Left hemisphere regions are critical for language in the face of early left focal brain injury.
A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we used functional magnetic resonance imaging to examine brain activity during category fluency in participants who had sustained pre- or perinatal left hemisphere stroke (n = 25) and in neurologically normal siblings (n = 27). In typically developing children, performance of a category fluency task elicits strong involvement of left frontal and lateral temporal regions and a lesser involvement of right hemisphere structures. In our cohort of atypically developing participants with early stroke, expressive and receptive language skills correlated with activity in the same left inferior frontal regions that support language processing in neurologically normal children. This was true independent of either the amount of brain injury or the extent that the injury was located in classical cortical language processing areas. Participants with bilateral activation in left and right superior temporal-inferior parietal regions had better language function than those with either predominantly left- or right-sided unilateral activation. The advantage conferred by left inferior frontal and bilateral temporal involvement demonstrated in our study supports a strong predisposition for typical neural language organization, despite an intervening injury, and argues against models suggesting that the right hemisphere fully accommodates language function following early injury.
Raja Beharelle
Anjali
A
Rotman Research Institute, Baycrest Centre for Geriatric Care, 3560 Bathurst St., Toronto, ON, M6A 2E1, Canada. anjali.raja@utoronto.ca
Dick
Anthony Steven
AS
Josse
Goulven
G
Solodkin
Ana
A
Huttenlocher
Peter R
PR
Levine
Susan C
SC
Small
Steven L
SL
D000293:Adolescent; D001931:Brain Mapping; D054022:Cerebrum / Q000503:physiopathology*; D015331:Cohort Studies; D004292:Dominance, Cerebral; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007802:Language; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D049188:Prenatal Injuries; D035781:Siblings; D020521:Stroke / Q000503:physiopathology*
Proc Natl Acad Sci U S A. 2006 Sep 19;103(38):14240-5
16968771
Neuroimage. 2007 Sep 1;37(3):866-75
17616402
Neuropediatrics. 2006 Feb;37(1):46-52
16541368
Neuroreport. 2006 Jul 17;17(10):957-62
16791084
Brain. 2002 Feb;125(Pt 2):361-72
11844736
J Child Neurol. 2001 Apr;16(4):241-52
11332458
Neuroimage. 2001 Oct;14(4):837-43
11554802
Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11702-5
14500906
Neuroimage. 2002 Aug;16(4):954-67
12202083
Curr Neurol Neurosci Rep. 2008 Nov;8(6):497-502
18957187
Brain. 2004 Jun;127(Pt 6):1229-36
15069021
Dev Psychol. 2009 Jan;45(1):90-102
19209993
Cereb Cortex. 2005 Mar;15(3):275-90
15297366
Dev Med Child Neurol. 1987 Feb;29(1):27-35
3556798
Brain Lang. 1991 May;40(4):491-527
1878781
Trends Neurosci. 2006 Jul;29(7):367-373
16815562
N Engl J Med. 1971 Mar 25;284(12):654-6
5545606
J Magn Reson Imaging. 1995 Jan-Feb;5(1):49-56
7696809
Trends Cogn Sci. 2005 Mar;9(3):136-43
15737822
Nature. 1988 Feb 18;331(6157):585-9
3277066
Prog Neuropsychopharmacol Biol Psychiatry. 1999 May;23(4):657-68
10390724
Neurology. 2001 Jul 10;57(1):122-5
11445639
Brain. 1977 Mar;100 Pt 1:1-18
861709
Brain Lang. 2008 Sep;106(3):165-6
18571227
Neurology. 1997 Apr;48(4):1003-12
9109891
Brain Lang. 1998 Feb 15;61(3):335-75
9570869
Brain Cogn. 2009 Jun;70(1):31-41
19162389
Brain. 2000 Jan;123 ( Pt 1):74-81
10611122
Brain Lang. 2001 Nov;79(2):223-65
11712846
Semin Neonatol. 2000 Feb;5(1):3-16
10802746
Prog Neuropsychopharmacol Biol Psychiatry. 1999 May;23(4):669-82
10390725
Ann Neurol. 1978 Mar;3(3):273-80
666267
Neuroimage. 2008 Feb 15;39(4):2038-46
18096407
Comput Biomed Res. 1996 Jun;29(3):162-73
8812068
Cortex. 2000 Feb;36(1):31-46
10728895
Trends Cogn Sci. 2008 May;12(5):193-200
18403252
Pediatr Neurosurg. 1997 Mar;26(3):144-56
9419031
Pediatrics. 2007 Sep;120(3):609-16
17766535
Neurology. 2006 Dec 26;67(12):2246-9
17190956
Science. 2002 Dec 6;298(5600):2013-5
12471265
Cortex. 2011 Feb;47(2):202-16
20138262
Ann Neurol. 2008 Apr;63(4):436-43
18306227
N Engl J Med. 1992 Feb 20;326(8):531-9
1732792
Ann N Y Acad Sci. 1977 Sep 30;299:355-69
101116
Hum Brain Mapp. 2006 Mar;27(3):202-12
16035047
Brain Lang. 1998 May;62(3):422-51
9593617