A myoclonic-atonic seizure is a myoclonic seizure followed by an atonic seizure. Sometimes a series of myoclonic jerks occurs prior to the atonia. The head and limbs are affected, typically resulting in rapid fall. The myoclonic jerk may be subtle.
NOTE Myoclonic-atonic seizures are one type of seizure that can result in a "drop attack", other causes of drop attacks include myoclonic (especially in younger children), tonic and atonic seizures.