Nystagmus in periventricular leucomalacia

Abstract

Background/aims: Periventricular leucomalacia (PVL) is a lesion in the immature brain involving the optic radiation. Children with PVL have visual problems including crowding, visual field defects, strabismus, and visual perceptual/cognitive deficits, together with nystagmus. They often have optic nerve hypoplasia seen either as small discs or as large cupping of normal sized optic discs. This study aimed to perform eye movement recordings in a group of children with PVL in order to characterise and classify the nystagmus.

Methods: 19 children with PVL on cerebral imaging underwent eye movement recordings with the Ober-2 infrared reflection technique.

Results: 16 of the 19 subjects had horizontal nystagmus.

Conclusion: The present study shows that nystagmus is commonly seen in children with PVL.

Figure 1

Eye movement record showing horizontal and vertical traces of the right (R) and left (L) eyes with the Ober-2 system. Patient no 9 when fixating in primary position with both eyes open. Note the variable amplitude and the asymmetrical waveforms with a SPD (slow phase decreasing velocity) waveform most visible in the right eye trace. Note also the difference in vertical stability between the right and left eye. Horizontal bar, 3 degrees; vertical bar, 500 ms.

Figure 2

Eye movement record showing horizontal and vertical traces of the right (R) and left (L) eyes with the Ober-2 system. Patient no 2 with only horizontal traces shown. The record showing a jerk nystagmus with a SPI (slow phase exponentially increasing velocity) waveform with a superimposed foveating saccade (arrow). Horizontal bar, 2 degrees; vertical bar, 200 ms.

Figure 3

Eye movement record showing horizontal and vertical traces of the right (R) and left (L) eyes with the Ober-2 system. Patient no 12 with a asymmetrical pendular nystagmus out of phase. Horizontal bar, 4 degrees; vertical bar, 500 ms.

Figure 4

(A) Fundus photograph of patient no 9 demonstrating large cups in normal sized discs. (B) This single MRI shows typical changes of periventricular leucomalacia with atrophic dilatation of the posterior parts of the lateral ventricles. The amount of periventricular white matter is reduced around the occipital horns and adjacent to the trigone bilaterally. Remaining white matter has an abnormally bright signal on this T2 weighted image, first echo, indicating permanent damage, gliosis. Variations of signal involving left posterior cortical structures represent artefacts in the image.