Epilepsy with myoclonic-atonic seizures, also known as Doose syndrome: Modification of the diagnostic criteria.

Abstract

The aim of this review is to propose the updated diagnostic criteria of epilepsy with myoclonic-atonic seizures (EMAS), which is a recent subject of genetic studies. Although EMAS has been well known as Doose syndrome, it is often difficult to diagnose due to a lack of consensus regarding some of the inclusion criteria. Along with progress in molecular genetic study on the syndrome, it becomes important to recruit electroclinical homogeneous EMAS patients, hence the validity of the clinical criteria should be verified based on recent clinical researches. At present, the most updated ILAE diagnostic manual of EMAS includes: (1) normal development and cognition before the onset of epilepsy; (2) onset of epilepsy between 6 months and 6 years of age (peak: 2-4 years); (3) myoclonic-atonic seizures (MAS) are mandatory (4) presence of generalized spike-wave discharges at 2-3Hz without persistent focal spike discharges; and (5) exclusion of other myoclonic epilepsy syndromes. In the criteria, we should emphasize that the age at onset of MAS is between 2-5 years in (2), presence of myoclonic-atonic, atonic or myoclonic-flexor seizures (MASs) causing drop attacks associated with generalized spike-wave discharges is mandatory in (3), and epileptic spasms causing drop attacks must be excluded in (5). In the modified criteria, I propose that EMAS is redesignated as genetic generalized epilepsy with MASs, consistent with the familial genetic study conducted by Doose and the recent identification of candidate genes. It should also be noted that EMASs evolves to transient or long-lasting epileptic encephalopathy.