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.

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.

Otoscopic Changes Before and After Shooting Amongst Military Army Personnel

The effect of loud noise to the army personnel is often identifi ed when hearing loss had already developed. Acoustic trauma during shooting training can also lead to acute changes in the ear which is shown on otoscopic examination. This study was undertaken to determine the effectiveness of hearing protective device (earplug) on the prevalence of external ear changes amongst military personnel during shooting. This is a prospective cross sectional study that was conducted among 76 military personnel, who were divided into two groups: those with and without earplugs during shooting. Each participant underwent 3 otoscopic examinations: (a) pre-shooting, (b) immediate post-shooting (within 48 hours) and (c) 2 weeks after shooting. A total of 78 army personnel who were scheduled to undergo shooting training were otoscopically examined. Eighty three percent of them did not wear earplugs before. The percentage of infl ammation of external auditory canal and tympanic membrane dullness increased tremendously among subjects from non–earplug group less than 48 hours post-shooting. Assessment after 2 weeks showed improvement in around 30% of the subjects. Loud noise has become an occupational hazard not only to the inner ear but it also predisposes the external and middle ear structures to some form of injury. Although improvement is seen after some period, a protective device such as an earplug should be recommended and the usage should be reinforced among the army personnel involved in shooting.

Clinical use of Malay Version of Vertigo Symptom Scale (MVVSS) in Patients with Peripheral Vestibular Disorder (PVD)

Introduction:The Vertigo symptom scale (VSS) is a well established tool for the evaluation of vestibular disorders and the associated symptoms of autonomic arousal and somatosensation. By using a validated Malay version of vertigo symptom scale (MVVSS) questionnaire, the severity of the vertigo from patients’ perspective can be determined and rated. Before MVVSS can be applied clinically among Malaysians, it was of interest to determine its clinical value in identifying vestibular disorders. Method: Forty normal and 65 PVD subjects participated in this cross-sectional study. Normal subjects were recruited amongst Universiti Sains Malaysia (USM) staff and students who had no history of ear and vestibular disorders. Results: Mean total score of MVVSS in normal and PVD subjects were 13.9 ± 11.1 and 30.1 ± 20.9, respectively. When the total scores of normal and PVD group were compared, the Mann-Whitney U test showed that there was a significant difference between the two groups (p<0.05). This is consistent with previous studies. It was also of interest to see if subtypes of PVD [benign paroxymal positional vertigo (BPPV), Meniere’s disease, labyrinthitis and unknown] have different MVVSS results. However, analysis of variance (ANOVA) found no significant difference in term of outcomes of MVVSS among the different PVD pathologies. Using receiver operating characteristic curve (ROC) method, the sensitivity and specificity of MVVSS were 71% and 60%, respectively. Conclusion: MVVSS is able to discriminate clinically among the normal and PVD subjects. However, it is not a good indicator for differential diagnosis of PVD subtypes, at least in this study. Its sensitivity and specificity in clinical diagnosis are reasonably high. Perhaps a bigger sample size would be useful to further study the clinical usefulness of MVVSS.

Assessment of 3-D nasal airway morphology in Southeast Asian adults with obstructive sleep apnea using acoustic rhinometry.

The aim of the present study is to investigate nasal airway morphology in Asian adults with and without obstructive sleep apnea (OSA) using acoustic rhinometry (AR), principal components analysis (PCA), and 3-D finite-element analysis (FEA). One hundred eight adult Malays aged 18-65 years (mean ± SD, 33.2 ± 13.31) underwent clinical examination and limited channel polysomnography, providing 54 patients with OSA and 54 non-OSA controls. The mean minimal cross section area 1 (MCA1) and the mean minimal cross sectional area 2 (MCA2) were obtained from AR for all subjects and subjected to t tests. The OSA and control nasal airways were reconstructed in 3-D and subjected to PCA and FEA. The mean MCA1 and MCA2 using AR were found to be significantly smaller in the OSA group than in the control group (p < 0.001). Comparing the 3-D OSA and control nasal airways using PCA, the first two eigenvalues accounted for 94% of the total shape change, and statistical differences were found (p < 0.05). Similarly, comparing the nasal airways using FEA, the 3-D mean OSA nasal airway was significantly narrower in the OSA group compared to the control group. Specifically, decreases in size of approx. 10-22% were found in the nasal valve/head of inferior turbinate area. In conclusion, differences in nasal airway morphology are present when comparing patients with OSA to controls. These differences need to be recognized as they can improve our understanding of the etiological basis of obstructive sleep apnea and facilitate its subsequent management.

Facial profile shape, malocclusion and palatal morphology in Malay obstructive sleep apnea patients.

