Proton magnetic resonance spectroscopy and cognitive impairment in patients with ischemic white matter lesions

BACKGROUND The purpose of this study is to investigate the relationship between the cognitive impairment and NAA/Cr and Cho/Cr ratios in the proton magnetic resonance spectroscopy ((1)HMRS), and to assess the importance of (1)HMRS in the early diagnosis of cognitive impairment in patients with ischemic white matter lesions (WMLs). MATERIALS AND METHODS A total of 45 patients (23 males and 22 females) with the ischemic WML were divided into mild WML group (n = 15), moderate WML group (n = 15), and severe WML group (n = 15). A total of 15 healthy controls (8 males and 7 females) with no WML on magnetic resonance imaging were included. (1)HMRS focusing on the frontal lobe white matter around the anterior horn of the lateral ventricle and Montreal Cognitive Assessment (MoCA) were conducted. RESULTS Patients with more severe WML had lower MoCA scores. The NAA/Cr ratio in (1)HMRS was reduced in all the patients and was strongly correlated with the total MoCA scores (r = 0.845, P < 0.001). The Cho/Cr ratio in (1)HMRS was increased in mild and moderate patients, was negatively correlated with the total MoCA scores (r = 0.907, P < 0.001). The Cho/Cr ratio was reduced in the severe patients and was positively correlated with the total MoCA scores (r = 0.937, P < 0.001). In addition, NAA/Cr and Cho/Cr ratios in (1)HMRS were changed in patients with the mild WML whose total MoCA scores were similar to the controls. CONCLUSION Our results suggest that NAA/Cr and Cho/Cr ratios in (1)HMRS are useful indicators for early diagnosis of ischemic WML and cognitive impairment in patients with ischemic WML.