Late-onset Juvenile Myoclonic Epilepsy or Frontal Lobe Epilepsy with Myoclonus

To the Editor：The term myoclonus refers to a form of fast,transient,lightning-like muscle twitch that originates in the nervous system.It is usually a manifestation of neurological dysfunction or intractable epilepsy and is clinically divided into cortical myoclonus,spinal myoclonus,physiological myoclonus,etc.It is also categorized as epileptic myoclonus or nonepileptic myoclonus.Juvenile myoclonic epilepsy （JME） is the most common form of epileptic myoclonus,while frontal lobe epilepsy （FLE） with myoclonus is relatively rare.The clinical manifestations of these two forms of epilepsy include shock-like muscle activity appearing in the upper limbs or involving the shoulder and arms together,with irregular and arrhythmic clonus in the morning after waking up that typically results in an involuntary hurtling of objects held in the hands.It is hard to make a distinction between the two conditions clinically.Herein,we report a case of FLE with myoclonus to provide clues to distinguish between the two.