Combining clinical and magnetic resonance imaging markers enhances prediction of 12-year employment status in multiple sclerosis patients

Changes in employment status over time in multiple sclerosis following a first episode of central nervous system demyelination, a Markov multistate model study

BACKGROUND AND PURPOSE

Understanding predictors of changes in employment status among people living with multiple sclerosis (MS) can assist health care providers to develop appropriate work retention/rehabilitation programs. We aimed to model longitudinal transitions of employment status in MS and estimate the probabilities of retaining employment status or losing or gaining employment over time in individuals with a first clinical diagnosis of central nervous system demyelination (FCD).

METHODS

This prospective cohort study comprised adults (aged 18-59 years) diagnosed with FCD (n = 237) who were followed for more than 11 years. At each review, participants were assigned to one of three states: unemployed, part-time, or full-time employed. A Markov multistate model was used to examine the rate of state-to-state transitions.

RESULTS

At the time of FCD, participants with full-time employment had an 89% chance of being in the same state over a 1-year period, but this decreased to 42% over the 10-year follow-up period. For unemployed participants, there was a 92% likelihood of remaining unemployed after 1 year, but this probability decreased to 53% over 10 years. Females, those who progressed to clinically definite MS, those with a higher relapse count, and those with a greater level of disability were at increased risk of transitioning to a deteriorated employment state. In addition, those who experienced clinically significant fatigue over the follow-up period were less likely to gain employment after being unemployed.

CONCLUSIONS

In our FCD cohort, we found a considerable rate of employment transition during the early years post-diagnosis. Over more than a decade of follow-up post-FCD, we found that females and individuals with a greater disability and a higher relapse count are at higher risk of losing employment.

Patterns of brain atrophy in recently-diagnosed relapsing-remitting multiple sclerosis

Recurrent neuroinflammation in relapsing-remitting MS (RRMS) is thought to lead to neurodegeneration, resulting in progressive disability. Repeated magnetic resonance imaging (MRI) of the brain provides non-invasive measures of atrophy over time, a key marker of neurodegeneration. This study investigates regional neurodegeneration of the brain in recently-diagnosed RRMS using volumetry and voxel-based morphometry (VBM). RRMS patients (N = 354) underwent 3T structural MRI <6 months after diagnosis and 1-year follow-up, as part of the Scottish multicentre 'FutureMS' study. MRI data were processed using FreeSurfer to derive volumetrics, and FSL for VBM (grey matter (GM) only), to establish regional patterns of change in GM and normal-appearing white matter (NAWM) over time throughout the brain. Volumetric analyses showed a decrease over time (q<0.05) in bilateral cortical GM and NAWM, cerebellar GM, brainstem, amygdala, basal ganglia, hippocampus, accumbens, thalamus and ventral diencephalon. Additionally, NAWM and GM volume decreased respectively in the following cortical regions, frontal: 14 out of 26 regions and 16/26; temporal: 18/18 and 15/18; parietal: 14/14 and 11/14; occipital: 7/8 and 8/8. Left GM and NAWM asymmetry was observed in the frontal lobe. GM VBM analysis showed three major clusters of decrease over time: 1) temporal and subcortical areas, 2) cerebellum, 3) anterior cingulum and supplementary motor cortex; and four smaller clusters within the occipital lobe. Widespread GM and NAWM atrophy was observed in this large recently-diagnosed RRMS cohort, particularly in the brainstem, cerebellar GM, and subcortical and occipital-temporal regions; indicative of neurodegeneration across tissue types, and in accord with limited previous studies in early disease. Volumetric and VBM results emphasise different features of longitudinal lobar and loco-regional change, however identify consistent atrophy patterns across individuals. Atrophy measures targeted to specific brain regions may provide improved markers of neurodegeneration, and potential future imaging stratifiers and endpoints for clinical decision making and therapeutic trials.

Long-term trajectories of employment status, workhours and disability support pension status, after a first episode of CNS demyelination

BACKGROUND

People with multiple sclerosis face significant employment-related challenges, with little known of the drivers of these outcomes.

OBJECTIVE

We examined prospective trajectories of employment-related outcomes up to 11 years following a first episode of central nervous system (CNS) demyelination (FCD).

METHODS

Participants were aged 18-59 years, at FCD, with at least two observations and were employed at study entry or anytime during follow-up (n = 207). Outcomes were employment status (full-time, part-time and unemployed), average workhours per week and disability support pension (DSP; receiving/not receiving). We used group-based trajectory modelling to identify groups with common trajectories. Factors associated with trajectory membership were explored using log-multinomial regression.

