Mining balance disorders' data for the development of diagnostic decision support systems.

In this work we present the methodology for the development of the EMBalance diagnostic Decision Support System (DSS) for balance disorders. Medical data from patients with balance disorders have been analysed using data mining techniques for the development of the diagnostic DSS. The proposed methodology uses various data, ranging from demographic characteristics to clinical examination, auditory and vestibular tests, in order to provide an accurate diagnosis. The system aims to provide decision support for general practitioners (GPs) and experts in the diagnosis of balance disorders as well as to provide recommendations for the appropriate information and data to be requested at each step of the diagnostic process. Detailed results are provided for the diagnosis of 12 balance disorders, both for GPs and experts. Overall, the reported accuracy ranges from 59.3 to 89.8% for GPs and from 74.3 to 92.1% for experts.

Inner ear disease and benign paroxysmal positional vertigo: a critical review of incidence, clinical characteristics, and management.

Background. This study is a review of the incidence, clinical characteristics, and management of secondary BPPV. The different subtypes of secondary BPPV are compared to each other, as well as idiopathic BPPV. Furthermore, the study highlights the coexistence of BPPV with other inner ear pathologies. Methods. A comprehensive search for articles including in the abstract information on incidence, clinical characteristics, and management of secondary BPPV was conducted within the PubMed library. Results. Different referral patterns, different diagnostic criteria used for inner ear diseases, and different patient populations have led to greatly variable incidence results. The differences regarding clinical characteristics and treatment outcomes may support the hypothesis that idiopathic BPPV and the various subtypes of secondary BPPV do not share the exact same pathophysiological mechanisms. Conclusions. Secondary BPPV is often under-diagnosed, because dizziness may be atypical and attributed to the primary inner ear pathology. Reversely, a limited number of BPPV patients may not be subjected to a full examination and characterized as idiopathic, while other inner ear diseases are underdiagnosed. A higher suspicion index for the coexistence of BPPV with other inner ear pathologies, may lead to a more integrated diagnosis and consequently to a more efficient treatment of these patients.

Nasopharyngeal cylindrical cell papilloma.

INTRODUCTION: Cylindrical cell papillomas are rare tumours which usually arise in the sinonasal region. CASE REPORT: We report a case of a nasopharyngeal cylindrical cell papilloma in a 56-year-old man who presented with a four-month history of right-sided hearing loss, otalgia, vertigo and tinnitus. Investigation revealed a soft, nodular lesion obstructing the pharyngeal opening of the right eustachian tube; this was treated by wide endoscopic excision. CONCLUSION: Cylindrical cell papilloma is a possible cause of eustachian tube obstruction in adults. Effective treatment of these lesions usually requires wide endoscopic excision, in order not to miss coexistent carcinoma.

GSTT1, GSTM1, GSTM3 and NAT2 polymorphisms in laryngeal squamous cell carcinoma in a Greek population.

OBJECTIVE: It is well known that laryngeal squamous cell carcinoma is strongly related to tobacco and alcohol consumption. Accumulating evidence suggests that alterations of detoxification enzymes, such as glutathione S-transferases and N-acetyltransferases, influence the risk of cancers associated with tobacco smoke and alcohol. METHODS: This was a retrospective case-control study. The study group consisted of 88 Greek patients with laryngeal squamous cell carcinoma; there were also 102 control subjects. Frequencies of the genotypes GSTT1, GSTM1, GSTM3 and NAT2 were evaluated by polymerase chain reaction restriction fragment polymorphism. RESULTS: The distribution of overall genotypes was 55.68 per cent rapid acetylator and 44.32 per cent slow acetylator in patients, and 36.27 per cent rapid acetylator and 63.72 per cent slow acetylator in controls. The odds ratio for rapid acetylator status in cases versus controls was 2.207 (95 per cent confidence interval 1.23-3.95, p = 0.0087). CONCLUSION: This study demonstrated a significant relationship between rapid acetylator genotypes and laryngeal squamous cell carcinoma in a Greek population.

Adult laryngeal rhabdomyosarcoma: is aggressive treatment justified in all cases? A case report and review of the literature.

