Pediatric nystagmus can be classified as infantile (onset in first 6 months of life) or acquired (later onset) [23]. The most common causes of infantile nystagmus are albinism, retinal disease, low vision, or vision deprivation (congenital cataract) and other retinal disorders [23,24]. These are typically diagnosed with a clinical ophthalmological examination and genetic workup. Infantile nystagmus may also occur in fusion maldevelopment syndrome, which occurs in children with normal ocular development and retinal function. Acquired nystagmus may be caused by anterior optic pathway lesions (tumors), lesions of the brainstem/cerebellum (structural lesions or space occupying lesions), or various metabolic diseases (leukodystrophies, mitochondrial diseases, etc) [23,25]. Neuroimaging is frequently needed in these cases to exclude above structural lesions, especially in patients with late onset nystagmus, in the presence of concurrent neurological symptoms, with decreased visual acuity, or in the presence of asymmetric/unilateral or progressive nystagmus [26-28]. Batmanabane et al [29] retrospectively reviewed charts of 148 children who underwent MRI for isolated nystagmus; 23 (15.5%) of these children had abnormal intracranial findings. Most common abnormalities on MRI included abnormal T2 hyperintense signal in white matter (4%), Chiari 1 malformation (3.4%), and optic pathway glioma (2%). This study did not find an association between the time of the onset of nystagmus and abnormal MRI. This study also suggested that administration of IV contrast is not required in all cases with isolated nystagmus and can be considered in children with a suspicious lesion on MRI. Similarly, only 2% of subjects in this study had intraorbital abnormalities that benefitted from dedicated orbital sequences. MRI of the orbits may be considered if the initial screening MRI brain is suspicious for orbital abnormalities [29]. Vestibular nystagmus is also a common form of acquired nystagmus.
Orbital Imaging and Vision Loss Child. Pediatric nystagmus can be classified as infantile (onset in first 6 months of life) or acquired (later onset) [23]. The most common causes of infantile nystagmus are albinism, retinal disease, low vision, or vision deprivation (congenital cataract) and other retinal disorders [23,24]. These are typically diagnosed with a clinical ophthalmological examination and genetic workup. Infantile nystagmus may also occur in fusion maldevelopment syndrome, which occurs in children with normal ocular development and retinal function. Acquired nystagmus may be caused by anterior optic pathway lesions (tumors), lesions of the brainstem/cerebellum (structural lesions or space occupying lesions), or various metabolic diseases (leukodystrophies, mitochondrial diseases, etc) [23,25]. Neuroimaging is frequently needed in these cases to exclude above structural lesions, especially in patients with late onset nystagmus, in the presence of concurrent neurological symptoms, with decreased visual acuity, or in the presence of asymmetric/unilateral or progressive nystagmus [26-28]. Batmanabane et al [29] retrospectively reviewed charts of 148 children who underwent MRI for isolated nystagmus; 23 (15.5%) of these children had abnormal intracranial findings. Most common abnormalities on MRI included abnormal T2 hyperintense signal in white matter (4%), Chiari 1 malformation (3.4%), and optic pathway glioma (2%). This study did not find an association between the time of the onset of nystagmus and abnormal MRI. This study also suggested that administration of IV contrast is not required in all cases with isolated nystagmus and can be considered in children with a suspicious lesion on MRI. Similarly, only 2% of subjects in this study had intraorbital abnormalities that benefitted from dedicated orbital sequences. MRI of the orbits may be considered if the initial screening MRI brain is suspicious for orbital abnormalities [29]. Vestibular nystagmus is also a common form of acquired nystagmus.