Convulsion

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 body.[8] Various areas of the brain can be disturbed by epileptic events.[10] Epileptic seizures can have contrary clinical features.[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 and lose control of their bladder. A familial history of seizures puts a person at a greater risk for 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 are 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 one that 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]