Electric acoustic stimulation of the auditory system: experience and results of ten patients using MED-EL's M and FlexEAS electrodes

OBJECTIVE

To evaluate the hearing preservation rate and speech perception scores in patients with profound high frequency hearing loss and acoustically aidable low frequency hearing, managed with the MED-EL electric acoustic stimulation system referenced to the insertion depth of the electrode array.

STUDY DESIGN

Retrospective data analysis.

PARTICIPANTS AND SETTING

Ten patients implanted at the Auditory Implant Centre, Guy's and St Thomas's Hospital, London, UK.

MAIN OUTCOME MEASURES

Pure tone audiometry, speech perception tests and electrode insertion depth angle.

RESULTS

Postoperatively, functional hearing preservation allowing electric acoustic stimulation was achieved in eight patients and total preservation of residual hearing in five patients with follow-up periods of more than 12 months. Three of four (75%) patients with an insertion depth of >360 degrees had a threshold shift of >25 dB, and all four patients had a threshold shift of >10 dB. All patients with total hearing preservation had the electrode inserted up to 360 degrees at maximum. Overall, speech perception outcomes increased significantly and hearing impairment was significantly reduced after electric acoustic stimulation or electric stimulation alone as compared with the preoperative scores.

CONCLUSION

Electric acoustic stimulation provides significant benefit to individuals with profound high frequency hearing loss. Studies with larger number of patients are needed to establish the optimal electrode insertion angle as well as to further analyse the benefit of electric acoustic stimulation.

Syphilis causing hearing loss

An HIV-positive man with hepatitis B co-infection, naïve to highly active antiretroviral therapy, with a CD4 of 594 copies/mL and HIV-1 viral load of 140,070 copies, presented with right-sided facial weakness and hearing loss. He had been treated for secondary syphilis three months earlier when his rapid plasma reagin (RPR) result was 1:16, this had fallen to neat. At presentation, his RPR had risen to 1:16 again. A magnetic resonance imaging scan showed enhancement of the internal auditory canal and right cochlea. His cerebrospinal fluid examination was normal. He was treated with acyclovir and prednisolone before the syphilis serology was known. He was then treated for syphilis with doxycycline. He made an excellent recovery.

Familial systemic amyloidosis associated with bilateral sensorineural hearing loss and bilateral facial palsies

The Finnish type of familial amyloid polyneuropathy due to variant gelsolin is a rare form of familial amyloidosis. The subtype was first described in 1969 and is characterized by progressive cranial neuropathies, corneal lattice dystrophy and distal sensorimotor dysfunction. It is extremely uncommon, with only two families known to be affected in the UK. We discuss the case of a 70-year-old woman who presented with bilateral facial nerve palsies, bilateral sensorineural hearing loss and Finnish type familial hereditary amyloidosis. A literature search of the Medline database (1966–2005) was performed, using the keywords ‘amyloid’, ‘hearing loss’ and ‘facial palsy’; however, this association appears to be a novel finding. We review the current literature and discuss otorhinolaryngological presentations of amyloidosis.

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.

Clinical experience with the Vibrant Soundbridge implant device

OBJECTIVE

To evaluate the full degree and range of benefits provided by the Vibrant Soundbridge (VSB; Symphonix Devices, Inc., San Jose, CA, U.S.A.) and analyze pre-and postoperative results of audiologic tests.

STUDY DESIGN

Single-subject study with each subject serving as his or her own control.

SETTING

Multicenter clinical study conducted at 10 centers in Europe.

PATIENTS

47 patients who met the selection criteria for participation in the study.

INTERVENTIONS

Implantation of the VSB direct-drive middle ear hearing device.

MAIN OUTCOME MEASURES

Average change in unaided thresholds with the patient wearing headphones at each frequency pre-and postsurgery was measured. A mean threshold change less than 5 dB across all frequencies was considered clinically nonsignificant.

RESULTS

47 patients had successful surgery for implantation and fitting with the VSB device.

CONCLUSION

The VSB is a new middle ear implant device that can be used safely in the treatment of patients with moderate to severe sensorineural hearing loss.

Multicenter audiometric results with the Vibrant Soundbridge, a semi-implantable hearing device for sensorineural hearing impairment

The Vibrant Soundbridge, a semi-implantable hearing device for subjects with moderate to severe sensorineural hearing impairment was introduced commercially. First audiologic results are presented on 63 patients from 10 European implant centers. Hearing loss was at 0.5, 1, 2, and 4 kHz varying between 43 and 81 dB HL. The patients used the analogue audio processor, type 302. Measured sound-field gain was compared with NAL-R target values. For most patients an acceptable agreement was found. There was a subgroup of patients, however, with relatively low gain. The results suggest that this was related to the suboptimal positioning and fixation of the transducer to the incus.

