Clinical and imaging assessment of cognitive dysfunction in multiple sclerosis (original) (raw)

The contribution of MRI in assessing cognitive impairment in multiple sclerosis

Neurology, 2010

Cognitive impairment affects a large proportion of patients with multiple sclerosis (MS) and has a profound impact on their daily-life activities. Improving the knowledge of the pathophysiology of cognitive impairment in MS and of the mechanisms responsible for its evolution over time might contribute to development of better outcome measures and targets for innovative treatment strategies. Due to their ability to detect MS-related abnormalities, MRI techniques are a valuable tool to achieve these goals. Following an updated overview of the assessment methods and profile of cognitive impairment in patients with MS, this review provides a state-of-the-art summary of the main results obtained from the application of conventional and modern magnetic resonancebased techniques to quantify MS-related damage, in terms of macroscopic lesions, as well as involvement of the normal-appearing white matter and gray matter and their association with cognitive impairment. The possible role of brain cortical reorganization in limiting the clinical consequences of disease-related damage is also discussed. Finally, the utility of the previous techniques to monitor the progression of cognitive deficits over time and the efficacy of possible therapeutic strategies is considered.

Contribution of cortical and white matter lesions to cognitive impairment in multiple sclerosis

2013

Background: Cortical lesions (CLs) have been reported to be a better predictor for cognitive impairment than white matter (WM) lesions in relapsing-remitting multiple sclerosis (RRMS). Objectives: The objectives of this article are to investigate the contribution of CLs and WM lesions to cognitive impairment in 91 patients with MS and clinically isolated syndrome, and to test potential associations of CLs and WM lesions with fatigue and depression. Methods: Lesions were scored and segmented on 3D double inversion recovery sequences, according to their location (cortical, WM). Normalised grey matter volume was also determined. Cognitive performance was assessed with the SDMT and PASAT-3, fatigue with the FSMC and depression with the German version of the CES-D. Results: CL volume did not correlate with fatigue or depression, but correlated significantly with both neuropsychological outcome measures: PASAT-3 (r = -0.275, p = 0.009) and SDMT (r = -0.377, p < 0.001). Multiple regression analyses with age, WM lesions, CLs and GM volume as independent variables, however, did not reveal CL volume as a significant predictor of neuropsychological outcomes, whereas WM lesion volume significantly predicted SDMT and by trend PASAT performance. Conclusions: These findings suggest a role of WM lesions in the development of cognitive deficits, especially informationprocessing speed, which may be higher than previously assumed.

Exploration of the relationships between regional grey matter atrophy and cognition in multiple sclerosis.

Cognitive impairment may result in significant disability in patients with Multiple Sclerosis (MS). Previous Magnetic Resonance Imaging (MRI) studies on cognition in MS were mainly based on measures of gross brain involvement. This study, using voxel-based morphometry (VBM), aims to investigate associations between the regional distribution of grey matter (GM) damage and cognitive performance in patients with MS. Eighteen MS patients underwent an extensive neuropsychological battery and MRI, including T2-weighted scans and T1-weighted volumes. A group of 18 healthy individuals were also investigated by MRI and served as controls for the VBM. A cross-sectional analysis was first performed, to assess the pattern of regional GM atrophy in MS patients. Then, the impact of regional GM damage on patients' neuropsychological performance was investigated by multiple regression analyses in the patient group. Correlations between global indexes of brain damage and neuropsychological measures were also assessed for comparison with previous literature. The comparison between MS patients and healthy controls revealed a widespread pattern of regional GM atrophy. Consistent with previous studies, associations were found between neuropsychological scores, and global brain atrophy and T2-lesion volumes. Critically, significant associations were found between scores on the Symbol Digit Modalities test and Long Delay Cued Recall on the California Verbal Learning Test, and regional GM volumes in well localized areas of the prefrontal, parietal, temporal, and insular cortex. This study confirms that global assessments of brain damage correlate with measures of cognitive impairment in MS. Interestingly, VBM contributes to clarify those brain regions that more likely determine the cognitive deficits observed in patients. These findings clarify the pathophysiology of cognitive impairment in MS, and propose measures which could be considered for longitudinal monitoring of patients.

Correlation between cortical lesions and cognitive impairment in multiple sclerosis

Brain and behavior, 2018

Gray matter (GM) damage is well known as a fundamental aspect of multiple sclerosis (MS). Above all, cortical lesions (CLs) burden, detectable at MRI with double inversion recovery (DIR) sequences, has been demonstrated to correlate with cognitive impairment (CI). The aim of this study was to investigate the role of CLs number in predicting CI in a cohort of patients with MS in a clinical practice setting. Thirty consecutive patients with MS presenting CLs (CL+) at high-field (3.0 T) MRI 3D-DIR sequences and an even group of MS patients without CLs (CL-) as a control, were investigated with the Rao Brief Repeatable Battery of Neuropsychological Tests (BRB), Version A. Total and lobar CLs number were computed in CL+ patients. Among the sixty patients with MS enrolled, forty-seven (78.3%) had a relapsing-remitting course, while thirteen (21.7%) a progressive one, eleven secondary progressive, and two primary progressive. Compared to CL-, CL+ patients had a greater proportion of progre...

