Prevalence and Auditory Characteristics of Auditory Neuropathy Spectrum Disorder in Adult Population with Sensory Neural Hearing Loss: A Hospital Based Study in South India.

Auditory neuropathy spectrum disorder (ANSD) is a heterogenous group of disorder characterized by abnormalities in auditory brainstem responses (ABR) with preserved otoacoustic emissions and/or cochlear microphonics. The aim of the study is to estimate the prevalence and evaluate the audiological characteristics of ANSD in adult population with sensory neural hearing loss. A prospective study was conducted on the adult population (≥ 18 years) attending ENT outpatients clinic at Rajiv Gandhi Government General Hospital, Chennai. All patients reported to the department with auditory and vestibular symptoms underwent case history, otoscopic examination, and routine audiological evaluation (pure tone audiometry, speech audiometry and immittance audiometry). Patients with indications of ANSD in case history and routine audiological evaluation were further evaluated using distortion product otoacoustic emissions and ABR. A total of 8682 adult population was evaluated during the period of 2017 to 2018. Out of 8682 patients, 1343 (15.46%) of them had sensory neural hearing loss of varying degrees. Out of 1343 adults with sensory neural hearing loss, 24 (1.78%) adults were diagnosed as ANSD. The prevalence of ANSD in adult population with sensory neural hearing loss in our study is 1.32% per 1000 adults. The clinical characteristics of ANSD shows impairment in speech perception irrespective of degree of hearing loss, preserved cochlear functions and abnormal ABR. Hence ANSD is not a rare clinical finding in adults with sensory neural hearing loss, but its prevalence was estimated to be lower in Indian population. Often young females are affected causing significant impairment in speech perception and disability.

Involvement of Incomplete Hippocampal Inversion in Intractable Epilepsy: Evidence from Neuropsychological Studies.

BACKGROUND: The age of onset of seizure, seizure types, frequency of seizure, structural abnormalities in the brain, and antiepileptic medication (polytherapy) causes increased incidence of anxiety and depression in intractable epilepsy patients. AIM: To compare the anxiety and depression levels in intractable epileptic patients with structural abnormalities [malformations of cortical development (MCD) and incomplete hippocampal inversion (IHI)] and without structural abnormalities. MATERIALS AND METHODS: Participants were selected from (239 males and 171 females) intractable epilepsy patients. They were grouped into four groups; Group 1: 51 nonepileptic age-matched controls, Group 2: 41 intractable epilepsy patients without any brain abnormality, Group 3: 17 intractable epilepsy patients with MCD, and Group 4: 30 intractable epilepsy patients with isolated IHI. Neuropsychiatric tools used were Multiphasic Personality Questionnaire and Weschlers Adult Intelligence Scale to assess anxiety, depression, and intelligence. Groups were classified using 1.5T conventional magnetic resonance imaging and hippocampal volumetric studies. Group comparison design was used. RESULTS: Demographic variables of intractable epilepsy, including seizure types, the frequency of seizure, the age of seizure onset, and antiepileptic drug therapies, did not show significant association between the groups using Chi-square P value. Analysis of variance showed significant anxiety and depression in epileptic patients than the control group (P < 0.01). Post hoc analysis using Tukey's B test showed significant difference in anxiety and depression scores between group value. In group 3 and 4, anxiety scores were significantly different but not depression scores. CONCLUSION: The present study concludes high prevalence of anxiety and depression in intractable seizure. Anxiety is observed predominantly when there is IHI along with depression. We emphasize the need to identify IHI in intractable epilepsy and assess anxiety and depression to treat them effectively.

Clinical Experience on Hearing Screening in Twins and Triplets: A Retrospective Study.

