McGee T, Kraus N, Killion M, Rosenberg R, King C
Auditory Evoked Potentials Laboratory, Northwestern University, Illinois.
Ear Hear. 1993 Apr;14(2):76-84. doi: 10.1097/00003446-199304000-00002.
The auditory middle latency response (MLR), a useful tool in the assessment of low-frequency auditory sensitivity, can be consistently recorded in young children during wakefulness, stages 1 and 2, and REM sleep. Responses are often absent or questionable during stage 4. An on-line measure indicating favorable periods for recording MLR during sleep is important for interpretation of absent potentials. Here, for children 5 to 7 years old, the reliability and detectability of MLR was compared to sleep state and the dominance of delta activity (0-3 Hz) in the EEG frequency spectrum. Dominance of delta activity, a characteristic of stage 4, was expressed in a "delta ratio," a measure of relative EEG energy in the 0 to 3 Hz frequency spectrum. A fixed delta ratio (DR = 9) allowed the differentiation of periods favorable for MLR. MLR wave Pa amplitude and latency also varied with delta ratio. Results indicate that on-line monitoring of the delta ratio will allow reliable testing of MLR in clinical situations.
听觉中潜伏期反应（MLR）是评估低频听觉敏感性的一项有用工具，在幼儿清醒、第1和第2阶段睡眠以及快速眼动睡眠期间均可持续记录到该反应。在第4阶段睡眠期间，反应通常缺失或存在疑问。一项用于指示睡眠期间记录MLR有利时段的在线测量指标对于解释电位缺失很重要。在此，针对5至7岁儿童，将MLR的可靠性和可检测性与睡眠状态以及脑电图频谱中δ活动（0-3赫兹）的优势进行了比较。δ活动的优势是第4阶段睡眠的一个特征，用“δ比率”来表示，这是一种测量0至3赫兹频谱中相对脑电图能量的指标。一个固定的δ比率（DR = 9）能够区分有利于记录MLR的时段。MLR波Pa的振幅和潜伏期也随δ比率而变化。结果表明，对δ比率进行在线监测将使得在临床情况下能够可靠地检测MLR。
