Profiling cognitive-motor interference in a large sample of persons with progressive multiple sclerosis and impaired processing speed: results from the CogEx study

BACKGROUND

Performing cognitive-motor dual tasks (DTs) may result in reduced walking speed and cognitive performance. The effect in persons with progressive multiple sclerosis (pwPMS) having cognitive dysfunction is unknown.

OBJECTIVE

To profile DT-performance during walking in cognitively impaired pwPMS and examine DT-performance by disability level.

METHODS

Secondary analyses were conducted on baseline data from the CogEx-study. Participants, enrolled with Symbol Digit Modalities Test 1.282 standard deviations below normative value, performed a cognitive single task ([ST], alternating alphabet), motor ST (walking) and DT (both). Outcomes were number of correct answers on the alternating alphabet task, walking speed, and DT-cost (DTC: decline in performance relative to the ST). Outcomes were compared between EDSS subgroups (≤ 4, 4.5-5.5, ≥ 6). Spearman correlations were conducted between the DTCmotor with clinical measures. Adjusted significance level was 0.01.

RESULTS

Overall, participants (n = 307) walked slower and had fewer correct answers on the DT versus ST (both p < 0.001), with a DTCmotor of 15.8% and DTCcognitive of 2.7%. All three subgroups walked slower during the DT versus ST, with DTCmotor different from zero (p's < 0.001). Only the EDSS ≥ 6 group had fewer correct answers on the DT versus ST (p < 0.001), but the DTCcognitive did not differ from zero for any of the groups (p ≥ 0.039).

CONCLUSION

Dual tasking substantially affects walking performance in cognitively impaired pwPMS, to a similar degree for EDSS subgroups.

Time matters: Early-phase multiple sclerosis is accompanied by considerable impairments across multiple domains

Impairments across multiple domains are a disabling consequence of multiple sclerosis (MS). Originating from preventive medical strategies, the “time matters”-perspective has become a focal point when treating MS. In particular, early detection of physical and cognitive deficits, along with deficits in patient-reported outcomes seems crucial to further optimize both pharmacological and non-pharmacological MS treatment strategies. Therefore, this topical review investigates the level of impairments across multiple domains (physical function, cognitive function, and patient-reported outcomes) in the early stage of MS (⩽5 years since diagnosis, including clinically isolated syndrome (CIS)), when compared to matched healthy controls. Even at early disease stages, studies show impairments corresponding to 8%–34% and small-to-large numerical effect sizes (0.35–2.85) in MS/CIS patients across domains. This evidence call for early screening programs along with early interventions targeting the multiple impaired domains. This further highlights the importance of preventive initiatives preserving and/or restoring physical and cognitive reserve capacity if possible.

No association between femoral or acetabular angles and patient-reported outcomes in patients with femoroacetabular impingement syndrome-results from the HAFAI cohort

Patients with femoroacetabular impingement syndrome (FAIS) are diagnosed using imaging, but detailed description especially the acetabular shape is lacking and may help give more insight to the pathogenesis of FAIS. Furthermore, associations between patient-reported outcomes (PROs) and the radiological angles might highlight which radiological angles affect outcomes experienced by the patients. Hence, the aims of this study were (i) to describe computer tomography (CT) acquired angles in patients with FAIS and (ii) to investigate the association between radiological angles and the Copenhagen Hip and Groin Outcome Score (HAGOS) in patients with FAIS. Patients scheduled for primary hip arthroscopic surgery for FAIS were included. Based on CT, following angles were measured before and 1 year after surgery; femoral anteversion, alpha, lateral centre edge, acetabular index, anterior sector, posterior sector and acetabular anteversion. All patients completed the HAGOS. Sixty patients (63% females) aged 36 ± 9 were included. One year after surgery, significant alterations in the alpha angle and the acetabular index angle were found. Neither baseline PROs nor changes in PROs were associated with the radiological angles or changes in angles. Since neither changes in CT angles nor baseline scores were associated with HAGOS, the improvements felt by patients must origin from somewhere else. These findings further underlines that morphological changes seen at imaging should not be treated arthroscopically without a patient history of symptoms and clinical findings.

