Influence of Stimulant Medication and Response Speed on Lateralization of Movement-Related Potentials in Attention-Deficit/Hyperactivity Disorder

Abstract

Background Hyperactivity is one of the core symptoms in attention deficit hyperactivity disorder (ADHD). However, it remains unclear in which way the motor system itself and its development are affected by the disorder. Movement-related potentials (MRP) can separate different stages of movement execution, from the programming of a movement to motor post-processing and memory traces. Pre-movement MRP are absent or positive during early childhood and display a developmental increase of negativity. Methods We examined the influences of response-speed, an indicator of the level of attention, and stimulant medication on lateralized MRP in 16 children with combined type ADHD compared to 20 matched healthy controls. Results We detected a significantly diminished lateralisation of MRP over the pre-motor and primary motor cortex during movement execution (initial motor potential peak, iMP) in patients with ADHD. Fast reactions (indicating increased visuo-motor attention) led to increased lateralized negativity during movement execution only in healthy controls, while in children with ADHD faster reaction times were associated with more positive amplitudes. Even though stimulant medication had some effect on attenuating group differences in lateralized MRP, this effect was insufficient to normalize lateralized iMP amplitudes. Conclusions A reduced focal (lateralized) motor cortex activation during the command to muscle contraction points towards an immature motor system and a maturation delay of the (pre-) motor cortex in children with ADHD. A delayed maturation of the neuronal circuitry, which involves primary motor cortex, may contribute to ADHD pathophysiology.

Attenuated Readiness Potential in the Absence of Executive Dysfunction in Adults With ADHD

“…posterior sites, the CNV attenuation in ADHD adults mainly affected more frontal sites. The developmental CNV changes were confirmed repeatedly (Bender et al, 2012; Jonkman, Lansbergen, & Stauder, 2003). An fMRI study in adults confirmed the presence of widespread activity throughout the frontal and cingulate cortex in controls, while the ADHD group activated only the frontal pole during Go/NoGo tasks (Kooistra et al, 2010).…”

“…Stimulants enhance dopaminergic activity in the basal ganglia. However, a single dose of methylphenidate failed to induce changes in the CNV of children with ADHD (Bender et al, 2012). In contrast, in a meta-analysis of morphometry studies, stimulant medication was found to be related to a more normal gray-matter volume in the right basal ganglia, independent of age (Nakao, Radua, Rubia, & Mataix-Cols, 2011).…”

“…In case of the usually used short interstimulus intervals of 2 s or less, the two components are superimposed (McCarthy & Donchin, 1978) and cannot be clearly attributed to either function. CNV studies showed decreased negativity in children with ADHD compared with healthy controls (Banaschewski et al, 2003; Banaschewski et al, 2008; Bender et al, 2012; Hennighausen, Schulte-Koerne, Warnke, & Remschmidt, 2000; Overtoom et al, 1998; Sartory et al, 2002; Steger et al, 2001). The results were considered to be indicative of deficits in stimulus as well as in executive response processing.…”

Annual Research Review: Reaction time variability in ADHD and autism spectrum disorders: measurement and mechanisms of a proposed trans‐diagnostic phenotype

“…Albrecht et al., ; Doehnert, Brandeis, Schneider, Drechsler, & Steinhausen, ). Furthermore, in typically developing child populations, slow cortical potentials associated with response preparation and output have been correlated with RTs (Bender et al., ; Kok, ; Wascher, Verleger, Jaskowski, & Wauschkuhn, ), suggesting a role for motor preparation in determining RT variability.…”

Attention-Deficit Hyperactivity Disorder and Pharmacotherapy—Past, Present, and Future: A Review of the Changing Landscape of Drug Therapy

“…Methylphenidate administration has also been associated with normalizing underactive frontocingulate networks 33 and striatal areas 34 and increased frontoparietal connectivity for working memory 35 . Other neurobiological changes observed in relation to methylphenidate administration include enhanced error-detection associated with the dorsal anterior cingulate cortex and inferior parietal lobe 36 , and optimized speed-of-reaction related to (pre-) motor cortex 37 . A number of other gross neurobiological effects have been associated with taking methylphenidate, including increased activation in the caudate, cerebellum, midbrain, substantia nigra, thalamus 38 , and many others.…”