Convulsion | |
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Specialty | Neurology, Psychiatry |
Symptoms | Muscle spasms, [1] uncontrollable shaking [1] |
Risk factors | Epilepsy |
A convulsion is a medical condition where the body muscles contract and relax rapidly and repeatedly, resulting in uncontrolled shaking. [1] Because epileptic seizures typically include convulsions, the term convulsion is often used as a synonym for seizure. [1] However, not all epileptic seizures result in convulsions, and not all convulsions are caused by epileptic seizures. [1] [2] Non-epileptic convulsions have no relation with epilepsy, and are caused by non-epileptic seizures. [1]
Convulsions can be caused by epilepsy, infections (including a severe form of listeriosis which is caused by eating food contaminated by Listeria Monocytogenes), brain trauma, or other medical conditions. [2] They can also occur from an electric shock or improperly enriched air for scuba diving. [1] [ failed verification ]
The word fit is sometimes used to mean a convulsion or epileptic seizure. [3]
A person having a convulsion may experience several different symptoms, [1] such as a brief blackout, confusion, drooling, loss of bowel or bladder control, sudden shaking of the entire body, uncontrollable muscle spasms, or temporary cessation of breathing. [1] Symptoms usually last from a few seconds to several minutes, although they can last longer. [4]
Convulsions in children are not necessarily benign, and may lead to brain damage if prolonged. [5] In these patients, the frequency of occurrence should not downplay their significance, as a worsening seizure state may reflect the damage caused by successive attacks. [5] Symptoms may include:[ verification needed ]
Most convulsions are the result of abnormal electrical activity in the brain. [2] [note 1] Often, a specific cause is not clear. Numerous conditions can cause a convulsion. [6]
Convulsions can be caused by specific chemicals in the blood, as well as infections like meningitis or encephalitis. Other possibilities include celiac disease, [7] head trauma, stroke, or lack of oxygen to the brain. Sometimes the convulsion can be caused by genetic defects or brain tumors. [1] Convulsions can also occur when the blood sugar is too low or there is a deficiency of vitamin B6 (pyridoxine). The pathophysiology of convulsion remains ambiguous. [5]
Convulsions are often caused by epileptic seizures, febrile seizures, non-epileptic seizures, or paroxysmal kinesigenic dyskinesia. [2] In rare cases, it may be triggered by reactions to certain medications, such as antidepressants, stimulants, and antihistamines. [2]
Epilepsy is a neuronal disorder with multifactorial manifestations. [8] It is a noncontagious illness and is usually associated with sudden attacks [9] of seizures, which are an immediate and initial anomaly in the electrical activity of the brain that disrupts part or all of the body. [8] Various areas of the brain can be disturbed by epileptic events. [10] Epileptic seizures can have contrary clinical features.[ further explanation needed ] [8] Epileptic seizures can have long-lasting effects on cerebral blood flow. [11]
Various kinds of epileptic seizures affect 60 million people worldwide. [9]
The most common type of seizure is called a generalized seizure, also known as a generalized convulsion. This is characterized by a loss of consciousness which may lead to the person collapsing. The body stiffens for about a minute and then jerks uncontrollably for the next minute. During this, the patient may fall and injure themselves or bite their tongue, their eyes roll back, and lose control of their bladder. A familial history of seizures puts a person at a greater risk of developing them. [12] [13] Generalized seizures have been broadly classified into two categories: motor and non-motor. [8]
A generalized tonic-clonic seizure (GTCS), also known as a grand mal seizure, is a whole-body seizure that has a tonic phase followed by clonic muscle retrenchments. [14] [15] GTCSs can happen in people of all ages. [15] GTCSs are very hazardous, and they increase the risk of injuries and sudden unexpected death in epilepsy (SUDEP). [16] SUDEP is a sudden, unexpected, nontraumatic death in patients with epilepsy. [16] Strong convulsions that are related to GTCSs can also cause falls and severe injuries. [16]
