Migraine aura and diplopia phenomenology associated with congenital nystagmus

Abstract

An observer with horizontal/torsional congenital nystagmus (CN) made two unique observations. One occurred during a migrainous aura and the other during a decompensated vertical phoria. The otherwise typical migraine aura was perceived as oscillating horizontally over a stable visual field – an oscillating scintillating scotoma. The vertical diplopia secondary to a decompensated phoria oscillated vertically – a diplopic oscillopsia. The implications raised by these observations strengthen the role of efference copy in the usual suppression of oscillopsia in CN. Retinal rivalry is proposed to explain the possible perception of vertical oscillopsia without vertical nystagmus.