Atomoxetine treatment of ADHD in Tourette syndrome: reduction in motor cortex inhibition correlates with clinical improvement.

Abstract

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.

SIGNIFICANCE:

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.

• Authors: Donald L Gilbert, Jie Zhang, Tara D Lipps, Nina Natarajan, Jared Brandyberry, Zhewu Wang, F Randy Sallee, Eric M Wassermann
• Journal: Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology (Clin Neurophysiol) Vol. 118 Issue 8 Pg. 1835-41 (Aug 2007) ISSN: 1388-2457 [Print] Netherlands
• PMID: 17588810 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Adrenergic Uptake Inhibitors
• Propylamines
• Atomoxetine Hydrochloride

Topics

• Adolescent
• Adrenergic Uptake Inhibitors (adverse effects, therapeutic use)
• Atomoxetine Hydrochloride
• Attention Deficit Disorder with Hyperactivity (drug therapy, etiology, physiopathology, psychology)
• Child
• Cohort Studies
• Female
• Humans
• Male
• Motor Cortex (drug effects, physiopathology)
• Neural Inhibition
• Propylamines (adverse effects, therapeutic use)
• Severity of Illness Index
• Single-Blind Method
• Time Factors
• Tourette Syndrome (complications)
• Transcranial Magnetic Stimulation
• Treatment Outcome