Neurologic examination abnormalities in children with bipolar disorder or attention-deficit/hyperactivity disorder.
BACKGROUND
Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BPD) are frequently comorbid and overlapping diagnoses. To move beyond diagnosis toward unique pathophysiology, we evaluated both ADHD and BPD children for neurologic examination abnormalities (NEAs) in comparison with normal control (NC) children.


METHODS
We performed the Revised Physical and Neurological Examination for Soft Signs in three groups (ADHD, BPD, NC). Then, a rater blind to diagnosis evaluated their motor performance. Results were analyzed with a multiple analysis of covariance.


RESULTS
Subjects with ADHD were impaired on repetitive task reaction time. In contrast, pediatric BPD subjects, both with and without comorbid ADHD, were impaired on sequential task reaction time.


CONCLUSIONS
This differential pattern of NEAs by diagnosis suggests pathophysiologic differences between ADHD and BPD in children. Repetitive motor performance requires inhibition of nonrelevant movements; ADHD subjects' impairment in this domain supports the hypothesis that ADHD involves a core deficit of fronto-striato-basal ganglia neurocircuitry. In contrast, BPD subjects' impaired sequential motor performance is consistent with behavioral data showing impaired attentional set-shifting and reversal learning in BPD subjects. Further study, going beyond symptom description to determine pathophysiologic differences, is required to refine neuronal models of these often comorbid diagnoses.
Dickstein
Daniel P
DP
National Institute of Mental Health, Pediatrics and Developmental Neuropsychiatry Branch, 10 Center Drive MSC 1255, Building 10/Room 4N208, Bethesda MD 20892-1255, USA. Dicksted@intra.nimh.nih.gov
Garvey
Marjorie
M
Pradella
Anne G
AG
Greenstein
Deanna K
DK
Sharp
Wendy S
WS
Castellanos
F Xavier
FX
Pine
Daniel S
DS
Leibenluft
Ellen
E
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D001714:Bipolar Disorder / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D002648:Child; D003071:Cognition / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D012193:Reversal Learning / Q000502:physiology