Atonic seizure

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at October 1, 2016
StartDiseasesAtonic seizure

Atonic seizures are often referred to as drop seizures or drop attacks. They are also known as akinetic seizures. These seizures result in a sudden loss of muscle tone. They don't usually last any longer than 15 seconds. In the moment that they occur, the muscles lose strength. 


Definition & Facts

The muscles of the body usually have what is considered as muscle tone or a normal amount of tension. However, when an atonic seizure occurs, there is an abnormal change in brain activity that causes the muscles to lose their tone. Atonic seizures are mostly associated with generalized epilepsy which affects both sides of the brain.

Atonic seizures can occur without any warning whatsoever and come on quite suddenly. When muscle tone vanishes, it can cause a person to drop to the floor immediately. In mild cases, it may only affect the head or the eyelids.

It can be quite frightening when the condition strikes. Fortunately, it does not last. While this condition can affect anyone at any age, it is more common to be a problem for children.

Symptoms & Complaints

When an individual is affected by atonic seizures, one of the most common symptoms is a sudden fall or collapse to the floor as the muscles go loose. The patient may begin to jerk or shake. The head may flop down or the eyelids can begin to droop. In some instances, a person suffering an atonic seizure will briefly lose consciousness.

Atonic seizures are generally brief. However, in some cases they may last for a few minutes. Atonic seizures are most obvious when a patient is standing because of the sudden drop as the body goes completely limp. When sitting or lying down, it may not be as obvious that a seizure is happening, especially if it is brief.

Atonic seizures generally do not involve muscle contraction, unlike tonic seizures or myoclonic seizures. When a patient having an atonic seizure falls, they will do so limply, as opposed to rigidly which would be the case of a person suffering from a tonic seizure.

Brief spasms or jerks may be a sign that an atonic seizure is about to occur. They may be isolated or a patient may have several in a row. The biggest concern is getting hurt from the fall. In some cases, the patient may experience confusion after the seizure.


Atonic seizures are actually considered a form of epilepsy, and they are caused by abnormal brain activity that happens on occasion. There is a possibility that genetic factors play a part in the development of atonic seizures. A patient may have suffered a traumatic head injury or experienced an injury during development in the womb.

Viral encephalitis, AIDS, and meningitis are illnesses that can affect the brain and bring on atonic seizures. They may develop in patients who have a condition that affects the brain.

For example, a stroke patient or an individual with a brain tumor may develop atonic seizures. They often begin in childhood. Brain injury and brain infection are matters of greatest concern that could be connected to atonic seizures.

Diagnosis & Tests

Atonic seizures are most often diagnosed after they have been described to a doctor. A physician may order a battery of tests to determine if a type of cardiovascular disease such as a problem with blood pressure (hypertension or high blood pressure, for example ) is causing a person to suddenly collapse.

The doctor will also perform a physical examination and inquire about the patient's medical history and family history of disease. The patient will also undergo a thorough neurological examination including tests of the patient's sensory and motor responses, reflexes, speech, hearing, and cognition.

It is important to rule out any medical conditions that could be causing the seizures, including brain infections or a tumor. Neuroimaging scans may also be conducted such as a magnetic resonance imaging (MRI) and a computed tomography (CT) scan. An electroencephalography (EEG) can be ordered to check brain activity. If no other issues are identified, atonic seizures may be considered to blame.

Treatment & Therapy

If the seizure is ongoing, treatment must incorporate first aid. Giving first aid involves staying with the patient until the seizure ends, keeping track of how long the seizure lasts, removing dangerous or sharp objects from the vicinity, and calling for emergency help if the seizure lasts longer than five minutes, if the person requests medical help, if the person's breathing is interrupted, or if the person is injured.

Various anticonvulsant medications can be used to treat and prevent atonic seizures. 7 out 10 people epilepsy cases are treated effectively with medicine. Medicines to treat seizures include valproic acid, lorazepam, clonazepam, carbamazepine, and diazepam, among others.

It may be possible to surgically eliminate the problem as well. Surgery is generally opted for by people who are unresponsive to medication for an extended period of time. It may be especially useful for those with a structural brain abnormality or disease like a brain tumor.

Dietary changes and vagus nerve stimulation have been found to be effective as well. Every situation is unique. Often, several approaches may be necessary in order to have optimal results. Clinical trials also offer hope to patients as new therapies and medications are introduced.

If one type of treatment does not work effectively, it is important to go back to the doctor to express concerns. Trial and error is often the best approach to find a course of action that will work to address atonic seizures. Regardless of what age it strikes, an atonic seizure can be frightening and result in painful injuries. Solutions are at the ready.

Prevention & Prophylaxis

It is important to identify atonic seizures and begin treatment in order to avoid injury. Getting hurt while enduring a seizure from falls and drowning are a concern, as well as car accidents caused by seizures. It may be necessary to wear a helmet. Child care providers and schools should be notified if a child suffers from seizures in order to be prepared in the event of a seizure.

It is important to look for signs of atonic seizures in the aging population as well. The elderly are more prone to the condition as alterations in brain functioning occur as they age. Caregivers and family members should do their best to provide a safe environment and follow through with medication, as well as medical exams at any time that atonic seizures first become apparent.