Brain imaging studies in children with attention-deficit hyperactivity disorder revealed by resting-state fMRI fALFF analysis

Objective To investigate pathological mechanism of dysfunction of executive control in children with attention-deficit hyperactivity disorder (ADHD) ,using a new resting-state functional magnetic resonance imaging(fMRI) index, fractional amplitude of low frequency fluctuation (fALFF). Methods Thirty children of school age with ADHD and thirty gender, age and education-matched healthy controls were experienced restingstate fMRI scans. fALFF approach was used to analyze blood oxygen level-dependent fMRI(BOLD-fMRI) data in resting state. Results Compared with the normal controls,the ADHD showed decreased fALFF in the bilateral superior frontal gyrus( BA10, t=5. 40,4.11 ,Z =4.81,3.82),bilateral middle frontal gyrus( BA9,BA46, t=5.72,5.37, Z = 5.04,3.08 ), right medial frontal gyrus ( BA 10, t = 5.53, Z = 4.90 ) and left precuneus ( t = 3.81, Z =3.57). And the ADHD showed increased fALFF in the bilateral limbic lobe (BA36, t = 4.37,5.20, Z = 4.02,4.66 ), right brainstem ( t = 4.77, Z = 4.34) and bilateral cerebellum ( t = 4.65,4.83, Z = 4.24,4.38 ). Conclusion The results suggest that lower activition of frontal may be the core deficit of executive control with ADHD in resting state,and high activation in several brain regions may be related to compensatory effect. Key words: Attention deficit disorder with hyperactivity; Functional magnetic resonance imaging; Resting state; Fractional amplitude of low frequency fluctuation