Diffusion kurtosis imaging characteristics of brain gray matter nucleus microstructure in Parkinson's disease with different movement disorder subtypes

Abstract

Objective To investigate the difference in the microstructure of gray matter nucleus in different movement subtypes of Parkinson’s disease (PD) by diffusion kurtosis imaging (DKI) technique, and to analyze the correlation with clinical manifestations. Methods Ninety-seven patients with PD and 83 healthy controls performed conventional MRI sequence and DKI sequence scan. The PD patients were classified into gait disorder subtype (PIGD, n=57) and tremor dominant subtype (TD, n=40)subtypes according to motor symptoms. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da), radial diffusivity(Dr), mean kurtosis (MK), axial kurtosis (Ka) and radial kurtosis (Dr) maps and data were generated by software after processing. DKI was performed for all subjects and data was collected from different brain regions in both hemispheres, including red nucleus(RN), substantia nigra pars reticulate(SNr), substantia nigra pars compacta(SNc), putamen(PUT), globus pallidus(GP), head of caudate nucleus (CN)and thalamus(THA). Results TD showed a higher MMSE score(P=0.019), but lower modified Hoehn-Yahr score than that in PIGD (P 0.05). Moreover, there was no significant correlation between DKI value and disease duration, MMSE score or Hoehn-Yahr scale (P>0.05) in TD and PIGD. Conclusion There is heterogeneity of clinical symptoms between these two subgroups of PD. DKI can quantify the microstructural changes of grey matter nucleus in different type PD patient. Key words: Parkinson's disease; Movement disorder subtypes; Diffusion kurtosis imaging; Heterogeneity