Establishing normative values for auditory brainstem response measurements among infants aged 3 to 6 months: Descriptive study

Background@#Establishing clinic-specific normative data for auditory brainstem response (ABR) tests is important due to variability in stimulus parameters and equipment.@*Objective@#To establish normative values for ABR measurements in infants aged 3 to 6 months.@*Design@#Descriptive study.@*Participants@#12 normal-hearing male and female infants, aged 3 to 6 months, who underwent ABR tests.@*Setting@#Audiology Unit, Department of Otorhinolaryngology - Head and Neck Surgery, Southern Philippines Medical Center, Davao City, January 2021 to December 2022.@*Main outcome measures@#Absolute latency readings for waves I, III, and V, and interpeak latencies for waves I-III, III-V, and I-V using Interacoustics Eclipse EP15 apparatus with a RadioEar IP30 Insert Earphone transducer at a stimulus intensity of 60-90 dBnHL and a rate of 45.1 clicks/sec.@*Main results@#All normative ABR ranges were computed with a threshold of ± 2 SD from the means. The computed means (normative ranges) for absolute latencies for waves I, III, and V were 1.49 ± 0.15 (1.19-1.78) msec, 4.45 ± 0.32 (3.81-5.10) msec, and 6.65 ± 0.26 (6.12-7.17) msec, respectively. The computed normative values for interpeak latencies for waves I-III, III-V, and I-V were 2.80 ± 0.22 (2.36-3.23) msec, 2.19 ± 0.21 (1.78-2.61) msec, and 4.99 ± 0.29 (4.41-5.57) msec, respectively.@*Conclusion@#In our study, we have established normative values for ABR test measurements for infants aged 3 to 6 months.

Comparative study of brainstem auditory evoked responses in females having premenstrual symptoms with normal population

Background: Premenstrual symptoms (PMS) have largely been ignored, because ages so present study are done in females specifically having PMS comparing with females with no PMS. Very little work has been done in past in this field, because females revealing menstrual history are a big taboo in our society. Aim and Objective: The aim of this study was to study brainstem auditory evoked potential (BAEP) in females having premenstrual symptoms and comparing it with females having no premenstrual symptoms. Materials and Methods: BAEP was conducted on 60 females age group of 18–40 years in two groups in Research laboratory, Department of Physiology, Lala Lajpat Rai Memorial Medical College in collaboration with SVBP Hospital, Meerut for 6 months. The subjects were divided into two groups, Group A having premenstrual symptoms and Group B having no premenstrual symptoms. The test was conducted in later part of luteal phase 23rd–25th day of menstrual cycle. The absolute latencies (ALs) and interpeak latencies (IPLs) were the parameters measured for the analysis of BAEP. Results: IPL, that is, interpeak latencies I–III and III–V in age group 18–25 years, showed statistically significant decrease in luteal phase in females having premenstrual syndrome (PMS) as compared to normal cycling females. Conclusion: Premenstrual symptoms females are showing few significant changes in auditory responses at mid brain level as recorded by BAEP study which can be due to the modulatory effect of female gonadal hormones progesterone and estrogen on neurotransmitters (serotonin, gamma-aminobutyric acid, and glutamate) in central nervous system.

Relationship between cervical diffusion tensor imaging and somatosensory evoked potential in patients with cervical intraspinal tumors / 中华神经医学杂志

Objective To explore the correlation between cervical diffusion tensor imaging (DTI) and median nerve short latency somatosensory evoked potential (MN-SLSEP) parameters in patients with cervical intraspinal tumors.Methods Twenty-two patients suffering from cervical intraspinal tumors treated with surgical resection were enrolled into study group from February 2015 to May 2016;meanwhile,22 age-matched volunteers were selected as control group.Cervical DTI and MN-SLSEP detection were performed 3 d before operation and one month after operation,respectively.The whole cervical spinal cord was divided into 3 areas,the tumor head area,the tumor area,and the tumor tail area;and the fractional anisotropy (FA) values of the 3 areas were calculated.The white matter fiber bundle was reconstructed by diffusion tensor tracking (DTT) to observe its integrity.Study group was further divided into delayed latency group (lat+ group) and normal latency group (lat group)according to the delayed latency of N9-N20 interpeak levels,and the FA values of the 3 groups at different areas were compared.Results Total removal of the tumors was achieved in 19 patients (86.4％) and subtotal in 3 patients (13.6％,two with nerve fibrolipomas and one with intramedullary neurilemmomas) of the study group.One month after the operation,the spinal function was improved in 17 patients (77.3％),and not improved in 5 patients (22.7％).The preoperative N9-N20 interpeak latency in the study group was significantly longer than that in the control group (P＜0.05).In term of preoperative fiber tract morphology of study group,the proportion of delayed N9-N20 interpeak latency in patients with interrupt type (75％) was significantly longer than that in the patients with intact type (21.4 ％,P＜0.05).FA values oflat+ and lat group in the tumor head area,tumor area,and tumor tail area were significantly lower than those in the control group (P＜0.05);and FA values of lat+ group in these three regions were significantly lower than lat group (P＜0.05).Conclusions DTI metrics correlate with MN-SLSEP measures.Through variations of quantitative parameter values and fiber tract morphology,cervical DTI can sensitively and intuitively reflect the electrophysiological changes,which could be served as a important diagnostic tool for cervical intraspinal tumors.

