Abstracts

Rationale: There are two types of premonitory symptoms reported by patients with epilepsy: auras and prodromes. Auras are traditionally considered specific for focal epilepsy, and usually occur seconds to minutes prior to a seizure. Prodromes occur over longer intervals prior to seizures and may serve as early warning signs of seizures to allow a patient to prevent injury. Our objective was to determine the frequency of auras and prodromes in an outpatient epilepsy clinic population, and to compare the characteristics of auras and prodromes in both focal and generalized epilepsy patients.Methods: Clinical records of all patients attending an adult epilepsy outpatient clinic over a six month time period were reviewed. Patients with a diagnosis of epilepsy based on International League Against Epilepsy criteria were included. Patients with only single seizures or febrile seizures were excluded. Detailed medical histories were obtained with characteristics of seizure semiology, including auras and prodromes, using standardized interviews. Prodromes were defined as symptoms minutes to days before a seizure. Auras were defined as symptoms up to one minute before a seizure.Results: A total of 1891 consecutive epilepsy outpatients were studied. Eight hundred ten patients (43% of total) were classified as having focal epilepsy, and 1081 patients (57% of total) were classified as having generalized epilepsy. Overall, 22.1% reported auras, and 54.8% reported prodromes. The majority of prodromes were described as headache or irritability. Four hundred ten patients (50.6%) with focal epilepsy and 626 patients (57.9%) with generalized epilepsy reported prodromes. One hundred forty seven patients (18.1%) with focal epilepsy and 270 patients (25.0%) with generalized epilepsy reported auras. The most common auras were characterized by nausea, and urinary or fecal urgency. Both nausea and déjà vu auras were seen with relatively equal frequency in both generalized and focal epilepsy patients. Auras were more frequent in idiopathic generalized epilepsy compared to symptomatic generalized epilepsy.Conclusions: These results suggest a substantial proportion of patients with both focal and generalized epilepsy have premonitory symptoms before their seizures. Interestingly, 25% of patients with generalized epilepsy in this study reported auras up to one minute before seizure occurrence. Prior studies suggest as many as 70% of idiopathic generalized epilepsy patients will report an aura. Clinicians should not let a reported aura exclude the diagnosis of generalized epilepsy if other features of the history and evaluation suggest generalized epilepsy. Patient-reported auras are not specific to focal epilepsy.