Autonomic seizures and autonomic status epilepticus peculiar to childhood: diagnosis and management

Abstract

Autonomic seizures and autonomic status epilepticus in children have a high prevalence, manifest with dramatic clinical symptoms, and have important clinical and management implications. They probably affect approximately 13% of children aged 3-6 years with one or more nonfebrile seizures, or 6% in the age group 1-15. The primary cause is an idiopathic age-dependent epileptogenic susceptibility (Panayiotopoulos syndrome), but 10-20% are due to cerebral pathology. Autonomic seizures and autonomic status epilepticus have been best studied in Panayiotopoulos syndrome, which has been confirmed worldwide in more than 800 cases and recently recognized in the new classification scheme of the International League Against Epilepsy. Seizures start with autonomic symptoms, mainly emesis, while the child is usually fully conscious. Other more conventional seizure manifestations often ensue, but autonomic manifestations commonly predominate to the end of the seizure. Ictal syncope (transient loss of consciousness and postural tone) is an intriguing common symptom. Half of the seizures last longer than 30 minutes, constituting autonomic status epilepticus. Prognosis is invariably excellent except for the symptomatic cases. The interictal EEG shows great variability from normal to severely epileptogenic, often with multifocal spikes. Pathophysiology of Panayiotopoulos syndrome is unknown, but it is likely that they are due to diffuse maturation-related epileptogenicity activating susceptible-for-children emetic centers and the hypothalamus. Thus, Panayiotopoulos syndrome is not occipital epilepsy, with which it is often erroneously equated. Autonomic seizures and autonomic status epilepticus are frequently misdiagnosed and often treated as encephalitis, atypical migraine, cardiogenic syncope, or other unrelated medical conditions such as gastroenteritis. This review examines the existing evidence, provides a means of improving diagnostic yield, and proposes practice parameters and guidelines for the diagnosis and management of autonomic seizures and autonomic status epilepticus in children.