Summary:Purpose: To study prospectively the evolution of visual attention in children with West syndrome to evaluate its development before the onset of spasms, its possible deterioration as a consequence of epileptic disorders, and its outcome at the age of 2 years, and the possible relation between the impairment of visual attention and cognitive development.Methods: Infants with symptomatic West syndrome were examined before the onset of spasms and until age 24 ± 2 months. Visual attention study (through a clinical observation and the fixation-shift test), cognitive assessment, and complete clinical examination including brain magnetic resonance imaging were performed.Results: A maturation defect of fixation shift skills was generally observed in infants with West syndrome. In some cases, the impaired visual-attention abilities paralleled a cognitive deterioration, even months before the onset of spasms. During the acute stage of West syndrome, infants lost the previously acquired visual and cognitive abilities, with a typical fluctuation of arousal. Usually at 2 years, there was a persistent defective visual attention detected with the fixation-shift test.Conclusions: The parallel defect of visual attention and of cognitive competencies is a constant finding in infants with West syndrome; these can precede the clinical onset of epileptic spasms. The severity and persistence of visual inattention might be explained by the age of visual maturation, corresponding to the usual onset of West syndrome.
Summary:Purpose: Several studies have reported behavioral and electrophysiological evidence of visual impairment during the active stage of West syndrome. The underlying mechanisms are, however, poorly understood, and little has been reported about the correlation between visual impairment, EEG patterns, and brain lesions. The aim of the study was to assess visual function at the onset of spasm and 2 months thereafter and relate visual findings to brain lesions and EEG features.Methods: Twenty-five infants with West syndrome were enrolled and studied with (a) a full clinical assessment including a battery of tests specifically designed to assess visual function, (b) a video-polygraphic study, and (c) brain magnetic resonance imaging (MRI). Besides brain neuroimaging and EEG comparison with visual function, an intra-EEG analysis was performed to investigate the possible relation of EEG patterns to fluctuating visual behavior (fixation and following).Results: Twenty-two children had at least one abnormal result on one or more of the tests assessing visual function at T 0 . Visual impairment at the spasm onset was related to the sleep disorganization rather than to the hypsarrhythmic pattern in awake EEG. After 2 months, both EEG features become significantly linked to visual function. Visual function improved in several cases after 2 months, in parallel with the seizure regression. No relation was found between EEG patterns and fluctuating visual behavior.Conclusions: The study supplies new evidence of the involvement of visual function in West syndrome. The presence of abnormal visual findings in infants without lesions on brain MRI suggests that visual abnormalities are due not only to brain injury but also to epileptic disorder per se. New insight is also provided into the possible mechanisms underlying clinical and EEG abnormalities.
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