| Atonic seizure | |
|---|---|
| Other names | Akinetic seizure, astatic seizure |
| Specialty |
Neurology 
|
An atonic seizure (also called drop seizure, akinetic seizure, astatic seizure, or drop attack) is a type of seizure that consists of partial or complete loss of muscle tone that is caused by temporary alterations in brain function. These seizures are brief – usually less than fifteen seconds. They usually begin in childhood and may persist into adulthood. The seizure itself causes no physical injury, but the loss of control, predominantly in trunk muscles, can result in direct injury from falling. Electroencephalography can be used to confirm diagnosis. It is rare and can be indicative of Lennox–Gastaut syndrome (see Henri Gastaut). Atonic seizures can occur while standing, walking, or sitting, and are often noticeable by a head drop (relaxing of the neck muscles). Head and eyelids may droop, and they may drop anything they were holding. Fall injuries may result in impact to the face or head. As with common epileptic occurrences, no first aid is needed post-seizure, except in the instances where falling injuries have occurred. In some cases, a person may become temporarily paralyzed in part of his or her body. This usually does not last longer than 3 minutes.
Symptoms
During an atonic seizure, electrical activity in the brain becomes interrupted; the person has a temporary inability to move or speak and loses muscle strength. The seizure start at one part of the brain or the entire brain. It occurs as a result of a period of uncontrolled electrical activity in the brain. It can cause muscle problems, strange behaviors, unusual sensations, and an altered state of awareness.
The symptoms may include:
- Sudden loss of muscle strength
- Going limp and falling to the ground
- Remaining conscious
- Experiencing a brief loss of consciousness
- Head nods
- Drooping eyelids
- Jerking
The duration of atonic seizures are generally short. People might feel disorganized after the seizure, especially when lose consciousness. If the seizure happened during some activity, people might fall. This could lead to aftereffects like:
- Pain
- Soreness
- Bruises
- Serious injury
- Cuts
Causes
The cause of atonic seizures is often unknown. Some patients have seizures because of changes in their genes. Hyperventilation and flickering lights can trigger seizures. There are two types of atonic seizures: focal and generalized. Focal seizures affect a small area of the brain and lead to muscle weakness in one area of the body. Generalized seizures can begin throughout both halves of the brain. The reason disturbing a more important part of the body. When an atonic seizure involves the entire brain it known as generalized onset atonic seizure. These seizures begin with a sudden drop of the head, trunk, or whole body. Sometimes, atonic seizures are connected to Lennox-Gastout syndrome. Atonic seizures typically appear in childhood. Atonic seizures are more likely to affect babies and children. Adults may also experience atonic seizures if they have learning disabilities. Atonic attacks are recurrently accompanying with myoclonic jerks either before, or during the attack. The underlying pathophysiology of atonic seizures comprises negative motor and primary motor area. And also activation of corticoreticulospinal pathways; but the exact mechanisms are not fully understood.
Probable causes include:
- Genetic mutations
- Abnormal Brain Development
- Stroke
- Severe brain injury
- Perinatal hypoxia
- Central nervous system infections
- An imbalance of neurotransmitters.
- Medications or illegal drugs.
- Family history of epilepsy.
Diagnosis
Physicians need to use various tests to diagnose atonic seizures. The standard test to diagnose epilepsy is an electroencephalogram (EEG).
- Medical history – Symptoms and activities before the seizure will help your doctor determine what caused it. Taking a detailed medical history, including symptoms and duration of the seizures, methods to determine what kind of seizures a person has. And it also determines any form of epilepsy. The medical history should include specifics about any past illnesses or other symptoms. The medical history should also include a family history of seizures. The medical history should include details about any past illnesses or other symptoms a person may have had, and any family history of seizures. Caregiver’s or other’s explanations of seizures are important to this evaluation as people who have suffered a seizure often do not remember what happened. The person who experienced the seizure is asked about any warning experiences. The observers will be asked to provide a detailed description of events in the timeline they occurred.
- Imaging tests – Imaging tests can show if a lesion or structural problem is causing the seizures. This includes tests like a magnetic resonance imaging (MRI) or computer tomography (CT) scan. Imaging helps to identify the structural abnormalities of the brain such as tumors and cysts, which may cause seizures. PET scans can be used to identify brain regions with lower than normal metabolism, a feature of the epileptic focus after the seizure has stopped.
- Blood tests – the Doctor will look for abnormal markers, like electrolytes, that may be causing your seizures. Blood samples taken to check for metabolic or genetic disorders which might be associated with the seizures. They also may be used to check for underlying health conditions such as infections, which lead to triggering seizures.
- Tests to check your heart – Abnormal heart rhythms or blood pressure levels can lead to falls.
- Developmental, neurological, and behavioral tests – Tests that determine motor abilities, behaviour, and intellectual ability are often used as a way to determine how epilepsy is affecting an individual. These tests also can provide clues about what kind of epilepsy the person has.
Treatment
There is no general treatment for patients with a seizure disorder. Each treatment plan is specifically tailored to the individual patient based on their diagnosis and symptoms. Treatment options may include medical therapy, nerve stimulation, dietary therapy, or surgery, as appropriate. Clinical trials may also be a valuable treatment alternative. Usually, anticonvulsants are given based on other symptoms and / or associated problems. Because the areas of the cerebellum which determine increases and decreases in muscle tone are close together, people experiencing atonic seizures are most likely experiencing myoclonic ones too, at some point. This may play a role in therapy and diagnostic.
One surgical approach, selective posterior callostomy, can greatly decrease instances of drop attacks and improve function and behavior in patients with intellectual disability.