The Diagnostic Role of Brain MRI in Detection of Multiple Sclerosis Related Cognitive Impairment

Journal of Behavioral and Brain Science, 2019

Background: Cognitive impairment (CI) is a common manifestation of multiple sclerosis (MS), which can severely affect patients' and their families' life. Early suspicion and detection of CI can improve general medical management of MS patients. Objectives: To correlate MS related CI to cortical brain lesions using brain magnetic resonance imaging (MRI). Materials and Methods: Cognitive impairment was detected using mini mental state examination (MMSE); Neurological examination and brain MRI were performed for all patients. Correlation was calculated between disease cortical burden detected by MRI and CI. Results: Fifty-three patients with proven MS were scanned by brain MRI; 69.8% of them had cognitive impairment diagnosed with MMSE. The presence and severity of cognitive impairment was correlated to cortical brain lesion. Cognitive impairment was not correlated with non-cortical brain lesions or neurological physical disability measured by Expanded Disability Status Scale (EDSS). Conclusions: Presence of brain frontal cortical lesions detected by MRI in MS patients can predict subsequent development of MS-related CI.

Clinical correlates of grey matter pathology in multiple sclerosis

BMC Neurology, 2012

Traditionally, multiple sclerosis has been viewed as a disease predominantly affecting white matter. However, this view has lately been subject to numerous changes, as new evidence of anatomical and histological changes as well as of molecular targets within the grey matter has arisen. This advance was driven mainly by novel imaging techniques, however, these have not yet been implemented in routine clinical practice. The changes in the grey matter are related to physical and cognitive disability seen in individuals with multiple sclerosis. Furthermore, damage to several grey matter structures can be associated with impairment of specific functions. Therefore, we conclude that grey matter damage -global and regional -has the potential to become a marker of disease activity, complementary to the currently used magnetic resonance markers (global brain atrophy and T2 hyperintense lesions). Furthermore, it may improve the prediction of the future disease course and response to therapy in individual patients and may also become a reliable additional surrogate marker of treatment effect.

Cognitive functions in multiple sclerosis: impact of gray matter integrity

Multiple Sclerosis Journal, 2013

Objectives: Our aim was to investigate the impact of gray matter (GM) integrity on cognitive performance in multiple sclerosis (MS), and its relationship with white matter (WM) integrity and presence of lesions. Methods: Sixty-seven patients with MS and 26 healthy controls underwent voxel-based analysis of diffusion tensor images (DTI) in GM and tract-based spatial statistics (TBSS) from WM to identify the regional correlations between cognitive functions and integrity. Lesion probability mapping (LPM) was generated for correlation analysis with cognition. Multiple linear regression analyses were used to identify the imaging measures associated with cognitive scores. Results: Compared with controls, patients showed abnormal DTI indices in several GM regions and in most WM tracts. Impairment in DTI indices in specific GM regions was associated with worse performance of distinct cognitive functions. Those regions showed anatomical correspondence with cognitively relevant tracts in TBSS and LPM. The combination of regional GM and WM DTI and lesion volume accounted for 36-51% of the variance of memory and attention scores. Regional GM DTI explained less than 5% of that variance. Conclusion: GM and WM integrity of specific networks influences cognitive performance in MS. However, GM damage assessed by DTI only adds a small increment to the explained variance by WM in predicting cognitive functioning.

Gray Matters in Multiple Sclerosis: Cognitive Impairment and Structural MRI

Multiple Sclerosis International, 2014

Multiple sclerosis (MS) is an immune-mediated disease affecting central nervous system (CNS). Although MS is classically considered a white matter (WM) disease, the involvement of gray matter (GM) in the pathogenic process has been confirmed by pathology studies and MRI studies. Impairment of cognitive domains such as memory, mental processing speed, attention, and executive function can occur from the early stage of the disease and tends to worsen over time, despite stable physical symptoms. WM demyelination is moderately correlated with CI, suggesting that probably WM abnormalities alone cannot fully explain the extent of clinical symptoms in MS, including CI. Several MRI techniques have shown the involvement of GM in MS and the association between GM damage, physical disability, and CI. The aim of this review is to provide an overview of CI and GM damage assessed by structural brain MRI.