Zd. Jiang et al., Maximum length sequence brainstem auditory evoked responses in term neonates who have perinatal hypoxia-ischemia, PEDIAT RES, 48(5), 2000, pp. 639-645
Maximum length sequence brainstem auditory evoked response (BAER) was studi
ed within the first week after birth in 28 term neonates who had perinatal
hypoxia-ischemia, or asphyxia. In the BAER recorded using conventional aver
aging techniques (click rate 21/s), the only abnormality was a slight incre
ase in III-V interval, in addition to an increase in wave latencies when in
cluding those who had an elevated threshold (t test, all p < 0.05). In the
maximum length sequence BAER, however, both the m-v and I-V intervals in th
e 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 inter
val 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 t
he 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 hypoxi
a-ischemia became more prominent as click rate was increased. Significant a
bnormalities occurred mainly at very high click rates (455/s and 910/s), wh
ich 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 detectio
n of brain damage after hypoxia-ischemia than using conventional averaging
techniques, enhancing the diagnostic value of the BAER.