Table 1.
Differences in electroencephalographic (EEG) features among syndromes.
| Reference | CAE | JAE | JME | GTCSA | |
|---|---|---|---|---|---|
| GSWD frequency (Hz) | (66) | 3.3 | 3.2 | 3.9 | 3.6 |
| Irregular and disorganized paroxysms | (7) | Least common | 8 times more likely than CAE | 110 times more likely than CAE | NA |
| Percentage of GSWD fragments containing polyspikes | (7) | A—0, D—13%, S—40% | A—0, D—12%, S—24% | A—50%, D—50%, S—50% | NA |
| Photoparoxysmal response | (7) | 21% | 25% | 83% | NA |
| Absence seizures during hyperventilation | (7) | 87% | 87% | 33% | NA |
| Mean duration of paroxysms (s) | (66) | 2.8 | 4.6 | 3.2 | 2.5 |
| Total spike density | (66) | + | +++ | +++ | + |
| Density of generalized paroxysms | (66) | + | +++ | + | + |
| Density of polyspikes and polyspike-wave discharges | (66) | + | +++ | ++ | + |
| Density of pure GSWD | (66) | ++ | ++ | + | + |
CAE, childhood absence epilepsy; GSWD, generalized spike-wave discharges; GTCSA, generalized tonic-clonic seizures alone; JAE, juvenile absence epilepsy; JME, juvenile myoclonic epilepsy; NA, not available; A, awake; D, drowsy; S, sleep; density; duration of epileptiform discharges (in seconds) per an hour of EEG recording; +++, highest value; +, lowest value; +++, middle value; pure GSWD, fragments and paroxysms containing only spike-wave discharges (without any polyspikes or polyspike-wave discharges) (7, 66).