Evaluating the functional activity of the subcortical nuclei in Wilson′s disease using resting state functional magnetic resonance imaging

Objective To evaluate functional activity of the subcortical nuclei in Wilson′s disease (WD) using resting state functional MRI (rs-fMRI), and to evaluate damage to the functional conjunction in the extracorticospinal tract in WD patients. Methods Twenty-two patients with WD (between January 2015 and January 2016), including 18 with cerebral type and 4 with hepatic type, and 20 age-matched healthy controls were enrolled. Neurological symptoms were scored using the modified Young Scale. Patients with cerebral type WD were divided into 4 subgroups. All study subjects underwent rs-fMRI of the brain. The values of amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (REHO) in the thalamus, caudate nucleus, putamen and globus pallidus were determined. The relationships between rs-fMRI metrics and clinical status were evaluated. Results ALFF values were lower in the caudate nucleus, putamen and right thalamus of WD patients than in controls(t=-3.07, -3.00, -3.12, -2.46, -2.20; P=0.005, 0.006, 0.004, 0.020, 0.036), while REHO values were lower in the left caudate nucleus and left thalamus of WD patients (t=-2.38, -2.16; P=0.025, 0.040). In the caudate nucleus (P=0.032, 0.029, 0.023), thalamus (P=0.022, 0.041, 0.035) ALFF values were lower in group 4 than in other groups. REHO values of the putamen (P=0.040, 0.017, 0.040) and thalamus (P=0.024, 0.029 7, 0.041) were higher in group 4 than in other groups. ALFF values in the caudate nucleus (t=-0.29, P=0.037), and thalamus (t=-1.77, P=0.042) were lower, and REHO values in the caudate nucleus (t=-1.46, P=0.040) were lower, in patients of cerebral type than in hepatic type patients. Conclusions The damage to the functional activity of the subcortical nuclei may occur in the WD patients. The functional activity of nuclei may be different between hepatic and cerebral type patients. Damage to the activity of neurons in the putamen and thalamus may correlate with psychiatric symptoms in WD patients. Key words: Hepatolenticular degeneration; Magnetic resonance imaging; Caudate nucleus; Thalamus; Globus pallidus