Quantitative assessment of the brain white matter myelination of patients with bipolar disorder using macromolecular proton fraction
T. Amstislavskaya, S. Gusakova, O. Borodin, E. Epimahova, L. Smirnova, S. IvanovaIntroduction
Introduction. In 2021, the global population of people with bipolar disorder (BD) was estimated at 37 million (or 0.5% of the global population), including approximately 34 million adults. Molecular proton fraction (MPF) has been recognized as a quantitative MRI parameter closely related to the myelin content of neural tissues and has already been used for non-invasive measurement of myelin deficiency in white matter (WM) and gray matter of patients with schizophrenia (Smirnova et al., Transl. Psychiatry, 2021).
Objectives
To study changes in white matter myelination in BD.
Methods
The main group consisted of patients (n = 18, including 13 women (72%), 5 men (28%), average age 27.5 ± 10.2), who were diagnosed with bipolar affective disorder (BD) according to ICD-10 criteria. All patients, as well as 14 patients in the control group, matched for sex and age, underwent magnetic resonance imaging of the brain using a 1.5T MR scanner (Ingenia Evolution, Philips, Netherlands) according to the standard protocol and the rapid MPF mapping protocol. Further segmentation of the brain masks was performed using FSL software (FMRIB Software Library, v. 6.0). Group differences were evaluated using the Mann–Whitney U test (p < 0.05) and the Pearson`s correlation test in Statistica 10.0.
Results
Assessing the average values of white matter MPF of the brain obtained by automatic segmentation, there was a significant increase in white matter MPF revealed in patients with bipolar disorder compared to the control group (p=0.02) (Fig. 1). There was no significant direct correlation between the MPF value and the duration of the disease (r=-0.08, p-value = 0.7631), as well as between the MPF value and the age of disease onset (r=0.2, p-value = 0.42).
Image 1: Long description.