Is hiragana decoding impaired in children with periventricular leukomalacia?

There are few studies on hiragana reading skill and phonological awareness in Japanese schoolchildren with periventricular leukomalacia (PVL).

Three seven-year-old children with PVL who had no intellectual disabilities or dysarthria were recruited. Their perinatal information, brain magnetic resonance image (MRI) at term equivalent age, accompanying neurodevelopmental disorders, ophthalmologic features, Kaufman Assessment Battery for Children (K-ABC), a hiragana reading test (four tasks), and a phonological awareness task (mora reversal tasks) were analyzed.

Patient (Pt) 1 and pt2 were male. Pt2 and pt3 were siblings of triplets. Their gestational age was 28 or 32 weeks, and their birth weights were 1196, 1554, and 1848 g, respectively. Their brain MRI revealed cystic or non-cystic periventricular white matter injury involving the deep white matter at the trigone of both lateral ventricles. Pt1 had attention-deficit/hyperactivity disorder and pt3 had pervasive developmental disorder not otherwise specified. All patients had strabismus with spared best-corrected visual acuity. Scores of Reading/Decoding in K-ABC ranged from 89 to 99. As for the single mora reading task or the non-word reading task in the kana reading test, Z scores of their reading time ranged from 2.3 to 5.9 compared to control children. Pt1 and pt3 made significant errors in the mora reversal task of three-mora words, whereas all patients could answer all words correctly in the mora reversal task of two-mora words.

All children showed significantly prolonged reading time despite their adequate letter recognition. Two patients showed delayed phonological awareness. It was suggested that hiragana decoding impairment due to subcortical and/or cortical injury related to PVL affected their reading ability.