Traditionally, status epilepticus (SE) has been arbitrarily defined as either a single generalized seizure lasting greater than 30 minutes, or a group of repetitive seizures between which the patient had not fully recovered. Recently, exactly when a prolonged seizure or set of recurrent seizures is deemed to have become SE has further evolved. In light of data now demonstrating the time-dependent risk of early neuronal injury, and the necessity to treat this disorder prior to irreversible cerebral insult, shorter seizure epochs have been emphasized. Since typical seizures last no longer than 1–2 minutes, and injury can be documented histologically by 30 minutes, it is reasonable to consider as SE any seizure events greater than 5–10 minutes in length. This epoch has been now adopted by both the American Academy of Neurology and the American Epilepsy Society.
THE PHENOTYPE OF STATUS EPILEPTICUS
There are three main subtypes of SE:
▪ The most common is generalized convulsive SE (GCSE).
▪ Focal Motor SE (FMSE), or epilepsy partialis continuans, is relatively uncommon and typically manifests as continuous motor twitching of a single limb or side of face.
▪ It is not clear whether FMSE may result in substantive injury to the cerebral cortex.
▪ Reasonable attempts at control are advocated, but high-risk therapies such as induced pharmacologic coma are rarely considered appropriate.
▪ Nonconvulsive SE (NCSE) incorporates a variety of continuous non-motor electrical paroxysms, often described as complex-partial SE, subtle SE, non tonic-clonic SE, or subclinical SE.