The Development of the Electroencephalogram in Normal Children from the Age of 1 Through 15 Years – 14 and 6 Hz positive spike phenomenon

Abstract

In a material of 1 trough 15-year-old normal children the occurrence of the 14 and 6 Hz positive spike phenomenon was studied. The children were considered normal as a result of 1: strict selection after thorough penetration of obstetric history, mental and physical development, diseases and injuries involving the CNS, and past and present behavior to exclude neurological and psychical disorders; 2: physical examination to exclude actual somatic and neurological aberrations, and at the same time 3: routine observation to reveal overt psychopathology.

599 EEG:s with successful sleep registrations were obtained in the same number of children. There were 315 girls and 284 boys. In classifying the data, it was noticed that a number of records contained typical complexes of the 14 and 6 Hz positive spike phenomenon; in some of these also atypical or abortive complexes were seen. These records were designated as having potential complexes called “14–6”. Records with only the atypical phenomenon were designated as “14–6?”. The “14–6” was found in 55 children (9.2 per cent) and only the “14–6?” in 42 children (7.0 per cent) with a combined frequency — “14–6-Tot.” — of 16.2 per cent. The two events are found to be related in several respects and can be dealt with as one variable. Some differences have been found, however, which will be further evaluated. There was no statistically significant difference in regard to sex.

There is a successive increase in incidence of the 14–6-PS throughout childhood. This relation to age is statistically significant and may reflect the development of the neuronal connections underlaying the rhythm-generating mechanisms parallel with other changes of the brain. The resemblance to the development of the alpha frequency has been discussed.

The 14 and 6 Hz positive spike phenomenon appeared most distinctly in bi-temporal derivations using bipolar recording technique. In 96 per cent of the children the phenomenon emerged within 5 minutes of light sleep — in 43 per cent already in deep drowsiness.

An equal level of probability density of 14–6-PS was kept during falling asleep as well as during a 5 min. period of light sleep. The importance of getting the child to the right stage of light sleep and maintaining him there must be heavily stressed.

The form and appearance of the 14 and 6 Hz positive spike phenomenon have been described as well as relations to other EEG manifestations. Statistically significantly positive correlations to paroxysmal effects were found.

The 14 and 6 Hz positive spike phenomenon is a not infrequent age dependent EEG pattern, which occurs to the same extent in girls and boys without support for a relation to certain clinical symptoms, as has been suggested in the literature. The origin is discussed and the phenomenon obviously appears due to underlying thalamo-cortical mechanisms.

Zusammenfassung

Das Auftreten von 14 und 6 Hz positiven scharfen Wellen wurde bei Kindern zwischen ein und 15 Jahren untersucht. Es handelte sich um normale Kinder ohne Risikofaktoren während der Schwangerschaft, der Geburt und ihre Entwicklung bis zum Zeitpunkt der Untersuchung. Die Kinder hatten keine somatischen oder psychopathologischen Erkrankungen oder Anomalien.

Die Untersuchungen wurden durchgeführt an 315 Mädchen und 284 Knaben mit insgesamt 599 elektroenzephalographischen Registrierungen während des Schlafes. Eine bestimmte Anzahl von Ableitungen enthielt die typischen und atypischen 14 und 6 Hz positiven sharp waves — „14–6”, bei einigen Kindern wurden sie nur in atypischer Form gesehen. Die letzteren Ableitungen wurden als „14–6?” bezeichnet.

Die „14–6” traten bei 55 Kindern (9,2%) auf, die „14–6?” bei 42 Kindern (in 7%), im ganzen wurde das Phänomen also bei 16,2% der Kinder gesehen. Es bestand kein statistisch signifikanter Unterschied zwischen den beiden Geschlechtern.

Die 14 von 6 Hz positiven sharp waves nehmen mit dem Alter während der Kindheit zu.

Die 14 und 6 Hz positiven sharp waves treten vorwiegend temporal auf bei bipolarer Ableitungstechnik. Bei 96% der Kinder trat das Phänomen fünf Minuten nach dem Einschlafen, bei 43% schon während des Müdewerdens auf.

Um das Phänomen zu studieren, muß man also die Kinder unbedingt während des Einschlafens und während der ersten Phase des noch unsicheren Schlafes halten.

In dieser Arbeit werden die Form, das Aussehen der 14 und 6 Hz positiven sharp waves auch in Abhängigkeit zu anderen EEG-Phänomenen genau beschrieben. Es besteht eine statistisch signifikante Beziehung zwischen den 14 und 6 Hz positiven sharp waves und paroxystischen Entladungen während des Einschlafens.

Die 14 und 6 positiven sharp waves sind ein häufiges altersabhängiges EEG Merkmal, das nicht als abnorm gewertet werden kann.

Keyword

Development - electroencephalography - 14 and 6 Hz positive spike phenomenon - normal children