Diagnosis of Nystagmus and Saccadic Intrusions

This chapter reviews the approach to the patient with nystagmus or saccadic intrusions and their clinical features (with illustrative video cases), etiology, pathophysiology, and management. Nystagmus caused by peripheral vestibular disorders; downbeat, upbeat, and torsional nystagmus; periodic alternating nystagmus, seesaw and hemi-seesaw nystagmus; gaze-evoked nystagmus; Bruns nystagmus; centripetal and rebound nystagmus; nystagmus occurring in association with disease of the visual system; acquired pendular nystagmus with multiple sclerosis; oculopalatal tremor; convergence-retraction nystagmus; infantile nystagmus syndrome; fusional maldevelopment nystagmus syndrome and latent nystagmus; spasmus nutans syndrome; and lid nystagmus are discussed. Saccadic intrusions and oscillations and the clinical features, etiology, pathophysiology, and management of square-wave jerks, macrosaccadic oscillations, saccadic pulses, ocular flutter, opsoclonus, and voluntary saccadic oscillations are summarized. Treatments for nystagmus and saccadic intrusions are summarized, including pharmacological treatments, optical treatments, procedures to weaken the extraocular muscles (e.g., Kestenbaum-Anderson procedure), and measures such as biofeedback and vibration.