Dalia Mohamed Hassan

Perception of temporally modified speech in auditory neuropathy.

Abstract Objective: Disrupted auditory nerve activity in auditory neuropathy (AN) significantly impairs the sequential processing of auditory information, resulting in poor speech perception. This study investigated the ability of AN subjects to perceive temporally modified consonant-vowel (CV) pairs and shed light on their phonological awareness skills. Design: Four Arabic CV pairs were selected: /ki/-/gi/, /to/-/do/, /si/-/sti/ and /so/-/zo/. The formant transitions in consonants and the pauses between CV pairs were prolonged. Rhyming, segmentation and blending skills were tested using words at a natural rate of speech and with prolongation of the speech stream. Study sample: Fourteen adult AN subjects were compared to a matched group of cochlear-impaired patients in their perception of acoustically processed speech. Results: The AN group distinguished the CV pairs at a low speech rate, in particular with modification of the consonant duration. Phonological awareness skills deteriorated in adult AN subjects but improved with prolongation of the speech inter-syllabic time interval. Conclusions: A rehabilitation program for AN should consider temporal modification of speech, training for auditory temporal processing and the use of devices with innovative signal processing schemes. Verbal modifications as well as visual imaging appear to be promising compensatory strategies for remediating the affected phonological processing skills. Sumario Objetivo: En la neuropatía auditiva (AN) la disrupción de la actividad del nervio auditivo impide significativamente el procesamiento secuencial de la información auditiva con la consecuente pobre percepción del habla. Este estudio investiga la habilidad de los sujetos con neuropatía auditiva para percibir pares temporalmente modificados de consonante vocal (CV) y nos da luz sobre sus habilidades en el reconocimiento fonológico. Diseño: Se seleccionaron cuatro pares de CV en árabe: /ki/-/gi/, /to/-/do/, /si/-/sti/ y /so/-/zo/. La transición de la formante en las consonantes y las pausas entre los pares de CV fueron prolongados. Se probaron las habilidades de rima, segmentación y combinación utilizando palabras a una tasa normal del habla y con prolongación del flujo del habla. Muestra: Se compararon catorce adultos con neuropatía auditiva con un grupo pareado en su percepción del habla acústicamente procesada, de pacientes con implante coclear. Resultados: El grupo de AN distinguió los pares CV a tasa de velocidad baja, en particular con modificaciones en la duración de las consonantes. Las habilidades de reconocimiento fonológico se deterioraron en los adultos con AN pero mejoraron con la prolongación del intervalo de tiempo inter-silábico. Conclusiones: Un programa de rehabilitación auditiva debe considerar las modificaciones temporales del lenguaje, el entrenamiento del procesamiento auditivo temporal y el uso de equipos con esquemas innovadores de procesamiento de la señal. Las modificaciones verbales así como las imágenes visuales parecen ser prometedoras estrategias compensatorias para remediar las afecciones en las habilidades del procesamiento fonológico.

Auditory- and Vestibular-Evoked Potentials Correlate with Motor and Non-Motor Features of Parkinson’s Disease

Degeneration of several brainstem nuclei has been long related to motor and non-motor symptoms (NMSs) of Parkinson’s disease (PD). Nevertheless, due to technical issues, there are only a few studies that correlate that association. Brainstem auditory-evoked potential (BAEP) and vestibular-evoked myogenic potential (VEMP) responses represent a valuable tool for brainstem assessment. Here, we investigated the abnormalities of BAEPs, ocular VEMPs (oVEMPs), and cervical VEMPs (cVEMPs) in patients with PD and its correlation to the motor and NMSs. Fifteen patients diagnosed as idiopathic PD were evaluated by Unified Parkinson’s Disease Rating Scale and its subscores, Hoehn and Yahr scale, Schwab and England scale, and Non-Motor Symptoms Scale. PD patients underwent pure-tone, speech audiometry, tympanometry, BAEP, oVEMPs, and cVEMPs, and compared to 15 age-matched control subjects. PD subjects showed abnormal BAEP wave morphology, prolonged absolute latencies of wave V and I–V interpeak latencies. Absent responses were the marked abnormality seen in oVEMP. Prolonged latencies with reduced amplitudes were seen in cVEMP responses. Rigidity and bradykinesia were correlated to the BAEP and cVEMP responses contralateral to the clinically more affected side. Contralateral and ipsilateral cVEMPs were significantly correlated to sleep (p = 0.03 and 0.001), perception (p = 0.03), memory/cognition (p = 0.025), and urinary scores (p = 0.03). The oVEMP responses showed significant correlations to cardiovascular (p = 0.01) and sexual dysfunctions (p = 0.013). PD is associated with BAEP and VEMP abnormalities that are correlated to the motor and some non-motor clinical characteristics. These abnormalities could be considered as potential electrophysiological biomarkers for brainstem dysfunction and its associated motor and non-motor features.

