myoclonic-atonic seizure
A type of generalized seizure characterized by a brief muscle contraction followed immediately by loss of muscle tone, causing sudden falls.
Full Definition
Myoclonic-atonic seizures, also known as drop attacks, are generalized seizures that begin with a brief myoclonic jerk (sudden muscle contraction) immediately followed by an atonic phase (loss of muscle tone). This sequence typically lasts 1-2 seconds and results in sudden falls that can cause injury. These seizures are most commonly seen in children with epileptic encephalopathies, particularly Doose syndrome (myoclonic-atonic epilepsy). The seizures are often resistant to antiepileptic medications and may require protective headgear to prevent injury from falls.
Usage
Usage note: Hyphenate when used as compound adjective; distinguish from pure atonic seizures which lack the initial myoclonic component.
In Context
- "The child experienced multiple myoclonic-atonic seizures daily, requiring use of protective headgear." — Epilepsy clinic follow-up
- "Video EEG captured several myoclonic-atonic seizures with characteristic brief jerking followed by drop attacks." — EEG report