Utility of magnetic resonance imaging in children with strabismus

Yoon L, Kim HY, Kwak MJ, Park KH, Bae MH, Lee Y, Nam SO, Choi HY, Kim YM. Utility of Magnetic Resonance Imaging (MRI) in Children With Strabismus. J Child Neurol. 2019 May 21:883073819846807. doi: 10.1177/0883073819846807. [Epub ahead of print]

Abstract

PURPOSE:

Magnetic resonance imaging (MRI) of the brain can provide valuable information about structural abnormalities in strabismus. The aim of this study was to evaluate the utility of MRI in this regard and to identify risk factors for abnormal MRI results in children with strabismus.

METHODS:

A retrospective analysis of children <18 years of age presenting with strabismus, who underwent brain MRI at Pusan National University Hospital (Busan, Korea) between January 2012 and March 2017, was performed. Clinical characteristics, MRI results, and ophthalmologic findings were reviewed. Findings were classified as normal or abnormal according to MRI results. Additionally, patients were divided according to age to compare characteristics of infantile and childhood strabismus.

RESULTS:

A total of 90 patients (47 [52.2%] male, 43 [47.8%] female; mean age, 2.19 ± 0.53 years) were enrolled. Of those, 64 (71.1%) presented with normal and 26 (28.9%) with abnormal MRI results. The age at presentation was lower and abnormal findings on fundus examination were more common in the abnormal MRI group ( P = .002 and P = .008, respectively). Among the patients, 46 (51.1%) had infantile strabismus and 44 (48.9%) had childhood strabismus. Global developmental delays, speech delays, and MRI abnormalities were more common in patients with infantile than in those with childhood strabismus. Ptosis and headaches were more common in patients with childhood strabismus ( P = .025, P = .025, respectively).

CONCLUSION:

Brain MRI was helpful for accurate diagnosis and treatment of strabismus in younger children, those with abnormal findings on fundus examination, and infants with developmental, especially speech, delays.

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From the manuscript

This study found that MRI produced abnormal results in 28% of patients with strabismus. Periventricular leukomalacia, the most frequently found in this study, is known to be a major cause of childhood strabismus.  In 2002, a study of patients with periventricular leukomalacia and vision impairment by Jacobson et al suggested that strabismus and nystagmus may be the only symptoms of periventricular leukomalacia. Studies involving premature infants with a gestation period <29 weeks also reported vision impairment in 6% of patients due to premature retinopathy and brain lesions; premature infants with retinopathy in early stages had a higher incidence of strabismus.  Periventricular leukomalacia is a major central nervous system complication in prematurity, and ischemic injury of the periventricular region interferes with the development of the visuomotor pathway, leading to ocular alignment abnormalities.  MRI is required to assess the periventricular region in prematurity, and in infants with a history of ischemic damage resulting in misalignment of the eyes.

In this study, developmental and speech delays were higher in patients with infantile than in those with childhood strabismus, with significant differences between the 2 groups (P = .014 and P = .030, respectively). We included patients who were referred to a pediatric neurology clinic by pediatric ophthalmologists because of the need to rule out underlying neurologic abnormalities. Strabismus may cause more damage during the critical period of brain development.  Early-onset strabismus not only affects visual function but also causes developmental delays.  Research investigating MRI abnormalities has been performed in a variety of ways and has also been used to examine patients with developmental and language delays. When comparing normal development and delayed speech, a high proportion of patients with delayed speech demonstrate abnormal MRI features.  Previous studies have consistently revealed a strong correlation between the appearance on MRI of impairment of the optic pathway to the visual cortex, reduced visual function, and decline of cognitive function.  Headache and ptosis were more common in patients with childhood strabismus. Ptosis affecting 5 patients in the childhood strabismus group was diagnosed before the age of 12 years, and their strabismus was noticed after 1 year of age. Headache may appear more common in patients with childhood strabismus because infants are unable to voice complaints.

Courtesy of:  https://www.mdlinx.com/journal-summaries/strabismus-magnetic-resonance-imaging-pediatrics/2019/05/23/7567640?spec=neurology