Opsoclonus

Clinic

• Opsoclonus is an oculomotor dyskinesia
• It is characterized by Rapid, Repetitive conjugate eye movements that are
  • Involuntary
  • Arrhythmic
  • Chaotic
  • Multi-directional (horizontal, vertical, and torsional components)
  • Without inter-saccadic intervals

• It is also referred to as saccadomania or reflexive saccade.
• The movements of opsoclonus may have a very small amplitude, appearing as tiny deviations from primary position.

Opsoclonus vs nystagmus

• They may be mistaken for each other
• Opsoclonus is a burst of back to back saccades with no intersaccadic interval, without the slow phases of nystagmus

Causes

• Neuroblastoma
• Encephalitis
• Breast, lung, or ovarian cancer
• OMS: It frequently occurs along with myoclonus in opsoclonus myoclonus syndrome

Related disease

• Multiple sclerosis
• Toxins, medication effects (Serotonin Syndrome)
• Celiac disease
• Infections (WNE, Lyme disease)
• Non-Hodgkin lymphoma
• Renal adenocarcinoma
• It can also be caused by a lesion in the omnipause neurons which tonically inhibit initiation of saccadic eye movement (until signaled by the superior colliculus) by blocking paramedian pontine reticular formation (PPRF) burst neurons in the pons.