Lateralization of cognitive functions after stroke in childhood.
BACKGROUND
A child's brain shows a remarkable ability to recover from adverse events such as stroke. Language functions recover particularly well, while visuo-spatial skills are more affected by brain damage, regardless of its localization. This study investigated the lateralization of language and visual search after childhood stroke.


METHODS
Ten patients with unilateral stroke (aged 10-19 years, five left-, five right-sided lesion) and 20 healthy controls (aged 8-20 years) completed a neuropsychological test battery and functional magnetic resonance imaging (fMRI) intended to activate predominantly right (visual search) and left-sided functional networks (language).


RESULTS
After stroke, patients demonstrated atypical lateralization of visual search functions (8/10 patients, left lateralization) more often than that of language (4/10 patients, right lateralization). There was a dissociation between the lateralization of productive and semantic language (4/10 patients, 1/20 controls) and between the lateralization of simple and complex visual search (3/10 patients, 3/20 controls). In patients, atypical contralateral activations occurred in the same areas that showed decreasing activation during development in healthy participants.


CONCLUSIONS
The lateralization of functions depends upon the cognitive function measured. Dissociation between the lateralization of different language or visual search tasks can occur.
Everts
Regula
R
Paediatric Neurology, University Children's Hospital, Inselspital, Bern, Switzerland. regula@everts.ch
Lidzba
Karen
K
Wilke
Marko
M
Kiefer
Claus
C
Wingeier
Kevin
K
Schroth
Gerhard
G
Perrig
Walter
W
Steinlin
Maja
M
D000293:Adolescent; D002648:Child; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009483:Neuropsychological Tests; D020521:Stroke / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D014705:Verbal Behavior / Q000502:physiology*; D014786:Vision Disorders / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation; D055815:Young Adult