Atonic seizures are associated with a sudden loss or decrease of muscle tone and frequently cause patients to fall. This type of drop attack may be observed in individuals suffering from distinct forms of epilepsy.
In general, AS are considered a form of generalized seizure. This concept has recently been challenged and it has been pointed out that focal seizures with atonic features may indeed imply epilepsy . In this context, the following may be stated:
- AS as a manifestation of generalized epilepsy most commonly affect the muscles of the trunk and cause patients to fall slowly. Patients who sustained such drop attacks frequently present with traumatic lesions of head, neck, or other regions of their body. Of note, drop attacks may also be reported by those suffering from clonic seizures.
- Focal loss or diminution of the muscle tone may result in head dropping, paresis or paralysis of the extremities . Focal AS are not to be confounded with Todd's paresis, a post-ictal phenomenon that may be observed in epilepsy patients.
According to a recent study regarding the circadian patterns of AS, such seizures only occur in wakefulness . Consciousness is generally maintained. AS typically last seconds to minutes.
Entire Body System
The first clinical description of atonic seizures was given by Ramsay Hunt in 1922 as “a type of epilepsy characterized by a sudden loss of postural tone,” which he called a “static fit” ( Hunt 1922 ). [medlink.com]
Neurol. 36:5–21 Google Scholar Hunt, J. (1922) On the occurrence of static seizures in epilepsy. [link.springer.com]
Apart from early clinical notes by Tissot and Newman dating back to the 18th and 19th centuries, respectively, the first detailed description of atonic seizures was given by Hunt in 1922, who called the condition “static epilepsy”—that is, a “form of [neupsykey.com]
An effect of the diet on gamma-aminobutyric acid reuptake mediated by gamma-aminobutyric acid transporter protein 1 is suggested. [ncbi.nlm.nih.gov]
- Type A Personality
There are two types of absence seizures: Simple Absence Seizures: With this type, a person will usually stare into space for about 10 seconds. [efepa.org]
- Learning Difficulties
All have learning difficulties, abnormal brain magnetic resonance images, and an abnormal electroencephalogram; six are developmentally delayed. [ncbi.nlm.nih.gov]
Angelman Syndrome Angelman syndrome is a type of epilepsy syndrome that causes learning difficulties, speech delays, and certain behavioral characteristics, such as a cheerful mood and bursts of sudden and unexplained laughter. [nyulangone.org]
- Truncal Ataxia
His truncal ataxia resolved without treatment. He experienced a relapse of truncal ataxia and atonic seizures at 2 years and one month of age. Five months later, he experienced myoclonic atonic seizures. [ncbi.nlm.nih.gov]
He had impaired coordination of the left hand as well as truncal ataxia. [onlinelibrary.wiley.com]
- Neurologic Manifestation
Convulsions are the most common neurologic manifestation in Eclampsia because the occurrence of convulsions confirms the diagnosis of Eclampsia. Convulsions are usually generalized tonic-clonic in nature. Usually a brief single seizure occurs. [epilepsywarriors.org]
Video-electroencephalography (EEG) with concomitant electromyography should be carried out to confirm central nervous system involvement and muscular hypotonia . With regards to the former, high-amplitude spike-and-slow-wave discharges have been reported to immediately precede AS . These signals may be followed by diffuse background suppression. AS may originate from single brain regions, e.g., the frontal, temporal, parietal, or occipital lobes, or result from multifocal anomalies .
Furthermore, neuroimaging may be helpful. In this context, magnetic resonance imaging is more sensitive technique and is thus preferred over computed tomography scans . The absence of anomalies does not permit to rule out AS, though. In general, organic abnormalities are more likely to be detected in patients presenting with focal seizures than in those suffering from generalized seizures.