Twin or multiple pregnancies often have neonatal complications. Common complications include low birth weight, respiratory distress, neonatal intensive care unit (NICU) admission (>5 days) and low APGAR score especially on second twin. (1) To compare referral rates of newborn hearing screening in twins and triplets between risk and non-risk babies for hearing loss, (2) to determine the effects of birth order on referral rates in twins and triplets. A retrospective study was carried out from the case records of the neonates enrolled in the referral based NICU hearing screening program during April 2013 to December 2014 at Institute of Obstetrics and Gynecology, Chennai. 1405 neonates (723 males and 682 females) in the age range of 3-28 days were screened during this period among which 76 were twins (38 pairs) and 9 were triplets (3 sets). We classified them further into non risk and risk babies among twins according to the Joint Committee for Infant Hearing (JCIH) recommendations. A dual step hearing screening protocol was used to screen the neonates. They were initially tested with distortion product otoacoustic emission (DPOAE) then with automated auditory brainstem response (AABR) before discharged from the hospital. Out of 76 (100%) twin babies 43 (56.58%) babies had one or more risk factors for hearing loss. Most common risk factors were low birth weight, premature birth, mechanical ventilation >5 days, hyperbilirubinemia, infections, ototoxic medications and family history of hearing loss. Each risk factor was observed in equal proportion in 1st born and 2nd born twins. 12 (15.76%) risk babies and 11 (14.47%) non risk babies failed in DPOAE testing. Out of 9 triplets babies (3 set) 3 babies had risk factors for hearing loss. One baby in 2nd born babies group failed AABR screening. Referral rates were slightly higher in 2nd born twins when compared to 1st born twins in DPOAE testing. Chi square test did not reveal any significant association between referral rates with risk factors and birth order (p > 0.05). The referral rates in twins are higher than the total population screened. There is some influence of birth order on the referral rates in twins. It needs to be further investigated on larger population.

Vestibular Evoked Myogenic Potentials After Epleys Manoeuvre Among Individuals with Benign Paroxysmal Positional Vertigo.

VEMP abnormalities in individuals with BPPV are often reported to be associated with utricle and saccule degeneration. The aim of the present study is to assess the frequency of VEMP abnormalities using vestibular evoked myogenic potentials in individuals with Posterior canal Benign Paroxysmal Positional Vertigo (BPPV) after Epley's manoeuvre. 36 individuals (36 ears) with definite posterior canal BPPV and 36 healthy controls were considered for the present study. All the them underwent otoscopic examination, Dix-Hallpike manoeuvre to diagnose posterior canal BPPV. Further Audiological Evaluation including pure tone audiometry was carried out to rule out vestibular disorders associated with hearing loss. Epley's manoeuvre was performed on all individuals with BPPV by an experienced otorhinolaryngologist. Cervical and Ocular Vestibular Evoked Myogenic Potentials (VEMP) were used to investigate the saccule and utricle functions following Epley's manoeuvre. Cervical VEMP and ocular VEMP abnormalities were observed in 8/36 (22.22%) and 18/36 (50%) affected ears with BPPV respectively. Cervical VEMP responses were reduced in amplitude among 1/36 (2.77%) and absent in 7/36 (19.44%) of affected ears with BPPV. Ocular VEMP responses were reduced in amplitude on 11/36 (30.55%), followed by absent responses in 5/36 (13.88%) ears with BPPV. Two patients with posterior canal BPPV i.e., 4/64 (5.55%) ears had bilateral absence of ocular VEMP responses. Two ears with BPPV 2/36 (5.55%) had absence of both cervical and ocular VEMP responses in BPPV affected ear. T test showed significant difference (p < 0.01) in the amplitude of ocular VEMP among posterior canal BPPV individuals when compared to cervical VEMP. The present study highlights individuals with Posterior canal BPPV may have otoconia dislodgement or macular degeneration of utricle, saccule, both utricle and saccule unilaterally, or bilaterally. VEMP may be useful in evaluating degeneration of both otolith organs associated with BPPV.

Prevalence and clinical characteristics of malformations of cortical development and incomplete hippocampal inversion with medically intractable seizures in Chennai - A prospective study.