Speech-evoked auditory potentials in attention deficit hyperactivity disorder

Abstract Objective: To explore the processing of auditory information through auditory brainstem and higher cortical regions in a sample of children with attention deficit hyperactivity disorder (ADHD) of the combined inattention and hyperactivity subtype (ADHD/C) using auditory evoked potentials. Study Design: Fifteen Arabic speaking ADHD/C children were compared to 15 age-matched normal controls, aged between five and ten years. A Mini-International Neuropsychiatric Interview for Children and Adolescents (Arabic version) was performed to confirm the diagnosis, subtype of ADHD and to exclude comorbid conditions. All children were subjected to Auditory Brainstem Evoked Response (ABR) to click, speech ABR and cortical Mis-Match Negativity (MMN) to speech stimuli. Results: Thirty-three percent of the ADHD/C group showed prolongation of absolute and/or inter-peak wave latencies of the click ABR beyond two standard deviations. The peak latency of the onset waves for speech ABR was abnormal in 87% of the study group. Only three ADHD/C children gave normal MMN. Conclusion: This study demonstrated that abnormal auditory brainstem timing with reduced cortical functions was a characteristic in the studied ADHD/C children. Speech ABR can serve as a biological marker for brainstem neural asynchrony in children with ADHD/C. It might help to organize the highly heterogeneous population of ADHD into more homogeneous subgroups, at least on a particular biological indicator, specifically in individuals who cannot perform the behavioural measures. Further research is needed to determine whether individuals within these subgroups share a similar auditory perceptual profile.

Auditory brainstem evoked responses and vestibular evoked myogenic potentials: potential biomarkers in Parkinson's disease

Objective The aim of this study was to investigate brainstem functions in Parkinson’s disease (PD) through studying auditory brainstem evoked responses (ABRs), and ocular and cervical vestibular evoked myogenic potentials (oVEMP and cVEMP) and to explore their relation with motor symptoms, if any. Study design Fifteen individuals diagnosed as having idiopathic PD and 15 age-matched controls were included. The PD patients were evaluated using the Unified Parkinson’s Disease Rating Scale, the Hoehn and Yahr Scale, and the Schwab and England Scale. The subscores of major symptom were calculated, such as tremor, rigidity, bradykinesia, and axial signs. During medication ‘on’ states, PD patients and controls underwent pure-tone audiometry, speech audiometry, tympanometry, ABR, oVEMP, and cVEMP. The test findings in PD patients were grouped into ipsilateral and contralateral results in relation to the clinically more affected motor side and were compared with the age-matched controls. Results PD patients showed abnormal ABR wave morphology, prolonged absolute latencies of ABR wave V, and I–V interpeak latencies. Absent responses were the evident abnormality seen in oVEMP. Prolonged latencies with reduced amplitudes were seen in cVEMP responses. The main motor features of PD (rigidity and bradykinesia) were correlated to the ABR and cVEMP responses contralateral to the clinically more affected side. Conclusion Dysfunction at different levels of the brainstem was confirmed in patients with PD. The impairment of ABRs and VEMP responses is related to characteristic clinical asymmetry of PD and its cardinal motor features. ABRs and VEMPs could be used as potential electrophysiological biomarkers for PD.

Evaluation of non-linear frequency compression hearing aids using speech P1-cortical auditory evoked potential

Objective: To investigate the potential effects of frequency lowering technology on outcome measures of hearing aid efficacy. The detection of mid- and high-frequency syllables in children with sensorineural hearing loss (SNHL) fitted with non-linear frequency compression (NLFC) hearing aids was studied using speech P1 cortical auditory evoked potentials (CAEP). Study design: Thirty Arabic speaking children with bilateral high frequency SNH and with a history of regular binaural hearing aid use were included. All children were fitted with binaural Phonak Naida III UP with a NLFC feature. Verification of NLFC was achieved through aided sound field testing and aided speech P1-CAEP recordings. Aided P1-CAEPs were elicited using synthetic speech stimuli ‘da’ and ‘ga’. Fifteen age-matched normal hearing children served as a control group to provide a reference of typically maturing CAEPs without the influence of hearing impairment. Results: NLFC improved aided thresholds in the mid and high frequencies. No statistically significant difference existed between the control and study group in their CAEP responses to the ‘ga’ stimulus in both NLFC-disabled/enabled conditions. The ‘da’ stimulus elicited P1-CAEP in only 27% of the study group with the NLFC disabled condition; this increased to 83% with activation of NLFC. The P1-CAEP latency of the study group was prolonged compared to children of the control group for both stimuli. The presence of P1-CAEP to both ‘ga’ and ‘da’ stimuli was significantly negatively correlated with the age of the child, duration of hearing loss, and duration of hearing aid use. Conclusion: The NLFC significantly improved the audibility of high frequency sounds for children with severe high frequency SNHL. Speech P1-CAEP can be used as an objective validation tool in children to evaluate the benefit from NLFC especially when behavioural aided thresholds are difficult to obtain.

