We report on two siblings who presented with juvenile myoclonic epilepsy, and in whom myoclonic jerks of the right arm and hand were also triggered by writing tasks. Both patients underwent intensive video-electroencephalography monitoring, with simultaneous neuropsychological tests. In both patients, reflex epileptic myoclonus was more easily triggered by writing that required a higher degree of concentration. Conversely, other cognitive tasks, such as reading, typing, thinking, or calculation never elicited any seizures or myoclonus. Valproate was effective in controlling both spontaneous and reflex epileptic seizures. The results of this study further support the notion that 'praxis-induced' reflex epilepsy precipitated by specific stimuli occurs in the context of idiopathic generalized epilepsy. Our results also illustrate that writing tasks are more effective in eliciting seizures when they require higher levels of concentration and mental elaboration.