Is hip muscle strength normalised in patients with femoroacetabular impingement syndrome one year after surgery?: Results from the HAFAI cohort

OBJECTIVES

Little is known about hip function after hip arthroscopic surgery in patients with femoroacetabular impingement syndrome. Hence, the aim of the study was (1) to investigate changes in hip muscle strength from before to one year after hip arthroscopic surgery, (2) to compare patients with a reference group.

DESIGN

Cohort study with a cross-sectional comparison.

METHODS

Before and after hip arthroscopic surgery, patients underwent hip muscle strength testing of their hip flexors and extensors during concentric, isometric and eccentric contraction in an isokinetic dynamometer. Reference persons with no hip problems underwent tests at a single time point. Participants completed completed the Copenhagen Hip and Groin Outcome Score (HAGOS) questionnaire and physical capacity (stair climbing loaded and unloaded, stepping loaded and unloaded and jumping) tests.

RESULTS

After surgery, hip flexion strength improved during all tests (6-13%, p<0.01) and concentric hip extension strength improved (4%, p=0.002). Hip flexion and extension strength was lower for patients than for reference persons (9-13%, p<0.05) one year after surgery. Higher hip extension strength after surgery was associated with better patient reported outcomes. Patients, who were unable to complete at minimum one test of physical capacity, demonstrated significantly weaker hip muscle strength. Compared with their healthy counterparts, female patients were more impaired than male patients.

CONCLUSIONS

One year after surgery, patients improved their maximal hip muscle strength. When compared to reference persons, maximal hip muscle strength was still impaired.

Effect of slow release-Fampridine on muscle strength, rate of force development, functional capacity and cognitive function in an enriched population of MS patients. A randomized, double blind, placebo controlled study

DESIGN

This study was conducted as a randomized, double blind, placebo-controlled parallel group trial preceded by open label enrichment phase.

OBJECTIVES

The objectives of this study were 1) to examine the effect of SR-Fampridine treatment on muscle strength in terms of maximal voluntary contraction (MVC) and rate of force development (RFD) of the lower extremities and 2) to replicate previously published data on the effect of slow release-Fampridine (SR-Fampridine) on the functional capacity of the lower limbs, the upper limb and cognitive function, in persons with multiple sclerosis (pwMS).

METHODS

Previously identified responders to SR-Fampridine were randomized to SR- Fampridine or placebo treatment for four weeks. On days 0 and 26-28 participants underwent testing by isokinetic dynamometry, Nine Hole Peg Test (9-HPT), Symbol Digit Modalities Test (SDMT), Six Spot Step Test (SSST), Timed 25 Foot Walk Test (T25FW) and 5-Times Sit-to-Stand (5-STS).

RESULTS

A statistical significant effect of SR-Fampridine on MVC was demonstrated during knee extension, knee flexion and hip flexion of the weakest leg, as well as on RFD during knee extension and knee flexion of the weakest leg. Furthermore, a significant effect of SR-Fampridine on T25FW, SSST and 5-STS was demonstrated.

CONCLUSION

Gold standard dynamometry assessment of muscle strength showed improved MVC and RFD in persons with MS treated with SR-Fampridine compared to placebo. Furthermore, previous findings on the effects of SR-Fampridine on functional capacity of the lower limbs were replicated. ClinicalTrials.gov identifier: NCT01656148.

Impact of high intensity exercise on muscle morphology in EAE rats

The impact of high-intensity exercise on disease progression and muscle contractile properties in experimental autoimmune encephalomyelitis (EAE) remains unclear. Control (CON) and EAE rats were divided into sedentary and exercise groups. Before onset (experiment 1, n=40) and after hindquarter paralysis (experiment 2, n=40), isokinetic foot extensor strength, cross sectional area (CSA) of tibialis anterior (TA), extensor digitorum longus (EDL) and soleus (SOL) and brain-derived neurotrophic factor (BDNF) levels were assessed. EAE reduced muscle fiber CSA of TA, EDL and SOL. In general, exercise was not able to affect CSA, whereas it delayed hindquarter paralysis peak. CON muscle work peaked and declined, while it remained stable in EAE. BDNF-responses were not affected by EAE or exercise. In conclusion, EAE affected CSA-properties of TA, EDL and SOL, which could, partly, explain the absence of peak work during isokinetic muscle performance in EAE-animals. However, exercise was not able to prevent muscle fiber atrophy.