Long-term middle-ear effects of middle-ear/eustachian tube packing after translabyrinthine surgery

The purpose of this study was to evaluate the long-term effect on middle ear and eustachian tube function following the packing of the middle-ear space to prevent cerebrospinal fluid rhinorrhoea at the termination of translabyrinthine vestibular schwannoma removal. This was an observational study of a sample of 14 patients examined between two and five years post-operatively. Photo-otoscopy and tympanometry were performed bilaterally to evaluate appearance and function. All operated middle ears were air-containing although eight out of 14 showed scarring as evidence of operative intervention. There were no drum retractions. Ten out of 14 middle-ear compliance peaks were lower in the operated ear with four flat traces. Two out of 14 were the same and two out of 14 showed high compliance. The middle-ear pressure was always within the normal range when determinable. This technique appears to have no detrimental effects on the middle ear and does not permanently obliterate the eustachian tube. The reduced compliance in the majority of cases is probably a result of scarring and fibrosis. When drum hypermobility is seen this is accounted for by incus removal.

Histological analysis of the greater auricular nerve and its use as a graft

Many factors are involved in successful nerve grafting. Morphometric similarity between donor and recipient nerve is one of these factors. A histological study was undertaken to determine the suitability of the greater auricular nerve as a graft in head and neck surgery. Nerves were obtained from fresh human cadavers and evaluated for length, total cross-sectional area, total fascicular cross-sectional area and fascicular number, at three separate points along the nerve. Comparisons were made with similar studies of the sural and facial nerve. The study confirms the clinical view that the greater auricular nerve is ideal when short sections of graft are required in head and neck surgery.

Regional postgraduate training in otolaryngology: a study programme

For the last three years the South East Thames Regional Training Committee (SETRTC) in Otolaryngology has held a series of training days for the Senior House Officers and Higher Surgical Trainees (HSTs) working in the region. These have proved popular and reportedly useful for the trainees. Although such a programme requires a widespread commitment from both trainers and trainees there are benefits in terms of both education and morale. We discuss these issues and make practical suggestions from our experience.

Air travel induced meningitis following vestibular schwannoma (acoustic neuroma) surgery

Two cases are presented in which patients flying home shortly after translabyrinthine removal of a vestibular schwannoma (acoustic neuroma) developed acute bacterial meningitis on landing. This complication has not been described before. The incidence and management of CSF leaks after vestibular schwannoma surgery is also discussed.

Repair of facial nerve after removal of cerebellopontine angle tumors: a comparative study

The results of repair of 18 facial nerves were examined by means of a modified House-Brackmann grading system. Six were repaired by end-to-end anastomosis and 12 by nerve graft. The reliability of the simplified House-Brackmann grading system was also assessed, using the kappa statistic to analyze the agreement between pairs of observers who examined the function of 40 nerves in 37 patients. Facial nerves studied had been either preserved, repaired or grafted, or divided and treated by faciohypoglossal nerve anastomosis. One nerve was not treated. The grading system proved to be somewhat unreliable, with complete agreement between observers in only 25% of cases. Facial nerve repair produced a fair return of function in just under two-thirds of the cases. The ability of an examiner ignorant of the patient's history to assess from the end result how the nerve had been managed was also estimated. Observers showed little ability to decide correctly on the previous treatment of the nerve when the patient showed moderate dysfunction postoperatively. The implications of these findings for grading systems and for management of the facial nerve in acoustic nerve tumor surgery are discussed.

Post laryngectomy diverticulum--a case report

A case of a pharyngeal diverticulum complicating a total laryngectomy is presented. Possible aetiology and management are discussed.

Oral and gastrointestinal manifestations of epidermolysis bullosa

The mouth, oesophagus, and anus are often involved in dystrophic and junctional epidermolysis bullosa, but the frequency is unknown. Among 246 patients with epidermolysis bullosa, dysphagia developed in 76% of those with recessive dystrophic, in 20% of those with dominant dystrophic, in 15% of those with junctional, and in 2% of those with simplex forms. Lingual adhesions or microstomia occurred in dystrophic epidermolysis bullosa only, but were eight times more common in recessive than in dominant subtypes. These lesions are provoked by the trauma of eating and further reduce food intake, which exacerbates constipation caused by anal blisters and results in malnutrition. Management requires specialised multidisciplinary care.

