TY  - JOUR
A1  - Ziegler, Mirjam
A1  - Kaiser, Anna
A1  - Igel, Christine
A1  - Geissler, Julia
A1  - Mechler, Konstantin
A1  - Holz, Nathalie E.
A1  - Becker, Katja
A1  - Döpfner, Manfred
A1  - Romanos, Marcel
A1  - Brandeis, Daniel
A1  - Hohmann, Sarah
A1  - Millenet, Sabina
A1  - Banaschewski, Tobias
T1  - Actigraphy-derived sleep profiles of children with and without attention-deficit/hyperactivity disorder (ADHD) over two weeks — comparison, precursor symptoms, and the chronotype
JF  - Brain Sciences
N2  - Although sleep problems are common in children with ADHD, their extent, preceding risk factors, and the association between neurocognitive performance and neurobiological processes in sleep and ADHD, are still largely unknown. We examined sleep variables in school-aged children with ADHD, addressing their intra-individual variability (IIV) and considering potential precursor symptoms as well as the chronotype. Additionally, in a subgroup of our sample, we investigated associations with neurobehavioral functioning (n = 44). A total of 57 children (6–12 years) with (n = 24) and without ADHD (n = 33) were recruited in one center of the large ESCAlife study to wear actigraphs for two weeks. Actigraphy-derived dependent variables, including IIV, were analyzed using linear mixed models in order to find differences between the groups. A stepwise regression model was used to investigate neuropsychological function. Overall, children with ADHD showed longer sleep onset latency (SOL), higher IIV in SOL, more movements during sleep, lower sleep efficiency, and a slightly larger sleep deficit on school days compared with free days. No group differences were observed for chronotype or sleep onset time. Sleep problems in infancy predicted later SOL and the total number of movements during sleep in children with and without ADHD. No additional effect of sleep problems, beyond ADHD symptom severity, on neuropsychological functioning was found. This study highlights the importance of screening children with ADHD for current and early childhood sleep disturbances in order to prevent long-term sleep problems and offer individualized treatments. Future studies with larger sample sizes should examine possible biological markers to improve our understanding of the underlying mechanisms.
KW  - sleep
KW  - actigraphy
KW  - attention-deficit/hyperactivity disorder (ADHD)
KW  - intra-individual variability (IIV)
KW  - chronotype
KW  - children
KW  - continuous performance task (CPT)
KW  - precursor symptoms
KW  - ESCAlife
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250084
SN  - 2076-3425
VL  - 11
IS  - 12
ER  - 
TY  - JOUR
A1  - Bender, Stephan
A1  - Resch, Franz
A1  - Klein, Christoph
A1  - Renner, Tobias
A1  - Fallgatter, Andreas J.
A1  - Weisbrod, Matthias
A1  - Romanos, Marcel
T1  - Influence of Stimulant Medication and Response Speed on Lateralization of Movement-Related Potentials in Attention-Deficit/Hyperactivity Disorder
JF  - PLoS One
N2  - 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.
KW  - deficit-hyperactivity disorder
KW  - anticipatory mechanisms
KW  - motor preparation
KW  - TIC disorder
KW  - children
KW  - ADHD
KW  - methylphenidate
KW  - contingent negative-variation
KW  - continuous performance-test
KW  - slow cortical potentials
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135262
VL  - 7
IS  - 6
ER  -