Fulminant intracranial hypertension as a result of otological surgery: case report and discussion of management.

BACKGROUND: Dural venous sinus injury is a rare complication of otological surgery that can lead to life-threatening sequelae, the management of which is complex and poorly described. CASE REPORT: This paper describes the case of a 40-year-old female who underwent routine right myringoplasty complicated by sigmoid sinus laceration. The patient subsequently developed right-sided lateral sinus thrombosis leading to fulminant intracranial hypertension. The patient underwent successful emergency management by surgical reconstruction of the sigmoid sinus, followed by endovascular thrombolysis, catheter balloon angioplasty and endovascular stenting. CONCLUSION: Torrential haemorrhage following otological procedures is uncommon and rarely requires packing of a bleeding venous sinus. This case highlights that injury to a highly dominant venous sinus can lead to venous outflow obstruction and life-threatening intracranial hypertension. To our knowledge, the development of this complication following otological surgery and its management has not been reported previously.

Hearing outcomes of cochlear implant recipients with pre-operatively identified cochlear dead regions.

Objectives: To determine how patients who did not meet UK TA166 NICE criteria for cochlear implantation (CI) but were subsequently found to have cochlear dead regions (DRs) performed with CI.Methods: A retrospective review of medical records was performed on CI recipients: 152 controls and 40 in the DR group. Of these, 34 pairs were matched by pre-operative Bamford-Kowal-Bench (BKB) scores and compared.Results: The forty DR patients had a median age at implantation of 56 years. Their mean pre-operative BKB score of 23% increased to 78% after CI. Thirty-seven experienced improvements in BKB scores. In matched case-control analysis, the improvement in mean BKB score with CI was no different (p = 0.19) between the DR group and control group; a similar proportion of patients benefitted in each group.Discussion: This study is the largestreport to date of performance of patients with DRs, before and after CI. The DR group gain similar benefit as the controls.Conclusion: Patients with DRs, who did not meet TA166 NICE criteria, received the same benefit as those who did. TEN testing to detect DRs should be included in routine CI work-up where standard criteria are not met.

The Cambridge Otology Quality of Life Questionnaire: an otology-specific patient-recorded outcome measure. A paper describing the instrument design and a report of preliminary reliability and validity.

OBJECTIVE: The Cambridge Otology Quality of Life Questionnaire (COQOL) is a patient-recorded outcome measurement (PROM) designed to quantify the quality of life of patients attending otology clinics. DESIGN: Item-reduction model. A systematically designed long-form version (74 items) was tested with patient focus groups before being presented to adult otology patients (n. 137). Preliminary item analysis tested reliability, reducing the COQOL to 24 questions. This was then presented in conjunction with the SF-36 (V1) questionnaire to a total of 203 patients. Subsequently, these were re-presented at T + 3 months, and patients recorded whether they felt their condition had improved, deteriorated or remained the same. Non-responders were contacted by post. A correlation between COQOL scores and patient perception of change was examined to analyse content validity. SETTING: Teaching hospital and university psychology department. PARTICIPANTS: Adult patients attending otology clinics with a wide range of otological conditions. MAIN OUTCOME MEASUREMENTS: Item reliability measured by item­total correlation, internal consistency and test­ retest reliability. Validity measured by correlation between COQOL scores and patient-reported symptom change. RESULTS: Reliability: the COQOL showed excellent internal consistency at both initial presentation (a = 0.90) and 3 months later (a = 0.93). Validity: One-way analysis of variance showed a significant difference between groups reporting change and those reporting no change in quality of life (F(2, 80) = 5.866, P < 0.01). CONCLUSIONS: The COQOL is the first otology-specific PROM. Initial studies demonstrate excellent reliability and encouraging preliminary criterion validity: further studies will allow a deeper validation of the instrument.

Bilateral vestibular schwannomas in older patients: NF2 or chance?

