Prefrontal dysfunction in pediatric Tourette's disorder as measured by near-infrared spectroscopy
Kazuhiko Yamamuro1, Toyosaku Ota2, Junzo Iida3
1Department of Psychiatry, Nara Medical University School of Medicine, 840 Shijyou-cho, Kashihara, Nara, 634-8522, Japan. muro@naramed-u.ac.jp.
Background:
Tourette's disorder (TD) is a chronic childhood-onset disorder characterized by the presence of multiple motor and vocal tics. Despite strong evidence that the pathophysiology of TD involves structural and functional disturbances of the basal ganglia and cortical frontal areas, in vivo imaging studies have produced conflicting results. Recent developments in near-infrared spectroscopy (NIRS) technology have enabled noninvasive assessment of brain function in people with psychiatric disorders.
Methods:
We asked 10 individuals with pediatric TD and 10 healthy controls who were age- and sex- matched to perform the Stroop color-word task during NIRS. We used prefrontal probes and a 24-channel NIRS machine to measure the relative concentrations of oxyhemoglobin (oxy-Hb) every 0.1 s during the task.
Results:
We found that oxy-Hb changes in the prefrontal cortex were significantly smaller in the TD group compared with the control group, especially in the left dorsolateral prefrontal cortex.
Conclusions:
Our data suggest that individuals with pediatric TD have a reduced prefrontal hemodynamic response as measured by NIRS.
