Genetic (idiopathic) generalized epilepsy with occipital semiology

Abstract

Idiopathic photosensitive occipital lobe epilepsy (IPOE) is a syndrome that should be suspected in patients with seizures with occipital semiology, photosensitivity, and normal MRI. It should be distinguished from occipital epilepsy of unknown aetiology (cryptogenic) given the differences in management. We reviewed patients with occipital seizures which were investigated in our epilepsy unit during the last three years. Three patients were identified with features of IPOE and genetic generalized epilepsy (GGE), formerly known as idiopathic generalized epilepsy, and their clinical characteristics were analysed. We propose the term "idiopathic generalized epilepsy with occipital semiology" based on the significance of managing and treating this syndrome as a GGE.

Generalized, focal, and combined epilepsies in families: New evidence for distinct genetic factors

“…It has been suggested that combined epilepsies may be subtypes of one of the other major epilepsy subtypes—for example, that idiopathic photosensitive occipital epilepsy (IPOE) is a form of generalized epilepsy with shared underlying genetic determinants, distinct from the determinants of focal epilepsy (Figure 1A). 13 We did not find evidence to support this hypothesis: Combined epilepsies were equally likely to occur in families with generalized as with focal epilepsies, and did not aggregate more closely with one phenotype or the other within families.…”

“…For individuals with combined epilepsy, we considered three hypotheses (Figure 1). First, combined epilepsy may represent a subtype of generalized epilepsy with the same genetic determinants, as has been hypothesized for idiopathic photosensitive occipital epilepsy 13 . (Conversely, it could be a subtype of focal epilepsy, not shown in the figure.)…”

“…First, combined epilepsy may represent a subtype of generalized epilepsy with the same genetic determinants, as has been hypothesized for idiopathic photosensitive occipital epilepsy. 13 (Conversely, it could be a subtype of focal epilepsy, not shown in the figure.) Second, combined epilepsies may represent a blended or intermediate phenotype caused by the co-occurrence of distinct genetic determinants of generalized epilepsy and focal epilepsy within the same individual.…”

Resection of bilateral occipital lobe lesions during a single operation as a treatment for bilateral occipital lobe epilepsy

“…Occipital lobe epilepsy[ 1 ] is an uncommon form of epilepsy that accounts for only 2%-13% of cases of symptomatic focal epilepsy[ 1 - 6 ]. The symptoms of occipital lobe epilepsy are mainly visual and oculomotor manifestations and include visual illusion, elementary visual hallucinations, blinking, a sensation of eye movement, nausea, dizziness, ictal blindness, and contralateral eye and head deviation[ 1 , 5 - 9 ].…”

“…The symptoms of occipital lobe epilepsy are mainly visual and oculomotor manifestations and include visual illusion, elementary visual hallucinations, blinking, a sensation of eye movement, nausea, dizziness, ictal blindness, and contralateral eye and head deviation[ 1 , 5 - 9 ]. The diagnosis of occipital lobe epilepsy can be challenging because of the rapid spread of the seizure to the frontal, temporal and parietal lobes and the midbrain tegmentum[ 5 , 6 , 10 ]. Therefore, achieving a definitive diagnosis generally requires the use of scalp electroencephalograms (EEGs), magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography (FDG-PET), single-photon emission computed tomography (SPECT), and/or video-EEG monitoring with intracranial electrodes[ 4 , 7 , 9 , 11 - 13 ].…”