Atomoxetine treatment of ADHD in Tourette syndrome: reduction in motor cortex inhibition correlates with clinical improvement.
OBJECTIVE
In children with attention deficit hyperactivity disorder (ADHD), clinical responses to the selective norepinephrine reuptake inhibitor atomoxetine (ATX) vary. We sought to determine in children with Tourette Syndrome (TS) whether clinical responses correlate with changes in short interval cortical inhibition (SICI).


METHODS
Fourteen children, ages 8-16, with ADHD and TS were treated open-label with ATX for one month. ADHD rating scale scores and SICI, measured with paired-pulse transcranial magnetic stimulation (pTMS), were assessed blindly and independently at treatment onset and one month later.


RESULTS
Eleven children, mean ADHD rating scale scores 31.8 (SD 8.2) at onset, completed the study. After one month, ADHDRS changes ranged from an increase of 4 points to a decrease (improvement) of 24 points (mean change -9.6, SD 9.1). The changes in ADHDRS scores correlated with reduction in SICI (r=.74, p=.010).


CONCLUSIONS
In children with TS, one month of atomoxetine treatment appears to induce correlated improvements in ADHD and, paradoxically, further reductions in cortical inhibition.


CONCLUSIONS
PTMS-evoked SICI in ADHD with TS may be a biomarker of both deficiency and compensatory changes within cortical interneuronal systems. Effective atomoxetine treatment may augment compensatory processes and thereby reduce SICI.
Gilbert
Donald L
DL
Division of Neurology, Cincinnati Children's Hospital Medical Center, and The University of Cincinnati, Department of Neurology, School of Medicine, OH 45229-3039, USA. d.gilbert@cchmc.org
Zhang
Jie
J
Lipps
Tara D
TD
Natarajan
Nina
N
Brandyberry
Jared
J
Wang
Zhewu
Z
Sallee
F Randy
FR
Wassermann
Eric M
EM
D000293:Adolescent; D018759:Adrenergic Uptake Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D000069445:Atomoxetine Hydrochloride; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000187:drug effects / Q000503:physiopathology; D009433:Neural Inhibition; D011437:Propylamines / Q000009:adverse effects / Q000627:therapeutic use*; D012720:Severity of Illness Index; D016037:Single-Blind Method; D013997:Time Factors; D005879:Tourette Syndrome / Q000150:complications*; D050781:Transcranial Magnetic Stimulation; D016896:Treatment Outcome
D018759:Adrenergic Uptake Inhibitors; D011437:Propylamines; D000069445:Atomoxetine Hydrochloride