Walking capacity and ability are more impaired in progressive compared to relapsing type of multiple sclerosis

BACKGROUND

Patients with progressive multiple sclerosis (MS) have been attributed greater walking disability than relapsing-remitting MS (RRMS) patients but quantitative data on walking speed and ability are lacking.

AIM

To investigate the impact of type of MS on severity of reduced walking ability and capacity taking into account age, sex, height and disease duration.

DESIGN

Cross-sectional observational multi-center study

SETTING

European MS centers providing either in- or out-patient services, or both.

POPULATION

This study included 502 patients: 259, 162 and 81 patients showed RRMS, secondary and primary progressive MS respectively.

METHODS

Walking was evaluated by T25FW, six minute walk test and MS-Walking Scale-12. Patient characteristics were compared using a one-way ANOVA, and simple and multivariate regression analysis were applied with the walking measures.

RESULTS

In adjusted (sex, age, weight, height and disease duration) analyses, walking impairments were more than 20% greater in progressive types of MS compared to RRMS. There were also indications of greater walking impairment in primary compared to secondary progressive MS patients.

CONCLUSION

Clinical walking impairment was larger in progressive compared to relapsing-remitting type of MS. The biological disease mechanism, being degeneration or inflammation, impacts on disability.

CLINICAL REHABILITATION IMPACT

Health care professionals must be aware of different severity of walking impairment in progressive compared to relapsing type of MS, and need for intensive treatment. Also, studies must report rehabiltiation effects according to MS type.

Changes in cognition, arm function and lower body function after slow-release Fampridine treatment

OBJECTIVE

We aimed to evaluate the effect of slow-release (SR) Fampridine on multiple outcome measures reflecting different domains, and to compare the responsiveness of the Six Spot Step Test (SSST) and the Timed 25 Foot Walk (T25FW).

METHODS

For this study 108 participants were included. On day 0 they were tested with the T25FW, the SSST, the 9-Hole Peg Test (9-HPT), the 5 Times Sit-To-Stand test (5-STS) and the Symbol Digit Modalities Test (SDMT). Four weeks of treatment with SR Fampridine 10 mg BID was commenced. Participants were tested again after 26-28 days of treatment.

RESULTS

Mean changes observed were: SSST -3.4±6.4 s (p<0.001), T25FW -1.2±3.7 s (p<0.001), 9-HPT -1.2±6.0 s (p<0.001), 5- STS -3.4±7.2 s (p<0.001) and SDMT 1.4±4.8 a.u. (p=0.003). Change on the SSST differed significantly from T25FW (SSST 17.0±19.6% vs. T25FW 11.2±17.1%, p=0.0013). Some 48.6% were found to have a meaningful change on the SSST compared with 25.7% on the T25FW. The response to treatment with SR Fampridine did not correlate with age, sex, Expanded Disability Status Scale and disease duration.

CONCLUSION

SR Fampridine treatment has significant effects on different domains including upper and lower body and cognition. Furthermore, the SSST is more responsive to the effect of SR Fampridine than is the T25FW. ClinicalTrials.gov identifier: NCT01656148.

Does multiple sclerosis affect glucose tolerance?

Based on current literature, it is not clear if multiple sclerosis (MS) patients are at increased risk to develop impaired glucose tolerance (IGT). Eighty-one MS patients and 45 healthy controls (HC) performed an oral glucose tolerance test. IGT was defined as a fasting glucose concentration of 6.1–6.9 mmol/l and two-hour post-load glucose of 7.8–11.1 mmol/l. The prevalence of impaired fasting glucose concentrations (17% vs 2%) and IGT (11% vs 0%) was higher in MS patients than HC. Accordingly, the areas under the glucose and insulin curves were higher in MS patients. The current study demonstrates an elevated IGT-prevalence in MS.

