Epilepsy With Generalized Tonic-Clonic Seizures Alone

Etiologies: considering that it is related to genetic factors (it may involve complex/polygenic inheritance, and some think it is related to the variation of CLCN2 gene), about 20% have a family history of epilepsy，and a family history of febrile seizures is reported in around 10% of cases [1].

Age of onset: onset of seizures generally from age 5 to 50 years (peak 10 to 20 years).

Seizure characteristics: All have generalized tonic-clonic seizures (some GTCS may have transient myoclonus or clonic action before onset, it often appearing within 1-2 hours after awakening), and there are basically no other seizure types [2-3].

EEG: Background: normal. Interictal: generalized 3-5Hz spike slow wave or multi spike slow wave (about 50% patients only appear in sleep). Ictal: EEG is often obscured by artifact. In tonic stage, Generalized fast rhythmic spikes can be seen. Spike slow complex wave are synchronous with clonic jerks, and irregular slow wave activity can appear in the follow-up.

Brain MRI: Most of them are bacically normal.

Developmental progress: Most of them are normal.

Reference

International League Against Epilepsy. epilepsy with generalized tonic-clonic seizures alone (Accessed March 15, 2021).
Panayiotopoulos. 癫痫综合征及临床治疗. 北京 : 人民卫生出版社, 2012.
刘晓燕. 临床脑电图学. 第2版. 北京 : 人民卫生出版社, 2017.