Brainstem auditory evoked potential in Parkinson's disease / 中华物理医学与康复杂志

Objective To evaluate the changes in and the regularity of brainstem evoked potentials (BA-EPs) in Parkiuson's disease (PD) as an objective criterion for early diagnosis and assessment. Methods Thirty-five healthy SD rats were divided into two groups at random. Twenty-two rats were in the experimental group and 13 in the control group. The rats were injected with 8 μg of 6-OHDA solution in the right substantia nigra pars compacta (SNc) and the right ventral tegmentum area (VTA) to create a PD model. The BAEPs of the rats in the experimental group were recorded in a quiet shielded room before the 6-OHDA injection, and one week and two weeks after injec-tion. The control group rats were injected with saline (Ns) and their BAEPs were recorded at the corresponding times. One week and two weeks later, the model rats were injected with apomorphine (APO) and their rotating cycles were counted. Results The Ⅱ , Ⅳ, andV PLs and the Ⅲ-Ⅴ IPLs on the fight ears of the experimental group were prolonged significantly compared with the control group one week after APO injection. There was no significant differ-ence in the BAEPs of the left ears after the first week. After two weeks, the Ⅱ , Ⅳ, and Ⅴ PLs and the Ⅲ-Ⅴ, and Ⅰ-Ⅴ IPLs of the right ears in the experimental group were prolonged significantly compared with the controls and the Ⅳ, and Ⅴ PLs and the Ⅲ -Ⅴ , and Ⅰ-Ⅴ IPLs on their left ears were prolonged significantly. Conclusion In the early course of a PD model in rats, their BAEPs show abnormal changes, which indicates that BAEP could be an ob-jective criterion for early diagnosis and assessment of PD. BAEP may serve as one index of damage in PD. The Ⅲ-Ⅴ PL and Ⅰ-Ⅴ iPL are sensitive indices of PD.

Auditory Brainstem Evoked Potentials in Preterm Infants

OBJECTIVE: To investigate the change of peak latency, interpeak latency and amplitude of auditory brainstem evoked potentials (AEPs) in normal preterm infants in accordance with the age, and to find out the correlation between reproducibility of AEPs and high risk of premature infants. METHOD: AEP studies were performed on 266 premature infants (male 143, female 123) within a month of the birth. Acquired potentials were grouped by the reproducibility of waveforms, and latency, interpeak latency and amplitude were measured in each group of potentials to interpret age appropriate changes of AEPs. RESULTS: 1) Peak latency of peak I, III and V were shortened in accordance with the age, especially latency of peak V was significantly decreased from 7.42 msec to 6.84 msec. 2) There was no significant change in interpeak latency or amplitude of AEPs according to the postmenstrual age. 3) Reproducibility of AEPs was worse in premature infants with history of asphyxia. CONCLUSION: Considering the results, the latency of peak V can be used as one of the useful parameter to investigate and follow up the premature infants. Significant negative correlation between low grade reproducibility and history of neonatal asphyxia was found.

Measurement on latency and interpeak latency of brain trigeminal evoked potentials in normal volunteers / 西安交通大学学报(医学版)

Objective To establish the database of brain trigeminal evoked potentials for our laboratory,latency and interpeak latency of brain trigeminal evoked potentials were measured in normal volunteers.Methods Trigeminal nerves in 40 normal volunteers were stimulated with the evoked potential instrument.The results were collected with three-channel records in different ways at the same time.Results It showed two main waves,T1′(-) and T2′(+),in the brain trigeminal evoked potential records with C3,and their latencies were (3.020 5?0.828 9)ms and(6.736 0?1.393 9)ms;its T2-T1 interpeak latency was(3.743 8?1.206 0)ms.Conclusion C3 records showed more stability on brain trigeminal evoked potentials in normal volunteers,it would be helpful to investigate the brain trigeminal evoked potentials in patients.