The development of the vertex sharp transient.
The development of the vertex sharp transient (VST) was studied in 35 infants of ages from 10 wk until 40 mo. At 10 wk bicentral rhythms of 3-4/sec can be seen, at first asymmetrical, later symmetrical and "pieces" of this rhythm can occasionally appear. At 6 mo a few broad VST appear, but the earliest discrete VST appears around 16 mo, becoming sharper with a shorter duration at 24 mo and repetitive at 30 mo. Measurements reveal considerable variability in both amplitude and duration before 18 mo, after which the duration is typically around 100 msec, but with increasing variability in the amplitude difference between the two sides. These changes in the VST are discussed in relation to a recent study on the K-complex showing 3 well-defined frequency bands at < 1 Hz, 1-4 Hz and 12-15 Hz. Thus, the major developmental changes of the vertex sharp transient are that they become sharper, shorter in duration and more repetitive in time, and at around 16 mo are similar to the typical discrete pattern seen in older children and adults.
Department of Neurology, Univ. Ill. Med. Ctr., Chicago 60612, USA.
J R
JR
Hughes
D000375:Aging / Q000502:physiology; D002675:Child, Preschool; D004569:Electroencephalography; D006801:Humans; D007223:Infant