Ilgin N, Senol S, Gucuyener K, Gokcora N, Sener S
Department of Nuclear Medicine, Gazi University, Ankara, Turkey.
Dev Med Child Neurol. 2001 Nov;43(11):755-60. doi: 10.1017/s0012162201001384.
The purpose of this study was to estimate striatal dopamine (D2) receptor availability in non-drug treated children with attention-deficit-hyperactivity disorder (ADHD) before and after methylphenidate therapy, and to examine correlations between severity of symptoms and response rates to stimulant medication with levels of striatal D2 receptor binding. Nine children (six males, three females; mean age 9.8 years, SD 2.3 years) with ADHD participated. All underwent iodobenzamide (123I IBZM) brain SPECT within 2 hours following intravenous injection of 123I IBZM before and 3 months after methylphenidate therapy. A semiquantitative approach was used to generate indices of specific D2 receptor binding in the basal ganglia. Specific binding ratios at baseline were higher than the previously reported specific binding values obtained in studies using young healthy adults. D2 availability reduced significantly (paired t-test,p<0.05) as a function of methylphenidate therapy in patients with ADHD in all four regions of the striatum. When the relation between therapy response and D2 availability was investigated, we observed that the higher the baseline D2 levels were, the higher the response rate was (detected as the percentage reduction of hyperactivity scores and Conners Teacher Rating Scale scores), while no such trend was observed between the initial D2 binding levels and the response in attention-deficit scores. Results indicate that in non-drug treated children with ADHD, higher D2 receptor availability is observed at baseline which is down-regulated back to reported near-normal values after methylphenidate therapy. The effect of methylphenidate on D2 receptor levels in patients with ADHD is similar to that observed in healthy adults; a down-regulation phenomenon within 0 to 30%. In addition, initially higher values of D2 availability seem to indicate better response to methylphenidate therapy in ADHD.
本研究的目的是评估未接受药物治疗的注意力缺陷多动障碍（ADHD）儿童在哌甲酯治疗前后纹状体多巴胺（D2）受体的可利用性，并研究症状严重程度和对兴奋剂药物的反应率与纹状体D2受体结合水平之间的相关性。9名患有ADHD的儿童（6名男性，3名女性；平均年龄9.8岁，标准差2.3岁）参与了研究。所有儿童在静脉注射123I碘苄酰胺后2小时内，于哌甲酯治疗前和治疗后3个月进行了123I碘苄酰胺（123I IBZM）脑单光子发射计算机断层扫描（SPECT）。采用半定量方法生成基底神经节中特定D2受体结合的指标。基线时的特异性结合率高于先前在使用年轻健康成年人的研究中获得的报告特异性结合值。在ADHD患者中，纹状体所有四个区域的D2可利用性均因哌甲酯治疗而显著降低（配对t检验，p<0.05）。在研究治疗反应与D2可利用性之间的关系时，我们观察到基线D2水平越高，反应率越高（以多动评分和康纳斯教师评定量表评分的降低百分比来检测），而在初始D2结合水平与注意力缺陷评分的反应之间未观察到这种趋势。结果表明，在未接受药物治疗的ADHD儿童中，基线时观察到较高的D2受体可利用性，哌甲酯治疗后其下调至报告的接近正常的值。哌甲酯对ADHD患者D2受体水平的影响与在健康成年人中观察到的相似；下调现象在0%至30%之间。此外，最初较高的D2可利用性值似乎表明ADHD患者对哌甲酯治疗的反应更好。
