[Differential diagnosis of infantile nystagmus]

Infantile nystagmus syndrome is classified into two main categories: idiopathic infantile nystagmus, in which no obvious structural or functional abnormalities of the eyes are present and infantile nystagmus associated with ocular pathologies (sensory defect nystagmus). In the latter, a defect located in the visual pathway but anterior to the lateral geniculate nucleus is responsible for the nystagmus, e.g., pathologies of the anterior segment, retinal diseases or optic neuropathies. Furthermore, oculocutaneous or ocular albinism is a common cause of infantile nystagmus syndrome. Acquired nystagmus of neurological origin also occurs in early childhood, e.g., in the context of complex hereditary malformations of the central nervous system, syndromic disorders or tumor-related diseases. This article provides an overview of the differential diagnosis of infantile nystagmus. It covers important aspects of the medical history and clinical examination that help to assign patients to the appropriate subgroups and to assess the urgency of further, possibly interdisciplinary, investigations.