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How to Obtain Reliable Visual Event-related Potentials in Newborns
Published on: October 24, 2019
Flash visual evoked potentials in patients with periventricular leucomalacia in children less than 1 year of age
Jitendra Jethani1, Monika Jethani
1Pediatric Ophthalmology and Squint Clinic, Dr. Thakorbhai V Patel Eye Institute, Vadodara, Gujarat, India.
Insights
Flash visual evoked potentials (fVEPs) in infants with periventricular leucomalacia (PVL) show delayed latency at 8 Hz but not 1.4 Hz. Amplitudes may appear normal, making them unreliable for assessing PVL-related visual changes.
Area of Science:
- Pediatric Neurology
- Ophthalmology
- Neurophysiology
Background:
- Periventricular leucomalacia (PVL) is a common cause of visual impairment in infants.
- Existing literature on visual evoked potentials (VEPs) in young children with PVL is limited.
- Visual impairments associated with PVL include reduced vision, visual field defects, and coordination issues.
Purpose of the Study:
- To evaluate flash visual evoked potentials (fVEPs) in children under one year of age diagnosed with PVL.
- To investigate the impact of different flash frequencies on fVEPs in this population.
- To determine the reliability of fVEPs in detecting visual pathway abnormalities in infants with PVL.
Main Methods:
- Nine infants diagnosed with PVL via MRI were included.
- The mean age of the participants was 9.7 months.
- Handheld fVEPs were performed under sedation at 1.4 Hz and 8 Hz flash frequencies.
Main Results:
- Mean N1 and P1 latencies at 1.4 Hz were 47.9 ms and 77.7 ms, respectively.
- Mean N1 and P1 latencies significantly increased to 189.8 ms and 238.4 ms at 8 Hz.
- Mean amplitudes were similar at both frequencies (5.6 μV at 1.4 Hz and 5.59 μV at 8 Hz), suggesting potential normality despite latency changes.
Conclusions:
- For the first time, a change in latency, specifically a delay at 8 Hz stimulation, was observed in infants with PVL.
- fVEP amplitudes may appear normal in the presence of PVL-related brain changes.
- fVEP amplitudes are not reliable indicators of visual pathway integrity in infants with PVL; latency changes are more indicative.
Background And Aim:
Children with periventricular leucomalacia (PVL) are known to have visual impairment of various forms starting from reduced vision, field defects, congnitive problems, and problems with hand eye coordination. There is very scant data/literature on the visual evoked potentials (VEPs) at an early age in children with PVL. We did a study to evaluate the flash visual evoked potentials (fVEPs) in children with PVL less than 1 year of age.
Materials And Methods:
A total of nine children diagnosed as having PVL on magnetic resonance imaging were included in the study. The mean age was 9.7μ 3.5 months. All children underwent handheld fVEPs under sedation at two different flash frequencies 1.4 and 8 Hz.
Results:
The mean latency of N1 and P1 on stimulation with 1.4 Hz was 47.9μ 15.2 and 77.7μ 26.0 ms, respectively. However, on stimulation with 8 Hz the mean latency of N1 and P1 was 189.8μ 25.6 and 238.4μ 33.6 ms, respectively. The mean amplitude with 1.4 Hz and 8 stimulation frequency was 5.6μ 4.5 and 5.59μ 3 mV, respectively.
Conclusion:
We have found for the first time that there is a change in the latency and the delay occurs at 8 Hz frequency but not at 1.4 Hz. We also conclude that amplitudes by fVEPs may be normal even in presence of periventricular changes. The amplitudes of fVEPs are not reliable in children with PVL.
