Abstracts

Rationale: The dichotomy between focal and generalized epilepsies has been blurred because of the existence of focal clinical, EEG and neuroimaging findings in patients with well-documented idiopathic generalized epilepsy (IGE). Patients diagnosed with IGE could report some auras. Among them visual aura deserves special attention due to its relationship with occipital lobe epilepsies, photosensitivity and migraine. We aimed to investigate the frequency of visual aura in IGE and its characteristics and syndromic relationships.Methods: All patients diagnosed with IGE admitting to our epilepsy center in the last 6 months were questioned about the presence of any visual aura just before their clinical seizures. The patients having EEG with typical generalized spike and wave discharges (GSW) were included and all EEGs were reviewed by 2 investigators, independently. Of 177 patients with IGE, 12 reported visual auras. One female patient with late onset IGE and migraine who reported isolated visual aura without headache was excluded from the analysis. Results: There were 7 males and 4 females with a mean age of 24.5 4.4 and mean age at onset of 12.5 4.8 years. Their seizure types were absences (n:6), myoclonia (n:4), generalized tonic-clonic seizures (n:11) and absence status epilepticus attacks were documented in one of them. 8 patients had also ictal recordings (4 had absences, 3 had myoclonus) and focal ictal activity from left occipital region provoked by photic stimulation was also recorded in the last one. Visual auras were reported as flashing of lights in 6 patients, macropsy/micropsy in 2 patients, illusional movement of the environment in one patient, blindness after the flashes in one patient, and ictal blindness only in the last patient. Blinking and conscious head deviations were also associated with visual auras in 6 and 4 patients, respectively. Headaches independent of seizures were diagnosed in 5 patients including migraine without aura in 3, tension type headache in one and idiopathic stabbing headache in the last patient. There was EEG photosensitivity in 8 patients. MRIs showed normal results in 10 patients, except one patient with nonspecific white matter lesions. Their syndromic diagnosis were juvenile myoclonic epilepsy in 4 patients, eyelid myoclonia with absences in 3 patients, juvenile absence epilepsy in 2 patients and other IGEs in the last 2 patients. 8 patients had benign course with either valproate or levatiracetam monotherapy. EEG recordings were further analyzed independently by 2 investigators for the presence of focal epileptic abnormality in addition to GSW and it was found in 4 patients with a Kappa index of 0.8 by interobserver agreement analysis. Conclusions: Our findings showed that visual auras are not very rare in IGE, constituting 6.2% of the main group. This study supports electro-clinical overlap of generalized and focal epilepsies. This finding has also practical management implications due to misdiagnosis of focal epilepsy instead of generalized epilepsies.