Identifying amyotrophic lateral sclerosis using diffusion tensor imaging, and correlation with neurofilament markers

To determine diagnostic value of diffusion tensor imaging (DTI) in amyotrophic lateral sclerosis (ALS) patients and investigate the association between DTI and neurofilaments (NFs), including serum and cerebrospinal fluid (CSF) levels of neurofilament light chain (NFL) and phosphorylated neurofilament heavy chain (pNFH). Forty-three clinically diagnosed ALS patients and 32 control subjects without neurological disorders underwent routine MRI (magnetic resonance imaging) and DTI scans. DTI parameters (mean diffusivity [MD] and fractional anisotropy [FA]) at axial levels of internal capsules and cerebral peduncles along the corticospinal tract (CST) were measured. The study compared the differences of DTI parameters between ALS patients and controls using the Mann-Whitney U test. Diagnostic efficacy of each DTI metric was evaluated using the receiver operating characteristic (ROC) curve. NFs (NFL and pNFH levels in serum and CSF) were measured by enzyme-linked immunosorbent assay. Correlation analyses were conducted between DTI parameters and NFs. Capsule-MD and Peduncle-MD in ALS patients were higher than those in controls; whereas Capsule-FA and Peduncle-FA in ALS patients were lower than those in controls (all, p < 0.05). The area under curve (AUC) was 0.730 for Capsule-FA, 0.828 for Capsule-MD, 0.890 for Peduncle-FA, and 0.896 for Peduncle-MD. Capsule-FA was negatively correlated with CSF-NFL (r = - 0.813, p < 0.001), Serum-NFL (r = - 0.493, p = 0.001), CSF-pNFH (r = - 0.637, p < 0.001), and Serum-pNFH (r = - 0.672, p < 0.001); Peduncle-FA negatively with CSF-NFL (r = - 0.562, p < 0.001), CSF-pNFH (r = - 0.506, p = 0.001), and Serum-pNFH (r = - 0.488, p = 0.001); Peduncle-MD positively with CSF-NFL (r = 0.516, p < 0.001), CSF-pNFH (r = 0.494, p = 0.001). DTI had superior performance in identifying ALS patients and could serve as a reliable predictor. DTI parameters related to neurofilament markers, and Capsule-FA may become a robust surrogate biomarker indicating disease severity and progression rate for ALS patients.