epilepsy develops between ages 12 and 18. People with
the disorder tend to have seizures that cause jerking in the shoulders or arms.
Generalized tonic-clonic seizures and absence seizures may be present along
with myoclonic seizures. Seizures often occur early in the morning.
People with juvenile myoclonic epilepsy have normal intelligence and
do not have other brain or nerve disorders. A family history of myoclonic
seizures is present in about half of the people with the disorder. But the exact
cause is unknown. Most people require lifelong treatment with