Not all generalized seizures produce convulsions. For example, in an absence seizure, also known as a petit mal seizure, the brain experiences electrical disturbances but the body remains motionless and unresponsive. [2]
A common cause of convulsions in children is febrile seizures, a type of seizure associated with a high body temperature. This high temperature is a usual immune response to infection, and in febrile convulsions, the reason for the fever is extra-cranial (such as a body-wide viral infection). [17] In Nigeria, malaria—which can cause sudden, high fevers—is a significant cause of convulsions among children under 5 years of age. [18]
Febrile seizures fall into two categories: simple and complex. [19] A simple febrile seizure is generalized, occurs singularly, and lasts less than 15 minutes. [19] A complex febrile seizure can be focused in an area of the body, occur more than once, and lasts for more than 15 minutes. [19] Febrile seizures affect 2–4% of children in the United States and Western Europe, it is the most common childhood seizure. [19] The exact reason for febrile convulsion is unidentified, though it might be the outcome of the interchange between environmental and genetic factors. [17]
Psychogenic non-epileptic seizures (PNES) are described as neurobehavioral conditions [20] or "psychogenic illnesses" which occur not due to the electrical disturbances in a person's brain but due to mental and emotional stress. [2] PNES are an important differential diagnosis and a common occurrence in epilepsy centers. [21] According to the 5th Edison of Diagnostic and Statistical Manual of Mental Disorders (DSM 5), PNES is classified as a "conversion disorder" or Functional Neurologic Symptom Disorder characterized by alterations in behavior, motor activity, consciousness, and sensation. [22] A few neuroimaging (functional and structural) studies suggest that PNES may replicate sensorimotor alterations, emotional regulation, cognitive control, and integration of neural circuits. [23]
There is a linkage between infantile convulsion and paroxysmal dyskinesia. [24] Paroxysmal kinesigenic dyskinesia (PKD) is characterized by sudden involuntary movement caused by sudden stress or excitement. [25] The relationship between convulsion and PKD is mainly due to the common mechanism of pathophysiology. [24]
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. An epileptic seizure is the clinical manifestation of an abnormal, excessive, and synchronized electrical discharge in the neurons. The occurrence of two or more unprovoked seizures defines epilepsy. The occurrence of just one seizure may warrant the definition in a more clinical usage where recurrence may be able to be prejudged. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrical activity in the brain. These episodes can result in physical injuries, either directly, such as broken bones, or through causing accidents. In epilepsy, seizures tend to recur and may have no detectable underlying cause. Isolated seizures that are provoked by a specific cause such as poisoning are not deemed to represent epilepsy. People with epilepsy may be treated differently in various areas of the world and experience varying degrees of social stigma due to the alarming nature of their symptoms.
A seizure is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness, to shaking movements involving only part of the body with variable levels of consciousness, to a subtle momentary loss of awareness. These episodes usually last less than two minutes and it takes some time to return to normal. Loss of bladder control may occur.
A febrile seizure, also known as a fever fit or febrile convulsion, is a seizure associated with a high body temperature but without any serious underlying health issue. They most commonly occur in children between the ages of 6 months and 5 years. Most seizures are less than five minutes in duration, and the child is completely back to normal within an hour of the event. There are two types: simple febrile seizures and complex febrile seizures. Simple febrile seizures involve an otherwise healthy child who has at most one tonic-clonic seizure lasting less than 15 minutes in a 24-hour period. Complex febrile seizures have focal symptoms, last longer than 15 minutes, or occur more than once within 24 hours. About 80% are classified as simple febrile seizures.
