III-V Interpeak Latencies Research Articles

Auditory brainstem response findings in autism spectrum disorder speech delay population

ObjectivesEvaluate pediatric auditory brainstem response (ABR) findings in children with Autism Spectrum Disorder (ASD) after the 2013 DSM-5 update. Study designThis was an IRB-approved, six-year retrospective chart review evaluating ABR results from pediatric patients with speech delay. Diagnosis of ASD and other neurodevelopmental abnormalities were collected for patient stratification. MethodsFrom 2017 to 2023, 148 pediatric patients with speech delay were identified through diagnosis of speech delay and underwent ABR testing. Patients were then separated into two groups: Neurotypical (N = 79) and ASD (N = 69). ABR results were obtained through chart review and waveform and interpeak latency (IPL) results were recorded. Differences in waveform and IPL results were determined via Pearson's chi-square test, with multivariate analysis accounting for race, sex, and age. Results28 patients with ASD (40.6 %) had at least one waveform/IPL prolongation. Analysis showed an increased incidence of waveform III (p = 0.028) and IPL III-V (p = 0.03) prolongation in the ASD group compared to their neurotypical counterparts. Waveform III prolongation was noted more in females with ASD (p = 0.001) than in males. No statistically significant difference when comparing race and age was found, except in the 2–3 age range (p = 0.003). ConclusionsThere were higher percentages of prolongation for all waveforms and IPLs in the ASD group versus neurotypical, though not as high as previously reported. Race and age did not appear to be factors in ABR findings though more data is needed to make clinical associations.

Evaluation of Hearing Loss in Patients with Essential Tremor

ABSTRACT Background: Essential tremor (ET) is a common chronic progressive disease, characterized by postural and action tremor. Abnormalities within the cerebello-thalamocortical pathways are thought to be involved in ET. In some studies, it was reported that there is an association between ET and hearing loss. Objective: In this study, our goal is to examine the electrophysiological changes of the structures forming the auditory pathway in ET cases, and the relationship of these changes with clinical findings and understand if the pathology underlying hearing loss in ET is cochlear or retrocochlear. Materials and Methods: One hundred sequential ET patients who had referred to Mersin University Faculty of Medicine Neurology Department, and 100 healthy individuals that are equivalent in terms of age and gender were conducted to investigate this association. Detailed medical history, neurologic examination, audiologic examination, pure-tone audiometry (PTA), tympanometry, and auditory brainstem response (ABR) analyses also known as brainstem auditory-evoked potentials were applied to all patients and controls. Results: The mean age of patients with ET was 56.38 ± 16.73, and the mean age of individuals in the control group was 56.47 ± 16.86. Nineteen of the patients with ET, and two healthy individuals from the control group had hearing problems (P < 0.001). In this study, there were no significant differences found in audiometric and ABR examinations in terms of hearing loss between the ET group and control group. However, in audiometric and ABR analyses, an increase in hearing loss was found to be correlated with an increase in tremor severity. In PTA test, hearing loss was higher in those with high-intensity tremor severity than in the group with mild tremor severity. This was statistically significant. P (KW) <0.05 Pposthoc < 0.05. In ABR analysis, it was found that there was a statistically significant difference with the increase of tremor severity at the dominant hand with: wave V latencies of the right and left ear; I-V interpeak latencies of the right ear, and III-V interpeak latencies of the right ear. The difference was between mild and moderate tremor groups. Conclusion: This study shows that there could be an impairment in inhibiting the functional transmission in the brainstem of patients with ET.

Evoked potential response in patients with idiopathic Parkinson’s disease and atypical parkinsonian syndromes: A comparative study

