[Change of white matter neuronal integrity associated with spatial navigation impairment in mild cognitive impairment].

Objective: To analyze the correlation between white matter integrity and spatial navigation impairment in patients with mild cognitive impairment (MCI). Methods: A total of 27 MCI subjects and 24 healthy controls were enrolled from the Affiliated Drum Tower Hospital of Nanjing University Medical School from May 2015 to February 2016, who underwent 3.0 T MRI scan and 2D-computer version spatial navigation test.DTI preprocessing and tract-based spatial statistics (TBSS) were performed by PANDA.Two sample t -test and partial correlation coefficients were performed to investigate the correlation of white matter impairments and spatial navigation decline. Results: Relative to controls, MCI showed worse egocentric navigation ( t =-2.202, P <0.05). Decreased FA in superior longitudinal fasciculus (left t =2.95, right t =2.95, P <0.05), inferior longitudinal fasciculus and inferior fronto-occipital fasciculus (left t =2.66, right t =2.96, P <0.05), corpus callosum ( t =2.09, P <0.05), cingulum (left t =2.76, right t =2.41, P <0.05), fornix ( t =4.83, P <0.05), and corticospinal tract (left t =2.33, right t =2.26, P <0.05), were found in the MCI subjects.The decreased FA value of superior longitudinal fasciculus (left r =-0.354, right r =-0.347, P <0.05), inferior longitudinal fasciculus (left r =-0.338, right r =-0.336, P <0.05), cingulum (left r =-0.395, right r =-0.370, P <0.05), right corticospinal tract ( r =-0.362, P <0.05) and fornix ( r =-0.369, P <0.05) were correlated with increased ego average total error.Allo average total error were negative correlated with FA value of superior longitudinal fasciculus (left r =-0.329, right r =-0.350, P <0.05), inferior longitudinal fasciculus (left r =-0.349, right r =-0.378, P <0.05), splenium of corpus callosum ( r =-0.364, P <0.05) and cingulum (left r =-0.340, right r =-0.406, P <0.05). Conclusion: This study implicated the potential white matter structural basis of spatial navigation impairment and will have an impact on the further study of the neurobiological mechanisms of human spatial navigation ability.