Bill Gibson

The University of Sydney · Discipline in Surgery

Objective To investigate ictal nystagmus and audiovestibular characteristics in episodic spontaneous vertigo after cochlear implantation (CI). Study Design Retrospective and prospective case series. Patients Twenty-one CI patients with episodic spontaneous vertigo after implantation were recruited. Interventions Patient-initiated home video-ocul...

Seventy Ménière’s disease (MD) patients with spontaneous vertigo (100%), unilateral aural fullness (57.1%), tinnitus (78.6%), and subjective hearing loss (75.7%) self-recorded nystagmus during their episodes of vertigo using portable video oculography goggles. All demonstrated ictal spontaneous nystagmus, horizontal in 94.3% (n = 66) and vertical i...

Objective: Menière's disease (MD) is characterized by recurrent vertigo and fluctuating aural symptoms. Diagnosis is straightforward in typical presentations, but a proportion of patients present with atypical symptoms. Our aim is to profile the array of symptoms patients may initially present with and to analyze the vestibular and audiological te...

The clinical uses of electrocochleography are reviewed with some technical notes on the apparatus needed to get clear recordings under different conditions. Electrocochleography can be used to estimate auditory thresholds in difficult to test children and a golf club electrode is described. The same electrode can be used to obtain electrical audito...

Objective: To investigate outcomes of cochlear implantation (CI) in patients with Ménière's disease (MD) with and without surgical labyrinthectomy. Study design: Retrospective study. Setting: Multiple tertiary referral centers. Subjects: Thirty one ears from 27 patients (17 men, 10 women, aged 42-84) with CI in ipsilateral MD ear. Intervent...

Objective: To assess cochlear implant (CI) outcomes, and factors affecting outcomes, for children with aplasia/ hypoplasia of the cochlea nerve. We also developed a new grading system for the nerves of the internal auditory meatus (IAM) and cochlea nerve classification. Study design: Retrospective patient review. Setting: Tertiary referral hos...

Single-sided deafness patients are now being considered candidates to receive a cochlear implant. With this, many people who have undergone a unilateral vestibular labyrinthectomy for the treatment of chronic vertigo are now being considered for cochlear implantation. There is still some concern regarding the potential efficacy of cochlear implants...

Objectives: A relationship between Meniere's disease and migraine has been postulated previously. This study investigates this relationship further and determines the most influential factors for developing Meniere's disease. Design: Epidemiological study. Setting: Two tertiary referral Neuro-Otological centres in Sheffield and Sydney. Partic...

CHARGE syndrome is a complex cluster of congenital abnormalities, these children may have absent or hypoplastic auditory nerves. Our objective was to assess preoperative factors and outcomes for paediatric cochlear implant recipients with CHARGE syndrome, to enable better surgical preparation and family counselling. The Sydney Cochlear Implant Cent...

Objective: To prospectively document the surgical pain, assessing analgesia use as a proxy, and postoperative dizziness in children over the first week after cochlear implantation. Study Design: Prospective. Setting: Tertiary referral hospital and cochlear implant program. Patients: Children aged 0 to 16 years inclusive undergoing cochlear implant...

To compare mean impedance levels, neural response telemetry (NRT), and auditory perception after initial and explant-reimplant pediatric cochlear implants. Retrospective case review. Tertiary referral hospital and cochlear implant program. Children 0 to 16 years inclusive who have undergone explant-reimplant of their cochlear implant. Impedance lev...

Program Description Ménière’s disease is currently diagnosed by the AAO-HNS Equilibrium Committee Guidelines (1995), which are used worldwide. In the guidelines a “Certain” diagnosis requires histopathological confirmation of endolymphatic hydrops, with no provision for any in vivo test which might confirm that. This seminar will present one well e...

To determine the prevalence of additional disabilities in a pediatric cochlear population, to identify medical and radiologic conditions associated with additional disabilities, and to identify the effect of additional disabilities on speech perception and language at 12 months postoperatively. Retrospective case review. Tertiary referral center an...

: To demonstrate the value of recording air-conducted ocular Vestibular Evoked Myogenic Potentials (oVEMP) in a patient with bilaterally enlarged vestibular aqueducts. : Cervical VEMP and oVEMP were recorded from a patient presenting with bilateral hearing loss and imbalance, attributable to large vestibular aqueduct syndrome. The stimuli were air-...

It can be difficult to distinguish vestibular migraine (VM) from Menière's disease (MD) in its early stages. Using vestibular-evoked myogenic potentials (VEMPs), we sought to identify test parameters that would help discriminate between these two vestibular disorders. We first recorded ocular and cervical VEMPs (oVEMP/cVEMP) to air-conducted clicks...

Whilst objective testing on music perception showed no individual differences between cochlear implant (CI) devices, subjective music perception was found to be superior with the MED-EL device in the majority of cases evaluated. To compare speech and music perception through two different CI systems in the same individuals. Six post-lingually deaf...

To assess the feasibility of intra-operative monitoring of residual hearing using electrocochleography (ECOG) during cochlear implantation. We present our methods and preliminary results. We attempted to monitor 21 consecutive paediatric and adult subjects during cochlear implantation. All subjects were implanted via a promontory cochleostomy with...

We have cyclically suppressed the 2f1-f2 distortion product otoacoustic emission (DPOAE) with low-frequency tones (17-97 Hz) as a way of differentially diagnosing the endolymphatic hydrops assumed to be associated with Ménière's syndrome. Round-window electrocochleography (ECochG) was performed in subjects with sensorineural hearing loss (SNHL) on...

To assess the degree of intracochlear trauma using the Cochlear™ Straight Research Array (SRA). This electrode has recently been released by Cochlear™ on the CI422 implant. Electroacoustic stimulation (EAS) enables recipients to benefit from cochlear implantation while retaining their natural low-frequency hearing. A disadvantage of short EAS elect...

This paper reports a case of a patient who has had bilateral cochlear implants that have been manufactured by different cochlear implant companies (Cochlear Corporation and Med-El). Comparison of speech perception tests following single implant insertion and bilateral insertion (3 and 12 months). The patient was also interviewed to obtain a subject...

Clinicians traditionally advise patients that implantation with a conventional full cochlear implant array will lead to loss of any remaining hearing in the implanted ear. We sought to assess the extent to which 'standard' insertion of a full electrode array affects cochlear function. Air conduction pure tone audiometry was performed as part of the...

This chapter describes electrocochleography (ECochG) as a method of recording the electrical activity of the cochlea and first order eighth nerve fibers in response to acoustic stimulation. It has been used over many years for animal studies and has provided much important data concerning the function of the inner ear. Although the methods of using...

To define the ocular and cervical vestibular evoked myogenic potential (oVEMP and cVEMP) profile in Ménière's Disease (MD), we studied air-conducted (AC) sound and bone-conducted vibration (BCV)-evoked responses in 77 patients and 35 controls. oVEMPs were recorded from unrectified infra-orbital surface electromyography (EMG) during upward gaze. cVE...

Past theories that have been proposed to account for the attacks of vertigo during the course of Meniere disease are reviewed. In the past, vascular theories and theories of perilymph and endolymph mixing due to ruptures or leakages were proposed. Recent research concerning the basic mechanisms of the inner ear anatomy and function cast doubt on th...

No significant changes in hearing thresholds were observed during vertigo attacks associated with Meniere's disease. To determine if the hearing alters during the period of the attacks of vertigo in Meniere's disease. The study group consisted of patients who had a clinical diagnosis of definite Meniere's syndrome according to the AAOOHNS criteria,...

Patients with a fluctuating hearing loss, episodic vertigo and tinnitus with no known aetiological cause were investigated as cases of Menière's disorder. Transtympanic electrocochleography was found to be helpful in reaching the diagnosis of an inner ear disorder. In 65% of the patients, a large DC potential was recorded which caused an apparent w...

Stimulus biasing modulated the amplitude of the tone burst evoked summating potential (SP) in ears affected by Meniere's disease less than in normal ears. A reduced SP bias ratio added diagnostic accuracy for the diagnosis of Meniere's disease. To evaluate the effect of stimulus biasing on the human tone burst SP, and to determine if stimulus biasi...

Transtympanic electrocochleography (TT ECochG) is helpful for the confirmation of Meniere's disease using tone burst stimuli to measure the amplitude of the frequency specific summating potentials (SP) but not when using the click evoked summating potential versus action potential ratio (SP/AP). To evaluate the effectiveness of TT ECochG as a means...

Currently, the physiological mechanisms underlying auditory neuropathy are unclear, and there are likely to be multiple sites of lesion. A better understanding of the disruption in individual cases may lead to more effective management and device selection. Frequency-specifi c round-window electrocochleography (ECochG) waveforms were used to assess...

