Objective measurement of hyperactivity, impulsivity, and inattention in children with hyperkinetic disorders before and after treatment with methylphenidate

Abstract

The mean pre-post changes found in all parameters investigated consistently correspond with benefits desired from medication with MPH in children with HD. Absolute differences in microevents and variability seem to depend on the daily dose of MPH after adjustment for BMI.

Increased ongoing neural variability in ADHD

“…One manifestation of the core ADHD symptoms is apparent in increased intra-individual behavioral variability over time as demonstrated by numerous reports of increased reaction time & Douglas, 2000), and Go-no-go Heiser et al, 2004;Hervey et al, 2006;Kuntsi, Andreou, Ma, B€ orger, & van der Meere, 2005;Spinelli et al, 2011). Increased RT variability in ADHD is apparent in both children (Epstein et al, 2011) and adults (Adams, Roberts, Milich, & Fillmore, 2011), is correlated with ADHD symptom severity (Kuntsi, Wood, Van Der Meere, & Asherson, 2009), and is reduced following administration of stimulants (Boonstra, Kooij, Oosterlaan, Sergeant, & Buitelaar, 2005;Epstein et al, 2006;Rosa-Neto et al, 2005;Spencer et al, 2009;Teicher, Lowen, Polcari, Foley, & McGreenery, 2004).…”

Perseveration by NK1R-/- (‘knockout’) mice is blunted by doses of methylphenidate that affect neither other aspects of their cognitive performance nor the behaviour of wild-type mice in the 5-Choice Continuous Performance Test

“…Although the lack of any response to methylphenidate could be explained by the high baseline accuracy of untreated mice (close to 100% at baseline), there are reports that methylphenidate has no effect on the % accuracy of rats in the 5CSRTT, despite their high incidence of incorrect responses at baseline (Paterson et al, 2011). However, methylphenidate can increase accuracy in human CPTs (Heiser et al, 2004; Klorman et al, 1991), especially when the task is made more challenging (Coons et al, 1981). In that context, it is interesting that NK1R-/- mice were less accurate than wild types at the onset of Stage 1 of training in the 5C-CPT (Porter et al, 2016), suggesting that habituation to the task eliminates any genotype difference in this measure.…”

A preliminary study of movement intensity during a Go/No-Go task and its association with ADHD outcomes and symptom severity

“…This task is a well-known measure of children’s sustained attention and response inhibition ([7, 8, 12, 13, 20, 21, 29–32]. In this version of the Go/No-Go task, a white block appeared inside of a white frame on a black background.…”

“…With respect to study limitations, we compared our movement intensity measures to a multi-method clinician-driven method of diagnostic classification, which is an approach commonly used in clinical trials [7, 18, 46]; however, it is important to point out that this is not considered the “gold standard” of ADHD assessment. Therefore, future studies should consider comparing these measures of movement intensity to this “gold standard” (e.g., multi-informant, multi-method evaluation of functioning across multiple settings) to further evaluate its diagnostic precision.…”

“…In contrast, infrared motion tracking systems have been previously shown to discriminate boys with ADHD from healthy controls; to correlate with teachers’ ADHD symptom severity ratings and measures of treatment response; and to identify medication doses that produce the best overall clinical results [7, 12, 20, 21]. The data acquired from infrared motion tracking systems are time-locked and able to record the path of movement (i.e., linear versus complex movement patterns); however, methods for integrating movement data across sensors have yet to be developed or reported (instead data from each sensor is reported separately), which potentially limits the precision of these data.…”