Dinsuhaimi Sidek

Outcome of a newborn hearing screening program in a tertiary hospital in Malaysia: the first five years.

Background and Objective : Universal newborn hearing screening (UNHS) was started in the Hospital Universiti Sains Malaysia (HUSM) in January 2003. To comply with international standards, we determined the outcome of the newborn hearing screening program for the first 5 years of its implementation, from January 2003 to December 2007. Methods : The program screened all infants who were delivered in HUSM. In a retrospective review, the outcomes in terms of coverage, prevalence of hearing impairment, referral rate for each screening, age at detection of hearing impairment and at hearing aid-fitting were analyzed. Results : Ninety-eight percent of newborns were screened. The study included 16 100 randomly selected newborns. The initial screening referral rate was 25.5%. The prevalence of default for second and third screening was 33.9% and 40.7%, respectively. The mean (SD) age at detection of hearing impairment was 3.3 months (0.86). The mean (SD) age at fitting of a hearing aid was 13.6 (4.8) months.The prevalence of hearing impairment was 0.09%. Conclusion : A newborn hearing screening program is an important tool for early diagnosis and treatment. Even though the prevalence of hearing impairment may be low, the problem needs to be addressed early as the development of infants requires normal hearing.

The performance of distortion product otoacoustic emissions and automated auditory brainstem response in the same ear of the babies in neonatal unit

OBJECTIVE To identify the outcomes of hearing screening using different protocols of both Distortion Product Otoacoustic Emissions (DPOAE) and Automated Auditory Brainstem Response (AABR) tests in the same ear of the babies in a neonatal unit population. METHODS A cross-sectional study was carried out on babies who were admitted into a neonatal unit. By using a formula of single proportion and considering 20% drop out, the number of sample required was 114. The subjects were chosen by using a systematic random sampling. The infants selected were subjected to DPOAE followed by AABR tests screening at the same setting before discharge. RESULTS There were 73 newborns (61.6% male and 38.4% female) participated in this study with a total of 146 ears screened. Ototoxic medication was the most common risk factor followed by hyperbilirubinaemia and low birth weight. AABR had higher passing rate (82.9%) as compared to DPOAE (77.4%). The highest passing rate was achieved if the protocol of either passed DPOAE or AABR was used (90.4%). The rate was lower when auditory neuropathy spectrum disorder (ANSD) has been considered (82.9%). Hyperbilirubinaemia, prematurity, craniofacial malformation and ototoxic drugs seem to be the high risk factors for auditory neuropathy. CONCLUSION AABR has a higher passing rate as compared to DPOAE. However, the use of both instruments in the screening process especially in NICU will be useful to determine the infants with ANSD who may need different approach to management. Therefore, a protocol in which newborns are tested with AABR first and then followed by DPOAE on those who fail the AABR is recommended.

Gender Disparities in Speech-evoked Auditory Brainstem Response in Healthy Adults: Any Relation to Head Size?

Objectives: Gender disparities in speech-evoked auditory brainstem response (speech-ABR) outcomes have been reported, but the literature is limited. The present study was performed to further verify this issue and determine the influence of head size on speech-ABR results between genders. Methods: Twenty-nine healthy Malaysian subjects (14 males and 15 females) aged 19 to 30 years participated in this study. After measuring the head circumference, speech-ABR was recorded by using synthesized syllable /da/ from the right ear of each participant. Speech-ABR peaks amplitudes, peaks latencies, and composite onset measures were computed and analyzed. Results: Significant gender disparities were noted in the transient component but not in the sustained component of speech-ABR. Statistically higher V/A amplitudes and less steeper V/A slopes were found in females. These gender differences were partially affected after controlling for the head size. Conclusions: Head size is not the main contributing factor for gender disparities in speech-ABR outcomes. Gender-specific normative data can be useful when recording speech-ABR for clinical purposes.

