Visually Induced Dizziness in Children and Validation of the Pediatric Visually Induced Dizziness Questionnaire

Aims

To develop and validate the Pediatric Visually Induced Dizziness Questionnaire (PVID) and quantify the presence and severity of visually induced dizziness (ViD), i.e., symptoms induced by visual motion stimuli including crowds and scrolling computer screens in children.

Methods

169 healthy (female n = 89; recruited from mainstream schools, London, UK) and 114 children with a primary migraine, concussion, or vestibular disorder diagnosis (female n = 62), aged 6–17 years, were included. Children with primary migraine were recruited from mainstream schools while children with concussion or vestibular disorder were recruited from tertiary balance centers in London, UK, and Pittsburgh, PA, USA. Children completed the PVID, which assesses the frequency of dizziness and unsteadiness experienced in specific environmental situations, and Strength and Difficulties Questionnaire (SDQ), a brief behavioral screening instrument.

Results

The PVID showed high internal consistency (11 items; α = 0.90). A significant between-group difference was noted with higher (i.e., worse) PVID scores for patients vs. healthy participants (U = 2,436.5, z = −10.719, p < 0.001); a significant difference was noted between individual patient groups [χ²(2) = 11.014, p = 0.004] but post hoc analysis showed no significant pairwise comparisons. The optimal cut-off score for discriminating between individuals with and without abnormal ViD levels was 0.45 out of 3 (sensitivity 83%, specificity 75%). Self-rated emotional (U = 2,730.0, z = −6.169) and hyperactivity (U = 3,445.0, z = −4.506) SDQ subscale as well as informant (U = 188.5, z = −3.916) and self-rated (U = 3,178.5, z = −5.083) total scores were significantly worse for patients compared to healthy participants (p < 0.001).

Conclusion

ViD is common in children with a primary concussion, migraine, or vestibular diagnosis. The PVID is a valid measure for identifying the presence of ViD in children and should be used to identify and quantify these symptoms, which require specific management incorporating exposure to optokinetic stimuli.

The Pediatric Vestibular Symptom Questionnaire: A Validation Study

OBJECTIVE

To develop and validate the Pediatric Vestibular Symptom Questionnaire (PVSQ) and quantify subjective vestibular symptom (ie, dizziness, unsteadiness) severity in children.

STUDY DESIGN

One hundred sixty-eight healthy children (female, n = 91) and 56 children with postconcussion dizziness or a vestibular disorder (female, n = 32), between ages 6 and 17 years, were included. The PVSQ contains questions regarding vestibular symptom frequency during the previous month. The Strengths and Difficulties Questionnaire (SDQ), a brief behavioral screening instrument, was also completed.

RESULTS

The PVSQ showed high internal consistency (10 items; Cronbach α = 0.88). A significant between-group difference was noted with higher (ie, worse) PVSQ scores for children with vestibular symptoms (P < .001); no significant differences were noted between patient groups. The optimal cut-off score for discriminating between individuals with and without abnormal levels of vestibular symptoms was 0.68 out of 3 (sensitivity 95%, specificity 85%). Emotional and hyperactivity SDQ subscale scores were significantly worse for patients compared with healthy participants (P ≤ .01). A significant relationship was noted between mean PVSQ and SDQ (parent-rated version) hyperactivity and total scores for patients (P ≤ .01) and the SDQ (self-rated) emotional, hyperactivity, and total score (P ≤ .01) in healthy controls. However, mean SDQ subscale and total scores were within normal ranges for both groups.

CONCLUSIONS

Self-reported vestibular symptoms, measured by the PVSQ, discriminated between children presenting with vestibular symptoms and healthy controls and should be used to identify and quantify vestibular symptoms that require additional assessment and management.

A detailed clinical and molecular survey of subjects with nonsyndromic USH2A retinopathy reveals an allelic hierarchy of disease-causing variants

Defects in USH2A cause both isolated retinal disease and Usher syndrome (ie, retinal disease and deafness). To gain insights into isolated/nonsyndromic USH2A retinopathy, we screened USH2A in 186 probands with recessive retinal disease and no hearing complaint in childhood (discovery cohort) and in 84 probands with recessive retinal disease (replication cohort). Detailed phenotyping, including retinal imaging and audiological assessment, was performed in individuals with two likely disease-causing USH2A variants. Further genetic testing, including screening for a deep-intronic disease-causing variant and large deletions/duplications, was performed in those with one likely disease-causing change. Overall, 23 of 186 probands (discovery cohort) were found to harbour two likely disease-causing variants in USH2A. Some of these variants were predominantly associated with nonsyndromic retinal degeneration (‘retinal disease-specific'); these included the common c.2276 G>T, p.(Cys759Phe) mutation and five additional variants: c.2802 T>G, p.(Cys934Trp); c.10073 G>A, p.(Cys3358Tyr); c.11156 G>A, p.(Arg3719His); c.12295-3 T>A; and c.12575 G>A, p.(Arg4192His). An allelic hierarchy was observed in the discovery cohort and confirmed in the replication cohort. In nonsyndromic USH2A disease, retinopathy was consistent with retinitis pigmentosa and the audiological phenotype was variable. USH2A retinopathy is a common cause of nonsyndromic recessive retinal degeneration and has a different mutational spectrum to that observed in Usher syndrome. The following model is proposed: the presence of at least one ‘retinal disease-specific' USH2A allele in a patient with USH2A-related disease results in the preservation of normal hearing. Careful genotype–phenotype studies such as this will become increasingly important, especially now that high-throughput sequencing is widely used in the clinical setting.

Natural history and retinal structure in patients with Usher syndrome type 1 owing to MYO7A mutation

PURPOSE

To evaluate the phenotypic variability and natural history of ocular disease in a cohort of 28 individuals with MYO7A-related disease. Mutations in the MYO7A gene are the most common cause of Usher syndrome type 1, characterized by profound congenital deafness, vestibular arreflexia, and progressive retinal degeneration.

DESIGN

Retrospective case series.

PARTICIPANTS

Twenty-eight patients from 26 families (age range, 3-65 years; median, 32) with 2 likely disease-causing variants in MYO7A.

METHODS

Clinical investigations included fundus photography, optical coherence tomography, fundus autofluorescence (FAF) imaging, and audiologic and vestibular assessments. Longitudinal visual acuity and FAF data (over a 3-year period) were available for 20 and 10 study subjects, respectively.

MAIN OUTCOME MEASURES

Clinical, structural, and functional characteristics.

