Myoclonic-astatic Seizures (atonic or drop attack)

The myoclonic-astatic seizure is rare and unique to MAE, and is one of the most important and distinct features which helps distinguish it from other epilepsy syndromes.

Like myoclonic seizures, myoclonic-astatic seizures (also called atonic or drop attacks) are sudden, single events. Myoclonic-astatic seizures involve abrupt loss of muscle control causing the person to fall to the ground, often resulting in injury. For any family and child, the sudden, violent impact and resultant injuries seen with myoclonic-astatic seizures makes them one of the most frightening and distressing types of seizures to live with.

As the label myoclonic-astatic epilepsy (MAE) suggests, myoclonic-astatic seizures are the core seizure type associated with the disorder. In MAE, myoclonic-astatic seizures can be serious because they may be difficult to control, occur frequently on a daily basis putting the child at persistent risk of injury, and because they are only one manifestation of this mixed seizure disorder.

What happens?
Astatic seizures are sudden involuntary events like myoclonic seizures, however, rather than a sudden increase in muscle tone causing a jerk, astatic seizures involve sudden loss of muscle tone.
Myoclonic-astatic seizures we see in MAE involve this astatic seizure (loss of muscle tone) often preceded by a short myoclonia (jerk) component as well. Arms, legs, or torso muscles that support the body by their tone, suddenly go limp; the body gives way with a jolt. The torso may slump, the legs may give way, or the body may fall to the ground. If a myoclonic-astatic seizure occurs while a child is standing, the seizure may cause the child to slam violently to the ground, perhaps hitting his/her face, breaking a tooth, or causing a facial laceration.

Like myoclonic seizures, astatic seizures arise from deep structures in the brain stem that control muscle tone. Since the areas that increase tone are close to those that decrease tone, children with seizures involving sudden changes in tone may have either myoclonic or astatic seizures and often both which is what we see typically with MAE.

As is the case with all generalised seizures, the child is not conscious during the event but the seizure is so brief that he/she usually recovers quickly. Sometimes a child may be mildly agitated or disorientated following an astatic seizure. If injury has resulted, he/she may be duly distressed.

What to do
Guide the child from danger
Look for an epilepsy identity card or identity jewellery
Attend to any injury which may have resulted
The child may be agitated so stay with him/her until recovery is complete
Be calmly reassuring
Explain anything that they may have missed

Restrain the child
Act in a way that could frighten the child, eg abrupt movements or shouting at them
Assume the person is aware of what is happening or what has happened
Give the child anything to eat or drink until they are fully recovered
Attempt to bring them round

Call an ambulance if
The seizure event continues for more than five minutes
One seizure follows another seizure without the child regaining consciousness between them
The child is injured during the seizure
You believe the child needs urgent medical attention