Endurance training is feasible in severely disabled patients with progressive multiple sclerosis

This study tested whether upper-body endurance training (ET) is feasible and can be performed at sufficient intensity to induce cardiovascular adaptations in severely disabled patients with progressive multiple sclerosis (MS). Eleven progressive MS patients (6.5 ≤ EDSS ≤ 8.0) scheduled for a four-week inpatient rehabilitation program were randomized to a control group (CON, n = 5) that received standard individualized MS rehabilitation or an intervention group (EXE, n = 6) that in addition received 10 sessions of predominantly upper-body ET. One patient dropped out of the EXE group (drop-out rate: 1/6~17%) and no adverse events were recorded. The EXE group completed on average 9.3±0.8 sessions (~96.0±5%). During the ET sessions an average heart rate of 93.9±9.3beats*min(-1) were sustained corresponding to 91.6±6.8% of the maximal pre-intervention heart rate. In the EXE group a trend toward a time*group interaction was seen for VO2peak (p = 0.06). ET is feasible in severely disabled patients with progressive MS and it can probably be performed at sufficient intensity to induce cardiovascular adaptations.

Effects of sprint interval training on VO2max and aerobic exercise performance: A systematic review and meta-analysis

Recently, several studies have examined whether low-volume sprint interval training (SIT) may improve aerobic and metabolic function. The objective of this study was to systematically review the existing literature regarding the aerobic and metabolic effects of SIT in healthy sedentary or recreationally active adults. A systematic literature search was performed (Bibliotek.dk, SPORTDiscus, Embase, PEDro, SveMed+, and Pubmed). Meta-analytical procedures were applied evaluating effects on maximal oxygen consumption (VO2max). Nineteen unique studies [four randomized controlled trials (RCTs), nine matched-controlled trials and six noncontrolled studies] were identified, evaluating SIT interventions lasting 2-8 weeks. Strong evidence support improvements of aerobic exercise performance and VO2max following SIT. A meta-analysis across 13 studies evaluating effects of SIT on VO2max showed a weighted mean effects size of g = 0.63 95% CI (0.39; 0.87) and VO2max increases of 4.2-13.4%. Solid evidence support peripheral adaptations known to increase the oxidative potential of the muscle following SIT, whereas evidence regarding central adaptations was limited and equivocal. Some evidence indicated changes in substrate oxidation at rest and during exercise as well as improved glycemic control and insulin sensitivity following SIT. In conclusion, strong evidence support improvement of aerobic exercise performance and VO2max following SIT, which coincides with peripheral muscular adaptations. Future RCTs on long-term SIT and underlying mechanisms are warranted.

Multiple sclerosis and progressive resistance training: a systematic review

Recently progressive resistance training (PRT) has been recognised as an effective tool in the rehabilitation of persons with multiple sclerosis (MS). The objective of this study was to systematically review the literature of PRT studies for persons with MS. A comprehensive literature search (PubMed, SveMed+, Embase, Cochrane, PEDro, SPORTDiscus and Bibliotek.dk) was conducted. Identified papers were rated according to the PEDro-scale. Sixteen studies were included and scored between 3 and 8 of 11 total points on the PEDro-scale, showing a general lack of blinding. Strong evidence regarding the beneficial effect of PRT on muscle strength was observed. Regarding functional capacity, balance and self-reported measures (fatigue, quality of life and mood) evidence is less strong, but the tendency is overall positive. Indications of an effect on underlying mechanisms such as muscle morphological changes, neural adaptations and cytokines also exist, but the studies investigating these aspects are few and inconclusive. PRT has a positive effect on muscle strength for persons with MS. Heterogeneous results exist regarding the effect on functional capacity and self-reported measures probably because of differences in training protocols, samples sizes, type and severity of MS. The area of underlying mechanisms deserves more attention in future research.

