P92. A case of a focal visual status epilepticus

Abstract

Objective Epileptic visual auras typically are elementary to complex, partially colored, located close to or within the central part of the contralateral hemi-field and last seconds to a few minutes which discriminates them from the, on average, longer lasting visual auras (5–30 min) of patients suffering from migraine. Case A right handed woman (41 years of age) had suffered an atypical intracerebral hemorrhage at age 39 due to an arteriovenous malformation (AVM) within the right occipital lobe. She reported a left paracentral visual scotoma and no other sequelae from the event. Half a year after the event and resection of the AVM ( Fig. 1 ) a first visual aura evolving into a tonic-clonic seizure occurred. Despite antiepileptic treatment she reportedly experienced visual auras on a weekly basis and described them as bright, at times rotating, otherwise largely immobile and sometimes colorful spots within the lower left visual field. Often this would last minutes and durations of 15 min had been perceived. Sometimes she would then develop an epigastric and/or unpleasant olfactory sensation which themselves could last more than a minute. Every other month she would experience a tonic-clonic seizure. Several days after her medication had been withdrawn within our epilepsy monitoring unit during a non-invasive presurgical workup we were able to document such a visual aura lasting 40 min and appearing within her left lower visual field close to the permanent scotoma. The EEG-seizure pattern remained highly localized to electrode O2 throughout most of the aura ( Fig. 2 ). After a moderate spread to electrodes T6 and P4, application of 1 mg Clonazepam i.v. quickly abolished the seizure. Discussion The reportedly most reliable criteria differentiating between an epileptic and a migrainous aura are the unilaterality of the former and the longer duration of the latter ( Panayiotopoulos, 1999 ). Rarely and apparently more often after introduction of anticonvulsive treatment - probably by reducing the propensity to seizure spread - an epileptic visual aura lasts several minutes and there are only a few cases of a visual focal status epilepticus with a symptom-duration of more than 30 min ( Walker et al., 1995 ). Conclusion Long-lasting epileptic visual auras can occur and demonstrate the wide spectrum of propagation-dynamics within epileptogenic networks.