The clinical and paraclinical correlates of employment status in multiple sclerosis

Prevalence, treatment and correlates of depression in multiple sclerosis

BACKGROUND

The prevalence of depression in Multiple Sclerosis (MS) is often assessed by administering patient reported outcome measures (PROMs) examining depressive symptomatology to population cohorts; a recent review summarised 12 such studies, eight of which used the Hospital Anxiety and Depression Scale-Depression (HADS-D). In clinical practice, depression is diagnosed by an individual structured clinical interview; diagnosis often leads to treatment options including antidepressant medication. It follows that an MS population will include those whose current depressive symptoms meet threshold for depression diagnosis, plus those who previously met diagnostic criteria for depression and have been treated such that depressive symptoms have improved below that threshold. We examined a large MS population to establish a multi-attribute estimate of depression, taking into account probable depression on HADS-D, as well as anti-depressant medication use and co-morbidity data reporting current treatment for depression. We then studied associations with demographic and health status measures and the trajectories of depressive symptoms over time.

METHODS

Participants were recruited into the UK-wide Trajectories of Outcome in Neurological Conditions-MS (TONiC-MS) study, with demographic and disease data from clinical records, PROMs collected at intervals of at least 9 months, as well as co-morbidities and medication. Interval level conversions of PROM data followed Rasch analysis. Logistic regression examined associations of demographic characteristics and symptoms with depression. Finally, a group-based trajectory model was applied to those with depression.

RESULTS

Baseline data in 5633 participants showed the prevalence of depression to be 25.3 % (CI: 24.2-26.5). There were significant differences in prevalence by MS subtype: relapsing 23.2 % (CI: 21.8- 24.5), primary progressive 25.8 % (CI: 22.5-29.3), secondary progressive 31.5 % (CI: 29.0-34.0); disability: EDSS 0-4 19.2 % (CI: 17.8-20.6), EDSS ≥4.5 31.9 % (CI: 30.2-33.6); and age: 42-57 years 27.7 % (CI: 26.0-29.3), above or below this range 23.1 % (CI: 21.6-24.7). Fatigue, disability, self-efficacy and self esteem correlated with depression with a large effect size (>0.8) whereas sleep, spasticity pain, vision and bladder had an effect size >0.5. The logistic regression model (N = 4938) correctly classified 80 % with 93 % specificity: risk of depression was increased with disability, fatigue, anxiety, more comorbidities or current smoking. Higher self-efficacy or self esteem and marriage reduced depression. Trajectory analysis of depressive symptoms over 40 months in those with depression (N = 1096) showed three groups: 19.1 % with low symptoms, 49.2 % with greater symptoms between the threshold of possible and probable depression, and 31.7 % with high depressive symptoms. 29.9 % (CI: 27.6-32.3) of depressed subjects were untreated, conversely of those treated, 26.1 % still had a symptom level consistent with a probable case (CI: 23.5-28.9).

CONCLUSION

A multi-attribute estimate of depression in MS is essential because using only screening questionnaires, diagnoses or antidepressant medication all under-estimate the true prevalence. Depression affects 25.3 % of those with MS, almost half of those with depression were either untreated or still had symptoms indicating probable depression despite treatment. Services for depression in MS must be pro-active and flexible, recognising the heterogeneity of outcomes and reaching out to those with ongoing symptoms.

Determinants of early working impairments in multiple sclerosis

Introduction

Unemployment can directly affect social status and identity. Assessing and adjusting determinants of early working impairments in a chronic disease can thus reduce its long-term burden. Hereby, we aim to evaluate differences in occupational history and early working impairments between people with multiple sclerosis (MS) and healthy workers.

Methods

This is a cross-sectional study comparing 71 workers with MS [age 41.7 ± 9.4 years; females 59.1%; EDSS 2.0 (1.0-6.0)] and 71 controls (age 42.6 ± 11.9 years; females 33.8%). All participants filled in Work Ability Index (WAI), Work Productivity and Activity Impairment (WPAI), European Questionnaire for Quality of Life (EuroQoL), Beck Depression Inventory II (BDI-II), and Pittsburgh Sleep Quality Index (PSQI). In MS, we further collected expanded disability status scale (EDSS), MS Questionnaire for Job difficulties (MSQ-Job), Fatigue severity scale (FSS), and the Brief International Cognitive Assessment for MS (BICAMS).

