Striatal Dysfunction in Attention Deficit and Hyperkinetic Disorder

TLDR

Periventricular structures are hypoperfused in ADHD. The study used xenon‑133 inhalation and emission tomography to measure regional cerebral blood flow in 19 ADHD patients (six pure ADHD and 13 with additional neurologic symptoms) and compared the results to a control group. Striatal hypoperfusion—significant in the right striatum for pure ADHD and bilaterally for ADHD with additional symptoms—was observed, while primary sensory and sensorimotor cortices were hyperperfused; methylphenidate increased striatal and posterior periventricular flow and tended to reduce sensory cortical flow, indicating that low striatal activity, partially reversible with medication, is a cardinal feature of ADHD.

Abstract

• We have previously reported that periventricular structures are hypoperfused in attention deficit and hyperactivity disorder (ADHD). This study has expanded the number of patients, who were divided into two groups: six patients with pure ADHD, and 13 patients with ADHD in combination with other neurologic symptoms. By using xenon 133 inhalation and emission tomography, the regional cerebral blood flow distribution was determined and compared with a control group. Striatal regions were found to be hypoperfused and, by inference, hypofunctional in both groups. This hypoperfusion was statistically significant in the right striatum in ADHD, and in both striatal regions in ADHD with other neuropsychologic and neurologic symptoms. The primary sensory and sensorimotor cortical regions were highly perfused. Methylphenidate increased flow to striatal and posterior periventricular regions, and tended to decrease flow to primary sensory regions. Low striatal activity, partially reversible with methylphenidate, appears to be a cardinal feature in ADHD.