Two types of isolated epileptic nystagmus: case report

Epileptic nystagmus (EN) is a quick, repetitive jerky movement of the eyeball caused by seizure activity, unaccompanied by other ictal phenomena rare. Here, we described two cases, one characterized by binocular and the other by monocular isolated epileptic nystagmus (IEN), and we identified the characteristics of the etiology, clinical manifestations, electroencephalogram, imaging, treatment and prognosis in epileptic nystagmus through reviewing literature. We found IEN occurs more frequently in children than in adults. Etiological factors included trauma, cerebral vascular disease, tumor, and anoxia. The frequency of IEN was high, which varied from several to hundreds of times per day, and the duration of it was usually less than 1 minute. EN and its subtypes, such as epileptic monocular nystagmus, vertical epileptic nystagmus, epileptic skew deviation, periodic alternating nystagmus, and partial oculo-clonic status, are rare. The fast phase of the nystagmus was contralateral to the epileptogenic zone in most cases. Periodic lateralized epileptiform discharges (PLEDs) is a distinct EEG pattern in EN. Our findings suggested that the occipital lobe may plays a key role in the origin of EN.