Myoclonic astatic epilepsy, also known as Doose syndrome, is a generalized idiopathic epilepsy. It is characterized by the development of myoclonic seizures and/or myoclonic astatic seizures.
Tonic–clonic Seizures with repetitive sequences of stiffening and jerking of the extremities.
Myoclonic Seizures with rapid, brief contractions of muscles.
Atonic Seizures with a sudden loss of muscle tone, often resulting in sudden collapse. These are also called drop seizures.
Absence A generalized seizure characterized by staring off and occasionally some orofacial automatisms.
Myoclonic astatic Seizures that involve a myoclonic seizure followed immediately by an atonic seizure. This type of seizure is exclusive to MAE and is one of the defining characteristics of this syndrome.
Tonic Muscle stiffening or rigidity. This seizure is rare in this syndrome.
The onset of seizures is between the ages of 2 and 5. EEG shows regular and irregular bilaterally synchronous 2- to 3-Hz spike-waves and polyspike patterns with a 4- to 7-Hz background. 84% of affected children show normal development prior to seizures; the remainder show moderate psychomotor retardation mainly affecting speech. Boys (74%) are more often affected than girls (Doose and Baier 1987a).
Epilepsy with myoclonic-astatic seizures has a variable course and outcome. Spontaneous remission with normal development has been observed in a few untreated cases. Complete seizure control can be achieved in about half of the cases with antiepileptic drug treatment (Doose and Baier 1987b; Dulac et al. 1990). In the remainder of cases, the level of intelligence deteriorates and the children become severely intellectually disabled. Other neurologic abnormalities such as ataxia, poor motor function, dysarthria, and poor language development may emerge (Doose 1992b). However, this proportion may not be representative because in this series the data were collected in an institution for children with severe epilepsy.
The outcome is unfavorable if generalized tonic-clonic, tonic, or clonic seizures appear at the onset or occur frequently during the course. Generalized tonic-clonic seizures usually occur during the daytime in this disorder, at least in the early stages. Nocturnal generalized tonic-clonic seizures, which may develop later, are another unfavorable sign. If tonic seizures appear, prognosis is poor.
Status epilepticus with myoclonic, astatic, myoclonic-astatic, or absence seizures is another ominous sign, especially when prolonged or appearing early.