Effect of time of day on walking capacity and self-reported fatigue in persons with multiple sclerosis: a multi-center trial

BACKGROUND

Many persons with multiple sclerosis (PwMS) report increased fatigue in the afternoon and evening compared with the morning. It is commonly accepted that physical capacity also decreases as time of day progresses, potentially influencing the outcomes of testing.

OBJECTIVE

The objective of this article was to determine whether self-reported fatigue level and walking capacity are influenced by time of day in PwMS.

METHODS

A total of 102 PwMS from 8 centers in 5 countries, with a diverse level of ambulatory dysfunction (Expanded Disability Status Scale [EDSS] <6.5), participated. Patients performed walking capacity tests and reported fatigue level at three different time points (morning, noon, afternoon) during 1 day. Walking capacity was measured with the 6-Minute Walk Test (6MWT) and the 10-m walk test performed at usual and fastest speed. Self-reported fatigue was measured by the Rochester Fatigue Diary (RFD). Subgroups with mild (EDSS 1.5-4.0, n = 53) and moderate (EDSS 4.5-6.5, n = 49) ambulatory dysfunction were formed, as changes during the day were hypothesized to depend on disability status.

RESULTS

Subgroups had different degree of ambulatory dysfunction (p < 0.001) but reported similar fatigue levels. Although RFD scores were affected by time of day with significant differences between morning and noon/afternoon (p < 0.0001), no changes in walking capacity were found in any subgroup. Additional analyses on subgroups distinguished by diurnal change in self-reported fatigue failed to reveal analogous changes in walking capacity.

CONCLUSIONS

Testing of walking capacity is unaffected by time of day, despite changes in subjective fatigue.

The effect of exercise therapy on fatigue in multiple sclerosis

Background: Fatigue occurs in the majority of patients with multiple sclerosis (MS) and therapeutic possibilities are few. Exercise therapy is a therapeutic option but no studies have systematically reviewed the existing literature evaluating the effect of exercise therapy on MS fatigue.

Objective: To determine the effect of exercise therapy on MS fatigue by systematically reviewing the literature.

Methods: A comprehensive literature search (PubMed, SweMed +, Embase, Cochrane, CINAHL, PEDro, Sport Discuss and Bibliotek.dk) was conducted.

Results: Studies evaluating the effect of exercise therapy on MS fatigue show heterogeneous results and only few studies have evaluated MS fatigue as the primary outcome. The heterogeneous findings seem to be related to the selected study population, which in many studies are non-fatigued. Most studies that have included fatigued patients with MS show positive effects, although it is not clear whether any exercise modalities are superior to others because there are no comparative studies regarding different exercise interventions.

Conclusion: Exercise therapy has the potential to induce a positive effect on MS fatigue, but findings are heterogeneous probably because many studies have applied non-fatigued study populations. Furthermore, only few studies have evaluated MS fatigue as the primary outcome measure, emphasizing the need for future studies within this field.

Muscle fiber size increases following resistance training in multiple sclerosis

Objective: To test the hypothesis that lower body progressive resistance training (PRT) leads to an increase of the muscle fiber cross-sectional area (CSA) and a shift in the proportion of fiber types in patients with multiple sclerosis (MS).

Methods: The present study was a two-arm, randomized controlled trial (RCT). Thirty-eight MS patients (Expanded Disability Status Scale (EDSS) 3—5.5) were randomized to a PRT group (Exercise, n = 19) or a control group (Control, n = 19). The Exercise group performed a biweekly 12-week lower body PRT program [five exercises progressing from 15RM (Repetition Maximum) towards 8RM], whereas the Control group maintained their usual daily activity level during the trial period. Muscle biopsies from vastus lateralis were taken before (pre) and after the trial (post). Thigh volume (TV) was estimated from anthropometric measurements. Isokinetic muscle strength of the knee extensors (KE) and flexors (KF) were evaluated at slow (90°/s) and fast (180°/s) angular velocities.

