A novel multidomain computerized cognitive assessment for attention-deficit hyperactivity disorder: evidence for widespread and circumscribed cognitive deficits.

Multidomain assessment may enhance the diagnosis of cognitive impairment in children with attention-deficit hyperactivity disorder (ADHD). A set of novel Web-enabled computerized tests has recently been shown to be valid for identifying mild cognitive impairment and characterizing the cognitive profile associated with various disorders. It was anticipated that these tests would be well suited for use in children with ADHD. The authors tested this idea in a pilot study of 15 children (12 males, 3 females; mean age, 11 years 10 months; range, 9-15 years) with ADHD and 15 age-, education-, and gender-matched controls. The profile of cognitive impairment in ADHD children off methylphenidate across 6 cognitive domains (memory, executive function, visual-spatial skills, verbal function, attention, and motor skills) was described relative to controls. The effect of treatment with methylphenidate was examined by comparing the ADHD children on methylphenidate and on placebo (administered in a double-blind randomized fashion) relative to controls and by comparing the ADHD children on methylphenidate relative to placebo. Significant impairment in ADHD was evident in memory, visual-spatial, verbal, and attention domains, and near-significant impairment was observed in executive function and motor skills. On methylphenidate but not placebo, performance was comparable to controls in immediate verbal memory, psychomotor accuracy, visual-spatial, verbal rhyming, and overall battery performance. Significant improvement with administration of methylphenidate relative to placebo was evident for psychomotor accuracy, verbal rhyming, and overall battery performance. Hence, on the limited basis of this pilot study, the set of computerized tests studied appears to be useful for measuring cognitive function in ADHD; however, additional studies are needed to confirm this.

Gait in attention deficit hyperactivity disorder : effects of methylphenidate and dual tasking.

BACKGROUND: Cognitive function and the loading of attention presumably play an important role in gait as well as in fall risk, but previous work has not demonstrated this in any cause-and-effect way. OBJECTIVES: To gain insight into the relationship between gait and cognitive function, we sought: (1) To compare the gait rhythmicity (stride time variability) of children with attention deficit hyperactivity disorder (ADHD) to controls, (2) To test the hypothesis that dual tasking leads to increased stride-to-stride variability in ADHD, and (3) To test whether pharmacological treatment that relieves ADHD symptoms reduces stride-to-stride variability. PATIENTS AND METHODS: Gait was quantified in children with ADHD and in age-matched healthy controls under single task and dual task conditions on three occasions: off medications (both groups) and, in the ADHD group, after double blinded, randomized administration of methylphenidate (MPH) or placebo. RESULTS: At baseline, children with ADHD tended to walk with increased stride-to-stride variability compared to the controls during the single task condition (p = 0.09). During dual task walking, stride time variability was significantly reduced in the children with ADHD (p < 0.004), but not in the controls. In the children with ADHD, the placebo did not significantly affect stride-to-stride variability or the dual tasking response. In contrast, stride time variability was significantly reduced on MPH (p < 0.001) such that dual tasking no longer affected variability. CONCLUSIONS: The present findings demonstrate alterations in the gait of children with ADHD, support a cause and effect link between cognitive function and gait, and suggest that enhancement of attention abilities may, in certain populations, improve gait rhythmicity.