Neurological emergencies are characterized by an acute decline in cerebral function, affecting both consciousness and clinical performance. Although these emergencies can arise from a huge number of various medical and neurological issues, electroencephalogram (EEG) changes are relatively few and therefore nonspecific. EEG patterns in emergencies can range from normal to focal or diffuse slowing, disorganization, periodicity, rhythmicity, and ictal phenomena. These changes may be dynamic and spread topographically leading to spatiotemporal patterns. While EEG changes primarily reflect disruption of brain function due to the underlying cause, additional epileptic activity can result in metabolic stress and even more severe EEG patterns. This chapter reviews EEG features of several neurological emergencies including nonconvulsive status epilepticus and patterns on the ictal-interictal continuum.