Patients with idiopathic Parkinson’s disease (IPD) and atypical parkinsonian syndromes (APSs) suffer from a range of disorders, especially in balance and locomotion, which necessitate visual, auditory, and somatosensory inputs. In this study, IPD patients, APS patients, and healthy controls (HCs) (n = 50 per group) underwent a series of assessments for visual evoked potentials (VEP), brainstem auditory evoked response (BAER), and short-latency somatosensory evoked potentials (SSEP). Results showed that VEP P100 latency was prolonged in multiple system atrophy-cerebellar type (MSA-C), multiple system atrophy-parkinsonian type (MSA-P), and corticobasal ganglionic degeneration (CBD) patients. The latency of peaks III and V was prolonged in IPD, MSA-C, dementia with Lewy bodies (DLB), and Parkinson’s disease dementia (PDD). BAER I-III and I-V interpeak latency were prolonged in IPD, DLB, and PDD, whereas BAER I-III, III-V, and I-V interpeak latencies were increased and the V/I amplitude ratio was decreased in MSA-C. The central sensory conduction time (N20-N13) was increased in MSA-P and MSA-C in SSEP. IPD patients had prolonged VEP P100 latency (P < 0.001), lower VEP N75-P100 amplitude (P < 0.001), prolonged BAER I, II, II, IV, V peak latencies (P < 0.001), I-III, I-V interpeak latencies (P < 0.001), lower BAER V/I amplitude ratio (P < 0.001), and prolonged SSEP N13, N20, central sensory conduction time (N20-N13) (P < 0.001) than HCs. IPD patients also had prolonged BAER I, II, II, IV, V peak latencies (P < 0.001), prolonged I-III, I-V interpeak latencies (P < 0.001), and shorter SSEP N13, N20, central sensory conduction time (N20-N13) (P < 0.001) than APS patients. Moreover, APS patients had prolonged VEP P100 and N145 latencies (P < 0.001) and decreased N75-N145 amplitude (P < 0.001) compared to HCs. APS patients also had prolonged BAER II, II, IV, V peak latencies (P < 0.001), prolonged I-III, III-V, I-V interpeak latencies (P < 0.001), decreased V/I amplitude ratio, and prolonged SSEP N13, N20, central sensory conduction time (N20-N13) (P < 0.001) than HCs. Postural instability and gait disorder (PIGD) IPD had significantly prolonged BAER III, V peak latencies (P < 0.05), and prolonged III-V interpeak latencies (P < 0.05) compared to tremor-dominant IPD. Overall, the IPD and APS patients had significant VEP, BAER, and SSEP abnormalities of demyelination and axonal variety in the visual, auditory, and somatosensory pathways. The changes were also correlated with the disease duration and severity. Although the diseases are predominantly motor disorders with significant non-motor components, these electrophysiological abnormalities might open a new avenue to assess the non-motor symptoms.

Studying the Inter-Peak Latencies of Auditory Brainstem Response in Menopause Women

Background: Changes in auditory function have been noted in post-menopausal women attributed in part to the lower levels of ovarian hormones. Decreased levels of ovarian hormones may alter auditory neurotransmission time, as evaluated by Auditory Brainstem Responses (ABR). Thus, objective of this study was comparison of mean inter-peak ABR latencies in post-menopausal women compared to non-menopausal women.
 Methods: In this cross-sectional study, research sample consisted of 60 women as case group in the age range of 45-55 years, who were post-menopausal and had normal hearing. The control group with similar characteristics were non-menopausal. Two groups were estimated by ABR and then the means of the variables that had a normal distribution were compared with each other by independent t-test. 
 Results: All differences between two groups were not significant, as follows; Mean I-III inter-peak ABR latencies (p-value=0.714), mean III-V inter-peak ABR latencies (p-value=0.691) and mean I-V inter-peak ABR latencies (p-value=0.483).
 Conclusion: Menopause does not cause abnormal results in auditory brainstem responses.

Evaluation of the Prevalence of Irritable Bowel Syndrome in Patients with Rheumatoid Arthritis

Background: Changes in auditory function have been noted in post-menopausal women attributed in part to the lower levels of ovarian hormones. Decreased levels of ovarian hormones may alter auditory neurotransmission time, as evaluated by Auditory Brainstem Responses (ABR). Thus, the objective of this study was to compare the mean inter-peak ABR latencies and post-menopausal women compared to non-menopausal women.
 Methods: In this cross-sectional study, research sample consisted of 60 women as case group in the age range of 45-55 years, who were post-menopausal and had normal hearing. The control group with similar characteristics were non-menopausal. Two groups were estimated by ABR and then the means of the variables that had a normal distribution were compared with each other by independent t-test. 
 Results: All differences between two groups were not significant, as follows; Mean I-III inter-peak ABR latencies (p-value=0.714), mean III-V inter-peak ABR latencies (p-value=0.691) and mean I-V inter-peak ABR latencies (p-value=0.483).
 Conclusion: Menopause does not cause abnormal results in auditory brainstem responses.

