Focal seizures often begin with certain experiences, known as an aura.[13] These may include sensory (including visual, auditory, etc.), cognitive, autonomic, olfactory or motor phenomena.[17]
In a complex partial seizure a person may appear confused or dazed and cannot respond to questions or direction.[17]
Jerking activity may start in a specific muscle group and spread to surrounding muscle groups—known as a Jacksonian march.[18] Unusual activities that are not consciously created may occur.[18] These are known as automatisms and include simple activities like smacking of the lips or more complex activities such as attempts to pick something up.[18]
Generalized seizures
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There are six main types of generalized seizures: tonic-clonic, tonic, clonic, myoclonic, absence, and atonic seizures.[19] They all involve a loss of consciousness and typically happen without warning.[20]
Tonic-clonic seizures present with a contraction of the limbs followed by their extension, along with arching of the back for 10–30 seconds.[20] A cry may be heard due to contraction of the chest muscles.[20] The limbs then begin to shake in unison.[20] After the shaking has stopped it may take 10–30 minutes for the person to return to normal.[20]
Tonic seizures produce constant contractions of the muscles.[20] The person may turn blue if breathing is impaired.[20]
Clonic seizures involve shaking of the limbs in unison.[20]
Myoclonic seizures involve spasms of muscles in either a few areas or generalized through the body.[20]
Absence seizures can be subtle, with only a slight turn of the head or eye blinking.[17] The person often does not fall over and may return to normal right after the seizure ends, though there may also be a period of post-ictal disorientation.[17]
Atonic seizures involve the loss of muscle activity for greater than one second.[18] This typically occurs bilaterally (on both sides of the body).[
Normally, brain electrical activity is non-synchronous.[17] In epileptic seizures, due to problems within the brain,[40] a group of neurons begin firing in an abnormal, excessive,[14] and synchronized manner.[17] This results in a wave of depolarization known as a paroxysmal depolarizing shift.[41]
Focal seizures Edit
In a complex partial seizure a person may appear confused or dazed and cannot respond to questions or direction.[17]
Jerking activity may start in a specific muscle group and spread to surrounding muscle groups—known as a Jacksonian march.[18] Unusual activities that are not consciously created may occur.[18] These are known as automatisms and include simple activities like smacking of the lips or more complex activities such as attempts to pick something up.[18]
Generalized seizures Edit
Tonic-clonic seizures present with a contraction of the limbs followed by their extension, along with arching of the back for 10–30 seconds.[20] A cry may be heard due to contraction of the chest muscles.[20] The limbs then begin to shake in unison.[20] After the shaking has stopped it may take 10–30 minutes for the person to return to normal.[20] Tonic seizures produce constant contractions of the muscles.[20] The person may turn blue if breathing is impaired.[20] Clonic seizures involve shaking of the limbs in unison.[20] Myoclonic seizures involve spasms of muscles in either a few areas or generalized through the body.[20] Absence seizures can be subtle, with only a slight turn of the head or eye blinking.[17] The person often does not fall over and may return to normal right after the seizure ends, though there may also be a period of post-ictal disorientation.[17] Atonic seizures involve the loss of muscle activity for greater than one second.[18] This typically occurs bilaterally (on both sides of the body).[