Juvenile Myoclonic Epilepsy

Background

• Juvenile myoclonic epilepsy also known as JME or Janz syndrome
• Most common generalized epilepsy syndromes in adolescents
• 1 in 1000 children
• Seizures start between 5 and 16 years old
• Sleep deprivation and stress are two very common triggers of myoclonic jerks and tonic clonic seizures.
• Sometimes triggered by flickering light

Clinic

• Typically myoclonic jerks that occur after sleep.
• Sometimes the myoclonic jerks are only in the fingers causing the patient dropping things.
• During the myoclonic jerks the patients are normally awake.
• Most of the patients have generalized tonic-clonic seizures
• Absence seizures in around 30-40% of the patients

EEG

• Generalized 3- to 6-Hz Spike slow wave complex or most often Polyspikes slow wave complexlasting 1-20 seconds
• Occasionally, short periods generalized Spikes and sharp waves can also be seen.
• Photosensitivity in 50% of the patients
• Normal background rhythm
• Focal abnormalities in a small amount of patients
• A morning EEG is more sensitive (69% epileptiform discharges) compared to afternoon EEG

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Generalized (poly)spike slow wave in a 15 year old male with JME (source)

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