Exploring brainstem auditory evoked potentials and mental development index as early indicators of autism spectrum disorders in high-risk infants.

This study of infants from Hubei Province, China examined brainstem auditory evoked potentials (BAEP) and mental development index (MDI) as possible early indicators associated with autism spectrum disorders (ASD). The 34 ASD cases and 102 controls who had recovered from perinatal conditions were matched for age, sex, gestational age, birth weight and maternal age. BAEP absolute latencies (AL) I, III, V and interpeak latencies (IPL) I-III, III-V, I-V were compared in ASD cases and controls at ages 1, 3 and 6months. MDI scores were compared in these infants from 1month to 2 years old. Multiple logistic regression analysis was performed to test associations among ASD, BAEP and MDI. Results showed BAEP AL I, V and IPL III-V prolonged in the ASD group (p < 0.001), and MDI scores in ASD cases sharply declining from 12 to 24 months (p < 0.001). Regression analysis revealed odds ratios (OR) indicating that ASD was likely associated with abnormal values of BAEP AL I at 1 and 3months (ORAL I : 4.27; ORAL I : 4.13), and AL V at 6months (ORAL V : 7.85). Lower MDI scores (MDI < 80) in infants at 1, 3, and 6months were likely associated with ASD (ORMDI : 2.58; ORMDI : 3.83; ORMDI : 4.87). These data show that abnormal BAEP values and low MDI scores are independent factors associated with ASD, and that monitoring of BAEP and MDI during infancy might facilitate screening for ASD development.

Assessment of Visual and Brainstem Auditory Evoked Potentials in Patients with Hashimoto's Thyroiditis.

Background The present study was aimed to evaluate parameters of visual and brainstem auditory evoked potentials (VEP, BAEP) in euthyreotic Hashimoto's thyroiditis (HT) patients without central nervous system involvement. Methods 100 HT patients (92 women, 8 men), mean age 46.9 years, and 50 healthy controls. They underwent a neurological examination, thyroid hormone levels, thyroid autoantibody titers, and brain imaging. Latencies and amplitudes of the N75, P100, and N145 component of VEP and the I-V components of BAEP were analyzed. Results The neurological examination revealed in 31 patients signs of increased neurovegetative excitability. Brain resonance imaging showed no abnormalities in HT patients. The mean P100, relative P100, and N145 VEP latencies were significantly longer, and P100 amplitude significantly higher in HT patients than the controls. HT patients also had a longer mean wave BAEP V latency and mean wave III-V and I-V interpeak latencies, and significantly lower mean wave I and V amplitudes. Abnormal VEP and BAEP were recorded in 34% of the patients. There were no statistically significant correlations between the mean VEP parameters and thyroid profile and the applied dose of L-thyroxine. There was a relationship between the level of TSH and the wave BAEP III-V interpeak latency. Conclusions There were changes in the brain's bioelectrical activity in one-third of the patients with HT without nervous system involvement. The increased amplitude of the VEP may indicate increased cerebral cortex activity. Disorders of the brain's bioelectrical activity in the course of HT may be associated with an autoimmune process.

Effect of Music Training on Auditory Brainstem and Middle Latency Responses

Purpose: The auditory system has potentials to reorganize its structure and function in response to environmental changes such as training, experience, learning, injury, and disease. This is called neuroplasticity. A typical example of neuroplasticity is the music training, which demands cognitive and neural challenges resulting in enhanced auditory perception. This study investigated the effect of music training on auditory evoked responses, particularly auditory brainstem and middle latency responses. Methods: Forty college students consisting of twenty students with music training (musicians) and twenty students without music training (non-musicians) participated in the study. All participants have normal ranges in terms of pure tone audiometry, speech audiometry, and tympanometry. Auditory brainstem response (ABR) and auditory middle latency response (AMLR) from both ears were tested. Absolute latencies and amplitudes of waves in ABR and AMLR were obtained and analyzed.Results: The absolute latencies of wave I and V significantly differed between musicians and non-musicians. They were shorter for musicians than for non-musicians. Significant differences were found in the interpeak latencies of wave III-V and I-V between musicians and non-musicians. They were also shorter in musicians than for non-musicians. In addition, there were only significant differences in the latency of Na in AMLR between musicians and non-musicians. It was shorter for a musician than for non-musician.Conclusion: ABR was more sensitive to the efficacy of the music training.