BACKGROUND: Adult laryngeal rhabdomyosarcomas are rare tumours commonly treated by laryngectomy. CASE REPORT: We present a case of subglottic laryngeal rhabdomyosarcoma in an elderly woman, treated by endoscopic resection. CONCLUSION: Despite the fact that this tumour is traditionally treated aggressively, this approach is not supported by the literature. Due to the varying biological behaviour of this tumour in adults, we believe that conservative surgical procedures or combination therapies should be preferred, rather than total laryngectomy.

Effect of cochlear implant electrode insertion on middle-ear function as measured by intra-operative laser Doppler vibrometry.

HYPOTHESIS: The aim of this study was to investigate the impact of cochlear implant electrode insertion on middle-ear low frequency function in humans. BACKGROUND: Preservation of residual low frequency hearing with addition of electrical speech processing can improve the speech perception abilities and hearing in noise of cochlear implant users. Preservation of low frequency hearing requires an intact middle-ear conductive mechanism in addition to intact inner-ear mechanisms. Little is known about the effect of a cochlear implant electrode on middle-ear function. METHODS: Stapes displacement was measured in seven patients undergoing cochlear implantation. Measurements were carried out intra-operatively before and after electrode insertion. Each patient acted as his or her own control. Sound was delivered into the external auditory canal via a speaker and calibrated via a probe microphone. The speaker and probe microphone were integrated into an individually custom-made ear mould. Ossicular displacement in response to a multisine stimulus at 80 dB SPL was measured at the incudostapedial joint via the posterior tympanotomy, using an operating microscope mounted laser Doppler vibrometry system. RESULTS: Insertion of a cochlear implant electrode into the scala tympani had a variable effect on stapes displacement. In three patients, there was little change in stapes displacement following electrode insertion. In two patients, there was a significant increase, while in a further two there was a significant reduction in stapes displacement. This variability may reflect alteration of cochlear impedance, possibly due to differing loss of perilymph associated with the electrode insertion. CONCLUSION: Insertion of a cochlear implant electrode produces a change in stapes displacement at low frequencies, which may have an effect on residual low frequency hearing thresholds.

Squamous cell carcinoma of the temporal bone.

OBJECTIVE: The aim of this study was to present the management and survival data of patients with squamous cell carcinoma of the temporal bone, and to discuss whether extensive surgery improves survival. PATIENTS AND METHODS: Retrospective, case-series review of 17 patients (18 cases) with temporal bone carcinoma (15 primary and three recurrent tumours), over a period of 20 years. SETTING: Tertiary referral centre-university hospital. MAIN OUTCOME MEASURES: Disease-specific and overall five-year survival. RESULTS: The mean age at presentation was 63 years, with a range of 39 to 75 years. Twelve cases of de novo tumour were managed by surgical resection followed by adjuvant radiotherapy in 10 cases, while three such patients were considered incurable from the outset and were given a combination of radiotherapy and chemotherapy. Of the three patients referred to our unit with recurrent disease, two were treated elsewhere with radical mastoidectomy and one with chemoradiation; all were subsequently managed by subtotal petrosectomy. The disease-specific and overall five-year survival for the entire cohort was 64.17 per cent (mean 89 months; 95 per cent confidence interval, 62-117) and 47.06 per cent (mean 70 months; 95 per cent confidence interval, 43-98), respectively. The disease-specific and overall survival for patients with advanced T3 and T4 tumours was 59 per cent (mean 83 months; 95 per cent confidence interval, 53-113) and 40 per cent (mean 62; 95 per cent confidence interval, 33-91 months), respectively. All but one recurrence developed within 12 months of initiating treatment. No deaths occurred after 26 months of follow up. CONCLUSIONS: A lateral temporal bone resection is adequate treatment for T1 and T2 tumours. Post-operative radiotherapy should probably be offered for large T2 tumours. For T3 and T4 tumours, a subtotal petrosectomy with parotidectomy followed by post-operative radiotherapy is adequate treatment, as it offers a similar outcome to that of more extensive procedures.

Temporal bone study of development of the organ of Corti: correlation between auditory function and anatomical structure.

