Convergence Retraction Nystagmus

Clinical Characteristics and Pathophysiology

• Convergence retraction nystagmus (CRN) is distinct from other forms of nystagmus that may occur in patients with strabismus, as noted by the American Academy of Ophthalmology 1, 2

Anatomical Localization

• Light-near dissociation of pupils is a characteristic feature of dorsal midbrain syndrome, which includes CRN, according to the American Academy of Ophthalmology 2

Etiology

• CRN is associated with multiple sclerosis, as reported by the American Academy of Ophthalmology 2
• Arteriovenous malformations are a possible cause of CRN, as indicated by the American College of Radiology 3

Diagnostic Approach

• MRI of the brain is the preferred imaging modality for patients presenting with CRN, as recommended by the American College of Radiology 3, 4
• Contrast enhancement may be necessary if a suspicious lesion is identified on MRI, according to the American College of Radiology 4
• CT has limited value in the initial evaluation of nystagmus, as stated by the American College of Radiology 3, 4

Important Pitfalls to Avoid

• CRN should not be confused with nystagmus blockage syndrome, which occurs in children with infantile esotropia, as noted by the American Academy of Ophthalmology 1, 2