Striatal neuronal loss or dysfunction and choline rise in children with attention-deficit hyperactivity disorder: a H-1-magnetic resonance spectroscopy study

Twelve previously untreated boys suffering from attention-deficit hyperacti vity disorder (ADHD) were investigated by using proton magnetic resonance s pectroscopy (H-1 MRS) before and after one dose (10 mg) of methylphenidate. Pre- and post-methylphenidate spectra were acquired bilaterally in the glo bus pallidus. Peaks of N-acetylaspartate (NAA), choline (Cho), myo-inositol , glutamate and creatine (Cr) were measured and the ratios of the peaks wer e calculated and compared with data from ten matched controls. In children having ADHD, NAA/Cr ratio decreased significantly in the bilateral striatum while Cho/Cr ratio showed a mild unilateral increase. One oral dose of met hylphenidate did not affect the ratios significantly. These findings sugges t that the striatum was bilaterally involved in pediatric ADHD patients. Ap proximately 20-25% of neurons may have died or may be severely dysfunctiona l. There seems to be a mild hyperactivity of the cholinergic system. (C) 20 01 Elsevier Science Ireland Ltd. All rights reserved.