Electrically evoked auditory brainstem responses (EABR) were obtained intra-operatively from children receiving full insertion of Cochlear CI24 implant. The EABR waveform was quantified according to the presence or absence of waves (eII-eV). Each trace was scored from 0-3 providing a maximum score for all 22 electrodes of 66 in the monopolar mode....

Objective: To describe the results from utilising intraoperative electrocochleography to measure cochlear potentials during stapedectomy. Materials and Methods: Patients undergoing stapedectomy with intraoperative electrocochleography monitoring were reviewed. Correlation of results from pure tone audiometry and intraoperative electrocochleography...

The physiological mechanisms underlying auditory neuropathy (AN) remain unclear and it is likely that the multiple disruptions are classified under the broadly defined term. Cochlear implantation is being more widely used in this population to bypass the suspected site-of-lesion although a number of cases have been identified within the Sydney Coch...

Our aim was to demonstrate whether one causative agent of meningitis is more likely to cause profound hearing loss and labyrinthitis ossificans. We obtained data from the New South Wales health department for cases of meningitis between 1995 and 2005 (1568 cases) and the Sydney Cochlear Implant Centre for cochlear implant patients with hearing loss...

To examine the outcome of cochlear implantation in children with auditory neuropathy (AN) and cochlear nerve deficiency (Group A). Results are compared with a cohort of children with AN and normal cochlear nerves (Group B). Retrospective cohort study. The Sydney Cochlear Implant Centre and the Children's Hospital at Westmead. Children younger than...

A review of current opinion concerning 'auditory neuropathy' is presented. It is suggested that electrophysiological tests, including electrocochleography, auditory brainstem responses and electrically evoked auditory brainstem responses, together with imaging, can provide information regarding the site of the underlying pathological conditions tha...

To describe the round window electrocochleography (RWECochG) and electric auditory brainstem responses (EABR) in ears affected by auditory neuropathy (AN), and to determine if these electrophysiological tests can predict the outcome following cochlear implant surgery. A longitudinal study of all pediatric cochlear implant patients between 1994 and...

Trans-tympanic electric auditory brainstem response (TT-EABR) is an established pre-operative investigation in cochlear implantation surgery. Various techniques have been employed to obtain electrical responses but there has been no universal agreement on the exact positioning of the stimulating electrode on the medial wall of the mesotympanum. The...

Waardenburg syndrome presents with dystopia canthorum, pigmentary abnormalities of hair, iris and skin (often a white forelock and heterochromia iridis) and sensorineural deafness. The authors review the electrophysiological and psychophysical findings of implanted children with Waardenburg syndrome at the Sydney Cochlear Implant Centre. Twenty chi...

An abstract is unavailable. This article is available as HTML full text and PDF.

A cochlear implant device is normally inserted into the scala tympani via a posterior tympanotomy and cochleostomy. There has been no previous report of displacement of the array into the vestibular part of the labyrinth. The authors present and discuss the audiological and electrophysiological measurements of a case in which part of the array hern...

To list the complications encountered in a series of 844 consecutive patients and to evaluate the long-term difference in wound and flap problems between large and small incisions. 844 consecutive patients underwent cochlear implantation at the Sydney Cochlear Implant Centre. 212 cases were operated on prior to October 1994 using the retroauricular...

To compare the maturation of the auditory pathway, as shown by electrical brainstem auditory potentials (EABRs), in ears with and without prior auditory stimulation. Electrophysiological data were collected prospectively from ears which had received cochlear implants. Implant-evoked (Imp)EABRs were recorded. Thirty children, implanted after January...

JLO Visiting Professor 2003 – Professor W. P. R. Gibson - Volume 118 Issue 1 - W.P.R. Gibson

The hypotheses of the study were that congenital hearing impairment in infants can result from the isolated loss of inner hair cells of the cochlea and that this is shown by the presence of abnormal positive summating potentials on round window electrocochleography. The objectives were to establish the proportion of infants with hearing loss affect...

To date, 290 adults have been implanted in the cochlear implant programme in Sydney (Australia), where the promontory stimulation test (PST) is routinely used to assess implant candidacy. There has been much controversy over the exact role and value of this test. Pre- and postoperative speech comprehension tests of 150 implantees were analysed, and...

The objective of this study was to identify common factors affecting speech perception scores in children with cochlear implants. Speech perception data for 167 implanted children were collected at two cochlear implant centres in Melbourne and Sydney. The data comprised audition-alone scores on open-set word and sentence tests. Children were select...

To describe an atypical waveform, termed an abnormal positive potential (APP), on round window electrocochleograms (RW ECochG) of children and to relate its occurrence to clinical history. APPs were identified prospectively, and a retrospective analysis was made of these patients' clinical histories, audiograms, and auditory outcomes (hearing aid,...