Emergency treatment of tracheal tear during pharyngolaryngectomy

Longitudinal tracheal tear (of the trachealis muscle), an unusual but acknowledged complication of pharyngolaryngectomy, was encountered during a total pharyngo-oesophagolaryngectomy with gastric replacement. Due to serious ventilatory difficulties a rapid repair was required to obtain an airtight seal to allow continued mechanical ventilation. A reinforced polytetrafluoroethylene (PTFE) vascular graft was used as an intratracheal stent to seal the air leak. This technique proved effective and the tracheal defect had healed by the time the stent was removed 10 days later.

Fine needle aspiration cytology of a head and neck swelling in a child: a non-invasive approach to diagnosis

A 12-year-old boy presented with a three-month history of a painful parotid swelling. Fine needle aspiration cytology indicated a pleomorphic adenoma--an uncommon lesion in a child. This diagnostic technique plays a useful role in the investigation of head and neck swellings.

Measurement of drill-generated noise levels during ear surgery

The results of intraoperative monitoring of the electrocochleogram in patients undergoing surgery for poorly controlled Menières Disease are presented with particular reference to the masking effect of drill-generated noise. The results obtained using a direct, in vivo, electrophysiological method of assessment of drill-generated noise levels are compared with previous postmortem and intraoperative studies and the implications with respect to the likelihood of drill-generated noise induced acoustic trauma are discussed.

Submucous resection of the nasal septum as an outpatient procedure

We report our experience of submucous resection of the nasal septum under local anaesthesia as an outpatient procedure. We have audited 50 consecutive cases and compared the results with a similar group of patients in whom the operation was carried out in the usual way under general anaesthesia. We have found the procedure to be safe, effective and economically advantageous.

Electrocochleography: a new technique

The near field monitoring of an auditory evoked response from the cochlear (electrocochleography) is a tried and trusted clinical tool. Conventional techniques for performing electrocochleography are cumbersome to use and frequently uncomfortable for the patient. We present a simple, modified technique which provides more flexibility with regard to where and when electrocochleography may be performed and also improves patient comfort during the test.

Treating malignant otitis with oral ciprofloxacin

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Autoimmunity and inner ear disorders: an immune-complex mediated sensorineural hearing loss

An immune-complex mediated form of autoimmune disease is described with the inner ear as one of its target organs. Around 40 dB bilateral sensorineural hearing loss improved on short-term corticosteroid therapy to normal levels. This case report is presented against the background of a general survey on autoimmunity and inner ear diseases. Cellular and humoral immune reactions may be etiologic moments in an audiovestibular dysfunction of autoimmune character.

Significance of tomography in Meniere's disease: visualization and morphology of the vestibular aqueduct

The revival of endolymphatic sac surgery has led to many investigations in Meniere's disease, including lateral tomography of the vestibular aqueduct. Contrary to recent literature, we found no difference in the presence and morphology of the vestibular aqueduct when assessed radiologically in a group of Meniere's patients and a control group. Our assessment of this information in regard to etiology and treatment of Meniere's disease is presented.

Significance of tomography in Meniere's disease: periaqueductal pneumatization

The revival of endolymphatic sac surgery has led to many investigations in Meniere's disease, including lateral tomography of the periaqueductal pneumatization. We radiologically assessed a series of Meniere's patients and a control group, and found hypocellularity to be more common in Meniere's disease as the literature has stated. However, we found this finding bilaterally in patients with unilateral disease. Our assessment of this information in regard to the etiology and treatment of Meniere's disease is presented.

Electrophoretic separation and identification of perilymph proteins in cases of acoustic neuroma

Previous studies of perilymph proteins have emphasised the difficulty of obtaining samples free of blood or serum proteins. The present investigation has established a method of polyacrylamide gel electrophoresis, which enables contaminated specimens to be readily identified and therefore discarded. Analysis of uncontaminated samples has confirmed the presence of an elevated perilymph protein in cases of acoustic neurinomata. Perilymph proteins have been separated and identified and although no characteristic pattern of proteins associated with acoustic neurinomata has emerged, further work should be undertaken to establish the site of origin of perilymph proteins and the pattern of abnormalities to be expected in pathological processes.

Autophony and the patulous eustachian tube

Autophony and the patulous Eustachian tube is a real but rare clinical entity often misdiagnosed because the symptoms so mimic those of middle ear effusion. The diagnosis is made by the history of fullness or blockage and hearing ones own voice and breath sounds in the ear. The drum is usually atrophic and moves with respiration but this may not be visible. The usual past history is of weight loss. The diagnostic test is to observe a regular increase or decrease in middle ear pressure when increasing or decreasing the ambient pressure while measuring the impedance in a pressure chamber. The usual variations in pressure with opening and closing of the tube are not seen because the tube remains open all the time. Few patients need operative intervention and explanation is all that is usually required. When surgical treatment is necessary the application of 20% silver nitrate to the lumen of the tube on a wire covered by cotton has given results with few complications. Injection of Teflon paste anterior to the mouth of the Eustachian tube has been stopped by the manufacturer of the paste because of serious complications caused by the Teflon paste being accidentally injected into the internal carotid artery. Why some patients with a patulous tube and movement of the drug with respiration have no symptoms and other patients with very bothersome symptoms have so few objective signs and no movement of the drum, that can be observed with respiration, remains a mystery that needs further study.

