Neurosteroids (NSs) are endogenous steroid hormones, which are synthesised and metabolised within the central nervous system (CNS). NSs aid myelination and glial differentiation and modulate cognitive functions. Herein, we aim to investigate the relationship between NS levels, 5-alpha-dihydroxyprogesterone (5-α-DHP) and allopregnanolone (ALPG), and their relationship with cognitive changes in relapsing remitting MS patients.A total of 43 cases with well controlled, relapsing remitting MS composed the study group. The control group included 21 age and gender matched healthy controls (HC). MS patients were assessed by calculating Expanded Disability Status Scale (EDSS) scores, and the Brief Repeatable Battery of Neuropsychological Tests (BRBNT) was performed in both MS group and HC. Levels of 5-α-DHP and ALPG levels were also evaluated for each participant.The median level of 5-α-DHP was 48 [IQR: 39.2-144.2] pg/mcgL in the MS group and 68.4 [IQR: 57.1-365.9] pg/mcgL in HC (p = 0.02). The median ALPG level was found to be 56.5 [IQR: 37.7-75.4] pg/mcgL in the MS group and 43.9 [IQR: 29.4-70.2] pg/mcgL in HC (p = 0.1). In both groups 5-α-DHP levels were positively correlated with Symbol Digit Modalities Test (SDMT) scores (HC: p = 0.01, r = 0.3 and MS: p = 0.03, r = 0.3). In the MS group, higher EDSS scores were associated with lower scores on Spatial Recall Test (SPART)-Delayed (p = 0.009, r= -0.4) and SDMT (p = 0.01, r= -0.4). The disease duration was negatively correlated with the scores on SPART-Immediate, SPART-Delayed and SDMT (p = 0.02, r= -0.4; p = 0.005, r= -0.4 and p = 0.05, r= -0.3).5-α-DHP may be lower even in well-controlled cases. 5-α-DHP may contribute to better perceptual processing and attention in cases with MS.
Keywords: 5-alpha-dihydroxyprogesterone; Multiple sclerosis; Neurosteroids; allopregnanolone; cognitive functions.