OBJECTIVE: To study the development of the organ of Corti in the human cochlea, and to correlate our findings with the onset of auditory function. MATERIAL AND METHODS: Step sections of 81 human fetal temporal bones were studied, from eight weeks of gestation to full term. RESULTS: By the end of the 10th week, the tectorial membrane primordium could be traced even in the most apical turns. Individual hair cells became identifiable at the basal turn at 14 weeks. At the same time, a small but well formed oval space was observed between the inner and outer hair cells in the basal turn. This does not correspond to the tunnel of Corti, as is erroneously quoted in the literature, as the individual pillar cells develop at later stages. Between 14 and 15 weeks, Hensen's cells were recognised for the first time. Individual pillar cells were identifiable at 17 weeks and the tunnel of Corti opened at 20 weeks. By 25 weeks, the cochlea had reached its adult size, but continued to develop until full term. DISCUSSION AND CONCLUSIONS: A temporal coincidence of different developmental events is responsible for early fetal audition at 20 weeks, including growth of pillar cells, opening of the tunnel of Corti and regression of Kollicker's organ, with the subsequent formation of the inner spiral sulcus and then separation of the tectorial membrane. The fine structures of the organ of Corti continue to develop well after the 25th week, and this may well alter the mechanical properties of the vibrating parts of the cochlea, which may in turn account for the frequency shift observed in preterm infants. These changes will have to be taken into account in the development of prenatal hearing screening tests.

Idiopathic temporal bone encephalocele.

Meningoencephaloceles are herniations of brain tissue through dehiscences of the skull base. These skull defects are either acquired (otologic infection, trauma, surgery, neoplasia) or spontaneous. Spontaneous temporal bone meningoencephaloceles are quite rare conditions, usually congenital in origin presenting during childhood, and only occasionally idiopathic presenting during adulthood. We present a case of temporal bone meningoencephalocele of adult onset. The patient was treated with exploratory mastoidectomy, amputation of the herniated cele and closure of the defect with temporalis fascia and an inferiorly based pedicled muscular flap. No reconstruction of the bony defect was performed, as the layered closure was considered adequate. Twelve months' follow-up revealed no relapse of the condition or postoperative complications.

The development of the spiral ganglion in the human foetus.

The development of the spiral ganglion was studied in steps sections of 81 human temporal bones. By the 8th week, the spiral ganglion has already separated from the vestibular ganglion. At 13 weeks two distinct populations are observed that correspond to neuron and Schwann cells. At 15 weeks the spiral ganglion has increased its distance from the cochlear duct and is surrounded by mesenchyme near the scala tympani. At 14 weeks a gradual decrease in the nucleus-to-cell area ratio was observed in spiral ganglion neurons that may reflect a morphological adaptation to function. By the 23rd week the modiolus begins to ossify and the spiral ganglion is surrounded by bony trabeculae. The time course of spiral ganglion development follows that of the stria vascularis and organ of Corti, although maturation changes are still observed in the neuronal population even beyond 20 weeks.

Chronic suppurative otitis media following paediatric cochlear implantation.

The objective of this study was to report and discuss the management of chronic suppurative otitis media (CSOM) following cochlear implantation in children. The study was a retrospective review of 650 patients receiving an implant at two paediatric tertiary referral centres for cochlear implantation. Nine patients were identified who developed CSOM following cochlear implantation (incidence 1.38%). The mean time interval between implantation and symptom development was 3.66 years (range 2-8 years) and the mean time interval between implantation and CSOM surgery was 5.02 years (range 2.2-8 years). All patients presented with otorrhoea and/or abscess formation over the implant site. Two patients underwent a modified radical mastoidectomy and seven underwent a combined approach tympanoplasty, three of whom required posterior canal wall reconstruction with cortical bone and one with cartilage. In four cases it was possible to remove the cholesteatoma without removing the implant. All but two patients were fitted with a contralateral implant. In the explanted ears the cochlear implant electrode was cut at the cochleostomy site, which was then covered with muscle. Chronic suppurative otitis media following cochlear implantation may occur either as a result of a posterior canal wall defect related to surgery or possibly de novo. Attempts should be made to save the implant, but explantation with reimplantation of the contralateral ear may be the only option. In these cases the intracochlear part of the electrode array should be left in situ to facilitate possible future reimplantation. Surgical options for management of CSOM should be individualized and may include both canal-wall up and canal-wall down techniques. To reduce the incidence of CSOM following implantation the authors recommend: (1) prompt treatment and careful follow-up of patients with a history of otitis media with effusion, (2) avoidance of excessive thinning of the posterior canal wall during mastoidectomy and (3) reconstruction of any accidental trauma to the annulus or posterior canal wall during posterior tympanotomy.