AUDITORY BRAINSTEM RESPONSE ABNORMALITIES IN SCHIZOPHRENIC PATIENTS WITH AUDITORY HALLUCINATIONS

Background : although the exact pathogenesis of auditory hallucinations is not yet known, some suggested the impairment of perception and processing of auditory information as a possible explanation. So, the aim of this study is to evaluate auditory pathways of schizophrenic patients using auditory brainstem responses (ABR). Methods : schizophrenic patients with auditory hallucinations and age and sex matched healthy non-relative controls were recruited in this case-control study. Scale for assessment of positive symptoms (SAPS) was used for rating the severity of hallucinations. Then, ABR recorded from all participants and the latencies of waves I, II, III, IV, V and inter-peak latencies (IPL) of waves I-III, III-V were analyzed on both sides. Chi squire and independent t tests were applied for statistical analysis. P-value≤0.05 was considered significant. Results : 39 patients and 35 controls were included. Latencies of waves III and V and IPL of III-V were significantly prolonged on the left side. Disease duration had no influence on the results. Conclusion : there is a link between abnormal ABRs and auditory hallucinations in schizophrenic patients that indicates dysfunction and abnormal asymmetry of auditory pathways in these patients.

Effects of Caffeine on Auditory- and Vestibular-Evoked Potentials in Healthy Individuals: A Double-Blind Placebo-Controlled Study.

Background and ObjectivesThe blockage of adenosine receptors by caffeine changes the levels of neurotransmitters. These receptors are present in all parts of the body, including the auditory and vestibular systems. This study aimed to evaluate the effect of caffeine on evoked potentials using auditory brainstem responses (ABRs) and cervical vestibular-evoked myogenic potentials (cVEMPs) in a double-blind placebo-controlled study.Subjects and MethodsForty individuals (20 females and 20 males; aged 18-25 years) were randomly assigned to two groups: the test group (consuming 3 mg/kg pure caffeine powder with little sugar and dry milk in 100 mL of water), and the placebo group (consuming only sugar and dry milk in 100 mL water as placebo). The cVEMPs and ABRs were recorded before and after caffeine or placebo intake.ResultsA significant difference was observed in the absolute latencies of I and III (p<0.010), and V (p<0.001) and in the inter-peak latencies of III–V and I–V (p<0.001) of ABRs wave. In contrast, no significant difference was found in cVEMP parameters (P13 and N23 latency, threshold, P13-N23 amplitude, and amplitude ratio). The mean amplitudes of P13-N23 showed an increase after caffeine ingestion. However, this was not significant compared with the placebo group (p>0.050).ConclusionsIt seems that the extent of caffeine’s effects varies for differently evoked potentials. Latency reduction in ABRs indicates that caffeine improves transmission in the central brain auditory pathways. However, different effects of caffeine on auditory- and vestibular-evoked potentials could be attributed to the differences in sensitivities of the ABR and cVEMP tests.

Hidden hearing deficits in military service members with persistent post concussive symptoms

Individuals with persistent symptoms after mild traumatic brain injury (mTBI) often have auditory complaints. In this study, we used the auditory brainstem response (ABR) to determine whether cochlear synaptopathy could explain auditory symptoms. 69 adult military service members with mTBI and 25 adults without brain injury (NCT01611194 and NCT01925963) completed pure-tone audiometry, ABR, and central auditory processing tests. All participants were male, ages 21-50. 37/69 mTBI participants had measurable hearing loss, while another 20%-30% had hearing complaints or tinnitus. While mTBI participants with measurable hearing loss had reduced wave I and III amplitude and decreased III-V interpeak latency, those with no measurable hearing loss did not significantly differ from controls on any ABR parameter. Those with measurable hearing loss were also more likely to have abnormal central auditory processing. mTBI participants with no measurable hearing loss but who reported hearing concerns had some ABR findings (III-V interpeak latency, I and V amplitudes, V/I amplitude ratio) more like the measurable hearing loss mTBI group than normative controls. Cochlear synaptopathy may have contributed to some of the auditory impairment in service members with mTBI with measurable hearing loss. However, these results are likely confounded by cochlear hair cell damage.