To show that congenitally deaf children who receive a cochlear implant between 10 and 15 years of age find it significantly more difficult to learn the new signal, and that a history of sound detection at high frequencies with hearing aids is predictive of better outcomes in these children. A retrospective study using a within-subjects design. Chil...

This study prospectively analyses electrocochleography (ECoG) recordings obtained from ears demonstrating symptoms highly suggestive of Meniere's disease. Comparison is made with ECoG recording from ears in which the diagnosis of Meniere's is considered unlikely (control ears). Electrocochleograph recordings were made through a transtympanic record...

The speech perception and speech production performance following cochlear implantation of congenitally deaf children and children deafened by meningitis were analysed. Three groups consisting of 70 congenitally deaf children, 22 children deafened by meningitis before two years of age and 14 children deafened by meningitis after two years of age we...

This case reports electrophysiological evidence for cochlear function in a child with radiological evidence of bilateral auditory nerve agenesis or severe hypoplasia. The diagnosis of auditory nerve agenesis was supported by a bilateral atresia of internal auditory canals on computed tomography (CT) scan and magnetic resonance imaging (MRI) absent...

This paper describes the abnormality of a large internal auditory meatus (LIAM). Computed tomography (CT) scans show the otic capsule to be affected by a widened, bulbar internal auditory meatus with loss of or reduction of the bony wall dividing the lateral fundus of the meatus from the cochlea. The vestibule is abnormally dilated. We report five...

This study analyzes the incidence of endolymphatic hydrops in the asymptomatic contralateral ear of patients with classic Meniere's disease. A retrospective study of 3000 subjects who underwent electrocochleography (ECOG) from 1988 to 1998. The presence of endolymphatic hydrops was determined by use of ECOG recordings, which were made through a tra...

A new cochlear implant (CI-24M) has recently been released by Cochlear Ltd. The shape and size of the receiver-stimulator differs from that of the CI-22M. Infants as young as one year of age are now receiving cochlear implants. We have examined the likely effect of skull growth following the implantation of a CI-24M cochlear implant in an infant of...

A new cochlear implant (CI–24M) has recently been released by Cochlear Ltd. The shape and size of the receiver-stimulator differs from that of the CI–22M. Infants as young as one year of age are now receiving cochlear implants. We have examined the likely effect of skull growth following the implantation of a CI-24M cochlear implant in an infant of...

There have been few studies investigating the mechanism and nature of the hearing loss that occurs in the mitochondrial disorders. We studied 18 patients with the MELAS A3243G point mutation from four different kindreds. Pure tone audiometry, speech discrimination testing, acoustic reflexes, tympanometry, and brain stem auditory evoked responses we...

The etiology of the attacks of vertigo that occur in Meniere's disease is discussed in this article. None of the current theories remain tenable in view of recent findings concerning the physiology and pathophysiology of the cochlea and endolymphatic sac. A new theory suggests that a narrowed duct becomes obstructed by debris that is cleared by a c...

Many reports have established that hearing-impaired children using the Nucleus 22-channel cochlear implant may show both significant benefits to lipreading and significant scores on open-set words and sentences using electrical stimulation only. These findings have raised questions about whether severely or severely-to-profoundly deaf children shou...

Experience with a straight, vertical incision for cochlear implantation in 168 patients of all ages is reported and comparison made with previous experience using a 'C' shaped incision in 173 patients with regard to complications encountered. With the straight incision the only complication was a wound infection which settled in one week; this is i...

This study aimed to evaluate the efficacy of round window electrocochleography for the estimation of hearing thresholds in difficult-to-test children. The study was a retrospective analysis. A standard day-stay operating room was used. Round window electrocochleography was performed on 198 children between January 1993 and January 1996. The interve...

Electrocochleography (ECochG) provides an electrical picture of the physiology and pathophysiology of the cochlea. The clearest and most robust potentials are obtained when the active electrode is placed through the tympanic membrane (transtympanic method). Less invasive techniques which record from the surface of the tympanic membrane or ear canal...

Between April 1990 and June 1996, the extraosseous portion of endolymphatic sac has been removed from the affected ear in 77 patients suffering from Menière's disease. Removal of the extraosseous part of the endolymphatic sac without any drainage procedure did not increase the frequency or severity of the attacks of vertigo in any patient. The resu...

