title: Maximum length sequence brainstem auditory evoked responses in term neonates who have perinatal hypoxia-ischemia.
abstract: Maximum length sequence brainstem auditory evoked response (BAER) was studied within the first week after birth in 28 term neonates who had perinatal hypoxia-ischemia, or asphyxia. In the BAER recorded using conventional averaging techniques (click rate 21/s), the only abnormality was a slight increase in III-V interval, in addition to an increase in wave latencies when including those who had an elevated threshold (t test, all p<0.05). In the maximum length sequence BAER, however, both the III-V and I-V intervals in the asphyxiated infants were significantly increased at all the 91/s, 227/s, 455/s, and particularly 910/s click rates (p<0.05-0.001). The I-III interval was also increased significantly at 455/s and 910/s click rates (both p< 0.05). Wave V amplitude was significantly reduced at all the click rates used (ANOVA, p<0.05-0.001), particularly at 910/s, which sometimes was the only abnormality indicative of brain damage. Both the amplitude ratios V/I and V/III were significantly decreased at 455/s and 910/s click rates (p<0.01 or 0.001). A general trend was that BAER abnormalities after hypoxia-ischemia became more prominent as click rate was increased. Significant abnormalities occurred mainly at very high click rates (455/s and 910/s), which can be achieved using the maximum length sequence technique but not by using conventional averaging techniques. Thus, this technique, which can be used at the cribside, appears to be a better method for the early detection of brain damage after hypoxia-ischemia than using conventional averaging techniques, enhancing the diagnostic value of the BAER.
authors.affiliation: Neonatal Unit, Department of Paediatrics, John Radcliffe Hospital, University of Oxford, Headington, Oxford OX3 9DU, United Kingdom.
authors.forename: Z D
authors.initials: ZD
authors.lastname: Jiang
authors.forename: D M
authors.initials: DM
authors.lastname: Brosi
authors.forename: X M
authors.initials: XM
authors.lastname: Shao
authors.forename: A R
authors.initials: AR
authors.lastname: Wilkinson
mesh_terms: D000161:Acoustic Stimulation; D000367:Age Factors; D001238:Asphyxia Neonatorum / Q000150:complications / Q000503:physiopathology*; D001930:Brain Injuries / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000150:complications / Q000503:physiopathology*; D007231:Infant, Newborn; D008297:Male