RESULTS

Distinct trajectories were identified for employment (4), workhours (4) and DSP (2). Compared with stable full-time, female sex was strongly associated with being in the stable part-time trajectory (risk ratio (RR): 5.35; 95% confidence interval (CI) = 2.56-11.20; p < 0.001). A greater level of disability at 5-year review (RR: 1.35; 95% CI = 1.19-1.53) and having more than two comorbidities at baseline (RR: 2.77; 95% CI = 1.37-5.64) were associated with being in early and late deteriorated employment trajectories, respectively. Compared with the increased part-time trajectory, every additional relapse during the 5 years post-FCD was associated with a 10% increased risk of being in the reduced part-time trajectory (RR = 1.10; 95%CI = 1.00-1.22). For every additional EDSS point at 5-year review, the risk of being in the DSP trajectory increased (RR = 1.21; 95% CI = 1.05-1.41).

CONCLUSION

These trajectories indicate substantial heterogeneity and the complex impact of MS on employment from its earliest timepoints. Understanding these trends could enable better targeting of interventions to facilitate workforce retention, particularly for females, those with a higher number of comorbidities, more frequent relapses and greater rate of disability accrual.

The clinical and paraclinical correlates of employment status in multiple sclerosis

PURPOSE

To identify the clinical and paraclinical markers of employment status in multiple sclerosis (MS).

METHODS

This was a cross-sectional sub-study investigating 1226 MS patients. To minimalized confounding effect, two groups of patients, matched by sex, age, and education, were selected: 307 patients with full time employment and 153 unemployed patients receiving disability pension. We explored associations between employment status and Expanded Disability Status Scale (EDSS), 25 Foot Walk Test (25FWT), Nine Hole Peg Test (9HPT), Brief International Cognitive Assessment for MS (BICAMS), Paced Auditory Serial Addition Test (PASAT), Beck Depression Inventory (BDI), SLOAN charts (SLOAN), and brain volumetric MRI measures.

RESULTS

Both groups differed significantly on all variables of interest (p < 0.001). In the univariate analyses, EDSS, SDMT (Symbol Digit Modalities Test) adjusted for BDI, 25FWT, and 9HPT best explained variability in vocational status. In multivariate analyses, the combination of EDSS, 25FWT, SDMT, BDI, and corpus callosum fraction (CCF) explained the greatest variability. As a next step, after patients were matched by EDSS, differences in SDMT, 25FWT (both p < 0.001), 9HPT, CCF, and T2 lesion volume were still present (all p < 0.005) between both groups. The best multivariate model consisted of SDMT, BDI, and T2 lesion volume.

CONCLUSIONS

EDSS, walking ability, cognitive performance, and MRI volumetric parameters are independently associated with employment status.

Brain atrophy and employment in multiple sclerosis patients: a 10-year follow-up study

Background

Multiple sclerosis is often associated with unemployment. The contribution of grey matter atrophy to unemployment is unclear.

Objectives

To identify magnetic resonance imaging biomarkers of grey matter and clinical symptoms associated with unemployment in multiple sclerosis patients.

Methods

Demographic, clinical data and 1.5 T magnetic resonance imaging scans were collected in 81 patients at the time of inclusion and after 5 and 10 years. Global and tissue-specific volumes were calculated at each time point. Statistical analysis was performed using a mixed linear model.

Results

At baseline 31 (38%) of the patients were unemployed, at 5-year follow-up 44 (59%) and at 10-year follow-up 34 (81%) were unemployed. The unemployed patients had significantly lower subcortical deep grey matter volume (P < 0.001), specifically thalamus, pallidus, putamen and hippocampal volumes, and cortical volume (P = 0.011); and significantly greater T1 (P < 0.001)/T2 (P < 0.001) lesion volume than the employed patient group at baseline. Subcortical deep grey matter volumes, and to a lesser degree cortical volume, were significantly associated with unemployment throughout the follow-up.

Conclusion

We found significantly greater atrophy of subcortical deep grey matter and cortical volume at baseline and during follow-up in the unemployed patient group. Atrophy of subcortical deep grey matter showed a stronger association to unemployment than atrophy of cortical volume during the follow-up.

Molecular biomarkers in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory-neurodegenerative disease of the central nervous system presenting with significant inter- and intraindividual heterogeneity. However, the application of clinical and imaging biomarkers is currently not able to allow individual characterization and prediction. Complementary, molecular biomarkers which are easily quantifiable come from the areas of immunology and neurobiology due to the causal pathomechanisms and can excellently complement other disease characteristics. Only a few molecular biomarkers have so far been routinely used in clinical practice as their validation and transfer take a long time. This review describes the characteristics that an ideal MS biomarker should have and the challenges of establishing new biomarkers. In addition, clinically relevant and promising biomarkers from the blood and cerebrospinal fluid are presented which are useful for MS diagnosis and prognosis as well as for the assessment of therapy response and side effects.