BACKGROUND: Neurofibromatosis type 2 (NF2) is an autosomal dominant condition with high spontaneous mutation rate which predisposes to the development of multiple nerve sheath tumours (schwannomas), meningiomas and ependymoma. The cardinal feature and main diagnostic criterion for the diagnosis of NF2 remains the development of bilateral vestibular schwannoma (BVS). With increasing use of MRI screening the possibility of a 'chance' diagnosis of BVS has been mooted with a potential frequency of one in two million people in their lifetime. Until now, however, no evidence for such an event has been published. We aimed to demonstrate that chance occurrence can occur and to estimate its frequency among those with just BVS late in life. METHODS: Two vestibular schwannomas from the same patient were DNA sequenced and underwent loss of heterozygosity analysis. RESULTS: We show that a man who developed BVS, at ages 52 and 67 years developed these tumours sporadically by demonstrating that there were no molecular events in common between the two tumours. Furthermore from a database of over 1200 patients with NF2, we have estimated that ~25% of cases of BVS over 50 years and 50% over 70 years of age where no other features of NF2 are present represent a chance occurrence rather than due to an underlying mosaic or constitutional NF2 mutation. CONCLUSIONS: Patients presenting with BVS later in life should be appraised of the potential likelihood they may not have NF2 and the resultant further reduction in risks of transmission to offspring.

Outcome of translabyrinthine surgery for vestibular schwannoma in neurofibromatosis type 2.

OBJECTIVES: To analyse the long-term outcome of translabyrinthine surgery for vestibular schwannoma (VS) in neurofibromatosis type 2 (NF2). RESEARCH TYPE: Retrospective cohort study. SETTING: Two tertiary referral NF2 units. PATIENTS: One hundred and forty eight translabyrinthine operations for patients with VS were performed. Preoperative stereotactic radiotherapy had been performed on 12(9.4%) patients. RESULTS: Mean tumour size was 3.1 cm. Total tumour excision was achieved in 66% of cases, capsular remnants were left in 24% of cases, and subtotal excision was achieved in 5% and partial removal was achieved in 5%. The radiological residual/recurrence rate was 13.9%. The perioperative mortality was 1.6%. At 2 years postoperatively, facial function was expressed in terms of House-Brackmann score (HB): HB 1 in 53.4%, HB 1/2 in 61.3%, HB 1-3 in 83.2% and HB 4-6 in 16.8%. All nine patients who underwent surgery following failed stereotactic radiotherapy had HB 3 function or better. Among 9.5% of the cases, 14 facial nerves were lost during surgery and repaired using direct anastomosis or grafting. There was no tinnitus present preoperatively in 27% of the cases, and 22% of patients developed tinnitus postoperatively. In patients with preoperative tinnitus, 61% remained the same, 17% got it resolved and only in 21% it worsened. The preoperative hydrocephalus rate was 26%, and among 15% of the cases five ventriculo-peritoneal (VP) shunts were performed. The cerebrospinal fluid leak rate was 2.5%. Fifty-six patients underwent auditory brainstem implantation (ABI) and two patients had cochlear implant (CI) sleepers inserted. CONCLUSIONS: The management of patients with NF2 presents the clinician with a formidable challenge with many patients still presenting themselves late with the neurological compromise and a large tumour load. There is still an argument for the management by observation until the neurological compromise dictates interventional treatment particularly with the option of hearing rehabilitation with ABI or CI. The translabyrinthine approach provides a very satisfactory means of reducing the overall tumour volume.

Cochlear implant failures: lessons learned from a UK centre.

OBJECTIVES: To review our experience of cochlear implant failure and subsequent revision surgery, and to illustrate the experience we have gained by presenting a series of lessons learned. METHODS: A combined retrospective and prospective study of revision surgery in a UK regional cochlear implant centre. RESULTS: Of the 746 cochlear implantations undertaken, 33 (4.7 per cent of adults and 4.1 per cent of children) had a registered failure requiring re-implantation. The mean time to device failure was 60 months in adults and 35 months in children. Causes of cochlear implant failure were medical (n = 11), electrode displacement (n = 2), 'hard device failure' (n = 15) and 'soft device failure' (n = 5). Chronic suppurative otitis media and post-auricular mastoid abscess were the commonest causes of medical failure. There was one case of electrode array displacement as a direct result of skin flap revision surgery. In 80 per cent of cases, audiological performances were stable or improved following re-implantation. CONCLUSION: As the number of cochlear implants increase and patients outlive the lifespan of their devices, we will face a growing number of revision procedures. Audiologists and otologists should be competent in diagnosing and managing device failure and medical complications requiring cochlear re-implantation.

Non echo planar, diffusion-weighted magnetic resonance imaging (periodically rotated overlapping parallel lines with enhanced reconstruction sequence) compared with echo planar imaging for the detection of middle-ear cholesteatoma.