Intratympanic dexamethasone injection in Meniere's disease

Aim The aim of the study was to investigate the role of intratympanic (IT) dexamethasone in the treatment of medically refractory Meniere′s disease (MD) using two different concentrations. Patients and methods Twenty-four adults with unilateral MD received a single IT injection of dexamethasone at 4 or 10 mg/ml concentration. Partial or no improvement over the next 1 month following injection necessitated a second injection. Before and after injection, all patients underwent detailed history taking, were evaluated with the Dizziness Handicap Inventory scale, and underwent basic audiological evaluation and assessment of cervical-vestibular evoked myogenic potential. The presence or absence of spontaneous, post-head-shaking, and positional nystagmus was assessed using a video-nystagmography system. Twelve patients served as the control group and were followed up subjectively for 1 month. Results Both 4 and 10 mg/ml IT dexamethasone improved all subjective symptoms and pure-tone audiometry thresholds. The cervical-vestibular evoked myogenic potential asymmetry ratio dropped after injection. However, the 10 mg/ml concentration was superior to the 5 mg/ml concentration in improving the signs of disease activity, Dizziness Handicap Inventory scores, and the duration of vertigo attacks. No change was reported by the controls. Conclusion IT dexamethasone injection might be helpful in controlling MD in some patients. The 10 mg/ml dexamethasone concentration controls vertigo at both the subjective and objective level. Especially if used early in the course of the disease

Single monotic auditory steady-state response in children with severe to profound sensorineural hearing loss

Aim The aim of the study was to find out the predictive value of single monotic auditory steady-state response (ASSR) in hearing threshold estimation in children with severe to profound sensorineural hearing loss (SNHL). Materials and methods Forty-eight children (96 ears) with severe to profound SNHL were included. They were subjected to age-based audiological evaluation. Single monotic ASSR was obtained and analyzed for all children using test signals of 250, 500, 1000, 2000, and 4000 Hz, modulated in either ears at high rates of 67, 74, 81, 88, and 95 Hz, respectively, using GSI Audera evoked potential system. Results The number and percentage of ASSR detected were highest at 1000, 500, and 2000 Hz, respectively in all children. The ASSR thresholds obtained were statistically correlated with the behavioral audiometric thresholds at the corresponding frequencies. A considerable number of ears with no sound field thresholds or click auditory brainstem response responses showed ASSR. Conclusion Single monotic ASSR, with high modulation frequencies, has shown to be a reasonable method for estimating hearing sensitivity in the mid-conventional audiometric frequencies in children with severe to profound SNHL.

Auditory steady-state response audiometry in children with severe to profound sensorineural hearing loss

Objective The aim of the study was to find out the predictive value of single monotic auditory steady-state response (ASSR) for hearing threshold estimation in children with severe to profound sensorineural hearing loss (SNHL). Methodology Forty-eight children (96 ears) with severe to profound SNHL were included in the present study, with age range 1-10 years. They were subjected to age-based audiological evaluation to estimate the behavioral thresholds. Single monotic ASSR was performed for all children using test signals of 250, 500, 1000, 2000, and 4000 Hz, modulated in both ears at high rates of 67, 74, 81, 88, and 95 Hz, respectively, using GSI Audera-evoked potential system. ASSR thresholds were obtained and analyzed according to the equipment default criteria. Results The number and percentage of ASSR detected were highest at 1000 Hz then 500 Hz followed by 2000 Hz and were the least at 4000 and 250 Hz in all children. The ASSR thresholds obtained were statistically correlated with the behavioral pure tone audiometry thresholds at 500, 100, and 2000 Hz. A considerable number of ears with no sound field thresholds or click auditory brainstem response responses showed ASSR. Conclusion Single monotic ASSR, with high modulation frequencies, has proven to be a reasonable method for estimating hearing sensitivity in the mid-conventional audiometric frequencies in children with severe to profound SNHL. Recommendations All children with no behavioral hearing threshold and/or absent click-evoked auditory brainstem response should be tested by ASSR at 500, 1000, and 2000 Hz to give information about the presence of useful residual hearing. ASSR can provide important information for use in the cochlear implant selection process