial paresis in 7% (3/41), 15% (6/41) and 32% (13/41) respectively. Mastoidectomy was performed on 56% (28/50) of the patients. Four (44%) of the intracranial complications were intracranial abscesses, four (44%) were meningitis and one (11%) was sinus thrombosis. Permanent hearing loss occurred in 13 (26%) patients and one patient died due to otogenic meningitis. CONCLUSIONS: Severe complications of the OM in adults are rare in Finland. The commonest cause is AOM rather than COM. Operative treatment is predominantly needed for intracranial complications and intratemporal abscesses. Complications of OM are still associated with considerable morbidity, and early recognition is most likely to form the basis for effective treatment.

The use of Preyer's reflex in evaluation of hearing in mice.

Preyer's reflex, the elicitation of startle response to auditory stimuli, has been widely used for the evaluation of hearing in rodents and other animals. Surprisingly, however, the sensitivity and specificity of Preyer's reflex in the assessment of hearing has not been adequately studied. The aim of this study was to investigate the utility of Preyer's reflex in the evaluation of auditory function in mice. Forty-six adult albino mice on an FVB background with variable hearing loss were used for this study. Two different methods for eliciting a Preyer's reflex were tested: a handclap and a sharp metallic sound. The reflex was considered positive when a rapid movement of the whole body of the animal was clearly noticed. Thereafter, the mice underwent auditory brain stem response (ABR) testing with broadband clicks. The presence or absence of Preyer's reflex was compared with the corresponding ABR thresholds. Five of the 46 animals studied (11%) showed a negative Preyer's reflex, while the remaining 41 animals demonstrated a positive Preyer's reflex. There was no difference between the abilities of the two different stimuli to elicit a Preyer's reflex. The click-evoked ABR thresholds in the test animals varied between 8 and 136 (mean 50) dB sound pressure level (SPL). Preyer's reflex was positive in all animals with an ABR threshold of < or = 76 dB SPL, but was absent in animals with an ABR threshold of > or = 81 dB SPL. Preyer's reflex is effective for identifying profound sensorineural hearing loss in experimental mice, but is insensitive for detecting less severe auditory dysfunction. For definitive hearing assessment, and for defining the hearing thresholds. objective electroacoustical methods such as ABR should be used.

Cochlear gene delivery through an intact round window membrane in mouse.

Cochlear gene transfer studies in animal models have utilized mainly two delivery methods: direct injection through the round window membrane (RWM) or intracochlear infusion through a cochleostomy. However, the surgical trauma, inflammation, and hearing loss associated with these methods lead us to investigate a less invasive delivery method. Herein, we studied the feasibility of a vector transgene-soaked gelatin sponge, Gelfoam, for transgene delivery into the mouse cochlea through an intact RWM. The Gelfoam absorbed with liposomes and adenovirus, but not with adeno-associated virus (AAV), was successful in mediating transgene expression across an intact RWM in a variety of cochlear tissues. The Gelfoam technique proved to be an easy, atraumatic, and effective, but vector-dependent, method of delivering transgenes through an intact RWM. Compared with the more invasive gene delivery methods, this technique represents a safer and a more clinically viable route of cochlear gene delivery in humans.

New method for coating tympanostomy tubes to prevent tube occlusions.

OBJECTIVE: tympanostomy tube insertion is currently the most common surgical procedure requiring general anesthesia performed on children. Occlusion of the tube and prolonged otorrhea through the tube are typical problems associated with the use of middle-ear ventilation tubes. In this study, a new method for coating ventilation tubes is introduced that prevents occlusion of the tube lumen by granulation tissue, blood clot or pus. METHODS: human serum albumin (HSA) was used to coat standard tympanostomy tubes of different materials. Fibronectin, a typical protein in serum and exudates and one of the most adhesive glycoproteins, was used as a model representative of exudates of the ear. RESULTS: when compared with the binding on uncoated tubes, the binding of fibronectin on HSA-coated tubes was inhibited from 59 to 85%, depending on the tube material used. CONCLUSIONS: HSA-coating markedly reduced the binding of fibronectin on tube surfaces in vitro. The study shows the potential role of HSA-coating in preventing the adherence of foreign material to tympanostomy tubes and reducing tube occlusions.