OBJECTIVE: To test the null hypothesis that there is no difference in facial profile shape, malocclusion class, or palatal morphology in Malay adults with and without obstructive sleep apnea (OSA). MATERIALS AND METHODS: Subjects were 120 adult Malays aged 18 to 65 years (mean +/- standard deviation [SD], 33.2 +/- 13.31) divided into two groups of 60. Both groups underwent clinical examination and limited channel polysomnography (PSG). The mean OSA and control values were subjected to t-test and the chi square test. RESULTS: Physical examination showed that 61.7% of the OSA patients were obese, and 41.7% of those obese patients had severe OSA. The mean body mass index (BMI) was significantly greater for the OSA group (33.2 kg/m2 +/- 6.5) than for the control group (22.7 kg/m2 +/- 3.5; P < .001). The mean neck size and systolic blood pressure were greater for the OSA group (43.6 cm +/- 6.02; 129.1 mm Hg +/- 17.55) than for the control group (35.6 cm +/- 3.52; 114.1 mm Hg +/- 13.67; P < .001). Clinical examination showed that the most frequent findings among OSA groups when compared with the control group were convex profiles (71.7%), Class II malocclusion (51.7%), and V palatal shape (53.3%), respectively; the chi square test revealed a significant difference in terms of facial profile and malocclusion class (P < .05), but no significant difference in palatal shape was found. CONCLUSION: The null hypothesis is rejected. A convex facial profile and Class II malocclusion were significantly more common in the OSA group. The V palatal shape was a frequent finding in the OSA group.

Craniofacial obesity in patients with obstructive sleep apnea.

INTRODUCTION: Obstructive sleep apnea (OSA) and obesity are serious, widespread public health issues. OBJECTIVE: To localize and quantify geometric morphometric differences in facial soft tissue morphology in adults with and without OSA. MATERIALS AND METHODS: Eighty adult Malays, consisting of 40 patients with OSA and 40 non-OSA controls, were studied. Both groups were evaluated by the attending physician and through ambulatory sleep studies. 3-D stereophotogrammetry was used to capture facial soft tissues of both groups. The 3-D mean OSA and control facial configurations were computed and subjected to principal components analysis (PCA) and finite-element morphometry (FEM). RESULTS: The body mass index was significantly greater for the OSA group (32.3 kg/m(2) compared to 24.8 kg/m(2), p < 0.001). The neck circumference was greater for the OSA group (42.7 cm compared to 37.1 cm, p < 0.001). Using PCA, significant differences were found in facial shape between the two groups using the first two principal components, which accounted for 50% of the total shape change (p < 0.05). Using FEM, these differences were localized in the bucco-submandibular regions of the face predominantly, indicating an increase in volume of 7-22% (p < 0.05) for the OSA group. CONCLUSION: Craniofacial obesity in the bucco-submandibular regions is associated with OSA and may provide valuable screening information for the identification of patients with undiagnosed OSA.

Cranial base and airway morphology in adult malays with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea (OSA) has been described as a public health problem comparable to smoking in its impacts upon society. OBJECTIVE: To compare the differences in cranial base and airway morphology in Malay adults with and without OSA using finite element analysis (FEM). METHOD: Lateral skull radiographs of 38 adult Malays aged 18-60 years were divided into two groups of 19 (13 male, 6 female). The first group consisted of 19 patients with OSA, defined as an apnoea-hypopnea index > 5/hr of sleep, diagnosed with overnight polysomnography. The second group consisted of 19 healthy, non-OSA control subjects. For each lateral skull radiograph 27 homologous landmarks, which encompassed the naso-oropharyngeal airway, were digitised using MorphoStudio software. The mean OSA and control 2D airway configurations were computed and subjected to t-tests and FEM. RESULTS: The mean 2D OSA airway was statistically different from the mean control airway (p < 0.01). Inter-landmark analysis revealed that the cranial base saddle angle was more acute in the OSA group (153.9 degrees +/- 3.4) compared to the control group (158.3 degrees +/- 2.5; p < 0.01). In addition, using pseudo-coloured FEM a relative 58 per cent decrease in nasopharyngeal airway area was found above and behind the soft palate. As well, a 32 per cent decrease in oropharyngeal airway area was located behind the base of the tongue, with a 23 per cent decrease in hypopharyngeal area near the level of the hyoid bone. In contrast, a 96 per cent increase in area associated with downward displacement of the hyoid bone was detected. CONCLUSION: Functional airway impairments associated with OSA can be quantified and localised in Malay patients, and are predominantly associated with the morphology of the posterior regions of the cranial base.

Clinical and audiological profiles in children with chronic otitis media with effusion requiring surgical intervention

To determine the characteristic presenting symptoms, otoscopic findings, audiological profiles and the intraoperative findings of children with chronic otitis media with effusion who required surgical intervention. A prospective cross sectional study was undertaken in the otorhinolaryngology clinic of USM Hospital (HUSM) involving 25 cases (50 ears) of children with chronic otitis media with effusion requiring surgical intervention from June 1999 to September 2001. Their ages ranged from 3 to 12 years old. The gender distribution included males at 72 % and females at 28 %. The presenting symptoms noted were hearing impairment (52%), otalgia (18%), ear block (16%) and tinnitus (14%). The otoscopic findings were fluid in the middle ear (40%), dullness (32%) and retraction of the tympanic membrane (28%). On audiometry, 24 ears had moderate deafness (48%), 16 ears had mild deafness (32%) while 4 ears had severe deafness (8%). With tympanometry, 42 ears out of the total 50 had a flat type B curve (84%) while 6 ears had type As curve (12%). During myringotomy, middle ear secretion was seen in 38 ears (76%) out of the 50 ears; 22 ears had mucoid secretion while 16 ears had serous secretion. Clinically, the commonest presenting symptom was hearing impairment (52%) while the most common otoscopic finding was fluid in the middle ear (40%). Audiologically, most patients had moderate conductive hearing loss (48%) and a type B curve (84%) on tympanometry. On myringotomy middle ear fluid was found in 76 % of the ears.