The effects of mass loading the ossicles with a floating mass transducer on middle ear transfer function.

HYPOTHESIS: The aim of this study was to measure the mass loading effect of an active middle-ear implant (the Vibrant Soundbridge) in cadaver temporal bones. BACKGROUND: Implantable middle ear hearing devices such as Vibrant Soundbridge have been used as an alternative to conventional hearing aids for the rehabilitation of sensorineural hearing loss. Other than the obvious disadvantage of requiring implantation middle ear surgery, it also applies a direct weight on the ossicular chain which, in turn, may have an impact on residual hearing. Previous studies have shown that applying a mass directly on the ossicular chain has a damping effect on its response to sound. However, little has been done to investigate the magnitude and the frequency characteristics of the mass loading effect in devices such as the Vibrant Soundbridge. METHODS: Five fresh cadaver temporal bones were used. The stapes displacement was measured using laser Doppler vibrometry before and after the placement of a Vibrant Soundbridge floating mass transducer. The effects of mass and attachment site were compared with the unloaded response. Measurements were obtained at frequencies between 0.1 and 10 kHz and at acoustic input levels of 100 dB sound pressure level. Each temporal bone acted as its own control. RESULTS: Placement of the floating mass transducer caused a reduction of the stapes displacement. There were variations between the bones. The change of the stapes displacement varied from 0 dB to 28 dB. The effect was more prominent at frequencies above 1,000 Hz. Placing the floating mass transducer close to the incudostapedial joint reduced the mass loading effect. CONCLUSION: The floating mass transducer produces a measurable reduction of the stapes displacement in the temporal bone model. The effect is more prominent at high frequencies.

Minimally invasive approach and fixation of cochlear and middle ear implants.

One of the conventional surgical approaches for cochlear implantation is a retro-auricular incision with a posterior-inferiorly based skin and subcutaneous tissue flap and a superiorly based periosteal flap. The obvious advantage is an open operating field but the disadvantages are a large wound and a lengthy operating time. It may also result in more wound-related complications. To overcome these disadvantages, we have developed a minimally invasive technique that includes a small retro-auricular single layer incision. We have used a metal bridge beneath the posterior flap to increase accessibility when creating a recess for the implant. A novel technique is used to place the securing suture deep to the flap. This technique has been used in 49 paediatric and adult patients, and there have been no wound-related complications. Although this technique was initially designed for the CLARION CII implant, it has been used to place and secure the new CLARION HiRes 90 K, the Nucleus device, the MEDEL device and the Vibrant Soundbridge.

3-D optical coherence tomography of the laryngeal mucosa.

Laryngeal carcinoma is one of the commonest primary head and neck malignancy and the need for early identification is very important for successful treatment. Outpatient fibreoptic examination of the larynx is unreliable in differentiating benign, pre-malignant and malignant lesions, and therefore surgeons have to rely on biopsies for a definitive diagnosis. This is an invasive procedure requiring general anaesthesia and may have a detrimental effect on the patient's voice. Conventional imaging modalities (ultrasound, computed tomography and magnetic resonance imaging) have a limited resolution and hence cannot give sufficient information on the extent or nature of laryngeal lesions. The aim of our study is to investigate the feasibility of optical coherence tomography (OCT) in imaging the normal larynx, to lay the foundations for an investigation of its ability to differentiate between benign and malignant disease. Ten tissue specimens from normal larynges were imaged with an 850 nm OCT system that was capable of providing both B-scan (longitudinal or cross-section) images as well as C-scan (en-face or images at constant depth). The en-face OCT mode allowed us to reconstruct 3-D OCT images of the tissue examined. Imaged specimens were processed with standard histopathological techniques and sectioned in the plane of the B-scan OCT images. Haematoxylin-eosin stained specimens were compared with the OCT images thus collected. Preliminary results showed good correlation between OCT images and histology sections in normal tissue.

