No abstract available.
Evoked Potentials, Auditory, Brain Stem*

No abstract available.
Evoked Potentials, Auditory, Brain Stem*

No abstract available.
Evoked Potentials, Auditory, Brain Stem*

No abstract available.
Child* ; Evoked Potentials, Auditory, Brain Stem* ; Humans

No abstract available.
Evoked Potentials, Auditory, Brain Stem* ; Humans ; Infant*

No abstract available.
Evoked Potentials, Auditory, Brain Stem* ; Rabbits*

No abstract available.
Adult* ; Evoked Potentials, Auditory, Brain Stem* ; Humans*

Objective The tests of three types of auditory evoked potentials （AEPs） were performed on normal young adults, to understand the frequency characteristics of different testing methods and the relationship between response threshold and pure tone audiometry threshold of different methods, and to discuss the forensic value of 3 types of AEPs to evaluate hearing function. Methods Twenty normal young adults were selected, their standard pure tone audiometry threshold, short-term pure tone audiometry threshold and the response threshold of 3 types of AEPs （tone burst-auditory brainstem response, 40 Hz auditory event-related potential and slow vertex response） at 0.5 kHz, 1.0 kHz, 2.0 kHz and 4.0 kHz were recorded. The relationship between the response threshold and standard pure tone audiometry threshold, short-term pure tone audiometry threshold of 3 types of AEPs at different frequencies as well as the differences between different types of AEPs were analyzed. Results The short-term pure tone audiometry threshold was higher than the standard pure tone audiometry threshold at each frequency. The response threshold and standard pure tone audiometry threshold of the 3 types of AEPs all had a certain correlation, and the response threshold of the 3 types of AEPs was higher than short-term pure tone audiometry threshold and standard pure tone audiometry threshold at each frequency. The differences in the differences between the response threshold and standard pure tone audiometry threshold of the 3 types of AEPs at different frequencies had statistical significance. Linear regression mathematical models were established to infer the standard pure tone audiometry threshold （hearing level） from response threshold （sound pressure level） of 3 types of AEPs of normal young adults. Conclusion When using response threshold of different types of AEPs to estimate pure tone audiometry threshold, conversion and correction are needed. Combined use of different types of AEPs could improve the accuracy of hearing function evaluation.
Audiometry, Evoked Response ; Audiometry, Pure-Tone ; Auditory Threshold ; Evoked Potentials, Auditory ; Evoked Potentials, Auditory, Brain Stem ; Hearing ; Humans ; Young Adult

OBJECTIVEWe aim to explore the central auditory nervous system (CANS) functioning in children with nonsyndromic cleft palates by analyzing the auditory evoked potentials and event-related potentials (ERP).

METHODSA total of 34 children with nonsyndromic cleft palates were recruited as subjects, and 27 normally developed children were selected as the normal controls. Auditory brainstem response (ABR), middle latency response (MLR), and mismatch negativity (MMN) of ERP were selected as indices to observe the function of CANS in children in both groups.

RESULTSAstatistically significant difference between the groups was obtainedin the MMN recording (F = 227.69, P < 0.01), whereas no significant group differences were obtained in the ABR and MLR results (P > 0.05). Children with nonsyndromic cleft palates showed diminished MMN responses compared with the normal controls, whereas ABR and MLR were within the normal range.

CONCLUSIONChildren with nonsyndromic cleft palates are at risk of central auditory discrimination dysfunction. The significant abnormal event-related potentials recorded in children with cleft palates suggest that the dysfunction of CANS maybe located at the cortical level and normal function of CANS was located at the brain stem and sub-cortical level.

BACKGROUND: P300 component of the long latency auditory evoked potentials (LLAEPs) provides information on conscious and cortical funtion. The P300 wave occures only for stimuli that somehow capture the patients attention. Therefore LLAEPs implys a degree of cognitive processing. We studied sedation scale and P300 wave to determine if LLAEPs could be utilized as electrophysiologic predictors of sedation. METHODS: The P300 component of LLAEPs from vertex was recorded from 10 ASA physical status I and II patients undergoing elective surgery while they listened via headphones to a series of clicks which were interrupted unpredictably by a tone burst (2 KHz) before and after diazepam 0.04 mg/kg and 0.08 mg/kg IV. The patients were asked to concentrate on the clicks and to press a button whenever they detected a 2 KHz tone. And sedation scale also was measured. RESULTS: Amplitude of P300 was decreased and latency of P300 was increased in a dose-dependent manner with IV diazepam. Amplitude was greatest and latency was shortest in awake. And sedation scale also was increased according to increased IV diazepam adminstration. CONCLUSIONS: Both amplitude and latency may be highly related to the sedation scale with progressively increasing dose of diazepam. Therefore we conclude that P300 component of LLAEPs can be utilized as an electrophysiologic predictor of awareness and sedation.
Diazepam* ; Event-Related Potentials, P300* ; Evoked Potentials, Auditory* ; Humans