Unequivocal clinical evidence of absence seizures with severe impairment of consciousness. Nearly all patients may have GTCS. More than half have myoclonic jerks but these are mild and do not show the circadian distribution of JME.

Documentation of ictal 3–4 Hz generalised discharges of spike or multiple spike and slow wave discharges longer than 4 seconds that are associated with severe impairment of consciousness and often with automatisms. Normal EEGs in treated patients are common.

Absences with marked eyelid or perioral myoclonus or marked single or rhythmic limb and trunk myoclonic jerks.

Absences with exclusively mild or clinically undetectable impairment of consciousness.

Consistent visual, photosensitive and other sensory precipitation of clinical absences is probably against the diagnosis of JAE. However, on EEG, intermittent photic stimulation often facilitates generalised discharges and absences.

Irregular, arrhythmic spike/multiple spike and slow wave discharges with marked variations of the intra-discharge frequency.

Significant variations between the spike/multiple spike and slow wave relations.

Predominantly brief discharges (<4 seconds).