A headache is often present in patients with epilepsy. If the headache occurs in the vicinity of a seizure, it is defined as peri-ictal headache, which can occur either before (pre-ictal) or after (post-ictal) the seizure, to which the term ictal refers. An ictal headache itself may or may not be an epileptic manifestation. In the first case, it is defined as ictal epileptic headache or simply epileptic headache. It is a type of pain seizure that can remain isolated or be followed by other manifestations of the seizure. On the other hand, a ictal non-epileptic headache is a headache that occurs during a seizure but it is not due to an epileptic mechanism. When the headache does not occur in the vicinity of a seizure, it is defined as inter-ictal headache. In the case it's a disorder separate from epilepsy, it's a comorbidity.
Lennox–Gastaut syndrome (LGS) is a complex, rare, and severe childhood-onset epilepsy syndrome. It is characterized by multiple and concurrent seizure types including tonic seizure, cognitive dysfunction, and slow spike waves on electroencephalogram (EEG), which are very abnormal. Typically, it presents in children aged 3–5 years and most of the time persists into adulthood with slight changes in the electroclinical phenotype. It has been associated with perinatal injuries, congenital infections, brain malformations, brain tumors, genetic disorders such as tuberous sclerosis and numerous gene mutations. Sometimes LGS is observed after infantile epileptic spasm syndrome. The prognosis for LGS is marked by a 5% mortality in childhood and persistent seizures into adulthood.
Psychogenic non-epileptic seizures (PNES), also referred to as pseudoseizures, non-epileptic attack disorder (NEAD), functional seizures, or dissociative seizures, are episodes resembling an epileptic seizure but without the characteristic electrical discharges associated with epilepsy. PNES fall under the category of disorders known as functional neurological disorders (FND) and are typically treated by psychologists or psychiatrists.
Non-epileptic seizures (NES), also known as pseudoseizures, non-epileptic attack disorder (NEAD), functional seizures, or dissociative seizures, are paroxysmal events that appear similar to an epileptic seizure, but do not involve abnormal, rhythmic discharges of neurons in the brain. Symptoms may include shaking, loss of consciousness, and loss of bladder control.
Frontal lobe epilepsy (FLE) is a neurological disorder that is characterized by brief, recurring seizures arising in the frontal lobes of the brain, that often occur during sleep. It is the second most common type of epilepsy after temporal lobe epilepsy (TLE), and is related to the temporal form in that both forms are characterized by partial (focal) seizures.
In the field of neurology, seizure types are categories of seizures defined by seizure behavior, symptoms, and diagnostic tests. The International League Against Epilepsy (ILAE) 2017 classification of seizures is the internationally recognized standard for identifying seizure types. The ILAE 2017 classification of seizures is a revision of the prior ILAE 1981 classification of seizures. Distinguishing between seizure types is important since different types of seizures may have different causes, outcomes, and treatments.
Abdominal epilepsy is a rare condition most frequently found in children, consisting of gastrointestinal disturbances caused by epileptiform seizure activity. Though a few cases of it have been reported in adults too. It has been described as a type of temporal lobe epilepsy. Responsiveness to anticonvulsants can aid in the diagnosis. Distinguishing features of abdominal epilepsy include (1) Abnormal laboratory, radiographic, and endoscopic findings revealing paroxysmal GI manifestations of unknown origin (2) CNS symptoms (3) Abnormal EEG. Most published medical literature dealing with abdominal epilepsy is in the form of individual case reports. A 2005 review article found a total of 36 cases described in the medical literature.
Generalized epilepsy is a form of epilepsy characterised by generalised seizures with no apparent cause. Generalized seizures, as opposed to focal seizures, are a type of seizure that impairs consciousness and distorts the electrical activity of the whole or a larger portion of the brain.
Ohtahara syndrome (OS), also known as Early Infantile Developmental & Epileptic Encephalopathy (EIDEE) is a progressive epileptic encephalopathy. The syndrome is outwardly characterized by tonic spasms and partial seizures within the first few months of life, and receives its more elaborate name from the pattern of burst activity on an electroencephalogram (EEG). It is an extremely debilitating progressive neurological disorder, involving intractable seizures and severe intellectual disabilities. No single cause has been identified, although in many cases structural brain damage is present.
