Eye Movement Disorders: Nystagmus and Nystagmoid Eye Movements

Nystagmus is a rhythmic biphasic oscillation of the eyes, and the slow phase eye drift initiates the movement. Nystagmus should also be distinguished from other ocular oscillations or nystagmoid eye movements. These other ocular oscillations usually do not have a slow phase and often represent disorders of saccades. Characteristically, they interrupt foveal fixation, and although they can be distinguished clinically, some may be best characterized by eye movement recordings. This chapter reviews the symptoms and examination of patients with nystagmus and details each of the important types of nystagmus and nystagmoid eye movements and their pathophysiology and management.