Article

Plasticity in the developing brain is a controversial issue. Although
language and motor function often recover remarkably well following early brain
injury, recent evidence suggests that damage to the developing brain results in
significant long-term neuropsychological impairment. Our aim was to investigate
the relationship among age at injury, lesion location and intellectual outcome.
METHOD: Using age-appropriate Wechsler scales of intellectual ability, we
explored this issue by evaluating a large group (n=145) of children (89 males, 56
females) who experienced unilateral arterial ischaemic stroke during the
perinatal period (diagnosed mean 73d, SD 29d), between the ages of 1 month and 5
years (mean 2y 10mo, SD 1y 9mo), or between the ages of 6 and 16 years (mean 11y
1mo SD 3y 6mo). The mean age at assessment was 8 years (SD 3y 10mo) in the
perinatal group, 7 years 5 months (SD 2y 9mo) in the 1 month to 5 years group,
and 12 years 5 months (SD 3y 9mo) in the 6 to 16 years group. The mean time
interval between stroke and assessment was 8 years (SD 18d) for perinatal, 4
years 6 months (SD 1y 5mo) for 1 month to 5 years, and 1 year 4 months (SD 2y
9mo) for 6 to 16 years. The relationship between age at stroke and lesion
location (subcortical, cortical, or combined) as it pertains to cognitive outcome
was also examined. RESULTS: Measures of overall intelligence, verbal ability,
working memory, and processing speed were significantly lower in children who had
had a stroke than in the normative sample (all z>2.5, all p<0.01). The perinatal
group performed more poorly than the other two groups on most cognitive measures,
regardless of lesion location. The combined lesion location group performed more
poorly than those with damage to either cortical or subcortical areas alone.
Further investigation revealed different periods of peak vulnerability for
subcortical lesions (perinatal) and cortical lesions (1mo-5y). INTERPRETATION:
Lesion location modulates the relationship between age at stroke and cognitive
outcome.

Langue : ANGLAIS