RESULTS

All patients with MYO7A mutations presented with features consistent with Usher type 1. The median visual acuity for the cohort was 0.39 logarithm of the minimum angle of resolution (logMAR; range, 0.0-2.7) and visual acuity in logMAR correlated with age (Spearman's rank correlation coefficient, r = 0.71; P<0.0001). Survival analysis revealed that acuity ≤ 0.22 logMAR was maintained in 50% of studied subjects until age 33.9; legal blindness based on loss of acuity (≥ 1.00 logMAR) or loss of field (≤ 20°) was reached at a median age of 40.6 years. Three distinct patterns were observed on FAF imaging: 13 of 22 patients tested had relatively preserved foveal autofluorescence surrounded by a ring of high density, 4 of 22 had increased signal in the fovea with no obvious hyperautofluorescent ring, and 5 of 22 had widespread hypoautofluorescence corresponding to retinal pigment epithelial atrophy. Despite a number of cases presenting with a milder phenotype, there seemed to be no obvious genotype-phenotype correlation.

CONCLUSIONS

MYO7A-related ocular disease is variable. Central vision typically remains preserved at least until the third decade of life, with 50% of affected individuals reaching legal blindness by 40 years of age. Distinct phenotypic subsets were identified on FAF imaging. A specific allele, previously reported in nonsyndromic deafness, may be associated with a mild retinopathy.

Screening for duplications, deletions and a common intronic mutation detects 35% of second mutations in patients with USH2A monoallelic mutations on Sanger sequencing

BACKGROUND

Usher Syndrome is the leading cause of inherited deaf-blindness. It is divided into three subtypes, of which the most common is Usher type 2, and the USH2A gene accounts for 75-80% of cases. Despite recent sequencing strategies, in our cohort a significant proportion of individuals with Usher type 2 have just one heterozygous disease-causing mutation in USH2A, or no convincing disease-causing mutations across nine Usher genes. The purpose of this study was to improve the molecular diagnosis in these families by screening USH2A for duplications, heterozygous deletions and a common pathogenic deep intronic variant USH2A: c.7595-2144A>G.

METHODS

Forty-nine Usher type 2 or atypical Usher families who had missing mutations (mono-allelic USH2A or no mutations following Sanger sequencing of nine Usher genes) were screened for duplications/deletions using the USH2A SALSA MLPA reagent kit (MRC-Holland). Identification of USH2A: c.7595-2144A>G was achieved by Sanger sequencing. Mutations were confirmed by a combination of reverse transcription PCR using RNA extracted from nasal epithelial cells or fibroblasts, and by array comparative genomic hybridisation with sequencing across the genomic breakpoints.

RESULTS

Eight mutations were identified in 23 Usher type 2 families (35%) with one previously identified heterozygous disease-causing mutation in USH2A. These consisted of five heterozygous deletions, one duplication, and two heterozygous instances of the pathogenic variant USH2A: c.7595-2144A>G. No variants were found in the 15 Usher type 2 families with no previously identified disease-causing mutations. In 11 atypical families, none of whom had any previously identified convincing disease-causing mutations, the mutation USH2A: c.7595-2144A>G was identified in a heterozygous state in one family. All five deletions and the heterozygous duplication we report here are novel. This is the first time that a duplication in USH2A has been reported as a cause of Usher syndrome.

CONCLUSIONS

We found that 8 of 23 (35%) of 'missing' mutations in Usher type 2 probands with only a single heterozygous USH2A mutation detected with Sanger sequencing could be attributed to deletions, duplications or a pathogenic deep intronic variant. Future mutation detection strategies and genetic counselling will need to take into account the prevalence of these types of mutations in order to provide a more comprehensive diagnostic service.

The effect of virtual reality on visual vertigo symptoms in patients with peripheral vestibular dysfunction: a pilot study

Individuals with vestibular dysfunction may experience visual vertigo (VV), in which symptoms are provoked or exacerbated by excessive or disorientating visual stimuli (e.g. supermarkets). VV can significantly improve when customized vestibular rehabilitation exercises are combined with exposure to optokinetic stimuli. Virtual reality (VR), which immerses patients in realistic, visually challenging environments, has also been suggested as an adjunct to VR to improve VV symptoms. This pilot study compared the responses of sixteen patients with unilateral peripheral vestibular disorder randomly allocated to a VR regime incorporating exposure to a static (Group S) or dynamic (Group D) VR environment. Participants practiced vestibular exercises, twice weekly for four weeks, inside a static (Group S) or dynamic (Group D) virtual crowded square environment, presented in an immersive projection theatre (IPT), and received a vestibular exercise program to practice on days not attending clinic. A third Group D1 completed both the static and dynamic VR training. Treatment response was assessed with the Dynamic Gait Index and questionnaires concerning symptom triggers and psychological state. At final assessment, significant between-group differences were noted between Groups D (p=0.001) and D1 (p=0.03) compared to Group S for VV symptoms with the former two showing a significant 59.2% and 25.8% improvement respectively compared to 1.6% for the latter. Depression scores improved only for Group S (p=0.01) while a trend towards significance was noted for Group D regarding anxiety scores (p=0.07).

CONCLUSION

Exposure to dynamic VR environments should be considered as a useful adjunct to vestibular rehabilitation programs for patients with peripheral vestibular disorders and VV symptoms.

Patient-reported speech in noise difficulties and hyperacusis symptoms and correlation with test results

OBJECTIVES/HYPOTHESIS

To compare self-reported symptoms of difficulty hearing speech in noise and hyperacusis in adults with auditory processing disorders (APDs) and normal controls; and to compare self-reported symptoms to objective test results (speech in babble test, transient evoked otoacoustic emission [TEOAE] suppression test using contralateral noise).

STUDY DESIGN

A prospective case-control pilot study.

METHODS

Twenty-two participants were recruited in the study: 10 patients with reported hearing difficulty, normal audiometry, and a clinical diagnosis of APD; and 12 normal age-matched controls with no reported hearing difficulty. All participants completed the validated Amsterdam Inventory for Auditory Disability questionnaire, a hyperacusis questionnaire, a speech in babble test, and a TEOAE suppression test using contralateral noise.

RESULTS

Patients had significantly worse scores than controls in all domains of the Amsterdam Inventory questionnaire (with the exception of sound detection) and the hyperacusis questionnaire (P < .005). Patients also had worse TEOAE suppression test results in both ears than controls; however, this result was not significant after Bonferroni correction. Strong correlations were observed between self-reported symptoms of difficulty hearing speech in noise and speech in babble test results in the right ear (ρ = 0.624, P = .002), and between self-reported symptoms of hyperacusis and TEOAE suppression test results in the right ear (ρ = -0.597 P = .003).

