Maturation of the Visual Evoked Response and Its Correlation With Visual Acuity in Preterm Infants

Abstract

SUMMARY Visual evoked responses (VERs) were elicited in 70 infants with postmenstrual ages between 30 and 39 weeks. On the basis of neurological and ultrasound examinations, 30 of the infants were classed as neurologically normal and 40 as abnormal: 26 of the latter had periventricular haemorrhage. Initially the VER consisted of a negative deflection only, and the appearance of a positive wave immediately preceding the negative deflection was taken to indicate maturation of the VER. Maturation was significantly delayed in the neurologically abnormal infants, and the delay was related to the degree of neurological insult. The visual acuity of 32 infants was estimated within seven days of the VER recording. There was a correlation of 79 per cent between the VER and the data for visual acuity. RÉSUMÉ Maturation des réponses évoquées visuelles et sa corrélation avec l'acuite visuelle des prématurés neurologiquement normaux et anormaux Des réponses visuelles évoquées (VERs) ont été provoquées chez 70 nourrissons d'âge postmenstruel compris entre 30 et 39 semaines. Sur la base d'examens neurologiques et ultrasons, 30 de ces nourrissons ont été classés neurologiquement normaux et 40 comme anormaux; 26 de ce dernier groupe présentaient des hémorragies périventriculaires. Initialement les VERs consistaient en une deflection négative seulement et l'apparence d'une onde positive précédant la déflection négative a été prise comme un indice de maturation de la VER. La maturation a été significativement retardée chez les nourrissons neurologiquement anormaux et le délai est apparu relié au degré de gravité du dommage neurologique. L'acuité visuelle de 32 nourrissons a été mesurée dans les 7 jours de l'enregistrement des VERs. II est apparu une corrélation de 79 pour cent entre les VERs et les données d'acuité visuelle. ZUSAMMENFASUNG Reifung der visuell evozierten Potentiate und ihre Korrelation zur Sehschärfe bei neurologisch normalen und abnormen Frühgeborenen Bei 70 Kindern mit einem postmenstruell berechneten Alter von 30 bis 39 Wochen wurden visuell evozierte Reaktionen (VER) abgeleitet. Auf der Basis von neurologischen und Ultraschall‐Untersuchungen wurden 30 der Kinder als neurologisch normal und 40 als abnorm eingestuft: von den letzteren hatten 26 eine periventrikuläre Blutung. Anfänglich bestand die VER nur aus einem negativen Ausschlag und das Auftreten einer positiven Welle direkt vor dem negativen Ausschlag wurde als Zeichen für die Reifung der VER angesehen. Bei den neurologisch abnormen Kindern war die Reifung signifikant verzögert und die Verzögerung war abhängig vom Grad der neurologischen Störung. Bei 32 Kindern wurde die Sehschärfe innerhalb von seiben Tagen nach Ableitung der VER bestimmt. Es fand sich eine Korrelation von 79 Prozent zwischen der VER und den Daten für die Sehschärfe. RESUMEN Maduración de la respuesla visual evocada y su correlación con la agundeza visual en prematuros neurológicamente normales y anormales Se obtuvieron las respuestas visuales evocadas (RVE) en 70 lactantes de edades postme...

Prognostic value of flash visual evoked potentials in preterm infants

“…Placzek et al (1985) recorded flash VEPs in 70 preterm infants, 26 of whom had evidence of a germinallayer intraventricular haemorrhage (GL-IVH) on cranial ultrasound. The major positive component P2, which is consistently present in all normal neonates from 37 weeks' gestation onwards (Placzek et al 1985), was present in over 90% of the neurologically normal infants by 35 to 36 weeks gestational age (GA), but a large proportion of infants with intraventricular haemorrhage (IVH) manifested immature flash-VEP waveforms. The authors concluded that the extent of delay in the maturation of the VEP was related to the degree of neurological insult.…”

Flash VEP findings in children with bilateral spastic cerebral palsy: Correlation with clinico-radiological parameters

“…De Vries et al [42] and Eken et al [43] found that infants with extensive cystic PVL often manifested abnormal VEP with poor-quality waveforms; a reproducible response could rarely be elicited in infants with subcortical lesions. Severe visual impairment was invariably present in infants in whom VEP could not be recorded [41][42][43]. Contrary findings have been reported by Ekert et al [44] who recorded VEP in the first and second weeks of life in 45 preterm infants.…”

“…Placzek at al. [41] recorded VEP in 70 premature infants, 26 of whom had IVH. A large proportion of infants with IVH manifested abnormal VEP.…”

Flash VEP in clinically stable pre-term and full-term infants

“…VEP is particularly useful to investigate the functional integrity of the visual system of high-risk infants where obvious retinal and neurological abnormalities are not observed [10]. Several flash VEP studies of high-risk infants are available in the literature [11][12][13][14][15]. These studies have demonstrated that immature P2 waveform [11], irreproducible waveform responses, and unrecordable VEP measurements [13] are associated with abnormal neurodevelopment [12] and visual impairment in pre-term infants.…”

“…Several flash VEP studies of high-risk infants are available in the literature [11][12][13][14][15]. These studies have demonstrated that immature P2 waveform [11], irreproducible waveform responses, and unrecordable VEP measurements [13] are associated with abnormal neurodevelopment [12] and visual impairment in pre-term infants. VEP has also been investigated for its prognostic value of long-term visual and neurodevelopmental outcomes in infants [16][17][18] but the results are ambiguous.…”