Echogenicity and size of substantia nigra on transcranial sonography (TCS) in patients with attention-deficit/hyperactivity disorder and healthy children aged 6–12 years: a comparative study

Abstract

Abstract Background Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders. Children with ADHD may experience significant functional problems, such as academic concerns at school, poor interpersonal relationships and low self-esteem. Current models of ADHD suggest that it is associated with functional impairments in dopamine and norepinephrine systems. The substantia nigra in the midbrain produces the largest amount of dopamine in the brain. The present study was conducted using TCS to compare the size and echogenicity of substantia nigra between ADHD and healthy children. Results This cross-sectional, analytical study was conducted on 68 (34 ADHD and 34 healthy individuals) aged 6–12 years. Based on the results obtained, the hyper-echogenicity of SN in control and ADHD groups were 33.3% and 66.7% (P < 0.001) and hypo-echogenicity of thalamic nuclei were 55.2% and 44.8% (P < 0.05), respectively. Interestingly, the TCS results of healthy children with a positive family history of ADHD were similar to results for patients with the disorder. Conclusions The echogenicity of Substantia nigra and thalamus nucleus among children and adolescents with ADHD is significantly higher from that in healthy children.

Keywords

• Attention-deficit/hyperactivity disorder
• Substantia nigra
• Transcranial sonography