EEG after sleep deprivation is a sensitive tool in the first diagnosis of idiopathic generalized but not focal epilepsy

•In patients with suspected generalized epilepsies sleep-deprived EEG (SD-EEG) should be considered a cost-effective additional diagnostic method.•In patients with suspected focal epilepsy SD-EEG does not show higher sensitivity than a repeated standard EEG.•In focal epilepsies further diagnostic steps as for example a long-term EEG should be considered.