CONCLUSIONS

There was no significant correlation between the two tests. A strong correlation was observed between right ear speech in babble and patient-reported intelligibility of speech in noise, and right ear TEOAE suppression by contralateral noise and hyperacusis questionnaire.

Patient-reported auditory functions after stroke of the central auditory pathway

BACKGROUND AND PURPOSE

Auditory functional limitations experienced by patients after stroke of the central auditory pathways remain underinvestigated. Purpose- To measure patient-reported hearing difficulties in everyday life in nonaphasic patients with stroke of the auditory brain versus normal control subjects. To examine how hearing difficulties correlate with auditory tests and site of lesion in individual cases.

METHODS

We recruited 21 individuals with auditory brain stroke (excluding those with aphasia) diagnosed on the basis of a brain MRI conducted 1 to 2 weeks after the stroke and assessed in the chronic stage of stroke. Twenty-three controls matched for age and hearing were also recruited. All subjects completed the Amsterdam Inventory for Auditory Disability (consisting of subscales of sound detection, recognition, localization, speech in quiet, speech in noise) and underwent baseline audiometry and central auditory processing tests (dichotic digits, frequency and duration patterns, gaps in noise).

RESULTS

Sound recognition and localization subscores of the inventory were significantly worse in case subjects versus control subjects, with severe and significant functional limitation (z score >3) reported by 9 out of 21 case subjects. None of the inventory subscales correlated with audiometric thresholds, but localization and recognition subscales showed a moderate to strong correlation with dichotic digits (left ear) and pattern tests.

CONCLUSIONS

A substantial proportion of patients may experience and report severe auditory functional limitations not limited to speech sounds after stroke of the auditory brain. A hearing questionnaire may help identify patients who require more extensive assessment to inform rehabilitation plans.

Comprehensive sequence analysis of nine Usher syndrome genes in the UK National Collaborative Usher Study

Background

Usher syndrome (USH) is an autosomal recessive disorder comprising retinitis pigmentosa, hearing loss and, in some cases, vestibular dysfunction. It is clinically and genetically heterogeneous with three distinctive clinical types (I–III) and nine Usher genes identified. This study is a comprehensive clinical and genetic analysis of 172 Usher patients and evaluates the contribution of digenic inheritance.

Methods

The genes MYO7A, USH1C, CDH23, PCDH15, USH1G, USH2A, GPR98, WHRN, CLRN1 and the candidate gene SLC4A7 were sequenced in 172 UK Usher patients, regardless of clinical type.

Results

No subject had definite mutations (nonsense, frameshift or consensus splice site mutations) in two different USH genes. Novel missense variants were classified UV1-4 (unclassified variant): UV4 is ‘probably pathogenic’, based on control frequency <0.23%, identification in trans to a pathogenic/probably pathogenic mutation and segregation with USH in only one family; and UV3 (‘likely pathogenic’) as above, but no information on phase. Overall 79% of identified pathogenic/UV4/UV3 variants were truncating and 21% were missense changes. MYO7A accounted for 53.2%, and USH1C for 14.9% of USH1 families (USH1C:c.496+1G>A being the most common USH1 mutation in the cohort). USH2A was responsible for 79.3% of USH2 families and GPR98 for only 6.6%. No mutations were found in USH1G, WHRN or SLC4A7.

Conclusions

One or two pathogenic/likely pathogenic variants were identified in 86% of cases. No convincing cases of digenic inheritance were found. It is concluded that digenic inheritance does not make a significant contribution to Usher syndrome; the observation of multiple variants in different genes is likely to reflect polymorphic variation, rather than digenic effects.

Computer-based auditory training (CBAT): benefits for children with language- and reading-related learning difficulties

This article reviews the evidence for computer-based auditory training (CBAT) in children with language, reading, and related learning difficulties, and evaluates the extent it can benefit children with auditory processing disorder (APD). Searches were confined to studies published between 2000 and 2008, and they are rated according to the level of evidence hierarchy proposed by the American Speech-Language Hearing Association (ASHA) in 2004. We identified 16 studies of two commercially available CBAT programs (13 studies of Fast ForWord (FFW) and three studies of Earobics) and five further outcome studies of other non-speech and simple speech sounds training, available for children with language, learning, and reading difficulties. The results suggest that, apart from the phonological awareness skills, the FFW and Earobics programs seem to have little effect on the language, spelling, and reading skills of children. Non-speech and simple speech sounds training may be effective in improving children's reading skills, but only if it is delivered by an audio-visual method. There is some initial evidence to suggest that CBAT may be of benefit for children with APD. Further research is necessary, however, to substantiate these preliminary findings.

Evaluation of musical skills in children with a diagnosis of an auditory processing disorder

Impaired musical skills are reported in parental questionnaires to be present in children with an auditory processing disorder (APD).

OBJECTIVES

To formally assess musical skills in children with a diagnosis of APD.

METHODS

We used a validated musical test battery with extensive normative pediatric data, the Gordon's Musical Aptitude Profile and the tests of metre and melody in particular, in order to assess the musical skills of 8 children with a previously given diagnosis of APD (APD group) and 8 normal controls (control group) aged 7-15 years old. The two groups were well matched for age, sex, handedness, socio-economic factors and musical training.

RESULTS

The APD group had significantly lower metre percentile scores than normal children (mean difference 28.9, p=0.003). Melody scores tended to be lower in the APD group than in the controls, but this did not reach significance, possibly due to low power of the study.

CONCLUSION

This is the first study that systematically assesses musical skills in children with a formal diagnosis of APD in the absence of other developmental disorders. The APD group did significantly worse than the control group in judging metre. Musical skills assessment in children with APD may help constrain our understanding of this heterogeneous condition and possibly inform the management plan for these children.

Nonsense mutation in TMEM126A causing autosomal recessive optic atrophy and auditory neuropathy

PURPOSE

To define the phenotype and elucidate the molecular basis for an autosomal recessively inherited optic atrophy and auditory neuropathy in a consanguineous family with two affected children.

METHODS

Family members underwent detailed ophthalmologic, electrophysiological, and audiological assessments. An autozygosity mapping strategy using high-density single nucleotide polymorphism microarrays and microsatellite markers was used to detect regions of genome homozygosity that might contain the disease gene. Candidate genes were then screened for mutations by direct sequencing.