OBJECTIVES: We evaluated use of the periodically rotated overlapping parallel lines with enhanced reconstruction diffusion-weighted imaging sequence, compared with conventional echo planar magnetic resonance imaging, in the detection of middle-ear cholesteatoma. MATERIAL AND METHODS: Sixteen patients awaiting second-stage combined approach tympanoplasty and three patients awaiting first-stage combined approach tympanoplasty underwent magnetic resonance imaging with both (1) the periodically rotated overlapping parallel lines with enhanced reconstruction sequence (i.e. non echo planar imaging) and (2) the array spatial sensitivity encoding technique sequence (i.e. echo planar imaging). Two neuroradiologists independently evaluated the images produced by both sequences. Radiology findings were correlated with surgical findings. RESULTS AND ANALYSIS: Seven cholesteatomas were found at surgery. Neither of the assessed imaging sequences were able to detect cholesteatoma of less than 4 mm. Rates for sensitivity, specificity, and positive and negative predictive values are presented. CONCLUSION: Decisions on whether or not to operate for cholesteatoma cannot be made based on the two imaging sequences assessed, as evaluated in this study. Other contributing factors are discussed, such as the radiological learning curve and technical limitations of the magnetic resonance imaging equipment.

Canal wall cholesteatoma following canalplasty.

INTRODUCTION: Bony canalplasty is a common otological procedure performed to widen a narrow ear canal. The aim of this report is to describe two unusual patients who presented with a canal wall cholesteatoma many years after bony canalplasty. CASES: Two patients, aged 28 and 52 years, are presented. Both underwent canalplasty, 14 and 17 years before re-presenting with cholesteatoma evident through posterior canal wall defects. Both patients underwent exploration of the mastoid cavities and cartilage reconstruction of the canal walls. There was no recurrence at 24 and three month follow-up examinations (variously), hearing was preserved in both cases, and the patients suffered no early complications. CONCLUSIONS: The most frequent long-term complication of canalplasty is re-stenosis of the external auditory canal. The importance of sealing any inadvertently opened mastoid air cells, in order to avoid the late complication reported, is emphasised.

Facial nerve palsy secondary to middle-ear lipoma.

OBJECTIVE: We present the first reported case of a middle-ear lipoma presenting with facial nerve palsy. We review the available literature on middle-ear lipomas and alert the surgeon to the possibility of a lipoma occurring in this location. CASE REPORT: A 33-year-old man presented to our unit with a right-sided, House-Brackmann grade two, lower motor neurone facial palsy. A computed tomography scan revealed abnormal soft tissue in the epitympanic recess, extending to the region of the geniculate ganglion. At middle-ear exploration, a lump of fatty tissue was found filling the anterior middle-ear cleft, juxtaposed to the horizontal portion of the facial nerve. The patient's facial palsy resolved within a few weeks of surgery. CONCLUSION: Lipomas are a rare but real differential diagnosis of a mass in the middle ear. Early imaging is advised.

Human auditory nerve compound action potentials and long latency responses.

CONCLUSION: The compound action potential (CAP) is followed by a long latency response (LLR), attributable to the post-auricular musculature. The LLR to one pulse may overlap with the CAP to a subsequent one, contributing to the clinically observed reduction in CAP at high pulse rates. OBJECTIVES: To measure refractory and other influences on CAPs in humans and guinea pigs. MATERIALS AND METHODS: CAPs were obtained from humans using trans-tympanic and extra-tympanic electrocochleography and from anaesthetized guinea pigs. Stimuli were single pulses presented at a slow rate, pairs of pulses, and 100 ms pulse trains where the inter-pulse interval alternated between 4 and 6 ms. RESULTS: For single pulses, the CAP shape was similar across species. For pairs of pulses, the CAP to the second pulse was smaller than that to the first, and decreased with increasing inter-pulse interval in a way that was similar across species. For pulse trains, CAPs were observed in response to each pulse in the train for the guinea pigs, but not for humans. For both filtered and unfiltered single pulses, there was a large LLR in humans, but not in guinea pigs, with peaks at latencies of 10-12 and 20-25 ms. Posture affected the LLR in a way consistent with the post-auricular response.

A review on the genetics of otosclerosis.

