High-Resolution Brain SPECT Imaging in ADHD

Abstract

Children and adolescents with ADHD were evaluated with high-resolution brain SPECT imaging to determine if there were similarities between reported PET and QEEG findings. Fifty-four children and adolescents with ADHD by DSM-111-R and Conners Rating Scale criteria were evaluated. A non-ADHD control group was also studied with SPEC?: Two brain SPECT studies were done on each group, a resting study and an intellectual stress study done while participants were doing a concentration task. Sixty-five percent of the ADHD group revealed decreased perfusion in the prefrontal cortex with intellectual stress, compared to only 5% of the control group. These are findings consistent with PET and QEEG findings. Of the ADHD group who did not show decreased perfusion, two-thirds had markedly decreased activitv in the mefrontal cortices at rest.

Regional differences in cerebral perfusion associated with the α-2A-adrenergic receptor genotypes in attention deficit hyperactivity disorder

“…24,25 In a meta-analysis of 16 functional neuroimaging studies in ADHD, Dickstein and colleagues 26 concluded that significant frontal hypoactivity patterns were present in patients with ADHD that affect the dorsolateral prefrontal, inferior prefrontal and anterior cingulate cortices. Bush and colleagues, 27 in their review of functional neuroimaging (PET, SPECT, functional MRI) studies in ADHD, found a consistent pattern of frontal dysfunction, including altered patterns of activity in the anterior cingulate and dorsolateral or ventrolateral prefrontal cortices and in associated striatal and cerebellar regions, which supports the findings of our study.…”

Deficits in visuo-spatial working memory, inhibition and oculomotor control in boys with ADHD and their non-affected brothers

“…Structural and functional imaging studies have revealed that working memory is primarily controlled by the dorsolateral prefrontal cortex and basal ganglia (D'Esposito et al 1995;Smith et al 1998) and that patients with ADHD have an altered architecture and less activation of these areas compared to controls (Zametkin et al 1990;Castellanos et al 1996;Aman and Carmichael 1997;Rubia et al 1999;Yeo et al 2003;Dickstein et al 2006). Inhibition is primarily mediated by the fronto-striatal circuitry and this circuitry has also been found to be involved in the pathology of ADHD (Durston et al 2003;Schulz et al 2004).…”

“…Remaining fixated on the fixation cross while the target is presented in the peripheral visual field requires top-down control processes, mediated by the superior frontal, inferior parietal and superior temporal brain areas (Hopfinger et al 2000). Since several of these brain areas and dopaminergic transmission have also been found altered in patients with ADHD (Zametkin et al 1990;Castellanos et al 1996;Aman and Carmichael 1997;Rubia et al 1999;Durston et al 2003;Yeo et al 2003;Schulz et al 2004;Dickstein et al 2006), it is hypothesized that children with ADHD will have difficulty executing memory-guided saccades and remaining fixated during the fixation period.…”

A risk factor model predicting the relationship between stress and performance in Explosive Ordnance Disposal (EOD) training

“…These findings are important for two reasons. First, the findings provide evidence that people with ADHD may differ biologically fi-om people with other psychiatric disorders (Lou, Henriksen, & Bruhn, 1984) and no diagnoses (Amen & Carmichael, 1997;Zametkin et al, 1990). Second, the abnormalities in prefi-ontal cortical activity are important because this region of the brain is associated with complex cognitive functions, including attention and problem solving.…”

“…Studies using several different technologies for brain imaging, including PET (Zametkin et al, 1990), QEEG with specti-al analysis (Lubar, 1991), and SPECT (Amen & Carmichael, 1997) have found that mental stress in people with ADHD symptoms is associated with decreased activity in prefontal cortex. These findings are important for two reasons.…”