Brainstem auditory evoked potentials (BAEP) in dairy calves

Brainstem auditory evoked potentials (BAEP) are useful to diagnose neurologic and genetic disorders in cattle but normal parameters and its application to detect changes in hearing are not demonstrated. The aims of this study were to develop a protocol for obtaining BAEP in Holstein calves and to establish the normal parameters of peak latencies, interpeak latencies (IPL) and waveforms of BAEP in this species. Ten male Holstein calves, aged 2.5 months and weighting 90.7 ± 4.0 kg were used. All animals were previously sedated with 0.08 mg/kg xylazine hydrochloride administered intramuscularly. The BAEP analysis was recorded using the IHS SmartEP-ASSR program connected with electrode needles placed on the standardized locations of the animal's head. Monoaurally presented broadband click stimuli (0.1 ms) were used for BAEP stimulation, with contralateral masking of 30 dB SPL. Stimuli were presented at a rate of 35.5 pulses per second (PPS) and evoked responses were collected and averaged 450–1500 times for each sound intensity. Earphones were inserted into the ear canal to present the acoustic stimulus and to attenuate environmental noise. Peak latencies, IPL, waveforms and auditory thresholds were recorded and analyzed in the right ear and were like those described in previous papers in adult male bulls. Auditory thresholds obtained in all animals were 33 ± 1.5 dB SPL. Peak latencies were 1.4 ± 0.07 ms (Peak I), 2.4 ± 0.10 ms (Peak II), 3.3 ± 0.10 ms (Peak III), 4.4 ± 0.19 ms (Peak IV) and 5.6 ± 0.28 ms (Peak V). IPL were 1.9 ± 0.12 ms (IPL I-III), 4.1 ± 0.29 ms (IPL I-V), 2.2 ± 0.19 ms (IPL II-V) and 2.2 ± 0.19 ms (IPL III-V). Brainstem auditory evoked potentials are a minimally-invasive method to evaluate level of audition in Holstein calves. In addition, BAEP is a method that can be applied in young calves and it would work on-farm to select the animals with better conditions.

T82. Neonatal brainstem audiometry is associated with language development

Preterm birth increases the risk for abnormal neurodevelopment including delayed language development. Function of the auditory pathway in neonatal period may correlate with language outcome in childhood. Our objective was to study if neonatal brainstem auditory evoked potential (BAEP) and brainstem audiometry (BA) results in preterm babies are associated with receptive lexicon at one year corrected age. In this retrospective study, we included 155 preterm babies (birth weight ⩽1500 g and/or birth ⩽32 gestational weeks) born 2007–2012 in Turku University Hospital providing the following information: BAEP and BA recording results at the mean corrected age of 1.1 months (0.28 SD) and information on early receptive and expressive lexicon growth at the mean corrected age of 12.1 months (0.55 SD) gathered using the Finnish version of the MacArthur Communicative Development Inventory (CDI). CDI is a structured rating instrument where parents denote the words that their child understands but does not say (receptive lexicon) and the words they say (expressive lexicon). In this study, we used only the receptive lexicon. This was done because the expressive lexicon is very small at one year of the age. All children were from Finnish speaking families. In addition, we gathered information about possible covarying factors: gestational age at birth, birth weight, small for gestational age, gender, hearing loss, age at the time of BAEP recording and CDI completion. Infants with small receptive lexicon at one year corrected age had longer latency of component V (r = −0.17, p = 0.036), interpeak latencies (IPL) I-V (r = −0.21, p = 0.0087) and IPL III-V (r = −0.17, p = 0.040) in BAEP recording with right ear stimulation at one month corrected age. Other BAEP variables on either side did not show similar associations with CDI. BA thresholds did not show associations with CDI. The possible covarying factors in the analyses did not affect the receptive lexicon. Our study suggests that in preterm infants prolonged conduction in the auditory pathway from the dominant right ear is associated with small receptive lexicon size at the corrected age of one year. Several studies show right-ear advantage (REA) in processing speech stimuli already in neonatal period. According to our results, delayed auditory maturation in the right ear seems to have greater influence on language development compared to the left ear, supporting REA. In the future, this information might help us to improve the recognition of preterm babies at risk for delayed language development already at term age which might lead to better results in language rehabilitation.