RESULTS

Both affected subjects had poor vision from birth and complained of progressive visual loss over time. Current visual acuity ranged from 6/60 to 6/120. Fundus examination revealed bilateral temporal optic nerve pallor in both patients with otherwise normal retinal findings. International-standard full-field electroretinograms were normal in both individuals, with no evidence of generalized retinal dysfunction. Pattern cortical visual evoked potentials were grossly abnormal bilaterally in both cases. The pattern electroretinogram N95:P50 ratio was subnormal, and the P50 was of shortened peak time bilaterally in both patients. The electrophysiological findings were consistent with bilateral retinal ganglion cell/optic nerve dysfunction. Audiological investigation in both siblings revealed abnormalities falling within the auditory neuropathy/dysynchrony spectrum. There were no auditory symptoms and good outer hair cell function (as demonstrated by transient evoked otoacoustic emissions) but impaired inner hair cell/neural function with abnormal stapedial reflex thresholds and abnormal or absent auditory brainstem-evoked responses. The single nucleotide polymorphism microarray data demonstrated a 24.17 Mb region of homozygosity at 11q14.1-11q22.3, which was confirmed by microsatellite marker analysis. The candidate target region contained the transmembrane protein 126A (TMEM126A) gene, and direct sequencing identified a previously described nonsense mutation (c.163C>T; p.Arg55X).

CONCLUSIONS

We describe the first detailed phenotyping of patients with autosomal recessive TMEM126A-associated optic atrophy and auditory neuropathy. These findings will facilitate the identification of individuals with this recently described disorder.

Sudden sensorineural hearing loss

Sudden sensorineural hearing loss is usually unilateral and can be associated with tinnitus and vertigo. In most cases the cause is not identified, although various infective, vascular, and immune causes have been proposed. A careful examination is needed to exclude life threatening or treatable causes such as vascular events and malignant diseases, and patients should be referred urgently for further assessment. About half of patients completely recover, usually in about 2 weeks. Many treatments are used, including corticosteroids, antiviral drugs, and vasoactive and oxygen-based treatments. Although no treatment is proven, we recommend a short course of oral high-dose corticosteroids. There is much to learn about pathogenesis of sudden sensorineural hearing loss, and more clinical trials are needed to establish evidence-based management.

Community-based infant hearing screening for early detection of permanent hearing loss in Lagos, Nigeria: a cross-sectional study

OBJECTIVE

To determine the feasibility and effectiveness of a community-based universal infant hearing screening programme for detecting permanent congenital and early-onset hearing loss (PCEHL) in Lagos, Nigeria.

METHODS

This is a cross-sectional study in which all infants aged 3 months or under attending four bacille Calmette-Guérin (BCG) immunization clinics accounting for over 75% of the BCG coverage in the study location were screened by community health workers between July 2005 and April 2006. Screening followed a two-stage protocol involving transient evoked otoacoustic emissions and automated auditory brainstem responses. The main outcome measures were screening coverage, referral rates, return rates for second-stage screening and evaluation, yield and age at PCEHL diagnosis.

FINDINGS

In total, 2003 (88%) of 2277 eligible infants attending the four BCG clinics were successfully screened between July 2005 and April 2006 at a mean age of 17.7 days, with no parent declining screening. The majority (55.2%) were born outside a hospital and, of such infants, 77% were born in traditional herbal maternity homes. The overall referral rate for diagnostic evaluation was 4.1%. Only 61% (50/82) of those referred returned for evaluation, and 45 of them were confirmed with PCEHL. Additionally, 11 infants who had previously passed the first screening stage were also found to have PCEHL, resulting in a yield of 28 per 1000 (56/2003). The mean age at diagnosis was 51 days. The sensitivity, specificity and positive predictive value of the first screening stage were 80.4%, 99.7% and 90.0%, respectively. The positive likelihood ratio was 268, while the negative likelihood ratio was 0.2.

CONCLUSION

Routine hearing screening of infants attending BCG immunization clinics by community health workers was feasible and effective for the early detection of PCEHL in Lagos, Nigeria. However, an efficient tracking and follow-up system is needed to improve return rates for second-stage screening and diagnostic evaluation.

Hospital-based universal newborn hearing screening for early detection of permanent congenital hearing loss in Lagos, Nigeria

OBJECTIVE

To determine the feasibility and effectiveness of hospital-based universal newborn hearing screening programme for the early detection of permanent congenital or early-onset hearing loss (PCEHL) in Lagos, Nigeria.

METHODS

A cross-sectional pilot study based on a two-stage universal newborn hearing screening by non-specialist health workers using transient evoked otoacoustic emissions (TEOAE) and automated auditory brainstem-response (AABR) in an inner-city maternity hospital over a consecutive period of 40 weeks. The main outcome measures were the practicality of screening by non-specialist staff with minimal training, functionality of screening instruments in an inner-city environment, screening coverage, referral rate, return rate for diagnosis, yield of PCEHL and average age of PCEHL confirmation.

RESULTS

Universal hearing screening of newborns by non-specialist staff without prior audiological experience is feasible in an inner-city environment in Lagos after a training period of two-weeks. Notwithstanding excessive ambient noise within and outside the wards, it was possible to identify a test site for TEOAE screening within the hospital. The screening coverage was 98.7% (1330/1347) of all eligible newborns and the mean age of screening was 2.6 days. Forty-four babies out of the 1274 who completed the two-stage screening were referred yielding a referral rate of 3.5%. Only 16% (7/44) of babies scheduled for diagnostic evaluation returned and all were confirmed with hearing loss resulting in an incidence of 5.5 (7/1274) per 1000 live births or a programme yield of 5.3 (7/1330) per 1000. Six infants had bilateral hearing loss and the degree was severe (> or =70 dB nHL) in three infants, moderate (40 dB nHL) in one infant and mild (<40 dB nHL) in two infants. The age at diagnosis ranged from 46 days to 360 days and only two infants were diagnosed within 90 days.

CONCLUSIONS

Hospital-based universal hearing screening of newborns before discharge is feasible in Nigeria. Non-specialist staff are valuable in achieving a satisfactory referral rate with a two-stage screening protocol. However, a more efficient tracking and follow-up system is needed to improve the return rate for diagnosis and age of confirmation of hearing loss.

Subjective visual vertical and horizontal: effect of the preset angle

OBJECTIVES

(1) To study the subjective visual vertical (SVV) and subjective visual horizontal (SVH) in patients with long-standing unilateral peripheral vestibular dysfunction (PVD) and unilateral Ménière's disease (MD) compared with controls. (2) To study the relationship between the direction of deviation of the linear marker (preset angle) and measures of SVV and SVH values.

DESIGN

Prospective case-control study.

SETTING

Outpatient clinic in a tertiary neuro-otology department.

