TY - JOUR
T1 - Relationship between GABA levels and task-dependent cortical excitability in children with attention-deficit/hyperactivity disorder
AU - Harris, Ashley D.
AU - Gilbert, Donald L.
AU - Horn, Paul S.
AU - Crocetti, Deana
AU - Cecil, Kim M.
AU - Edden, Richard A.E.
AU - Huddleston, David A.
AU - Mostofsky, Stewart H.
AU - Puts, Nicolaas A.J.
N1 - Publisher Copyright:
© 2021 International Federation of Clinical Neurophysiology
PY - 2021/5
Y1 - 2021/5
N2 - Objective: Compared to typically developing (TD) peers, children with attention deficit hyperactivity disorder (ADHD) manifest reduced short interval cortical inhibition (SICI) in the dominant motor cortex measured with transcranial magnetic stimulation (TMS). This multimodal study investigates the inhibitory neurophysiology and neurochemistry by evaluating the relationship between SICI and γ-amino butyric acid (GABA+) levels, measured with magnetic resonance spectroscopy (MRS). Methods: Across two sites, 37 children with ADHD and 45 TD children, ages 8–12 years, participated. Single and paired pulse TMS to left motor cortex quantified SICI during REST and at times of action selection (GO) and inhibition (STOP) during a modified Slater-Hammel stop signal reaction task. MRS quantified GABA+ levels in the left sensorimotor cortex. Relationships between SICI and GABA+, as well as stopping efficiency and clinical symptoms, were analyzed with correlations and repeated-measure, mixed-models. Results: In both groups, higher GABA+ levels correlated with less SICI. In TD children only, higher GABA+ levels correlated with larger TMS motor evoked potentials (MEPs) at REST. In GO and STOP trials, higher GABA+ was associated with smaller MEP amplitudes, for both groups. Overall, GABA+ levels did not differ between groups or correlate with ADHD clinical symptoms. Conclusions: In children with higher motor cortex GABA+, motor cortex is less responsive to inhibitory TMS (SICI). Comparing the relationships between MRS-GABA+ levels and responses to TMS at REST vs. GO/STOP trials suggests differences in inhibitory neurophysiology and neurotransmitters in children with ADHD. These differences are more prominent at rest than during response inhibition task engagement. Significance: Evaluating relationships between GABA+ and SICI may provide a biomarker useful for understanding behavioral diagnoses.
AB - Objective: Compared to typically developing (TD) peers, children with attention deficit hyperactivity disorder (ADHD) manifest reduced short interval cortical inhibition (SICI) in the dominant motor cortex measured with transcranial magnetic stimulation (TMS). This multimodal study investigates the inhibitory neurophysiology and neurochemistry by evaluating the relationship between SICI and γ-amino butyric acid (GABA+) levels, measured with magnetic resonance spectroscopy (MRS). Methods: Across two sites, 37 children with ADHD and 45 TD children, ages 8–12 years, participated. Single and paired pulse TMS to left motor cortex quantified SICI during REST and at times of action selection (GO) and inhibition (STOP) during a modified Slater-Hammel stop signal reaction task. MRS quantified GABA+ levels in the left sensorimotor cortex. Relationships between SICI and GABA+, as well as stopping efficiency and clinical symptoms, were analyzed with correlations and repeated-measure, mixed-models. Results: In both groups, higher GABA+ levels correlated with less SICI. In TD children only, higher GABA+ levels correlated with larger TMS motor evoked potentials (MEPs) at REST. In GO and STOP trials, higher GABA+ was associated with smaller MEP amplitudes, for both groups. Overall, GABA+ levels did not differ between groups or correlate with ADHD clinical symptoms. Conclusions: In children with higher motor cortex GABA+, motor cortex is less responsive to inhibitory TMS (SICI). Comparing the relationships between MRS-GABA+ levels and responses to TMS at REST vs. GO/STOP trials suggests differences in inhibitory neurophysiology and neurotransmitters in children with ADHD. These differences are more prominent at rest than during response inhibition task engagement. Significance: Evaluating relationships between GABA+ and SICI may provide a biomarker useful for understanding behavioral diagnoses.
KW - Attention deficit hyperactivity disorder
KW - GABA-edited MRS
KW - Inhibition
KW - Short interval cortical inhibition
KW - Transcranial magnetic stimulation
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U2 - 10.1016/j.clinph.2021.01.023
DO - 10.1016/j.clinph.2021.01.023
M3 - Article
C2 - 33780723
AN - SCOPUS:85103285897
SN - 1388-2457
VL - 132
SP - 1163
EP - 1172
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
IS - 5
ER -