Makindo Medical Notes

Related Subjects: |Status Epilepticus (Epilepsy) |Coma management |Lorazepam |Phenytoin |Levetiracetam |Epilepsy - General Management |First Seizure |Epilepsy in Pregnancy |Febrile seizures

Patients diagnosed with JME usually need to remain on AEDs for life due to the high rate of recurrence. JME responds to treatment with Sodium Valproate. Newer broad-spectrum drugs such as topiramate, and possibly Levetiracetam, may also be beneficial.

About

• Juvenile Myoclonic Epilepsy (JME) is a subtype of idiopathic generalized epilepsy often misdiagnosed due to its unique presentation.
• Can be worsened with inappropriate anti-epileptic drugs, particularly carbamazepine or phenytoin.

Aetiology

• Genetic predisposition with a molecular defect affecting neuronal excitability.
• Family history is positive in about 50% of cases.
• Occurs slightly more frequently in females.

Genetics

• JME has some familial forms, though no single causative gene has been definitively identified.
• Ongoing research is investigating potential genetic markers.

Epidemiology

• Incidence is 1 per 2000, with typical onset between ages 5 and 16 years.
• Absence seizures often appear first, followed by myoclonic jerks approximately 10 years later, with generalized tonic-clonic seizures developing in late adolescence.

Types of Seizures in JME

• Absence Seizures: More frequent in the mornings; consciousness may be preserved.
• Myoclonic Seizures: Sudden jerks in the arms, legs, or face, often occurring upon awakening.
• Generalized Tonic-Clonic Seizures (GTCS): Typically within 1-2 hours of waking and may follow frequent myoclonic jerks.

Clinical Features

• Myoclonic jerks are more common in the morning, leading to the nickname "cornflake epilepsy" due to jerking movements often noticed during breakfast.
• Triggered by sleep deprivation, stress, or alcohol.
• Photosensitivity may cause seizures triggered by flashing lights.
• Non-progressive disorder without intellectual deficits or physical abnormalities.

Investigations

• Blood Tests: Typically normal.
• CT/MRI: Brain imaging is usually unremarkable.
• EEG: Generalized polyspikes and 3 Hz spike-wave complexes; abnormalities are more evident during hyperventilation.

Management

• Patients require lifelong treatment. Advice includes avoiding sleep deprivation and ensuring medication compliance due to high recurrence rates.
• First-line Treatment: Sodium Valproate, although often avoided in fertile females. Response to Valproate supports JME diagnosis.
• Alternatives: Lamotrigine, Levetiracetam, Topiramate, and Zonisamide can also be effective.
• Avoid: Phenytoin, Gabapentin, Carbamazepine, Phenobarbital, Tiagabine, and Vigabatrin as they may exacerbate JME or be ineffective.

References

• JUVENILE MYOCLONIC EPILEPSY