The Hyperactivity of Efferent Auditory System in Patients with Schizophrenia: A Transient Evoked Otoacoustic Emissions Study

Objective Electrophysiological studies, which are mostly focused on afferent pathway, have proven that auditory processing deficits exist in patients with schizophrenia. Nevertheless, reports on the suppressive effect of efferent auditory pathway on cochlear outer hair cells among schizophrenia patients are limited. The present, case-control, study examined the contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in patients with schizophrenia. Methods Participants were twenty-three healthy controls and sixteen schizophrenia patients with normal hearing, middle ear and cochlear outer hair cells function. Absolute non-linear and linear TEOAEs were measured in both ears by delivering clicks stimuli at 80 dB SPL and 60 dB SPL respectively. Subsequently, contralateral suppression was determined by subtracting the absolute TEOAEs response obtained at 60 dBpe SPL during the absence and presence of contralateral white noise delivered at 65 dB HL. No attention tasks were conducted during measurements. Results We found no significant difference in absolute TEOAEs responses at 80 dB SPL, in either diagnosis or ear groups (p>0.05). However, the overall contralateral suppression was significantly larger in schizophrenia patients (p<0.05). Specifically, patients with schizophrenia demonstrated significantly increased right ear contralateral suppression compared to healthy control (p<0.05). Conclusion The present findings suggest increased inhibitory effect of efferent auditory pathway especially on the right cochlear outer hair cells. Further studies to investigate increased suppressive effects are crucial to expand the current understanding of auditory hallucination mechanisms in schizophrenia patients.

Evaluation of auditory hallucinations in patients with schizophrenia: A validation study of the Malay version of Psychotic Symptom Rating Scales (PSYRATS)

The Psychotic Symptom Rating Scales (PSYRATS) is the most widely used validated scale to measure the specific symptoms of auditory hallucination and delusion. The aim of this study was to validate and to examine the psychometric properties of the auditory hallucination component of the Malay PSYRATS (MyPSYRATS). The research was done in the Universiti Kebangsaan Malaysia Medical Center (UKMMC) among 51 schizophrenia inpatients and outpatients who had experienced or reported verbal auditory hallucination. The psychometric properties of MyPSYRATS (auditory hallucination) were studied and a comparison was made between the psychometric properties obtained and the Positive and Negative Syndrome Scale (PANSS). The internal consistency of MyPSYRATS was good as revealed by Cronbachs alpha value. Factor analysis replicated three components (emotional, cognitive, and physical) similar to the factorial structure of the original auditory hallucination scale. However, two items were regrouped under the emotional component. Spearmans rank-order correlation showed a significant positive relationship between the total score of auditory hallucinations and PANSS auditory hallucinations item (P3). In conclusion, the auditory hallucination domain of MyPSYRATS is a reliable and valid assessment tool for further clinical applications.

Extensive dural sinus thrombosis and bilateral lateral rectus palsy as an uncommon complication of chronic suppurative otitis media

Dural venous sinus thrombosis, especially of the sigmoid sinus, is a known but uncommon intracranial extradural complication of chronic suppurative otitis media. Even rarer is the simultaneous occurrence of bilateral abducens palsy in the same patient. We report the case of an adolescent male who presented with signs of raised intracranial pressure, diplopia and bilateral lateral rectus palsy associated with a history of left ear discharge and neck swelling. Extensive dural sinus thrombosis extending right up to the left internal jugular vein was confirmed on CT imaging. The patient was successfully treated with thrombolytic agents and antibiotic therapy. The pathophysiology of the concurrent complications is discussed.

Listening to sentences in noise: Revealing binaural hearing challenges in patients with schizophrenia

Objective The present, case-control, study investigates binaural hearing performance in schizophrenia patients towards sentences presented in quiet and noise. Methods Participants were twenty-one healthy controls and sixteen schizophrenia patients with normal peripheral auditory functions. The binaural hearing was examined in four listening conditions by using the Malay version of hearing in noise test. The syntactically and semantically correct sentences were presented via headphones to the randomly selected subjects. In each condition, the adaptively obtained reception thresholds for speech (RTS) were used to determine RTS noise composite and spatial release from masking. Results Schizophrenia patients demonstrated significantly higher mean RTS value relative to healthy controls (p=0.018). The large effect size found in three listening conditions, i.e., in quiet (d=1.07), noise right (d=0.88) and noise composite (d=0.90) indicates statistically significant difference between the groups. However, noise front and noise left conditions show medium (d=0.61) and small (d=0.50) effect size respectively. No statistical difference between groups was noted in regards to spatial release from masking on right (p=0.305) and left (p=0.970) ear. Conclusion The present findings suggest an abnormal unilateral auditory processing in central auditory pathway in schizophrenia patients. Future studies to explore the role of binaural and spatial auditory processing were recommended.