PATIENTS

Seventeen healthy volunteers (mean age, 35.5 years), 9 patients with PVD (mean age, 43.1 years), and 10 patients with MD (mean age, 50.7 years) were included in the analysis.

INTERVENTIONS

All subjects had a detailed neuro-otological evaluation. Twelve replicate readings of SVV and SVH were taken for each subject, with random preset angles, 6 in the clockwise and 6 in the counterclockwise direction.

MAIN OUTCOME MEASURE

The SVV and SVH values were correlated with clinical features and the direction of the preset angle.

RESULTS

The 2 subjects with PVD who had abnormal mean SVV and SVH values had symptoms of dysequilibrium and otolithic involvement. The 5 patients in the MD group who had abnormal mean SVV and SVH values had either recent acute vertiginous attacks or total canal paresis on the affected side. A previously unreported finding, to our knowledge, is that the SVV value depends on the direction of the preset angle in all subject groups, more so in the PVD and MD groups compared with controls. The SVV is inclined toward the direction of the preset angle. A weaker relation is seen between the SVH and preset angle.

CONCLUSION

The preset angle should be considered when comparing SVV and SVH values.

Auditory Efferent Function Is Affected in Multiple Sclerosis

OBJECTIVE

This study evaluated efferent medial olivocochlear (MOC) function in patients with multiple sclerosis (MS). Various afferent auditory abnormalities have been described in MS, but there is a paucity of data on efferent function. The brain stem is a site of predilection for MS plaques and the efferent MOC pathway may be affected at this level.

METHODS

The study included 30 patients who had normal hearing. According to MRI findings, they were divided into two groups: those with an identifiable brain stem lesion (n = 10) and those with MS lesions in other parts of the central nervous system but without demonstrable MS plaques in the brain stem (n = 20). MOC function was evaluated by the olivocochlear suppression test, using transient evoked otoacoustic emissions. All subjects underwent standard auditory tests, including pure-tone audiometry and recording of auditory brain stem evoked responses. Twenty-two healthy subjects with normal hearing, matched for age and gender, served as a reference group for the auditory data.

RESULTS

The results showed that 66.6% of all patients had reduced MOC function, particularly those (90%) with identified lesions of the brain stem on MRI. Furthermore, abnormal MOC function was found in 55% patients without evidence of a brain stem lesion on MRI.

CONCLUSIONS

This study provides the evidence for a deficit of efferent auditory function in the majority of patients with MS. Taking into consideration the possible roles of the MOC system in processing of auditory information, abnormal MOC suppression in patients with MS may explain a variety of auditory presentations that are currently largely overlooked. This study also highlights the diagnostic value of the MOC suppression test as a site-of-lesion diagnostic test in MS and in identifying subtle brain stem lesions undetected by MRI, suggesting that subtle brain stem lesions may exist and that the MOC suppression test is sufficiently sensitive to detect them. Accordingly, the MOC suppression test may provide a tool for an early diagnosis of MS.

Auditory and verbal working memory deficits in a child with congenital aniridia due to a PAX6 mutation

PAX6 encodes a transcriptional regulator that is essential for brain morphogenesis. Heterozygous PAX6 mutation is associated with aniridia and abnormalities of the interhemispheric pathway in humans. We present the case of a 12 year old boy with a known mutation of the PAX6 gene. There were parental concerns regarding his hearing, but repeated pure-tone audiograms were normal. He had a battery of standard central auditory tests, which gave abnormal results in tests which required auditory interhemispheric transfer (dichotic digits and pattern tests). A speech and language assessment, which yielded age-appropriate scores for speech, receptive and expressive language, revealed impaired verbal working memory. These test results were interpreted as indicating impaired auditory sensory and higher order interhemispheric transfer, consistent with reported findings in adults with mutations in PAX6, and correlated with his parent-reported hearing difficulties. This is the first report of central auditory and verbal working memory deficits in a child with a PAX6 mutation. Further research is needed to assess how these deficits impact on academic performance particularly in childhood.

The role of the interhemispheric pathway in hearing

The corpus callosum consists of heavily myelinated fibres connecting the two hemispheres. Its caudal portion and splenium contain fibres that originate from the primary and second auditory cortices, and from other auditory responsive areas. The anterior commissure in humans is much smaller than the corpus callosum, and it also contains interhemispheric fibres from auditory responsive cortical areas. The corpus callosum is exclusively present in placental mammals, while in acallosal mammals, most of the corpus callosum-related functions are carried out by the anterior commissure. The exact contribution of these two structures and of interhemispheric transfer in hearing in humans is still a matter of debate. In more recent years, human behavioural studies which employ psychoacoustic tasks designed to tap into interhemispheric transfer, combined with sophisticated neuroimaging paradigms, have helped to interpret information from animal experiments and post-mortem studies. This review will summarize and discuss the available information of the contributions of the human interhemispheric pathway in hearing in humans from behavioural, neuroimaging and histopathological studies in humans.

Clinical value of tone burst vestibular evoked myogenic potentials at threshold in acute and stable Ménière's disease

Introduction:

The objectives of this preliminary, prospective, cohort study were to ascertain the characteristics of vestibular evoked myogenic potentials at threshold levels in two groups of Ménière's disease patients – acute and stable – and to identify whether vestibular evoked myogenic potentials can provide any specific, objective information to distinguish acute from stable Ménière's disease.

Subjects and methods:

The study was based at a tertiary neuro-otology centre. Twenty adult patients who fulfilled the American Academy of Otolaryngology–Head and Neck Surgery1 criteria for Ménière's disease were divided into two groups: 11 patients with acute Ménière's disease and nine patients with stable Ménière's disease. Eighteen healthy adult volunteers served as controls. All subjects underwent vestibular evoked myogenic potential testing with ipsilateral, short tone burst stimuli at 500 Hz, as well as pure tone audiometry. The patients also underwent caloric testing.

Results:

Vestibular evoked myogenic potentials were present in all controls, and were present in 65 per cent of patients but absent in 35 per cent. The mean absolute threshold (Tvestibular evoked myogenic potential) ± standard deviation in normal controls was 116 ± 7.7 dBSPL; this did not differ statistically from that in patients, nor did it differ between acute and stable Ménière's disease. The p13/n23 latencies at the threshold levels in the normal, acute and stable groups (mean ± standard deviation) were respectively: 15 ± 2.2 ms/23.0 ± 2.5 ms; 15.7 ± 0.9 ms/23.7 ± 0.9 ms; and 15.3 ± 2.0 ms/24.2 ± 1.9 ms. The mean interaural amplitude difference ratio (IAD) ± standard deviation was significantly higher in the stable group compared with the acute group (0.54 ± 0.33 vs −0.15 ± 0.22; p = 0.007) and with the controls (0.54 ± 0.33 vs 0.1 ± 0.22; p = 0.05).