Orbital growth retardation in retinoblastoma survivors: work in progress.

BACKGROUND: Orbital growth retardation, after enucleation and/or external beam radiation for retinoblastoma (RB), is a serious late effect. We measured orbital volumes of RB survivors treated at Hadassah University Hospital, Jerusalem, between 1980-1998. PROCEDURE: Forty-five orbits of 28 children with RB (17 bilateral, 11 unilateral) were examined. Thirty-six orbits were irradiated, 19 enucleated, and 10 both enucleated and irradiated. The orbital volumes were calculated from a three-dimensional orbital CT reconstruction. The orbits of RB survivors were compared to age-matched controls. RESULTS: The mean age at diagnosis was 13 months, mean follow-up time was 56 months. The mean volume of RB orbits (14.4 cc) was statistically significantly smaller than control orbits (17.8 cc). There was no difference between the mean volume of orbits treated with enucleation, irradiation or both. The orbital volume of children treated before the age of 12 months was statistically significantly smaller than those treated later. There was no difference between mean volume of fellow orbits in unilateral RB and controls. The mean orbital asymmetry index in control children (2.6%) was statistically significantly smaller than in RB survivors (14%). CONCLUSIONS: There was a significant orbital growth retardation after enucleation and/or irradiation for RB. There was no difference between mean orbital volumes after enucleation, radiation or both. Orbital growth retardation was most prominent in children treated in the first year of life. Although small in number, our study suggests that deferring enucleation and/or irradiation until after the age of 12 months may reduce long-term complications.

p53, p21 and p27 protein expression in head and neck cancer and their prognostic value.

Histological specimens from 62 laryngeal and 31 oral carcinomas were immunohistochemically assessed for p53, p21 and p27 proteins; cases with > 10% labelled nuclei were considered as positive. p21 showed higher expression in patients > 65-years-old (P = 0.04), in chemotherapy responders (P = 0.02), and in stage III patients with longer overall survival (P = 0.02), representing the only independent prognostic factor in the multivariate analysis. In addition, stage III patients with p53-/p21+ showed the longest survival whereas those with p53+/p21- tumors showed the shortest overall survival (P = 0.02). A significant influence on the survival of stage III patients was also found for the combinations of p21 and p27 proteins with p21+/p27- imparting the best and p21-/p27+ the worst prognosis (P = 0.04). p27 expression was significantly related to oral cancer specimens (P = 0.04) and to moderate and high tumor grade (P = 0.01). p53 expression was not significantly related to any of the examined clinicopathological characteristics. Our findings indicated that, by functionally promoting apoptosis, p21 seems to play a key role in the successful response to chemotherapy and may be considered as a predictive factor of a better prognosis in stage III patients with head and neck cancers.

Facial paralysis in Wegener's granulomatosis of the middle ear.

A case of Wegener's granulomatosis, which presented as chronic otitis media with facial nerve palsy, is described. Early diagnosis is vital if unnecessary surgical exploration is to be avoided. A false negative cANCA may delay the diagnosis, especially in cases of locoregional disease, and a policy of repeated titres should be adopted, if clinical suspicion is high.

Transnasal endoscopic repair of cerebrospinal fluid rhinorrhoea.

The complications associated with the employment of neurosurgical techniques for the management of cerebrospinal fluid rhinorrhoea has led to the development of extracranial approaches. The nasal endoscope can be used to improve visualisation of the site of the leak and to facilitate free graft or septal flap placement. This ensures a high rate of dural defect healing with minimal morbidity. This study describes four cases with CSF fistulas that were repaired endoscopically and the specific surgical techniques that were used. The authors believe that, in carefully selected cases, transnasal endoscopic management of CSF leaks can be the initial surgical treatment of choice.