Results

Workers with MS were more working disabled (p < 0.01), less exposed to workplace risks (p < 0.01), and more limited in fitness to work (p = 0.01), compared with controls. On linear regression models adjusted by age, sex, education, and type of contract, people with MS had worse WAI (Coeff=-5.47; 95% CI = -7.41, -3.53; p < 0.01), EuroQoL (Coeff = -4.24; 95% CI = -17.85, -6.50; p < 0.01), BDI-II (Coeff = 3.99; 95% CI = 2.37, 7.01; p < 0.01), and PSQI (Coeff = 4.74; 95% CI = 3.13, 7.61; p < 0.01), compared with controls, but no differences in WPAI (p = 0.60). EuroQoL, BDI-II, and PSQI were equally associated with both WAI and WPAI in MS and controls (all p< 0.01). In MS, worse MSQJob was associated with higher EDSS (Coeff = 5.22; 95% CI = 2.24, 7.95; p < 0.01), progressive disease (Coeff = 14.62; 95% CI = 5.56, 23.69; p < 0.01), EuroQoL (Coeff = 4.63; 95% CI = 2.92, 6.35; p < 0.01), FSS (Coeff = 0.55; 95% CI = 0.38, 0.72; p < 0.01), and cognitive impairment (Coeff = 4.42; 95% CI = 0.67, 8.22; p = 0.02).

Discussion

Early factors associated with working difficulties in MS include disability, fatigue, depression, and cognitive dysfunction. Early identification of clinical features potentially causing working difficulties should be considered to enhance job retention, along with targeted prevention and protection measures.

Persistence with Botulinum Toxin Treatment for Spasticity Symptoms in Multiple Sclerosis

Botulinum toxin (BT) is an effective treatment for spasticity symptoms in multiple sclerosis (MS). Despite its wide use in clinical practices, only few studies have explored long-term persistence. We aim to evaluate the rate of discontinuation of BT treatment and the correlation with MS, spasticity, and injection variables. This retrospective study on 3-year prospectively collected data included 122 MS patients receiving BT injections for spasticity. We collected MS clinical variables (disease durations, Expanded Disability Status Scales [EDSSs], disease-modifying treatments [DMT], and Symbol Digit Modalities Tests [SDMTs]), modified Ashworth scales [MASs], concomitant treatments, and injection variables (formulation, dose, number of injections, and intervals between injections). A total of 14 out of the 122 patients discontinued BT after a mean time of 3.0 ± 1.5 years. In the Cox regression model including the MS clinical variables, the probability of BT discontinuations increased in patients with DMT changes during follow-ups (HR = 6.34; 95%Cl = 2.47, 18.08; p < 0.01) and with impaired SDMTs (HR = 1.20; 95%Cl = 1.04, 1.96; p < 0.01). In the model including the spasticity variables, there were no associations between BT discontinuation and MAS or other spasticity treatments. In the model including the injection variables, the probability of discontinuation decreased by 80% for each cumulative injection (HR = 0.16; 95%Cl = 0.05, 0.45; p < 0.01), but increased by 1% for each additional day over the 3-month interval between injections (HR = 1.27; 95%Cl = 1.07, 1.83; p < 0.01). BT discontinuation was associated with concomitant MS-related issues (e.g., treatment failure and DMT change) and the presence of cognitive impairment, which should be accounted for when planning injections. The interval between injections should be kept as short as possible from regulatory and clinical perspectives to maximize the response across all of the spasticity symptoms and to reduce discontinuation in the long term.

Visual Search in Naturalistic Scenes Reveals Impaired Cognitive Processing Speed in Multiple Sclerosis

BACKGROUND

Standardized neuropsychological testing serves to quantify cognitive impairment in multiple sclerosis (MS) patients. However, the exact mechanism underlying the translation of cognitive dysfunction into difficulties in everyday tasks has remained unclear. To answer this question, we tested if MS patients with intact vs. impaired information processing speed measured by the Symbol Digit Modalities Test (SDMT) differ in their visual search behavior during ecologically valid tasks reflecting everyday activities.

METHODS

Forty-three patients with relapsing-remitting MS enrolled in an eye-tracking experiment consisting of a visual search task with naturalistic images. Patients were grouped into "impaired" and "unimpaired" according to their SDMT performance. Reaction time, accuracy and eye-tracking parameters were measured.

RESULTS

The groups did not differ regarding age, gender, and visual acuity. Patients with impaired SDMT (cut-off SDMT-z-score < -1.5) performance needed more time to find and fixate the target (q = 0.006). They spent less time fixating the target (q = 0.042). Impaired patients had slower reaction times and were less accurate (both q = 0.0495) even after controlling for patients' upper extremity function. Exploratory analysis revealed that unimpaired patients had higher accuracy than impaired patients particularly when the announced target was in unexpected location (p = 0.037). Correlational analysis suggested that SDMT performance is inversely linked to the time to first fixation of the target only if the announced target was in its expected location (r = -0.498, p = 0.003 vs. r = -0.212, p = 0.229).

CONCLUSION

Dysfunctional visual search behavior may be one of the mechanisms translating cognitive deficits into difficulties in everyday tasks in MS patients. Our results suggest that cognitively impaired patients search their visual environment less efficiently and this is particularly evident when top-down processes have to be employed.