Middle Latency Responses (MLR) in Brazilian children and adolescents: systematic review

Purpose: Systematically review the scientific literature on Middle Latency Response (MLR) in Brazilian children and adolescents. Research strategy: We searched articles published since 2009 in Portuguese, English or Spanish at MEDLINE, SciELO, BIREME and LILACS electronic basis. Selected articles involved the use of MLR in children and / or Brazilian adolescents. After screening process, articles were analyzed according to “Strengthening the Reporting of Observational Studies in Epidemiology” (STROBE) initiative. Selection criteria: Repeated articles (due to database repetition) and case reports were excluded. Results: From 1315 identified articles, eight were selected for the review. It was predominantly observed: cross-sectional studies (75%); click stimulation (100%), with rate up to 11/s (100%) and 70 dBHL intensity (88%); filtering high-pass 10 Hz (50%) and low-pass 200 Hz (75%); electrode array with actives placed at C3/ C4, references at A1/A2 and neutral at Fpz (88%); Na-Pa amplitude as main measure of comparison and normality; and the use of ANOVA test (63%) for statistical analyses. The average latency of Pa wave and Na-Pa amplitude in normal-hearing children and adolescents of the studies was 32 milliseconds and 1.57 microvolts respectively. Conclusion: There is no consensus on MLR collection parameters in Brazilian children and adolescents. Still, the Pa latency average and Na-Pa amplitude found in Brazilian normal-hearing children and adolescents evaluated on the eight articles of this review agreed with normative parameters established internationally.