Sleep-related hypermotor seizures originating from the occipital lobe

Abstract

We present two unique cases of sleep-related hypermotor epilepsy (SHE) originating from the occipital lobe. Patients with sleep-related seizures and drug-resistant occipital lobe epilepsy were identified from the ANPHY lab stereo-electroencephalography (SEEG) research database at the Duke Comprehensive Epilepsy Center. We identified two young females with frequent sleep-related focal seizures and occasional focal to bilateral tonic clonic seizures characterized by hypermotor movements. During wakefulness, the semiology also involved an elementary visual aura. They meet the 2016 diagnostic criteria for SHE, and SEEG monitoring with cortical stimulation mapping identified an epileptogenic zone (EZ) within the occipital lobe, with most seizures occurring out of NREM 2 sleep. Responsive neurostimulation devices were implanted, which indicated a trend for event detections in nocturnal periods. Extrafrontal SHE has characteristically been described in the temporal, insular-opercular, and parietal lobes. Here, we demonstrate using SEEG-confirmed EZ identification, that SHE can also originate in the occipital lobe. In patients with sleep-related seizures and hypermotor behavior, occipital lobe seizures thus should not be excluded from the differential diagnosis. Key in identifying this rare localization is non-frontal aura semiology and delay to motor symptoms, which may be supported by a visual field deficit and structural MRI abnormality.