Generalised seizures Sample Clauses

Generalised seizures. Generalized seizures are presumed bilateral in origin and account for 1/3 of all seizures, (Xxxxxxxxxxxxxxx, 2005b). They can be split into numerous subtypes including absence, myoclonic, tonic, clonic, tonic clonic and atonic seizures. The most common form of generalised seizure and arguably the most stereotyped is the tonic- clonic. This is characterized by initial increased muscle tone and stiffness (tonic phase) often accompanied by cyanosis and respiratory arrest; followed by a clonic phase of rhythmic jerking, generally lasting for less than two minutes, loss of consciousness and postictal confusion follows with flaccid muscle tone and disorientation. Tonic and clonic seizures can also be seen in isolation, these are highly distinctive from generalised tonic clonic seizures (GTCS) and generally only found in severe epilepsies of childhood onset such as Xxxxxx-Xxxxxxx syndrome. Another common type of generalized seizure is the absence, which can be further divided into typical and atypical absences. Absences are characterised by abrupt transient loss of awareness. Atypical absences can last several minutes, these are often accompanied by myoclonic activity or atonic attacks, with slow spike-wave discharge. These typically occur in the context of severe epilepsies of childhood, with neurologic and learning difficulties. Typical absences commence abruptly and generally last for shorter periods than their atypical counterparts (10-30 seconds) with a distinctive 3-4 Hz spike and wave activity on the electroencephalogram (EEG). Generalised seizures can also manifest as myoclonic jerks, which are sudden, brief and involuntary jerks in a limb or sometimes affecting more widespread regions without impairment of consciousness. Evidence suggests that generalised seizures are not necessarily fully generalised, but affect discrete brain networks, while others are relatively spared; (Xxxxxx et al., 2002) (Xxxxxxxxxx, 2003).