A surgical approach appropriate for targeted cochlear gene therapy in the mouse.

Therapeutic manipulations of the mammalian cochlea, including cochlear gene transfer, have been predominantly studied using the guinea pig as the experimental model. With the significant developments in mouse genomics and the availability of mutant strains of mice with well-characterized hearing loss, the mouse justifiably will be the preferred animal model for therapeutic manipulations. However, the potential advantages of the mouse model have not been fully realized due to the surgical difficulty of accessing its small cochlea. This study describes a ventral approach, instead of the routinely used postauricular approach in other rodents, for accessing the mouse middle and inner ear, and its application in cochlear gene transfer. This ventral approach enabled rapid and direct delivery of liposome-transgene complex to the mouse inner ear while avoiding blood loss, facial nerve morbidity, and mortality. Transgene expression at 3 days was detected in Reissner's membrane, spiral limbus, spiral ligament, and spiral ganglion cells, in a pattern similar to that previously described in the guinea pig. The successful access and delivery of material to the mouse cochlea and the replication of gene expression seen in the guinea pig demonstrated in this study should promote the use of the mouse in future studies investigating targeted cochlear therapy.

Otitis media as a sign of Wegener's granulomatosis in childhood.

Wegener's granulomatosis (WG) is a rare disease among paediatric patients. Chronic otitis media with or without facial nerve dysfunction is a known manifestation of the disease among adults. A case of a 15-year-old boy with WG, whose initial symptoms were acute otitis media and facial nerve paralysis, is presented. The otorhinolaryngological manifestations, as well as diagnostic and current treatment modalities in paediatric patients with WG, are discussed.

Palatal myoclonus and clicking tinnitus in a 12-year-old girl--case report.

Palatal myoclonus is a rare neurological disorder of the soft palate and other oropharyngeal muscles, which causes clicking tinnitus. The latter is audible both to the patient and to an observer. The aetiology may be a brain stem lesion, and it is only rarely that a cause cannot be identified. The condition has been described in adults, but seldom in children. We present here a case of palatal myoclonus with distressing tinnitus in a 12-year-old girl and its successful treatment with electromyography (EMG)-guided injections of Clostridium botulinum toxin.

Clinical outcome of acute pneumococcal otitis media and serum antibody responses to pneumococcal pneumolysin and polysaccharides in children.

Serum antibody responses to pneumococcal antigens and their relationship to the clinical outcome were determined in a prospective study of 121 children with acute otitis media (AOM). Pneumococcus positive children with a pneumolysin response more often had a recurrence and middle ear effusion (MEE) after 1 month than did the non-responders (p = 0.005 and p = 0.04, respectively). All the children who responded to pneumolysin also had clinically strong symptoms and signs of AOM. Children who responded to pneumococcal polysaccharides developed otitis media with effusion within a 6-month follow-up period more often than did the non-responders (p = 0.005). The results of this study suggest that children with pneumococcal AOM and an antibody response to the intracellular pneumococcal protein pneumolysin behave clinically differently from children with an antibody response to polysaccharides.

Factors associated with the development of recurrent acute otitis media--the significance of choosing the right and accurate dependent and independent variables in the multivariate analysis.

The results of univariate and multivariate statistical analysis were compared in identifying predictive factors of the development of recurrent acuta otitis media (RAOM) after an initial episode of acute otitis media (AOM) in 121 children. Univariate correlations between the development of RAOM and potential risk factors were analysed, and variables at p < 0.10 were incorporated into the stepwise multiple logistic regression analysis. The comparisons between the univariate and multivariate analysis in identifying the predictive factors were made and the importance of changing the dependent variables in the multivariate analysis was analysed. It seems that univariate analysis is over-sensitive, but multivariate analysis is over-conservative in finding possible predictors of RAOM. Choosing the right and accurate dependent and independent variables in the multivariate analysis is extremely important, when this method is used.