EPILEPSY WITH GENERALIZED TONIC-CLONIC SEIZURES ALONE (EGTCA)

	Mandatory	Alerts	Exclusionary
Seizures	Generalised tonic-clonic seizures	Consistent focal features at seizure onset	Generalised myoclonic-tonic-clonic seizures (suggests juvenile myoclonic epilepsy) All other seizure types
EEG	3-5.5Hz generalised spike- or polyspike-wave		Focal slowing Consistently unifocal epileptiform abnormality Generalised slow (<2.5Hz) spike-wave (measured at the beginning of the spike-wave discharge) Diffuse background slowing (outside the postictal period)
Age at onset		5-9 or 26-40 years	<5 or >40 years
Development at onset		Mild intellectual impairment	Moderate or greater intellectual impairment
Neurological exam		Abnormal, potentially clinically significant
Imaging		Abnormal, potentially clinically significant	Structural cause for the epilepsy
Course of illness			Progressive cognitive decline
Are MRI or ictal EEG required for diagnosis? An MRI is not required for diagnosis, but should be considered in patients who have alerts or clinical concern for a structural aetiology An ictal EEG is not required
Syndrome without laboratory confirmation: in resource-limited regions, this syndrome cannot be diagnosed without interictal EEG showing generalised spike-wave, as a focal epilepsy cannot be excluded

NOTE Alert criteria are absent in the vast majority of patients with the syndrome, but rarely can be seen. Their presence should result in caution in diagnosing the syndrome and consideration of other conditions