Conclusions:

The parameter that best differentiated acute from stable Ménière's disease at threshold was the interaural amplitude difference ratio. Therefore, this parameter may be used to monitor the clinical course of Ménière's disease.

Auditory interhemispheric transfer deficits, hearing difficulties, and brain magnetic resonance imaging abnormalities in children with congenital aniridia due to PAX6 mutations

OBJECTIVE

To assess auditory processing, hearing difficulties, and brain magnetic resonance (MR) imaging abnormalities in children with panocular developmental aniridia due to PAX6 mutations.

DESIGN

Case-control study.

SETTING

Great Ormond Street Hospital and Institute of Child Health.

PARTICIPANTS

Eleven case subjects with PAX6 mutations and 11 age-matched and sex-matched healthy control subjects.

INTERVENTIONS

All subjects completed a structured hearing questionnaire, baseline audiometry, and central auditory tests (dichotic speech tests, frequency and duration pattern tests, and gaps-in-noise test). Case subjects underwent brain MR imaging with volumetry, and the results were compared with those of age-matched and sex-matched healthy control subjects randomly selected from the Radiology and Physics Unit database.

MAIN OUTCOME MEASURES

Brain MR imaging, central auditory test results, and questionnaire scores.

RESULTS

The corpus callosum area was significantly smaller on brain volumetry in the cases compared with the controls. The anterior commissure was small in 7 cases and was normal in 3 cases on visual inspection of brain MR images (conducted in 10 of 11 cases). Audiograms showed no abnormalities in any of the children. Central auditory test results were normal in all the controls and were abnormal in all the cases except for 1 case with a pattern of abnormalities consistent with reduced auditory interhemispheric transfer. The cases had greater difficulty localizing sound and understanding speech in noise than the controls.

CONCLUSIONS

Despite normal audiograms, children with PAX6 mutations may experience auditory interhemispheric transfer deficits and have difficulty localizing sound and understanding speech in noise. In view of their additional visual difficulties, thorough audiological evaluation of these children is indicated to initiate appropriate management.

Ethical issues in screening for hearing impairment in newborns in developing countries

Screening of newborns for permanent congenital or early-onset hearing impairment has emerged as an essential component of neonatal care in developed countries, following favourable outcomes from early intervention in the critical period for optimal speech and language development. Progress towards a similar programme in developing countries, where most of the world's children with hearing impairment reside, may be impeded by reservations about the available level of support services and the possible effect of the prevailing healthcare challenges. Ethical justification for the systematic introduction of screening programmes for hearing in newborns based on the limitations in current primary prevention strategies, lack of credible alternative early-detection strategies and the incentives for capacity-building for the requisite support services is examined.

Auditory temporal processing deficits in patients with insular stroke

OBJECTIVE

To assess central auditory function in a series of patients with stroke of the insula and adjacent areas.

METHODS

The authors recruited eight patients with stroke affecting the insula and adjacent areas and eight neurologically normal controls (matched to the patients for age, sex, handedness, and hearing thresholds). The lesion spared the adjacent auditory areas in three patients and included other auditory structures in five cases. The authors conducted pure-tone audiometry and tympanometry and a central auditory test battery, which included the dichotic digits, and three temporal tests, the duration pattern, frequency pattern, and gaps in noise tests. They collected information from the hospital notes on symptoms at presentation and neuropsychological assessment data during the acute phase.

RESULTS

The central auditory tests gave normal results in all controls. The temporal tests gave abnormal results in all three cases in which other auditory areas were spared, as well as in the other five cases. Results of the gaps in noise test were abnormal contralaterally to the lesion in three and bilaterally in five cases. The central auditory deficits did not cosegregate with the presence of cognitive impairment during the acute stage.

CONCLUSION

Insular lesions may affect central auditory function and, in particular, temporal resolution and sequencing, consistent with neuroimaging studies.

Maternal views on infant hearing loss in a developing country

BACKGROUND

Parental support for infant hearing loss is essential for a successful infant screening programme. However, in developing countries where unfavourable customs and beliefs towards childhood disabilities have been reported, parental support towards infant screening is uncertain and there is presently no published evidence on the subject.

OBJECTIVE

To elicit the views of mothers and would-be mothers in order to ascertain their knowledge on infant hearing loss and their attitudes towards infant hearing screening.

METHODS

A structured questionnaire consisting of 15 questions was administered to 101 mothers (mean age 31.6+/-7.3 years, range: 21-55 years) attending two community hospitals in Lagos, Nigeria. The responses were evaluated by descriptive statistics, factor analysis of the principal components and multiple regression analysis. The reliability of the two main domains (knowledge and attitude) was tested for internal consistency by Cronbach's alpha coefficient.

RESULTS

Maternal knowledge was highest for measles (73%; mean score 2.54) and ear discharge (73%; mean score 2.51) but low for birth asphyxia (37%; mean score 1.90), traditional medicine (42%; mean score 2.03) and jaundice (47%; mean score 2.09) as causes of hearing loss. Attitude towards neonatal screening was positive in majority of mothers (92%; mean score 2.84) and there was a high acceptance of hearing aids as an early intervention option (84%; mean score 2.70). Five factors (eigenvalue>1) were extracted after principal component analysis with the attitude variables loading highly and exclusively on one factor. Age was the only demographic variable that was associated with a domain (knowledge) after multiple regression analysis. The component scales for the two domains were highly internally consistent (alpha coefficients of 0.84 and 0.83).

CONCLUSIONS

Contrary to the concerns often expressed about parental support for infant hearing screening programmes in developing countries, this study suggests that current parental knowledge and attitude favour early detection and intervention of childhood hearing impairment.

Immune-mediated inner-ear disorders in neuro-otology

PURPOSE OF REVIEW

Immune-mediated inner-ear disorders may present to different medical disciplines and new research findings emerge rapidly. The purpose of this review is to draw the different strands together to produce an overview describing the clinical presentation of immune-mediated inner-ear disorders and to discuss useful diagnostic criteria with a focus on tissue-specific and tissue-non-specific antibodies.