Results: In the Exercise group the mean CSA of all muscle fibers (7.9 ± 15.4% vs. -3.5 ± 9.0%, p = 0.03) and of type II muscle fibers (14.0 ± 19.4% vs. -2.6 ± 15.5%, p = 0.02) increased in comparison with the Control group. No changes occurred in the proportion of fiber types in the Exercise group. Neither was there any change in total TV. Isokinetic strength at KE180, KF90 and KF180 improved significantly after PRT when compared with the control group (10.2—21.3%, p ≤ 0.02).

Conclusions: We conclude that progressive resistance training induces a compensatory increase of muscle fiber size in patients with the central nervous system disorder, multiple sclerosis.

Fatigue, mood and quality of life improve in MS patients after progressive resistance training

Fatigue occurs in the majority of multiple sclerosis patients and therapeutic possibilities are few. Fatigue, mood and quality of life were studied in patients with multiple sclerosis following progressive resistance training leading to improvement of muscular strength and functional capacity. Fatigue (Fatigue Severity Scale, FSS), mood (Major Depression Inventory, MDI) and quality of life (physical and mental component scores, PCS and MCS, of SF36) were scored at start, end and follow-up of a randomized controlled clinical trial of 12 weeks of progressive resistance training in moderately disabled (Expanded Disability Status Scale, EDSS: 3—5.5) multiple sclerosis patients including a Control group ( n = 15) and an Exercise group ( n = 16). Fatigue (FSS > 4) was present in all patients. Scores of FSS, MDI, PCS—SF36 and MCS—SF36 were comparable at start of study in the two groups. Fatigue improved during exercise by —0.6 (95% confidence interval (CI) —1.4 to 0.4) a.u. vs. 0.1 (95% CI —0.4 to 0.6) a.u. in controls ( p = 0.04), mood improved by —2.4 (95% CI —4.1 to 0.7) a.u. vs. 1.1 (—1.2 to 3.4) a.u. in controls ( p = 0.01) and quality of life (PCS—SF36) improved by 3.5 (95% CI 1.4—5.7) a.u. vs. —1.0 (95% CI —3.4—1.4) a.u. in controls ( p = 0.01). The beneficial effect of progressive resistance training on all scores was maintained at follow-up after further 12 weeks. Fatigue, mood and quality of life all improved following progressive resistance training, the beneficial effect being maintained for at least 12 weeks after end of intervention.

Physical Exercise and MS Recommendations

The use of physical exercise programmes in the rehabilitation of patients with multiple sclerosis (MS) has been a controversial issue for many years. During the last decade, however, evidence from a number of studies has suggested that exercise is a safe and efficient way to induce improvements in a number of physiological functions, which ultimately can lead to functional improvements that have a positive effect on a patients daily life. The purpose of this review is, based on the existing research, to provide clinicians with some easily administrable recommendations for the application of exercise in the rehabilitation strategy of MS.

Multiple sclerosis and physical exercise: recommendations for the application of resistance-, endurance- and combined training

This review summarizes the existing knowledge regarding the effects of physical exercise in patients suffering from multiple sclerosis (MS). Furthermore, recommendations are given regarding exercise prescription for MS patients and for future study directions. Previously, MS patients were advised not to participate in physical exercise. During recent years, it has been increasingly acknowledged that exercise benefits MS patients. The requirement for exercise in MS patients is emphasized by their physiological profile, which probably reflects both the effects of the disease per se and the reversible effects of an inactive lifestyle. To date the effects of exercise have only been studied in moderately impaired MS patients with an EDSS score of less than 7. Evidence exists for recommending participation in endurance training at low to moderate intensity, as the existing literature demonstrates that MS patients can both tolerate and benefit from this training modality. Also, resistance training of moderate intensity seems to be well tolerated and to have beneficial effects on MS patients, but the methodological quality of the existing evidence is in general low and the number of studies is limited. Only two studies have evaluated the effects of combined resistance- and endurance training, making solid conclusions regarding this training modality impossible.