OBJECTIVE: To study the prevalence and clinical characteristics of malformation of cortical development (MCD) and incomplete hippocampal inversion (IHI) in adults with intractable seizures. MATERIALS AND METHODS: In this prospective study of 3220 epileptic patients in our epilepsy clinic between 2012 and 2014, 416 had intractable seizures. In all patients, a detailed clinical history, neurological examination, electroencephalography (EEG), computed tomography (CT) scan, magnetic resonance imaging (MRI) brain, and neuropsychological assessment was conducted to identify MCD and IHI. RESULTS: Out of 416 patients with intractable seizures, MCD and IHI were confirmed in 85 patients (48 males, 37 females). MCD was observed in 46 (11.05%) patients and IHI were observed in 39 (9.37%) patients. Chi square test revealed no signi cant difference between the MCD and IHI groups across the patients in different age groups, gender, type of seizure, duration and onset of seizure, seizure frequency, clustering, status epilepticus, EEG, febrile seizures, and family history. Statistically significant differences (P < 0.05) were observed between the MCD and IHI groups for change in seizure semiology and in intelligence quotient (IQ) and memory quotient (MQ) scores obtained using Wechsler's adult intelligence scale III and Wechsler's memory scale. The IHI group showed higher IQ and MQ scores when compared to the MCD group. Furthermore, IHI occurred along with MCD in 6.52% (N = 3) of the population. CONCLUSION: MCD and IHI patients are often associated with intractable complex partial seizures. Intractable epilepsy patients with normal intelligence and normal MRI should be investigated with hippocampal volumetric studies to identify the presence of IHI. Isolated IHI can be considered as a form of MCD because it mimics the clinical features of MCDs.

Development of Improved Software Intelligent System for Audiological Solutions.

Of late, there has been an increase in hearing impairment cases and to provide the most advantageous solutions to them is an uphill task for audiologists. Significant difficulty faced by the audiologists is in effective programming of hearing aids to provide enhanced satisfaction to the users. The main aim of our study was to develop a software intelligent system (SIS): (i) to perform the required audiological investigations for finding the degree and type of hearing loss, and (ii) to suggest appropriate values of hearing aid parameters for enhancing the speech intelligibility and the satisfaction level among the hearing aid users. In this paper, we present a Neuro-Fuzzy based SIS to automatically predict and suggest the hearing-aid parameters such as gain values, compression ratio and threshold knee point, which are needed to be fixed for different octave frequencies of sound inputs during the hearing-aid trial. The test signals for audiological investigations are generated through the standard hardware present in a personal computer system and with the aid of a software algorithm. The proposed system was validated with 243 subjects' data collected at the Government General Hospital, Chennai, India. The calculated sensitivity, specificity and accuracy of the proposed audiometer incorporated in the SIS were 98.6%, 96.4 and 98.2%, respectively, by comparing its interpretations with those of the 'gold standard' audiometers. Furthermore, 91% (221 of 243) of the hearing impaired subjects attained satisfaction in the first hearing aid trials itself with the gain values as recommended by the improved SIS. The proposed system reduced around 75% of the 'trial and error' time spent by audiologists for enhancing satisfactory usage of the hearing aid. Hence, the proposed SIS could be used to find the degree and type of hearing loss and to recommend hearing aid parameters to provide optimal solutions to the hearing aid users.

Prevalence and Audiological Characteristics of Auditory Neuropathy Spectrum Disorder in Pediatric Population: A Retrospective Study.

