Werkgroep Elektroencefalografie

EEG

Grafo elementen
Normale ritmes | Benigne varianten | Fysiologische slaapfenomenen |
Klik op een bolletje op een specifieke lokalisatie in de hersenen om naar het desbetreffende grafo-element te gaan. Of klik op één van de bolletjes aan de zijkant voor grafo-elementen zonder vaste lokalisatie. 

K-complex  
A normal graphoelement. A well delineated negative sharp wave followed by a positive component standing out
from the background EEG, with total duration 0.5 s, usually maximal in amplitude when recorded from fronto-central derivations and often associated with a sleep spindle. 
Positive occipital sharp transient of sleep (POSTS)  
A normal graphoelement. Sharp transient maximal over the occipital regions, positive relative to other areas, apparently occurring spontaneously during sleep. May be single or repetitive. Amplitude varies but is generally below 50 mV.
Sleep spindle  
A normal graphoelement. Train of distinct waves with frequency at 11–16 Hz (most commonly at 12–14 Hz) with a duration 0.5 s. Generally higher amplitude over the central regions of the head, occurring during sleep. Amplitude varies but is maximal using central derivations.
Vertex sharp transient or vertex sharp wave (V wave)  
A normal graphoelement. Sharply contoured wave with duration <0.5 s, maximal at the vertex, negative relative to other areas, apparently occurring spontaneously during light sleep or in response to a sensory stimulus (usually auditory). Vertex sharp waves may be single or repetitive. Amplitude varies but rarely exceeds 250 mV.