Laura Cacciaguerra (Italy)
San Raffaele Scientific Institute Neuroimaging Research UnitAuthor Of 2 Presentations
HIPPOCAMPAL SUBFIELDS IN RRMS: THE MODULATORY ROLE OF GENDER AND FATIGUE
- Damiano Mistri (Italy)
Abstract
Background and Aims:
Several factors exert modulatory effects on hippocampal structural plasticity. Since fatigue and depression affect a large proportion of multiple sclerosis (MS) patients, we aimed to investigate their impact on hippocampal subfields volume. The effect of gender was also explored.
Methods:
Forty-six healthy controls (HC) and 44 early relapsing-remitting (RR) MS patients (23 females, 21 males; median disease duration 2.0 years) underwent 3.0 T MRI, clinical examination including Modified Fatigue Impact Scale (MFIS) and Montgomery-Asberg Depression Rating Scale (MADRS). Global and subregional hippocampal volumes were assessed with the cross-sectional pipeline of the Freesurfer 6.0. Normalized brain volumes (NBV) were also measured. We computed hierarchical linear regression analysis to investigate the influence of demographic, MRI structural measures, fatigue and depression on hippocampal subfields volumes. The analysis was repeated for females and males, separately.
Results:
Compared to HC, RRMS had lower NBV (p≤0.03), were more fatigued and depressed (p≤0.03). In RRMS (but not in HC) female sex was significant predictor of higher volumes of CA1, dentate gyrus complex (DC), subicular complex and bilateral hippocampal fissure (HF) (ΔR2≥0.125; p≤0.03). In female MS patients, age contributed to explain significant proportion of variance in bilateral HF volume (ΔR2≥0.263; p≤0.03). In male MS patients, higher cognitive fatigue was related to lower bilateral DC and right CA1 volumes (ΔR2≥0.190; p≤0.05).
Conclusions:
These results suggest a protective effect of female gender on hippocampal volumes in RRMS, and a detrimental influence of fatigue on DC and right CA1 volumes in male RRMS patients.
FUNCTIONAL AND STRUCTURAL MRI CORRELATES OF EXECUTIVE FUNCTIONS IN MULTIPLE SCLEROSIS
- Olga Marchesi (Italy)
Abstract
Background and Aims:
To investigate resting state (RS) functional connectivity (FC) and white matter (WM) microstructural abnormalities underlying executive function (EF) impairment in multiple sclerosis (MS).
Methods:
One-hundred and sixteen MS patients and 65 age- and sex-matched healthy controls (HC) underwent 3T brain T1-weighted, RS and diffusion-weighted sequences and Wisconsin Card Sorting Test (WCST) to test EF. The main large-scale brain RS cognitive networks were derived with independent component analysis. Mean fractional anisotropy (FA) was calculated from a priori-selected WM tracts. Associations between WCST scores and RS FC and FA abnormalities were investigated with multivariable models.
Results:
In MS patients, independent predictors of working memory/updating (WCST achieved categories) were: lower corpus callosum (CC) genu FA, lower left working-memory network (WMN) (precuneus), right WMN (middle temporal gyrus) RS FC for worse performance; lower executive control network (ECN) (superior temporal gyrus), higher default-mode network (DMN) (superior parietal lobule) and salience network (SN) (superior frontal gyrus, SFG) RS FC for better performance (R2=0.35). Predictors of attention (WCST errors) were lower CC genu FA, lower left WMN (precuneus) and DMN (anterior cingulate gyrus) RS FC for worse performance; higher left WMN (cerebellum lobule IX) and ECN (SFG) RS FC for better performance (R2=0.24). Predictors of inhibition (WCST perseverative errors/responses) were lower CC genu and superior cerebellar peduncle (SCP) FA, lower left WMN (precuneus) RS FC for worse performance; and higher ECN (SFG) RS FC for better performance (R2=0.24).
Conclusions:
CC and SCP microstructural damage and RS FC abnormalities in cognitive networks underlie EF frailty in MS.