Atypical motor and sensory cortex activation in attention-deficit/hyperactivity disorder: a functional magnetic resonance imaging study of simple sequential finger tapping.
BACKGROUND
Attention-deficit/hyperactivity disorder (ADHD) has been shown to be associated with anomalous motor development, including excessive overflow movements. The neurological basis of these deficits has not been established. Functional magnetic resonance imaging (fMRI) was used to determine whether differences in brain activation during sequential finger tapping are present in children with ADHD compared with typically developing control subjects.


METHODS
Twenty-two right-handed children between 8 and 12 years old, 11 with ADHD and 11 typically developing control subjects closely matched for age and gender, performed self-paced sequential finger tapping during fMRI acquisition.


RESULTS
There were no significant between-group differences in speed of sequential finger tapping. The between-group whole-brain comparison showed greater magnitude of activation for control subjects than children with ADHD in the right superior parietal lobe during both right-handed and left-handed finger tapping. The region-of-interest analysis within Brodmann Area 4 revealed that children with ADHD showed a significantly smaller extent of fMRI activation in the primary motor cortex contralateral to the finger-sequencing hand.


CONCLUSIONS
Despite similar speed of sequential finger tapping, children with ADHD showed decreased contralateral motor cortex and right parietal cortex activation during both right-handed finger sequencing (RHFS) and left-handed finger sequencing (LHFS). The fMRI findings suggest that children with ADHD have anomalous development of cortical systems necessary for execution of patterned movements.
Mostofsky
Stewart H
SH
Kennedy Krieger Institute, Baltimore, MD 21205, USA. mostofsky@kennedykrieger.org
Rimrodt
Sheryl L
SL
Schafer
Joanna G B
JG
Boyce
Avery
A
Goldberg
Melissa C
MC
Pekar
James J
JJ
Denckla
Martha B
MB
D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D000077463:Carbamide Peroxide; D016022:Case-Control Studies; D002648:Child; D004338:Drug Combinations; D005260:Female; D005385:Fingers / Q000294:innervation / Q000503:physiopathology*; D007839:Functional Laterality / Q000502:physiology; D019416:Head Movements / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000098:blood supply* / Q000503:physiopathology; D010545:Peroxides / Q000097:blood; D011597:Psychomotor Performance / Q000502:physiology*; D013003:Somatosensory Cortex / Q000098:blood supply* / Q000503:physiopathology; D018709:Statistics, Nonparametric; D013647:Task Performance and Analysis; D014508:Urea / Q000031:analogs & derivatives / Q000097:blood
D004338:Drug Combinations; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea