Infantile nystagmus without overt eye abnormality: Early features and neuro‐ophthalmological diagnosis

Abstract

To analyse the neuro-ophthalmological data of children referred for further work-up of infantile nystagmus where ophthalmological evaluation had not achieved a diagnosis. METHOD: We retrospectively reviewed medical records of patients presenting with infantile nystagmus at our institution between 2007 and 2019. Inclusion criteria were onset before 6 months of age, availability of complete ophthalmic examination, visual electrophysiological tests, and neurological examination. Children with a previous definite ophthalmological diagnosis at onset and those with uncertain nystagmus onset age were not recruited. RESULTS:Out of 142 infants (mean age at nystagmus onset 3.6 mo, SD 1.7, range 0-6 mo; 56 females, 86 males), 23% had neurological nystagmus, 7% mixed neurological and sensory nystagmus, 48% sensory defect, and 22% idiopathic infantile nystagmus. The neurological diagnoses were inborn errors of metabolism, white matter genetic disorders, and brain malformations. The prevalent diagnosis in the sensory defect subgroup was retinal dystrophy.

Visual Function and Neuropsychological Profiling of Idiopathic Infantile Nystagmus

“…IIN is a diagnosis of exclusion, requiring a full phenotyping that includes clinical (ophthalmologic and neurologic) and electrophysiological examinations as well as brain MRI and OCT when necessary [ 3 , 4 , 5 , 30 ]. Nevertheless, exams such as ERG and OCT are not routinely available, as they require expertise in their administration and a level of cooperation that may be difficult to obtain in paediatric settings, especially when a child has an impaired fixation [ 8 , 50 ]. For this work, we ruled out ophthalmological and neurological conditions associated with infantile nystagmus based on a clinical follow-up, an ERG and VEP (which excluded overt pre- and retro-geniculate conditions and only showed aspecific prolongation previously reported in IIN [ 30 , 51 ]), a brain 3T-MRI (when necessary), and genetic testing (see Supplementary Table S1 for details on the diagnostic exams).…”

“…Optical coherence tomography (OCT) was not performed in our cohort. OCT is not frequently available nor easy to perform in paediatric contexts, being even less reliable when the fixation is impaired, and IIN has been diagnosed in the absence of such an examination [ 8 , 30 ].…”

“…A wide epidemiologic study conducted in England found a total prevalence of 1.9 per 10,000 in a population of unassociated IN patients (i.e., nystagmus in patients with negative ocular and electrodiagnostic tests), equal to 20% of nystagmus in childhood overall [ 7 ]. Accordingly, a recent Italian study on paediatric nystagmus reported a prevalence of 22% for IIN out of 132 children presenting with nystagmus [ 8 ]. IIN incidence in a retrospective, population-based study by Nash et al was of 6.72 per 100,000 live births [ 9 ].…”

Early Manifestation of Benign Paroxysmal Positional Vertigo: A Case Report

“…Differential diagnosis for paroxysmal abnormal eye movement in infants was established. Occulogenic etiologies are the most common [ 6 ] but less likely, given the paroxysmal nature of the symptoms. Epileptic nystagmus [ 7 ] may be a plausible cause, even despite the negative EEG findings during the presumed interictal period.…”

Nistagmo no vestibular e intrusiones sacádicas no nistágmicas

“…Se recomienda hablar de nistagmo infantil y no de nistagmo congénito puesto que no comienza hasta el inicio de la fijación de objetos por parte del niño, que es aproximadamente a los tres meses [3,7]. De la misma manera, se recomienda no hablar de nistagmo motor idiopático, puesto que en un amplio porcentaje de los pacientes existen alteraciones en la retina visibles al realizar OCT (tomografía de coherencia óptica), por lo que en estos casos se trata de nistagmo por defecto sensitivo [8,9].…”