BACKGROUND: The aetiology of otosclerosis is not fully understood despite intensive research. It is, however, certain that a genetic component plays a significant role in the manifestation of otosclerosis, although the precise mode of inheritance is still uncertain. OBJECTIVE OF REVIEW: To provide an up-to-date review for the genetics of otosclerosis. The mode of inheritance, chromosomal and linkage studies are presented. In addition, the possible genetic relationship between otosclerosis and osteogenesis imperfecta, and the association between otosclerosis and specific human leucocyte antigen types are described. TYPE OF REVIEW: Systematic analysis of the literature was focused on any information related to the genetics of otosclerosis. SEARCH STRATEGY: A MEDLINE search (1960-2007) was undertaken to perform a comprehensive review. Articles were also identified through searches of the files of authors. RESULTS: The majority of epidemiological studies on families with otosclerosis suggest an autosomal dominant mode of inheritance with reduced penetrance of approximately 40%. Genetic linkage studies have demonstrated the presence of six loci (OTSC1, OTSC2, OTSC3, OTSC4, OTSC5 and OTSC7) located on chromosomes 15q, 7q, 6p, 16q, 3q and 6q respectively. Although these loci have been mapped, no causative genes have been identified, and we have little idea of the molecular process involved in this disease. While clinical similarities and some unreplicated genetic association studies suggest an aetiological relationship between otosclerosis and osteogenesis imperfecta-type I, there is no definite evidence of a common pathological process between the two diseases. CONCLUSIONS: Otosclerosis may be considered as a complex disease with relatively common monogenic forms. Knowledge of these genes could lead to substantial improvements in our ability to diagnose and possibly even prevent or treat this type of hearing deterioration.

Superior semicircular canal dehiscence with a large tegmental defect.

We report on the presentation and clinical manifestations of superior semicircular canal dehiscence in association with a large defect of the tegmen tympani in a 41-year-old woman with no previous history of trauma. Based on this case we recommend that clinicians consider the possibility of superior semicircular canal dehiscence in patients presenting with symptoms associated with tegmen defects.

Two stage management of petrositis with associated mycotic aneurysm of the intrapetrous carotid artery.

Mycotic aneurysm of the petrous temporal bone is extremely rare, with only 12 cases previously reported. We review the literature to date and present a case of petrositis complicated by a mycotic aneurysm of the internal carotid artery, which was managed by endovascular balloon occlusion and subsequent total petrosectomy. We can find no other case in the literature where balloon occlusion has been used to treat a mycotic aneurysm of the intrapetrous carotid artery prior to total petrosectomy to treat petrositis.

Far advanced otosclerosis and intractable benign paroxysmal positional vertigo treated with combined cochlear implantation and posterior semicircular canal occlusion.

This paper presents a combined procedure for the management of intractable benign paroxysmal positional vertigo (BPPV) and profound hearing loss in a patient with far advanced otosclerosis. The procedure comprised of a posterior semicircular canal occlusion and cochlear implantation as one combined procedure in the same ear. The combined approach added little to the operative morbidity and proved effective in this patient's management. A search of the literature reveals this to be a unique case.

Novel ATP6V1B1 and ATP6V0A4 mutations in autosomal recessive distal renal tubular acidosis with new evidence for hearing loss.

Autosomal recessive distal renal tubular acidosis (rdRTA) is characterised by severe hyperchloraemic metabolic acidosis in childhood, hypokalaemia, decreased urinary calcium solubility, and impaired bone physiology and growth. Two types of rdRTA have been differentiated by the presence or absence of sensorineural hearing loss, but appear otherwise clinically similar. Recently, we identified mutations in genes encoding two different subunits of the renal alpha-intercalated cell's apical H(+)-ATPase that cause rdRTA. Defects in the B1 subunit gene ATP6V1B1, and the a4 subunit gene ATP6V0A4, cause rdRTA with deafness and with preserved hearing, respectively. We have investigated 26 new rdRTA kindreds, of which 23 are consanguineous. Linkage analysis of seven novel SNPs and five polymorphic markers in, and tightly linked to, ATP6V1B1 and ATP6V0A4 suggested that four families do not link to either locus, providing strong evidence for additional genetic heterogeneity. In ATP6V1B1, one novel and five previously reported mutations were found in 10 kindreds. In 12 ATP6V0A4 kindreds, seven of 10 mutations were novel. A further nine novel ATP6V0A4 mutations were found in "sporadic" cases. The previously reported association between ATP6V1B1 defects and severe hearing loss in childhood was maintained. However, several patients with ATP6V0A4 mutations have developed hearing loss, usually in young adulthood. We show here that ATP6V0A4 is expressed within the human inner ear. These findings provide further evidence for genetic heterogeneity in rdRTA, extend the spectrum of disease causing mutations in ATP6V1B1 and ATP6V0A4, and show ATP6V0A4 expression within the cochlea for the first time.