If neither study yields convincing results but differential diagnoses like transient ischemic attack or a migraine have been ruled out, the observance of accompanying symptoms may support a tentative diagnosis of AS. These are not characteristic of AS but merely imply epilepsy :
The initial anticonvulsant treatment was temporarily effective, and the purposeful isoprinosine therapy had no significant beneficial effect. [ncbi.nlm.nih.gov]
Adjunctive treatment in children, young people and adults with Lennox–Gastaut syndrome Do not offer carbamazepine, gabapentin, oxcarbazepine, pregabalin, tiagabine or vigabatrin. [nice.org.uk]
Learn about arteriosclerotic (vascular) dementia diagnosis, symptoms, causes and treatments at Northwell Health Learn about Arteriovenous (AV) Fistula diagnosis, symptoms, causes and treatments at the Northwell Health Brain Aneurysm Center and Cerebrovascular [northwell.edu]
It reviews the usual treatment, including pharmacology, and gives the prognosis for these entities. [ncbi.nlm.nih.gov]
Prognosis is uncertain because of various diagnostic criteria and treatment strategies. In general, seizures remit 2 to 4 years after onset, but some cognitive impairment may occur. [medlink.com]
Good prognosis is associated with a low rate of undesirable outcomes; poor prognosis is associated with a high rate of undesirable outcomes. [nice.org.uk]
No structural or metabolic etiology was identified. Based on the electroclinical features and evolution, two groups could be distinguished. [ncbi.nlm.nih.gov]
This term denotes the concept that the epileptic activity itself might directly contribute additional cognitive and behavioral impairments over those expected from the underlying etiology alone, and that suppression of epileptic activity might minimize [epilepsydiagnosis.org]
Epilepsy with myoclonic-atonic seizures is seen in families with other individuals with genetic epilepsy with febrile seizures plus, suggesting common genetic etiological factors. EEG. Background. [medlink.com]
The etiology is variable in each of these groups and may be effective in either the prenatal, paranatal or postnatal periods. [pediatrics.aappublications.org]
AS have also been related to nodding syndrome, a childhood disorder endemic to South Sudan, Uganda, and Tanzania, whose etiology remains poorly understood. Both anti-epileptic medication and surgery may be considered to treat AS. [symptoma.com]
et al. (1998) Epidemiology of epilepsy in children: a cohort of 440 consecutive patients. Pediatr. Neurology 18:46–50 CrossRef Google Scholar Copyright information Springer Science Business Media, LLC 2012 Authors and Affiliations David W. [link.springer.com]
Epilepsy Classification Epilepsy Epidemiology Epilepsy Pathophysiology Epilepsy Syndromes [news-medical.net]
Epidemiology Because of controversies in terminology and the need of a polygraphic recording to perform a reliable diagnosis, exact figures for the incidence of these seizure types are not available. [neupsykey.com]
Definition References:      Epidemiology References:  Epidemiological data refers to the US, unless otherwise specified. [amboss.com]
Descriptive epidemiology of epilepsy: Contributions of population-based studies from Rochester, Minnesota. Mayo Clinic Proceedings, 71(6). 576-586. [epilepsyaustralia.net]
Ictal SPECT is valuable in demonstrating the pathophysiology of both atonic seizures and secondary bilaterally synchronous spike-and-wave complexes in the EEG. [ncbi.nlm.nih.gov]
In this article, the author details the clinical manifestations, pathophysiology, EEG, and optimal management of patients with myoclonic-atonic seizures. [medlink.com]
Epilepsy Classification Epilepsy Epidemiology Epilepsy Pathophysiology Epilepsy Syndromes [news-medical.net]
Myoclonic astatic seizures are likely to reflect the prevalence of myoclonic–astatic epilepsy, accounting for 1% to 2% of all childhood epilepsies. 17 Anatomic pathways and pathophysiology Because of the variety of seizures featuring atonia as the main [neupsykey.com]
Adequate management of inpatient-witnessed seizures lies in understanding the time-related pathophysiologic stages of the seizure. [thepermanentejournal.org]
If they fall forward and injure the face frequently, a face mask or helmet to prevent facial injury should be considered. Think of other ways to prevent injury. For example... [epilepsy.com]
When an atonic seizure occurs, make sure the person is in a safe place to prevent injuries from a fall. How can I tell if someone is having an atonic seizure? These seizures tend to be fairly obvious to the patent. [hellodoktor.com]
Hospital for Sick Children Health A-Z Search a complete list of child health articles expand_more View All Drug A-Z Search a list of articles about medications expand_more View All Learning Hubs Browse a complete list of content groups Healthy Living & Prevention [aboutkidshealth.ca]
Children may have to wear helmets and restrict their activities to prevent serious injury. [myhealth.alberta.ca]
Atonic seizures (AS) are a rare type of epileptic seizures characterized by a sudden reduction of a patient's muscle tone. Because affected individuals frequently fall during such epileptic attack, AS are also considered a type of drop attack . Injuries sustained during falls significantly contribute to AS-related morbidity.
AS may occur in patients suffering from different types of epilepsy, mainly severe forms of childhood epilepsy (e.g., Lennox-Gastaut syndrome, myoclonic-astatic epilepsy) and epilepsy due to brain lesions endured at any point in life . Accordingly, AS patients may also sustain tonic, clonic and absence seizures . AS have also been related to nodding syndrome, a childhood disorder endemic to South Sudan, Uganda, and Tanzania, whose etiology remains poorly understood  .
Both anti-epileptic medication and surgery may be considered to treat AS .
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