The Epilepsy Foundation points out that every year, 300,000 people have their first seizure. In a seizure, electrical activity in the brain becomes disrupted, resulting in physical or behavioral changes. One type of seizure is an atonic seizure, also known as akinetic seizure, drop attack or astatic seizure.
Time Frame
Epilepsy.com notes that atonic seizures, which start during childhood, usually run their course in under 15 seconds. In an International League Against Epilepsy (ILEA) article titled "Atonic Seizures," the authors point out that some types of atonic seizures last longer. Patients can continue to have these seizures into adulthood.
Types
Two types of seizures are recognized: generalized seizures and partial seizures. These two types of atonic seizures differ according to the areas of the brain affected. Generalized atonic seizures affect the entire brain. The Epilepsy Foundation points out that atonic seizures are typically classified as generalized seizures. But ILEA authors Michelucci, Tassinari and Seino explain that some people have partial atonic seizures. In a partial atonic seizure, the abnormal electrical activity occurs in one area of the brain and does not spread to affect the other cerebral hemisphere. The authors note that patients with partial atonic seizures have abnormal activity in the frontal lobe or the parietal lobe. The frontal lobe is located behind the forehead, and the parietal lobe is towards the top of the head and behind the frontal lobe.
Symptoms
During an atonic seizure, patients quickly lose their muscle tone. The Epilepsy Foundation notes that patients can suddenly collapse, which can lead to head and face injuries. A loss of consciousness does not occur during an atonic seizure. Other symptoms of an atonic seizure include loss of posture and dropping of the head. Michelucci, Tassinari and Seino add that partial atonic seizure patients can lose their ability to move one or more body parts during the seizure.
Diagnosis
Doctors diagnose atonic seizures using tests and observation. Epilepsy.com explains that the diagnosis often begins when someone watching the patient, such as a parent, describes the observed symptoms to a doctor. To rule out other causes of falling, doctors test patients' blood pressure and heart rhythm. An atonic seizure screening also includes an electroencephalogram test, or EEG, which measures changes in the brain's electrical activity.
Treatment
The Epilepsy Foundation notes that atonic seizure patients may need to wear protective headgear to help prevent head injuries during a seizure. Since atonic seizures do not respond to conventional antiepileptics, finding medication that can control the seizures can be difficult. Michelucci, Tassinari and Seino note that valproic acid, a benzodiazepine class drug, or a combination of valproic acid and lamotrigine, a newer antiepileptic, can help some atonic seizure patients. Some atonic seizure patients may require surgery. An option is a callosotomy, in which the surgeon cuts the corpus callosum, which connects the two cerebral hemispheres. A callosotomy prevents abnormal electrical activity in one cerebral hemisphere from spreading to the other. But with the corpus callosum cut, the two cerebral hemispheres can no longer communicate with each other.
