Right hemisphere dysfunction in ADHD: visual hemispatial inattention and clinical subtype.
The relationship between right hemisphere dysfunction and attention-deficit/hyperactivity disorder (ADHD) remains controversial. We administered a random letter cancellation test to 58 carefully selected adult patients meeting DSM-IV criteria for ADHD and 29 age- and education-matched controls. Patients with ADHD had a higher mean omission rate on the left side than the controls, and a greater percentage of ADHD patients than controls made more omissions on the left than on the right (L > R errors). ADHD patients who made L > R errors had lower performance IQ scores than ADHD patients who did not make L > R errors. However, ADHD patients who made L > R errors did not differ from ADHD patients who did not make L > R errors in ADHD subtype, medication response, or neuropsychological measures of attention, executive function, verbal memory, nonverbal memory, or academic achievement. Patients without a family history of ADHD were more likely to make L > R errors than patients with a family history of ADHD. This study provides support for the concept of right hemisphere dysfunction in a subset of patients with ADHD. However, ADHD patients who make L > R errors do not appear to represent a distinct clinical subgroup in terms of medication response, ADHD subtype, or neuropsychological test performance.
Sandson
T A
TA
Harvard Medical School, Boston, MA, USA. tsandson@bidmc.harvard.edu
Bachna
K J
KJ
Morin
M D
MD
D000328:Adult; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology* / Q000523:psychology*; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology / Q000502:physiology*; D003071:Cognition; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004522:Educational Status; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008568:Memory; D008875:Middle Aged; D011594:Psychometrics; D011897:Random Allocation; D013028:Space Perception; D014796:Visual Perception