Reduced ipsilesional cortical volumes in fetal periventricular venous infarction.

Background And Purpose: Perinatal stroke causes most term-born hemiplegic cerebral palsy. Many suffer additional sequelae. Periventricular venous infarction (PVI) is a common fetal stroke in which isolated subcortical injury may cause only motor deficits. However, cognitive, language, and behavioral deficits also occur. We hypothesized that ipsilesional cortical gray matter volumes are reduced in PVI.

Methods: Children (12 months to 18 years) with MRI-confirmed PVI were identified through the Alberta Perinatal Stroke Project. We developed an MRI method to quantify sectional gray (GM) and white matter (WM) volumes from lesioned and unlesioned (control) hemispheres (OsiriX software). Differences in cortical GM and WM volumes were compared between hemispheres in preselected regions "above" the lesion (middle) and anterior and posterior to this. Outcomes dichotomized for "cortical dysfunction" (cognitive, behavioral, language) and motor deficit severity (Pediatric Stroke Outcome Measure) were compared with GM volumes.

Results: Twenty-two children (81% boys; median age, 8 years) were included. Methods demonstrated high intrarater and inter-rater reliabilities (ρ=0.988, ρ=0.943) and minimal observer bias. Ipsilesional GM volume was significantly reduced in the middle (P=0.007) and posterior (P=0.03) regions. Middle ipsilesional WM volumes were reduced (P<0.001). The degree of GM reduction was not associated with cortical dysfunction or severity of motor deficit.

Conclusions: Ipsilesional GM volume is diminished in PVI. Speculative mechanisms include retrograde neuronal degeneration and disrupted migration. Neuropsychological testing of larger samples is required to determine clinical significance.