The effect of vestibular nerve section upon tinnitus.

This paper reviews the published evidence regarding the effect of vestibular nerve section upon tinnitus. This is of relevance not only for those performing and undergoing this procedure, but also for those considering the hypothesis that auditory efferent system dysfunction may be influential in tinnitus perception. The auditory medial efferent fibres within the internal auditory canal run within the inferior vestibular nerve, only joining the cochlear nerve at the anastomosis of Oort, a bundle of 1300 fibres running from the saccular branch of the inferior vestibular nerve to the cochlear nerve. Vestibular nerve section procedures therefore section this efferent olivocochlear pathway, and ablate efferent influence upon that cochlear. If auditory efferent dysfunction is involved in tinnitus perception, this ablation might influence the tinnitus status of that patient. A literature search identified 18 papers mentioning tinnitus status after vestibular nerve section, describing the experiences of a total of 1318 patients. The proportion of patients in whom tinnitus was said to be exacerbated postoperatively ranged from 0% to 60%, with a mean of 16.4% (standard deviation 14.0). The proportion of patients in whom tinnitus was unchanged was 17% to 72% (mean 38.5%, standard deviation 15.6), and in whom tinnitus was said to be improved was 6% to 61% (mean 37.2%, standard deviation 15.2). In the majority of patients undergoing this procedure, ablation of auditory efferent input (and thus total efferent dysfunction) to the cochlea was not associated with an exacerbation of tinnitus. The finding of this review is that efferent dysfunction after vestibular nerve section does not consistently worsen tinnitus.

'Hairy polyp' of the pharynx in association with an ipsilateral branchial sinus: evidence that the 'hairy polyp' is a second branchial arch malformation.

The pharyngeal 'hairy polyp', or 'dermoid' has caused considerable debate as to its origin since the original classification proposed by Arnold in 1870. This classification implies that the hairy polyp is either a teratoma or sequestration dermoid cyst. Many papers contest this view, in favour of a developmental malformation. We describe the first case of a hairy polyp in association with an ipsilateral branchial sinus as further supportive evidence of a developmental malformation of the second branchial arch.

Facial nerve action potentials: a study to assess waveform reliability.

OBJECTIVE: To assess the reliability of the orthodromic facial nerve action potential (FNAP), recorded from the intratemporal portion of the facial nerve on stimulation within the cerebellopontine angle. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. PATIENTS: Ten consecutive patients undergoing translabyrinthine resection of vestibular schwannoma. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURES: Ten consecutive FNAPs were recorded on stimulation of the facial nerve within the cerebellopontine angle. The FNAP recording probe was placed directly on the nerve surface after the fallopian canal was opened at the second genu. Ten consecutive compound muscle action potentials (CMAPs) were recorded simultaneously from surface electrodes overlying the facial musculature, by use of a standardized electrode placement technique. The stimulating and recording equipment were removed (excluding CMAP surface electrodes) and reapplied, and FNAP and CMAP data were recorded for a second time (test/retest). Peak-to-peak amplitudes of all waveforms were calculated. RESULTS: The average FNAP peak-to-peak amplitude for all patients was larger than the CMAP peak-to-peak amplitude (2.60 mV and 1.07 mV, respectively). Random effects analysis of variance was performed to assess the individual components of variation. This showed that CMAP was less variable than FNAP for replicate error (10 consecutive FNAPs and CMAPs) and test/retest error. However, subject variance was less for FNAP, where subject variance was by far the largest contributor to overall variation. The reliability coefficient for FNAP was 0.995 and for the CMAP was 0.982, where absolute reliability is 1.0. CONCLUSION: These data confirm that the FNAP, recorded by the technique described here, is a reliable waveform when compared with the CMAP and is a valid method for assessing facial nerve function.