Acquired nystagmus

Nystagmus is the repetitive to and fro movement of the eyes, which may be physiological or pathological. The movements can be horizontal, vertical, torsional or a combination of these movements. It starts by a slow movement of the eye away from the visual target. The second movement brings the eye back to the visual target. If this second movement is quick, the nystagmus is called jerk nystagmus. If the second movement is slow, the nystagmus is said to be pendular. Maintaining steady gaze is dependent upon visual fixation, the vestibulo-ocular reflex and the gaze-holding neural integrator system. Pathological nystagmus typically presents with the symptom of oscillopsia, which is the illusory movement of the surrounding environment. Nystagmus that develops outside of early infancy is termed acquired nystagmus. There may be serious underlying pathology that will require further investigation and management. This article reviews the terminology, pathophysiology, causes and treatment of acquired nystagmus.

Diagnostic approach to abnormal spontaneous eye movements

PURPOSE OF REVIEW

Abnormal spontaneous eye movements, including nystagmus and saccadic intrusions, are often encountered in neurologic practice and can cause disabling visual symptoms, such as oscillopsia and blurred vision. This article reviews the spectrum of abnormal spontaneous eye movements and describes their characteristics, etiology, and management.

RECENT FINDINGS

The number of prospective, controlled, and masked clinical trials evaluating candidate treatments for abnormal spontaneous eye movements has increased significantly over the past decade. The findings of recent clinical trials are highlighted, and the dosing and potential side effects of proposed medical treatments are summarized.

SUMMARY

Abnormal spontaneous eye movements are often encountered in neurologic practice. Recent clinical trials provide an evidence base to guide treatment decisions for these disorders.