Acute symptomatic seizures: a clinically oriented review

Acute symptomatic seizures are seizures closely related to neurological or systemic insults and represent about 40% of all first seizures. Diagnosis may be difficult to perform due to the subjectivity involved in recognizing the severity of insult needed to provoke epileptic seizures or in determining a clear temporal relationship. Appropriate therapeutic management, risk of developing epilepsy, and mortality depend largely on the underlying disorder.

A general overview regarding definition, epidemiology, and causes of acute symptomatic seizures is provided. Diagnosis, frequency, risk factors, pathophysiology, therapeutic management, and prognosis of acute symptomatic seizures related to each insult individually are discussed. The insults considered are: acute stroke, traumatic brain injury, central nervous system infections, medication, alcohol and illicit drugs, electrolytic and metabolic disorders, anoxic encephalopathy, eclampsia, reversible posterior leukoencephalopathy, and limbic encephalitis.

Operational diagnostic criteria have been recommended by the International League Against Epilepsy and are based on temporal relationship, severity, and type of insult. Antiepileptic drug prophylaxis is recommended in severe head trauma, preeclampsia, and possibly high-risk subarachnoid or intracranial hemorrhage. It is crucial to rapidly identify all insults possibly involved, treat underlying diseases, revert corrigible factors, and in case of central nervous system involvement, use antiepileptic drugs during the acute period. Risk of epilepsy is increased in patients with neurological insults but not with metabolic disorders. Some refractory epilepsies in adults, mostly epilepsy due to hippocampal sclerosis, are preceded by acute symptomatic seizures related to selected insults occurring at a specific time. Mortality rate is globally increased.