BS14. Visual and brainstem auditory evoked potentials in Hashimoto’s thyroiditis

Introduction A normal thyroid gland activity is essential for the optimal development, maturation and function of the nervous system. Neurological syndromes can develop in certain thyroid diseases that may have normal levels of thyroid hormones. One such example is Hashimoto’s thyroiditis (HT), which is currently considered to be the most common autoimmune disease in humans. The exact cause of those symptoms has not yet fully been explained. Their pathomechanism is still being studied. Precise and non-invasive methods of assessment of the nervous system function is evoked potentials study (EP). It is a sensitive technique that enables the evaluation of the brain bioelectrical activity also in patients with HT. EPs are particularly useful in patients with mild or without clinical neurological symptoms. The aim of the study was to evaluate parameters of visual and brainstem auditory evoked potentials (VEP, BAEP) in euthyreotic HT patients without clinical neurological deficit, and without ophthalmological and otolaryngological abnormalities. Methods 100 HT patients (92 women, 8 men) from 20 to 68 years old (mean 46.9 years). They did not suffer from concurrent diseases that could have affected the brain electrical activity. The visual and auditory receptors were not damaged in any of the patients and the patients did not suffer from any central nervous system damage. The matched control group comprised 50 healthy subjects. HT patients underwent a subjective and objective neurological examination, thyroid hormone levels and thyroid autoantibody titers, brain imaging (CT or MRI), VEP and BAEP. Results Abnormal VEP and BAEP were recorded in 34% of the patients. The mean P100, relative P100, N145 VEP latencies were significantly longer and P100 amplitude significantly higher in HT patients than in the control group. HT patients also had a longer mean wave V latency and mean wave III-V and I-V interpeak latencies and significantly lower mean wave I and V amplitudes than the controls. There were no statistically significant correlations between the mean VEP parameters and the levels of TSH, free thyroid hormones, antithyroid antibody titers and the applied dose of L-thyroxine. There was a relationship between the level of TSH and the wave BAEP III-V interpeak latency. The number of abnormal VEP and BAEP depended on the dose of L-thyroxine and was the highest in patients without treatment and decreased with the increase in the dose of levothyroxine. Conclusion 1. There were changes in the brain bioelectrical activity in the form of abnormal VEP and BAEP in one third of the patients with Hashimoto’s disease who did not have central nervous system deficits. 2. The increased amplitude of the VEP in the course of HT may indicate increased cerebral cortex activity. 3. Disorders of the brain bioelectrical activity in the course of HT may be associated with an ongoing autoimmune process. 4. The analysis of the VEP and BAEP may be useful in assessing the brain bioelectrical activity in the course of HT.

Improving the efficiency of Auditory Brainstem Responses in newborns, using a 60 clicks/s stimulation rate

Recent evidence suggests that Auditory Brainstem Responses (ABR), in neonates with risk factors for neurological damage, may show auditory brainstem abnormalities, even in patients with normal hearing. To compare the recording and diagnostic accuracy of neonatal Auditory Brainstem Responses (ABR), using 10 and 60clicks/s stimulation rates, two groups of neonates were prospectively studied: 30 healthy full-term neonates, with no peri- or postnatal complications; and 30 high-risk newborns with two or more of the following conditions: hyperbilirubinemia, use of ototoxic drugs, birth weight inferior to 1500g, perinatal sepsis, intraventricular hemorrhage, and/or mechanical ventilation. Correlation between ABR trials, recording duration, and the absolute and interpeak latencies of ABR waves I, III and V, were measured. ROC-curve analysis assessed the diagnostic accuracy of both stimulation rates. The correlations between ABRs trials were significantly higher at 60clicks/s than at 10clicks/s (F(1,116)=14.5, p<0.0002). Recording duration at 60clicks/s was significantly lower (t=20.9, p<0.0001). ROC-curve comparisons showed increased diagnostic accuracy at the stimulation rate of 60clicks/s, for waves I (D=2.04, p=0.04), V (D=2.02, p=0.04), interpeak latencies III-V (D=2.2, p=0.02), and I-V (D=2.86, p=0.004). In neonates, the use of 60clicks/s stimulation rate permits a substantial shortening of the ABR recording, with greater diagnostic accuracy and replicability.