Perilymph total protein levels associated with cerebellopontine angle lesions

The total protein levels in the perilymph of patients with acoustic neuromas, meningiomas, and Meniere's disease are contrasted. All specimens were obtained from the lateral semicircular canal during removal of the bony labyrinth. Any specimens with significant contamination by hemoglobin or serum proteins, as judged by the presence of hemoglobin/haptoglobin complexes, were discarded from this study. The findings of greatly increased perilymph protein levels in the tumor groups confirmed the reports of other workers. The levels in the Meniere's disease group compared favorably with the normal protein levels in perilymph. A very significant (p Less Than 0.05) difference between the acoustic neuroma group and the meningioma group is noted. This difference is probably tumor related, because in all cases of both groups, tumor entered and filled the internal auditory meatus.

Out-patient myringoplasty

A simple technique for closing small-to-medium sized perforations of the tympanic membrane in the Out-Patient Department has been described. Homograft temporalis fascia was used as a graft material. In a series of eighteen patients a closure rate of 78.2 per cent was obtained. The advantages of the method have been discussed.

Clinical usefulness of electrocochleography in Meniere's disease: an analysis of dehydrating agents

Both electrocochleography and glycerol dehydration have an important diagnostic and prognostic role in the management of patients with endolymphatic hydrops, whether idiopathic as in Meniere's disease or secondary to certain diseases of the otic capsule. Abnormal electrocochleographic responses in a "normal" ear can be used to predict when Meniere's disease will become bilateral. There is a significant correlation between the effects of glycerol and of endolymphatic sac surgery on the pars inferior, at least over the span of several years. The subject hearing gains, the objective improvements in electrocochleographic responses, and the objective evidence of diminished inner ear impedance, all following proven glycerol dehydration, indicate that even in fairly advanced Meniere's disease, but especially in the earlier stages, reversibility is possible. This is a tantalizing therapeutic challenge.

Bilateral internal carotid aneurysms in the petrous temporal bones

A unique case of bilateral intrapetrous internal carotid aneurysms is reported. The importance of an accurate diagnosis before surgical intervention is stressed and the literature is reviewed.

Otogenic intracranial hypertension. Otitic hydrocephalus

Otogenic intracranial hypertension is a rare complication of suppurative otitis media. Two patients with the typical features of the disease are presented. An historical review of the literature on the subject and a discussion of the differential diagnosis have been carried out. In the light of recent neuro-otological advances the management has been reappraised.

Anaesthesia for laryngoscopy: a technique using the Nuffield Anaesthetic Ventilator

An inflation catheter technique has been devised for providing general anaesthesia during laryngoscopy using the control module of the Nuffield Anaesthetic Ventilator driven by 50% nitrous oxide in oxygen. The system is simple and reliable in use and ensures adequate pulmonary ventilation.

Iodoform toxicity following the use of B.I.P.P.: a potential hazard

1. A case of severe iodoform toxicity is presented in a patient after a total maxillectomy whose cavity was packed with B.I.P.P. The patient subsequently recovered after removal of the B.I.P.P. pack. 2. A simple spectrophotometric method for measuring plasma iodine concentration is described. Plasma iodine determinations were carried out on the toxic patient and three others with iodoform containing packs. The concentrations found correspond well with the presence or absence of iodoform toxicity. 3. From the clinical and biochemical evidence presented we suggest that B.I.P.P. gauze is a satisfactory packing for small operative cavities, but that caution should be exercised if large cavities, such as those following maxillectomies, are to be packed with the material. Another iodoform containing mixture, Whitehead's varnish, is a safer alternative to B.I.P.P. gauze.

Cinefluorography in the diagnosis of pharyngeal palsies

(1) The aetiology of dysphagia may be difficult to diagnose when it presents without clinical signs or an associated clinical syndrome. (2) Pharyngeal palsies present in acute and chronic forms. (3) Cinefluorographic techniques are helpful in making an objective diagnosis of pharyngeal palsy. (4) Advice may be given to the patient on head and neck positions during swallowing that is based on the findings of the cinefluorographic examination, in order to alleviate symptoms. (5) Good fluoroscopy, preferably with video-tape recording facilities may be perfectly adequate provided that the diagnosis is considered at that time.