Sodium channel protein type 1 subunit alpha (SCN1A), is a protein which in humans is encoded by the SCN1A gene.
Benign Rolandic epilepsy or self-limited epilepsy with centrotemporal spikes is the most common epilepsy syndrome in childhood. Most children will outgrow the syndrome, hence the label benign. The seizures, sometimes referred to as sylvian seizures, start around the central sulcus of the brain.
Paroxysmal kinesigenic dyskinesia (PKD), also called paroxysmal kinesigenic choreoathetosis (PKC), is a rare hyperkinetic movement disorder of the paroxysmal dyskinesias characterized by attacks of involuntary movements, which are triggered by sudden voluntary movements. The number of attacks can increase during puberty and decrease in a person's 20s to 30s. Involuntary movements can take many forms such as ballism, chorea or dystonia and usually only affect one side of the body or one limb in particular.
Paroxysmal exercise-induced dystonia (PED) is a rare neurological disorder that belongs to the paroxysmal dyskinesias, a group of rare movement disorders that involve attacks of hyperkinesia with intact consciousness. It is characterized by sudden, transient, involuntary movements, often including repetitive twisting motions and painful posturing triggered by exercise or other physical exertion. The term paroxysmal indicates that the episodes are sudden and short lived and usually unpredicted, and return to normal is rapid. The number of reported cases of people with PED is very small leading to difficulty in studying and classifying this disease and most studies are limited to a very small number of test subjects.
Epilepsy is a neurological condition of recurrent episodes of unprovoked epileptic seizures. A seizure is an abnormal neuronal brain activity that can cause intellectual, emotional, and social consequences. Epilepsy affects children and adults of all ages and races, and is one of the most common neurological disorders of the nervous system. Epilepsy is more common among children than adults, affecting about 6 out of 1000 US children that are between the age of 0 to 5 years old. The epileptic seizures can be of different types depending on the part of the brain that was affected, seizures are classified in 2 main types partial seizure or generalized seizure.
Infantile convulsions and choreoathetosis (ICCA) syndrome is a neurological genetic disorder with an autosomal dominant mode of inheritance. It is characterized by the association of benign familial infantile epilepsy (BIFE) at age 3–12 months and later in life with paroxysmal kinesigenic choreoathetosis. The ICCA syndrome was first reported in 1997 in four French families from north-western France and provided the first genetic evidence for common mechanisms shared by benign infantile seizures and paroxysmal dyskinesia. The epileptic origin of PKC has long been a matter of debates and PD have been classified as reflex epilepsies. Indeed, attacks of PKC and epileptic seizures have several characteristics in common, they both are paroxysmal in presentation with a tendency to spontaneous remission, and a subset of PKC responds well to anticonvulsants. This genetic disease has been mapped to chromosome 16p-q12. More than 30 families with the clinical characteristics of ICCA syndrome have been described worldwide so far.
An epilepsy syndrome is defined as "a characteristic cluster of clinical and Electroencephalography (EEG) features, often supported by specific etiological findings ."
A neonatal seizure is a seizure in a baby younger than age 4-weeks that is identifiable by an electrical recording of the brain. It is an occurrence of abnormal, paroxysmal, and persistent ictal rhythm with an amplitude of 2 microvolts in the electroencephalogram,. These may be manifested in form of stiffening or jerking of limbs or trunk. Sometimes random eye movements, cycling movements of legs, tonic eyeball movements, and lip-smacking movements may be observed. Alteration in heart rate, blood pressure, respiration, salivation, pupillary dilation, and other associated paroxysmal changes in the autonomic nervous system of infants may be caused due to these seizures. Often these changes are observed along with the observance of other clinical symptoms. A neonatal seizure may or may not be epileptic. Some of them may be provoked. Most neonatal seizures are due to secondary causes. With hypoxic ischemic encephalopathy being the most common cause in full term infants and intraventricular hemorrhage as the most common cause in preterm infants.