The Effect of Methylphenidate on the Hearing of Children with Attention Deficit Hyperactivity Disorder.

Introduction There has been a sudden idiopathic hearing loss case presented after methylphenidate treatment in a child with attention deficit hyperactivity disorder (ADHD). Objective This study was performed to reveal the probable ototoxic side effects of methylphenidate use in patients with ADHD. Methods Thirty pediatric patients with ADHD were included in the study. Pure tone audiometry, speech discrimination scores, waves I, III, V absolute latencies and waves I-III, I-V, III-V interpeak latencies at the 80 dB nHL intensity after click stimulus auditory brainstem response (ABR) results were compared before and 3 months after methylphenidate treatment. Results There were no statistically significant difference between pretreatment and posttreatment pure tone and speech audiometry findings and ABR results (p > 0.05 for all parameters). Conclusion Methylphenidate can be regarded as a safe drug regarding ototoxic side effects. Additional studies with a larger sample size and longer follow-up may be needed.

Prognostic value of SSEP and BAEP in a cohort of deeply sedated mechanically ventilated critically ill patients

Somatosensory evoked potentials (SSEP) and brainstem auditory evoked potentials (BAEP) might be useful for predicting outcome in critically ill patients who require deep sedation and mechanical ventilation [1] . However, the impact on outcome of the assessment of brain dysfunction using SSEP and BAEP in this population remains unproven. In this pilot study, we investigated the prognostic value and clinical correlates of the lengthening of inter-peak latencies of SSEP and BAEP components, in a cohort of deeply sedated mechanically ventilated critically ill patients. Median nerve SSEP, BAEP and neurological examination were assessed at bedside, under deep sedation, before day 5 after admission, in intensive care unit (ICU). Interpeak latencies (IPL) of SSEP and BAEP were considered delayed when they were over the mean + 2.5 SD of the ones obtained from our cohort of healthy adults. Primary outcome was mortality in the ICU. Secondary outcome was post-sedation altered mental status defined as the occurrence of delirium or delayed awakening after discontinuation of sedation. Eighty six consecutive patients were enrolled, mean age 61 ± 19 years, and 65% with severe sepsis. Richmond Assessment Sedation Scale (RASS) score at inclusion was -5 (-5 to -4). Thirty seven patients (43%) died in the ICU. A prolonged subcortical-cortical conduction time (P14-N20 IPL SSEP component) i. e. > 5.3 ms, was found an independent predictor of in-ICU mortality after adjustment on total Sequential Organ Failure Assessment score (SOFA) [OR (95% CI) = 2.69 (1.05 to 6.85); P = 0.039]; and after adjustment on non-neurological SOFA [OR (95% CI) = 2.67 (1.05 to 6.81) ; P = 0.040]. Furthermore, delayed P14-N20 IPL SSEP component was associated with absent cough reflex. Finally, there was a trend for association between delayed III-V IPL BAEP component (ponto-mesencephalic conduction time) and post-sedation altered mental status (P = 0.053). These results support the hypothesis of brainstem dysfunction during critically illness [2] , [3] . Studies with larger sample are needed.

Delayed auditory conduction in diabetes: is metformin-induced vitamin B12 deficiency responsible?

