Evaluation of white matter integrity by diffusion tensor imaging in the deficiencies of vitamin B12 and folate in older patients

Abstract

Objectives: The aim of this study is to investigate whether white matter (WM) integrity is impaired in vitamin B12 and folate deficiency with Diffusion Tensor Imaging (DTI) in older patients. Methods: All the patients aged ≥65 years admitted to the geriatric clinic and performed DTI-MRI were included in the study. DTI parameters (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity) were calculated by ROI-based method in white matter tracts. Deficiency threshold for vitamin B12 were defined as <200 pg ml−1 and <400 pg ml−1 separately; and for folate as <3 ng ml−1 and <6 ng ml−1, separately. Results: DTI was performed to older patients having serum vitamin B12 level (n = 106, mean age = 80.7±7.7, 66% female) and folate level (n = 101, mean age = 80.7±7.5, 67.3% female). Significantly lower FA and higher MD and RD levels were observed in multiple WM areas including superior and middle cerebellar peduncles, cingulum and genu of corpus callosum in patients with vitamin B12 <400 pg ml−1 (p < 0.05). DTI indices also showed significant changes in the genu of corpus callosum, and right and left superior longitudinal fasciculus in patients with folate <6 ng ml−1 (p < 0.05). Conclusions: Deficiencies of vitamin B12 and folate may be associated with impaired white matter integrity in elderly even at high laboratory levels, and DTI is a useful method to detect it. Advances in knowledge: Early detection of impaired WM integrity caused by micronutrient deficiencies poses a great significance in terms of prevention and intervention, and DTI is an effective non-invasive method to be used for this purpose.