RECENT FINDINGS

The importance of diagnosing an immune-mediated inner-ear disorder is highlighted in the context of it being one of few forms of treatable inner-ear disorder with a good response to immunosuppressive therapy. Due to a lack of reliable tests, the criteria upon which the diagnosis of immune-mediated inner-ear disease is based are often arbitrary. Previous and current research focuses mainly on the investigation of the aetiology of immune-mediated disorders, studying the presence of autoantibodies and the antigens responsible for their production. The prognostic and therapeutic values of inner-ear-specific antibodies are still unclear. Various antigens have been suggested. However, most antigens identified have been ubiquitous proteins not specific to the inner ear and therefore lack logical association with localized inner-ear pathology.

SUMMARY

Early diagnosis of immune-mediated inner-ear disorders with prompt treatment may prevent irreversible damage to inner-ear structures. Accordingly, it is important to include immune-mediated inner-ear disorders in the differential diagnosis of patients presenting with 'idiopathic' audiovestibular dysfunction. To enable early diagnosis, we recommend that the current available routine immunological laboratory tests (antinuclear, antineutrophil cytoplasmic, antiendothelial cell, antiphospholipid/anticardiolipin and antithyroid antibodies) are used when assessing a patient with suspected immune-mediated inner-ear disorder.

Screening for early childhood hearing loss in Nigeria

Newborn hearing screening has been recognized as an essential component of public health care in early childhood in developed countries. However, such screening is yet to be widely embraced in the developing world. The new national health policy in Nigeria seeks, for the first time, to reduce the impact of permanent hearing loss on early childhood development through early detection and timely intervention services. The aim of this paper is to ascertain if newborn hearing screening satisfies the conventional criteria for a screening programme as an early detection strategy in this developing country. A review of the available literature shows that permanent childhood hearing loss is a significant health condition and its detection through screening with oto-acoustic emissions and/or auditory brainstem response is feasible in the target population. Amplification with hearing aids is an effective and preferred option for early intervention by parents. The risk of maternal anxiety from potential false-positives or the psychological cost of false assurance from false-negatives is unlikely to outweigh the benefit of screening. Newborn hearing screening is therefore a potential early detection strategy for permanent childhood hearing loss in Nigeria.

Deficient auditory interhemispheric transfer in patients with PAX6 mutations

PAX6 mutations are associated with absence/hypoplasia of the anterior commissure and reduction in the callosal area in humans. Both of these structures contain auditory interhemispheric fibers. The aim of this study was to characterize central auditory function in patients with a PAX6 mutation. We conducted central auditory tests (dichotic speech, pattern, and gaps in noise tests) on eight subjects with a PAX6 mutation and eight age- and sex-matched controls. Brain magnetic resonance imaging showed absent/hypoplastic anterior commissure in six and a hypoplastic corpus callosum in three PAX6 subjects. The control group gave normal central auditory tests results. All the PAX6 subjects gave abnormal results in at least two tests that require interhemispheric transfer, and all but one gave normal results in a test not requiring interhemispheric transfer. The left ear scores in the dichotic speech tests was significantly lower in the PAX6 than in the control group. These results are consistent with deficient auditory interhemispheric transfer in patients with a PAX6 mutation, which may be attributable to structural and/or functional abnormalities of the anterior commisure and corpus callosum, although the exact contribution of these two formations to our findings remains unclear. Our unique findings broaden the possible functions of PAX6 to include neurodevelopmental roles in higher order auditory processing.

Infant hearing screening: route to informed choice

The decision to participate in infant screening often rests with parents. Medical ethics require that parental decision is elicited from informed choice. Such a decision is influenced by the parental knowledge and attitude towards screening and a careful evaluation of these factors is essential in seeking informed consent for infant hearing screening.

An unusual case of X-linked adrenoleukodystrophy with auditory processing difficulties as the first and sole clinical manifestation

X-linked adrenoleukodystrophy (X-ALD) is characterized by demyelination that is associated with a deficient beta-oxidation of very long chain fatty acids. We report the unusual case of a male adult with X-ALD who was diagnosed at the age of 26 by a brain MRI performed because his brother had been diagnosed with a rapidly deteriorating form of X-ALD. His sole symptom was hearing difficulties in the presence of a normal audiogram since childhood. He has remained stable for seven years. Central auditory testing in our patient revealed severe deficits in several auditory processes. These findings correlated with involvement of the auditory pathway at the level of the trapezoid body, and posterior corpus callosum in particular, on his brain MRI. This case highlights not only the need for thorough audiological investigation of the patient who complains of hearing difficulties in the presence of a normal audiogram, but also that audiological investigations could be of value in the phenotypic evaluation of cases with adrenoleukodystrophy.

Progressive auditory neuropathy in patients with Leber's hereditary optic neuropathy

OBJECTIVE

To investigate auditory neural involvement in patients with Leber's hereditary optic neuropathy (LHON).

METHODS

Auditory assessment was undertaken in two patients with LHON. One was a 45 year old woman with Harding disease (multiple-sclerosis-like illness and positive 11778mtDNA mutation) and mild auditory symptoms, whose auditory function was monitored over five years. The other was a 59 year old man with positive 11778mtDNA mutation, who presented with a long standing progressive bilateral hearing loss, moderate on one side and severe to profound on the other. Standard pure tone audiometry, tympanometry, stapedial reflex threshold measurements, stapedial reflex decay, otoacoustic emissions with olivo-cochlear suppression, auditory brain stem responses, and vestibular function tests were undertaken.

RESULTS

Both patients had good cochlear function, as judged by otoacoustic emissions (intact outer hair cells) and normal stapedial reflexes (intact inner hair cells). A brain stem lesion was excluded by negative findings on imaging, recordable stapedial reflex thresholds, and, in one of the patients, olivocochlear suppression of otoacoustic emissions. The deterioration of auditory function implied a progressive course in both cases. Vestibular function was unaffected.

CONCLUSIONS

The findings are consistent with auditory neuropathy-a lesion of the cochlear nerve presenting with abnormal auditory brain stem responses and with normal inner hair cells and the cochlear nucleus (lower brain stem). The association of auditory neuropathy, or any other auditory dysfunction, with LHON has not been recognised previously. Further studies are necessary to establish whether this is a consistent finding.

