Role of diffusion tensor imaging or magnetic resonance spectroscopy in the diagnosis and disability assessment of amyotrophic lateral sclerosis

• NAA/Cr in the motor cortex could help to diagnose ALS.
• FA in the corticospinal tract of both sides could help with the diagnosis of ALS.
• Regional brain NAA/Cr and FA values could not be used to assess the ALSFRS-R.

ObjectiveTo compare the results of magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) in amyotrophic lateral sclerosis (ALS) patients.MethodsNineteen ALS patients and thirteen age-matched healthy controls underwent MRS and DTI between October 2013 and July 2014. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) were collected as the quantitative results of the imaging study. The ALS functional rating scale-revised (ALSFRS-R) and disease progression rate were evaluated to assess patients' disability. The imaging study results were compared between ALS patients and healthy controls. The relationship between disability assessment and imaging study results was analyzed.ResultsNAA/Cr in the motor cortex and FA in the corticospinal tract (CST) of both sides were significantly lower in patients than controls. There was no significant difference between the two groups in Cho/Cr, tract length, tract volume, ADC or NAA. No relationship was found between ALSFRS-R and FA (r = 0.243, p = 0.316) in the right CST; NAA (r = 0.095, p = 0.699) or NAA/Cr (r = 0.172, p = 0.481) in the left motor cortex; or NAA (r = 0.320, p = 0.182) or NAA/Cr (r = 0.193, p = 0.492) in the right motor cortex. There was no relationship between the disease progression rate and FA, NAA, or NAA/Cr on either side.ConclusionNAA/Cr and FA can help diagnose ALS. Regional brain NAA/Cr and FA values could not assess the ALSFRS-R or disease progression rate.