Incidence and mechanism of central pontine myelinolysis based on analysis of MRI images and risk factors

In this study, the incidence of central pontine myelinolysis (CPM)-like lesions on MRI images was studied in 1917 subjects, 1,500 of which were psychiatric patients and 417 were patients attending a brain health examination. The CPM-like lesions were first classified into four groups based on the characteristics of their MRI images: group 1 showed symmetrical lesions on both T1 low and T2 high images and were considered to be typical CPM; group 2 showed symmetrical high intensity lesions only on T2 images; group 3 had asymmetrical lesions only on T2 images; and group 4 had asymmetrical lesions on both T1 low and T2 high images. Furthermore, the relationships of each group with particular risk factors, such as alcoholism, hypertension, hyperlipidemia were statistically analysed. The cause of CPM-like features in the MRI images were discussed. Among our subjects, the incidence of CPM-like lesions was 3.8%, and that of group 1 was 1.2%. Significant correlations between group 1 and alcoholism, and group 3 and 4 with brain ischemic lesions were observed. A previous hypothesis that group 2 may be a premature state of CPM is not supported by our results. (author)