Benefits and challenges of newborn hearing screening for developing countries

The late detection of permanent congenital and early-onset hearing loss (PCEHL) often has severe effects on linguistic, speech, cognitive and educational development in affected children. Since newborn hearing screening (NHS) allows most PCEHL to be detected early enough for optimal intervention, the prospects of its introduction in the developing world are reviewed in this paper. It is observed that a simple generalisation on the feasibility of NHS for the developing countries seems inappropriate in view of the diversities in the health and socio-economic status of these countries and the recent favourable reports of universal newborn hearing screening from the region. NHS empowers parents to make timely choices that will allow their hearing impaired children to be given a good start in life and be fully integrated into the wider community. It also compels attention towards the development of essential hearing healthcare services, besides the specific documented benefits. Existing child-healthcare structures such as the expanded programme on immunisation (EPI), baby friendly hospital initiatives (BFHI) and integrated management of childhood illness (IMCI) provide opportunities for the introduction of some form of NHS in many of these countries where routine or systematic childhood hearing screening does not exist. Limited funding, manpower shortages, inadequate support services, low public awareness and the uncertainty regarding the commitment from healthcare practitioners may present some challenges but these are not insurmountable. Pilot studies are necessary in each country to provide empirical data that will guide healthcare providers who wish to introduce such a programme at any level of healthcare delivery.

Hearing loss in adult Refsum's disease

Refsum's disease is characterized by defective peroxisomal alpha oxidation of phytanic acid, with clinical features that include retinitis pigmentosa, polyneuropathy, anosmia and hearing loss. Although hearing loss in Refsum's disease is common, there are few detailed assessments of the site of the abnormality. We examined the audiometric findings in patients with biochemically diagnosed Refsum's disease in order to assess the site of origin of the hearing loss. We found hearing loss, ranging from mild, predominantly high frequency to moderate degree, in seven out of nine patients with biochemically diagnosed adult Refsum's disease. In addition, we found evidence to suggest subtle auditory nerve involvement in six out of the seven patients with hearing loss and in one out of the two patients with a normal pure tone audiogram, on the basis of the ABR test results. We conclude that patients with Refsum's disease who report hearing difficulties should have full audiometric investigations in order to provide appropriate audiological rehabilitation.

The insula (Island of Reil) and its role in auditory processing. Literature review

The insular cortex is a complex structure which contains areas that subserve visceral sensory, motor, vestibular, and somatosensory functions. The role of the insular cortex in auditory processing was poorly understood until recently. However, recent case studies indicate that bilateral damage to the insulae may result in total auditory agnosia. Functional imaging studies demonstrate that the insulae participate in several key auditory processes, such as allocating auditory attention and tuning in to novel auditory stimuli, temporal processing, phonological processing and visual-auditory integration. These studies do not clarify the issue of further specialisation within the insular cortex, e.g. whether the posterior insulae are primarily sensory areas, while the anterior insulae serve mainly as integration/association auditory areas, two hypotheses that would be compatible with the cytoarchitectonic structure and connectivity of the insulae. The functional characterisation of the insulae remains incomplete, underlining the need for further studies.

Neuro-otological findings in Pendred syndrome

Pendred syndrome is an autosomal recessive inherited disorder characterized by profound hearing impairment and inappropriate iodine release by the thyroid on perchlorate challenge. Thirty-three cases comprising members of 13 families and eight isolated cases were studied, with detailed audiological and vestibular investigation and computerized tomography. A uniform, profound, symmetrical sensorineural hearing loss was identified in all cases. Approximately one-third of the group reported progressive hearing impairment, in childhood or adolescence, associated with head injury, infection, or delayed secondary hydrops. Ninety per cent of the cases scanned showed dilated vestibular aqueducts, and all cases with progression of the hearing impairment demonstrated this structural abnormality. Approximately one-third of the cases had normal vestibular function, but a further third demonstrated a unilateral peripheral deficit, while the remaining third showed bilateral vestibular hypofunction. There was no intra-familial concordance of vestibular findings, and no correlation between vestibular abnormality and presence or absence of a dilated vestibular aqueduct, with or without a Mondini malformation. In older children and adults, Pendred syndrome was associated with a profound, symmetrical, sensorineural auditory impairment, and a variety of vestibular abnormalities, which are not uniform within families, or correlated with structural labyrinthine deformities.

Aetiology and clinical presentations of auditory processing disorders--a review

Auditory processing disorders may have detrimental consequences on a child's life, if undiagnosed and untreated. We review causes of auditory processing disorders in order to raise clinical awareness. Auditory processing disorders may present against a background of neurological disease or developmental disorders, as well as in isolation. Clinicians need to be aware of potential causes and implications of auditory processing disorders.

Labyrinthine involvement in Behçet's syndrome

We report the neuro-otological findings in 26 consecutive patients with definite and probable Behçet's syndrome unselected for audiovestibular complaints. Auditory and/or vestibular abnormalities were found in 19 (73 per cent) patients, with auditory involvement in 14 (54 per cent) and vestibular in 10 (38.5 per cent) of patients. Peripheral involvement was more common than central involvement for both auditory and vestibular lesions. Bilateral cochlear hearing impairment was the most common audiological finding, whereas unilateral peripheral dysfunction was the prevailing vestibular abnormality. No correlation has been found between audiovestibular lesions and other organ lesions, disease duration or age or sex of the patients. Moreover, there was a lack of interdependence between cochlear and vestibular labyrinthine lesions. We conclude that a full neuro-otological assessment in patients under investigation for Behçet's syndrome may reveal labyrinth involvement in a substantial proportion of patients. In view of the absence of a specific diagnostic test for Behçet's syndrome, audiovestibular lesions may provide further diagnostic support for this disorder.

Symptoms, disability and handicap in unilateral peripheral vestibular disorders. Effects of early presentation and initiation of balance exercises

The aim of this study was to obtain a profile of disability and handicap in patients with unilateral peripheral vestibular disorders presenting to a specialist tertiary care unit. Two validated questionnaires were sent to patients who had a unilateral peripheral vestibular disorder as defined by strict criteria. Some patients still suffered moderate handicap and disability 5 years after the initial symptoms related to a unilateral vestibular disorder, although the duration of symptoms (onset to questionnaire completion) did not correlate with severity of disability and handicap, as judged by questionnaire scores. However, patients presenting to the unit within 6 months of onset of vertigo commenced balance exercises significantly earlier and had significantly lower disability scores than patients presenting later. A high proportion of non-compliance with, and delay in initiation of, vestibular rehabilitation exercises was noted in the total patient sample, while compliance with, and early initiation of, Cooksey Cawthorne exercises were significantly correlated with low disability and questionnaire scores. These findings suggest that early referral to a specialist balance unit for patients with persistent dizziness is associated with better outcome.

The future of audiological rehabilitation

The field of audiological rehabilitation in adults faces an array of opportunities. Some of these are technological, as with the advent of fully digital hearing-aids, and some involve clinical practice, such as opportunities for true multidisciplinary working, and for changes in hearing-aid prescription and provision. The development of well-validated questionnaire instruments should facilitate robust research into the effectiveness of clinical interventions in adult audiological rehabilitation, for such evidence is urgently needed if the field is to thrive.