Elderly patients with altered mental status present commonly to the Emergency Department. Nonconvulsive status epilepticus is a common cause of altered mental status in the elderly population. It has been traditionally divided into 2 groups, largely on electroencephalographic criteria: 1) complex-partial status epilepticus and 2) absence status epilepticus. Nonconvulsive status epilepticus has a wide range of clinical presentations, ranging from confusion to obtundation. Although attempts have been made to define and classify this disorder, there is yet no universally accepted definition or classification that encompasses all subtypes or electroclinical scenarios. Nonconvulsive status epilepticus is an important, under-recognized and reversible cause of acute prolonged confusion.

An urgent electroencephalogram is considered as the method of choice in the diagnostic evaluation of nonconvulsive status epilepticus. Treatment options are briefly addressed.

Overall, further work is needed to better define nonconvulsive status epilepticus.