The present study aims to evaluate the functional integrity of the auditory pathway in patients with diabetes taking metformin. A further aim is to assess its association with vitamin B12 deficiency induced by metformin. Thirty diabetics taking metformin and 30 age-matched non-diabetic controls were enrolled. Stimulus-related potentials and vitamin B12 levels were evaluated in all the subjects. The diabetics showed deficient vitamin B12 levels and delayed wave III latency and III-V interpeak latency in the right ear and delayed Na and Pa wave latencies in the left ear compared with the controls. The dose and duration of metformin showed no association with the stimulusrelated potentials. Therefore, although vitamin B12 levels were deficient and auditory conduction impairment was present in the diabetics on metformin, this impairment cannot be attributed to the vitamin B12 deficiency.

Latent iron deficiency at birth influences auditory neural maturation in late preterm and term infants

In utero latent iron deficiency has been associated with abnormal neurodevelopmental outcomes during childhood. Its concomitant effect on auditory neural maturation has not been well studied in late preterm and term infants. The objective was to determine whether in utero iron status is associated with auditory neural maturation in late preterm and term infants. This prospective cohort study was performed at Sir Ganga Ram Hospital, New Delhi, India. Infants with a gestational age ≥34 wk were eligible unless they met the exclusion criteria: craniofacial anomalies, chromosomal disorders, hemolytic disease, multiple gestation, third-trimester maternal infection, chorioamnionitis, toxoplasmosis, other infections, rubella, cytomegalovirus infection, and herpes simplex virus infections (TORCH), Apgar score <5 at 5 min, sepsis, cord blood not collected, or auditory evaluation unable to be performed. Sixty consecutive infants with risk factors for iron deficiency, such as small for gestational age and maternal diabetes, and 30 without risk factors for iron deficiency were enrolled. Absolute wave latencies and interpeak latencies, evaluated by auditory brainstem response within 48 h after birth, were measured and compared between infants with latent iron deficiency (serum ferritin ≤75 ng/mL) and infants with normal iron status (serum ferritin >75 ng/mL) at birth. Twenty-three infants had latent iron deficiency. Infants with latent iron deficiency had significantly prolonged wave V latencies (7.10 ± 0.68 compared with 6.60 ± 0.66), III-V interpeak latencies (2.37 ± 0.64 compared with 2.07 ± 0.33), and I-V interpeak latencies (5.10 ± 0.57 compared with 4.72 ± 0.56) compared with infants with normal iron status (P < 0.05). This difference remained significant on regression analyses after control for confounders. No difference was noted between latencies I and III and interpeak latencies I-III. Latent iron deficiency is associated with abnormal auditory neural maturation in infants at ≥34 wk gestational age. This trial was registered at clinicaltrials.gov as NCT02503397.

Auditory dysfunction in patients with type 2 diabetes mellitus with poor versus good glycemic control

Abstract Auditory functions among patients with type 2 diabetes mellitus (DM) are controversial regarding cochlear or neural changes and the relationship between these changes and serum level of glycosylated hemoglobin (HbA 1c%). The aim of the study was to investigate auditory dysfunctions in type 2 DM patients with poor versus good glycemic control. The present study was conducted on three groups: two diabetic groups with poor and good glycemic control (n = 18 and 14, respectively) based on serum HbA 1c% and one healthy control group (n = 30) matched with age, sex, and BMI. All participants were subjected to clinical assessment, audiometry, brainstem auditory evoked potential (BAEP), and evoked acoustic emissions transient evoked otoacoustic emissions and distortion product otoacoustic emissions (TEOAEs and DPOAEs). Diabetic patients with poor glycemic control had significantly elevated hearing thresholds compared with other groups at low and high frequencies in audiometry (P < 0.01 and P < 0.001). They showed significantly prolonged absolute latency in wave I and interpeak latency (III-V) in the BAEP test compared with other groups (P < 0.001). DM patients with poor glycemic control had significantly low amplitudes at all frequencies in the TEOAE test, as well as at high frequencies (4 and 6 kHz) on the DPOAE test, compared with other groups (P < 0.001 and P < 0.05, respectively). There were significant correlations between HbA 1c% and interpeak latency III-V (r = 0.340, P = 0.004) on the one hand and overall response of TEOAE amplitude (r = −0.471; P = 0.000) on the other. Diabetic patients with poor glycemic control had worse auditory dysfunctions on both cochlear and neural findings.