Abstract
Purpose: :
Infantile Spasms is a childhood epilepsy and is sometimes associated with vision abnormalities. The aim of this study was to investigate factors which are associated with an abnormal ERG 30Hz flicker amplitude in patients with Infantile Spasms.
Methods: :
Cross-sectional retrospective hospital chart review of 55 patients with Infantile Spasms. The mean age was 12 months ± 9.76 (range 0.26 - 40 months) and the mean age of seizure onset was 6 months ± 6.18. All patients had clinical spasms (flexor, extensor, mixed flexor-extensor) and EEG changes of hypsarrhythmia or modified hypsarrhythmia. Infantile Spasms were classified according to cause: symptomatic (prenatal, perinatal or postnatal) or cryptogenic. Flicker ERGs were recorded to a 30 Hz 3.0 cd•s/m2 white flash on a 30 cd/m2 white background. The outcome measure was amplitude. Flicker ERG amplitudes were defined as abnormal if they were outside the 95% confidence interval of the age-expected distribution for healthy subjects (published lab normal data). A logistic regression was conducted with flicker ERG finding (normal/abnormal) as the dependent variable and Infantile Spasm classification as the independent variable.
Results: :
Infants with a postnatal event linked to Infantile Spasms were more likely to have an abnormal ERG 30 Hz flicker amplitude than the prenatal and perinatal symptomatic groups and the cryptogenic group (odds ratio = 9.97, p=0.048).
Conclusions: :
We have identified an aetiology of Infantile Spasms that is associated with retinal abnormalities. Children with Infantile Spasms related to a postnatal event are more likely to have an abnormal ERG 30Hz flicker amplitude. This is an important step in identifying sources of retinal abnormalities in children with Infantile Spasms.
Keywords: electroretinography: clinical • visual development: infancy and childhood • visual impairment: neuro-ophthalmological disease