The sharp theta rhythm on the occipital areas of prematures (STOP): a newly described waveform

This study on 500 prematures and neonates with conceptional ages (CA) of 23-49 wks describes the STOP pattern (sharp theta on the occipitals of prematures). STOP is similar to PT theta (premature temporal theta) in configuration, but is faster in frequency, lower in amplitude, more often unilateral, aside from the obvious difference in location. The incidence (%) was highest at the youngest age, decreasing to zero near term, and the amount (number of bursts) was greatest at 25 wks (CA). Three different parts appear in the incidence and amplitude curves, and these three parts may be related to changes in the laterality of the pattern. In the youngest age these rhythms are mainly bilateral, in the older neonates they are unilateral and are either for the ages between those extremes. STOP is seen more often in active sleep, but is reduced in incidence in patients with abnormal slow waves, ictal or immature patterns. Right-sided STOP was more frequently associated with abnormal EEGs, especially in males with right-sided sharp waves, often noted in the patients with seizures and intraventricular hemorrhages.