Auditory neuropathy spectrum disorder (ANSD) is a type of hearing disorder which is challenging for assessment and rehabilitation. This disorder has been studied over a decade and prevalence of the disorder is variable. The study aimed at estimating the prevalence and audiological characteristics of ANSD in children. A retrospective study was conducted from the medical records of pediatric patients evaluated at Rajiv Gandhi Government General Hospital and Madras Medical College, Chennai to estimate the prevalence of ANSD. Medical records of 2,624 children evaluated during the period of November 2010 to October 2012 within the age range of 6 months to 12 years were analyzed. Out of 2,624 pediatric population assessed 217 (8.26 %) of them had unilateral or bilateral sensory neural hearing loss with varying degrees. Out of 217 children with sensory neural hearing loss 5.06 % (N = 11) had ANSD. Audiological characteristics varied among the group. Children with ANSD had varied degree of hearing thresholds from normal to profound hearing impairment. All of them had 'A' type tympanogram with absent stapedial reflexes. DPOAEs or TEOAEs were observed in 54 % of population with ANSD. All of them had abnormal auditory brainstem responses (ABR). Replicable cochlear microphonics was observed in 46 % of children with ANSD. These results indicate that ANSD is not a rare condition among children and we emphasize the use of objective tests like tympanometry, Stapedial Reflex test, otoacoustic emissions and ABR in routine hearing assessment procedure for all children to identify ANSD.

Identifying Early Onset of Hearing Loss in Young Adults With Diabetes Mellitus Type 2 Using High Frequency Audiometry.

Diabetes mellitus (DM) is a metabolic disorder caused by hyperglycemia which leads to dysfunction of various organs. Hearing acuity is equally hindered by this disorder. Among individuals with DM audiological characteristics of DM type 1 are of great concern in the literature. This study aims at establishing high frequency audiometry (HFA) as a useful tool in identifying early onset of hearing loss in individuals with DM type 2. 20 non-diabetic participants and 20 individuals with DM type 2 in the age range of 20-40 years were considered for the study. Subjects in both groups underwent otoscopic examination, PTA at 0.25, 0.5, 1, 2, 4 and 8 kHz and HFA at 9, 10, 11.2, 12.5, 14 and 16 kHz. Results revealed statistically significant difference in thresholds of both PTA and HFA at all frequencies across the group, but the mean threshold difference between the diabetic and non-diabetic group was marked in HFA than in PTA. In the diabetic subjects the thresholds of PTA was within 25 dBHL at all frequencies when compared to the thresholds of HFA. Individuals with DM type 2 showed bilateral symmetrical mild hearing loss in HFA and the hearing loss increased with ascending test frequencies from 9,000 to 16,000 Hz. Mild hearing loss in HFA is an indicator for early onset of hearing loss in DM type 2. Hence this present study emphasis the clinical utility of HFA in young adults with DM type 2.

Prevalence and referral rates in neonatal hearing screening program using two step hearing screening protocol in Chennai - A prospective study.

OBJECTIVE: To estimate the prevalence and referral rates in well born and high risk babies using two step hearing screening protocol with Distortion Product Otoacoustic Emissions (DPOAE) and Automated Auditory Brainstem Response (AABR). METHOD: A prospective study was carried out on 1405 neonates (983 well born babies and 422 high risk babies) who were screened during May 2013 to January 2015 at Institute of Obstetrics and Gynecology, Madras Medical College, Chennai. All neonates were screened using two step screening protocol. They were initially tested with DPOAE. Referred babies in DPOAE were screened with AABR subsequently. RESULTS: Among 1405 (100%) neonates 983 (69.96%) were well born babies and 422 (30.03%) were high risk babies. Total referral rate in DPOAE was found to be 311 (22.13%) among which 195 (13.87%) were well born babies and 116 (8.25%) were high risk babies. Out of 311 babies 31 (2.20%) babies were referred in AABR screening. In 31 babies referred in AABR 11(0.78%) were from well born group and 20 (1.42%) were from the high risk group. Further diagnostic evaluation of these babies, 2 (0.14%) were confirmed to have hearing loss. This study reveals, the prevalence of congenital hearing loss in our population is 1.42 per 1000 babies. CONCLUSION: Using two step protocol especially AABR along with DPOAE at the initial level of testing significantly reduces referral rates in new born screening programs. Also AABR decreases the false positive responses hence increasing the efficiency of screening program.