Racial differences in the size, shape and structure of the cranium exist. This paper evaluates the importance of race in influencing the required sizes of craniotomies for gaining access to the lateral end of the internal auditory meatus without breaching the labyrinth via the retrosigmoid approach. Fine-cut CT scans of the temporal bones (axial cu...

A method of inserting a multielectrode cochlear implant into a cochlea that has become totally ossified following meningitis is described. The method, called the inlay technique, involves drilling a cleft so that the electrode array can be inserted along the position of the basal coil. First, the technique involves drilling along the scala tympani....

A straight, vertical post-aural incision for the ‘Cochlear’ multichannel cochlear implants has been evaluated in 52 patients (20 adults and 32 children). Nineteen of the children were under three years of age and five of these were under two years of age. The 7cm long incision is placed approximately 3 mm behind the post-auricular crease and runs f...

The position of the jugular bulb (JB) is of great clinical significance to the otologist. A high and laterally situated jugular bulb may pose difficulties when dealing with the middle ear while a high and medially sited jugular bulb can create problems in neuro-otological surgery. This paper aims to study possible racial differences in the position...

A Cochlear Mini System 22 Channel cochlear implant extruded through the skin of a young girl. The implant was saved by use of a transposition flap. Extrusion appeared to be due to pressure necrosis from the implant on the overlying tissues. It is believed that this problem can be prevented by angulation of the implant before insertion so that it co...

Severe ossification within the cochlea occurs in more than 20% of children deafened by meningitis. A multi-electrode cochlear implant can dramatically restore useful hearing to such children, providing it can be inserted satisfactorily within the cochlea. Various surgical techniques for cochlear implantation into an ossifying cochlea are discussed....

It is important to be able to accurately assess residual cochlear function in profoundly deaf children. Profound hearing loss in children requires special consideration, because the choice between a cochlear implant and a hearing aid depends on accurate estimation of the residual hearing. Previous reports confirm that promontory (needle) electrococ...

A new method for the intraoperative diagnosis of a perilymphatic fistula is presented. Two cases are reported in which the test clearly indicated the presence of a fistula even though no visible leak of fluid was noted by the surgeon. In each case, there was a clear history of vertigo and hearing loss. Preoperatively, the presence of a perilymphati...

The case against the occurrence of spontaneous perilymphatic fistulas is presented. Electrophysiologic findings both in animals and in man suggest that small holes in either the round or oval window are not associated with any significant hearing loss. Removal of perilymph may cause some changes in the electrocochleogram that can be reversed when t...

Seventy-seven ears of patients with Menière's disease (n = 69) and other ears with secondary endolymphatic hydrops (n = 8) underwent valved shunt surgery, and were monitored with intraoperative electrocochleography (ECoG) using clicks stimuli (n = 77), and both clicks and tone bursts (n = 37). Of the 41 ears in which the "baseline" measurement was...

To describe three children in whom there had been major errors in the diagnosis of hearing loss. In three children (two developmentally delayed, one not developmentally delayed) hearing thresholds obtained by behavioural testing were later proven wrong. This resulted in significant family distress and inappropriate educational approaches. Electroco...

The intraoperative electrocochleogram (ECochG) was investigated during stapedectomy surgery and during cochleostomy surgery. This provided the justification for obtaining recordings with the oval window (OW) or round window (RW) intact and then when there was a definite fistula. It was noteworthy that no ECochG changes occurred on merely opening th...

Epithelial migration occurs in a lateral direction from the tympanic membrane to the external auditory canal. The underlying mechanism which determines the direction of this laterally directed movement has not been elucidated. This study attempts to analyze whether migration is stimulated at the chondro-osseous junction, the very place where squamo...

The use of transtympanic electrocochleography (ECochG) is discussed in the diagnosis of endolymphatic hydrops. The electrophysiological concepts which may explain the finding of an increased negative summating potential (SP) in human recordings are discussed. The click SP/AP ratio and the absolute values of the 1 kHz 90 dB NHL tone burst were obtai...

Intra-operative electrocochleography was undertaken during surgery for Meniére's disease. It was found that the electrocochleogram (ECoG) provided a stable measure which accurately reflected changes within the inner ear during surgery. During salt osmosis of the round window, a rapid change in the summating potential versus action potential ratio (...

The purpose of this review of cases was to determine whether or not the SP/AP amplitude ratio changes during unidirectional inner ear valved shunt surgery for the decompression of the hydropic labyrinth in Meniere's disease. A series of 62 patients underwent shunt surgery over a 20 month period. In 43 cases (43 ears), ECoG responses were successful...