Evaluation of Seizure Etiology From Routine Testing to Genetic Evaluation.
Recognizing the cause of a first seizure and identifying the etiology of epilepsy are essential for management. A systematic approach to patients who present with a first seizure helps distinguish between an acute symptomatic seizure, a provoked or unprovoked seizure, and potential mimickers. Routine testing with EEG and MRI may reveal a predisposition for further seizures and help to establish the underlying epilepsy syndrome. An acquired etiology can be identified in 30% of patients with established epilepsy. The remaining 70% of patients have a presumably genetic etiology. Particularly in patients with specific epilepsy syndromes or suspicion for an autosomal dominant inheritance, genetic testing and counseling should be considered. Neuroimaging, autoimmune antibodies, and genetic testing have revolutionized our ability to investigate the etiology of many epilepsies. The new epilepsy classification distinguishes structural, metabolic, genetic, infectious, and immune-mediated etiologies, which often help determine prognosis and treatment. There is growing acceptance and demystification of the term epilepsy as the most common cause for recurrent seizures. The new classification of epilepsy does not stop with the recognition of particular epilepsy syndromes but aims to determine the underlying etiology. This can lead to earlier recognition of surgical candidates, a better understanding of many of the genetic epilepsies, and medical treatments aimed at the underlying mechanism causing the disease.