Any time you see a generalized seizure, look closely to ensure that it isn't actually a focal to bilateral tonic clonic seizure, in which the onset is localized but there is rapid propagation/generalization into both hemispheres. Generalized seizures are most often seen with idiopathic or symptomatic generalized epilepsy syndromes subtypes of generalized seizures are discussed below and include generalized tonic clonic (GTCs, previously termed grand mal), absence, tonic, myoclonic, and atonic seizures. discharges becoming faster until offset) or distribution (ex. As with nearly any seizure type, the exact appearance varies widely, but must evolve in frequency (ex. Generalized seizures are marked by a nonlocalizable onset, often involving all the leads but sometimes having a predominance in the anterior or other regions. Also remember the ten second rule: bursts of interictal activity that evolve but last less than 10 seconds in duration are not seizures (they could be classified as B(I)RDs-brief (ictal) rhythmic discharges-but that term is somewhat inconsistent in use throughout the EEG community). Especially in ICU patients, you may see patterns that are disturbing for seizures, such as fluctuating rhythmicity or periodicity, but if it does not consistently evolve (fluctuation is not evolution), it is not a seizure. Interictal activity can fluctuate and become very frequent, but if it never evolves into a broader area or its frequency doesn't become progressively faster or slower, it is not considered a seizure. Electrographically, like interictal activity, seizures (aka ictal activity) can be either generalized or focal but either way seizures must evolve temporally and/or spatially. Clinically, they can present as anything the brain can experience, including sensorimotor activity, emotion, autonomic changes and more. A seizure is an abnormal, organized and evolving burst of cortical activity that interrupts the brain's usual function.
0 kommentar(er)
