MAE is an epilepsy syndrome of early childhood that is often resistant to medication and for this reason it is typically difficult to treat. It is usually characterized by difficult-to-control generalized seizures, and is idiopathic (no known cause) in nature. The generalized seizure types seen in this syndrome vary, but many of the afflicted children can experience large numbers of seizures daily, part of what makes this condition so difficult to manage.
Onset generally occurs between ages one and five, usually in children with an uneventful history. In some cases, there is a positive family history of seizures, and family studies over the years have supported a genetic basis. Hallmark features on an EEG help define MAE and, in almost all cases, rhythmic parietally accentuated 4-7 Hz background seizure activity develops early in the course.
In about 60% of cases, MAE starts with febrile or afebrile generalized tonic-clonic convulsions. Alternating grand mal and hemi-grand mal seizures are a possible presentation. Some days or a few weeks later, myoclonic and/or myoclonic-astatic seizures appear in abundance, frequently in combination with short absences.
• Myoclonic-Astatic Epilepsy usually occurs in children with an uneventful history; there is likely to be no pre-existing neurological disorder.
• It clearly affects more boys than girls at a ratio of about 3:1.
• In 24% of the cases, the epilepsy starts during the first year of life (at 2, 4 or 5 months of age).
• In 94% of the cases, the epilepsy starts within the first five years of life.
• In 100% of cases, the child develops myoclonic and/or myoclonic-astatic (or drop) seizures. The -astatic (loss of muscle tone) feature of the myoclonic-astatic seizure is rare and unique to MAE, and is the most important and distinct feature which helps differentiate it from other syndromes.
• In addition to myoclonic seizures, children may also have a combination other generalized seizures including tonic-clonic, absence and non-convulsive status epilepticus and, rarely, tonic seizures. See Seizure types.
Hallmark features on an EEG help define MAE and, in almost all cases, rhythmic parietally accentuated 4-7 Hz background seizure activity develops early in the course.