The use of valproic acid and multiple sclerosis

BACKGROUND

Animal studies have suggested that drugs inhibiting the enzyme histone deacetylase might have a beneficial effect on multiple sclerosis (MS). Valproic acid (VPA), an anti-epileptic drug, is the only widely used human drug with a histone deacetylase inhibitory effect.

OBJECTIVE

The objective of this paper is to examine if VPA use is associated with a reduced risk of MS.

METHODS

We conducted a propensity score-matched cohort study in the period 1997-2011 linking nationwide register data on filled VPA prescriptions, MS cases, and several covariates. The VPA users were matched on propensity scores in a 1:4 ratio with non-users of VPA. Incidence rates of MS were compared among VPA users and non-users of VPA using Cox regression to estimate hazard ratios (HRs).

RESULTS

Among 16 028 ever-users of VPA and 54 172 non-users, 18 and 26 cases of MS were identified, respectively. Neither current VPA users nor recent users of VPA, who had ceased VPA treatment within the last year, were at a reduced risk of MS compared with non-users of VPA (HR = 1.30 (95% confidence interval, 0.44-3.80), n = 4, and HR = 1.22 (0.28-5.32), n = 2, respectively). Similarly, in an intention-to-treat analysis, ever-users of VPA were not at reduced risk of MS (HR = 2.41 (1.32-4.43), n = 18).

CONCLUSION

In the first human study addressing a possible beneficial effect of VPA use on the risk of MS, we found no support for a protective effect. However, given the wide confidence intervals, only large effects can be ruled out with sufficient certainty.

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.

Stressful life-events in childhood and risk of multiple sclerosis: a Danish nationwide cohort study

Background:

Current knowledge concerning the association between exposure to stressful life-events (SFLEs) in childhood and later risk of multiple sclerosis (MS) is sparse.

Objectives:

We studied the associations between SFLEs in childhood and subsequent risk of MS in a nationwide cohort of 2.9 million Danes born from 1968 to 2011.

Methods:

A SFLE in childhood was defined as exposure before age 18 years to parental divorce, parental death, or death of a sibling, using information from the Danish Civil Registration System. MS cases in the cohort were identified in the Danish Multiple Sclerosis Registry. Associations of SFLE with MS risk were evaluated by incidence rate ratios (RR) of MS obtained in log-linear Poisson regression models.

Results:

Persons exposed to any SFLE in childhood were at 11% elevated risk of MS (RR = 1.11; 95% confidence interval: 1.03–1.20), compared to non-exposed persons. Stratification by subtype of SFLE showed that parental death and death of a sibling were not associated with MS risk. However, persons exposed to parental divorce were at 13% increased risk of developing MS compared to non-exposed (RR = 1.13; 1.04–1.23).

Conclusions:

Associations of SFLEs in childhood with risk of MS are weak. However, parental divorce is somehow associated with modestly increased risk of MS.

[There is evidence for the use of cannabinoids for symptomatic treatment of multiple sclerosis]

We identified 16 randomized placebo-controlled trials investigating cannabinoids as symptomatic treatment in multiple sclerosis (MS). There is evidence that nabiximols oromucosal spray may reduce subjective symptoms of spasticity and that dronabinol is effective against neuropathic pain in patients with MS. The existing treatment system in Denmark is in conformity with the existing data and there is not sufficient evidence to modify it.

4-Aminopyridine for symptomatic treatment of multiple sclerosis: a systematic review

This systematic review summarizes the existing evidence on the effect of 4-aminopyridine (4-AP) as a symptomatic treatment of decreased walking capacity in patients with multiple sclerosis (MS) when administered as an immediate release compound and a slow release compound. It summarizes existing evidence on the basic mechanisms of 4-AP from experimental studies and evidence on the clinical use of the compound. A systematic literature search was conducted of the following databases: PubMed and EMBASE. Thirty-five studies were included in the review divided into 16 experimental studies, two clinical studies with paraclinical endpoints and 17 clinical studies with clinical endpoints. Animal studies show that 4-AP can improve impulse conduction through demyelinated lesions. In patients with MS this translates into improved walking speed and muscle strength of the lower extremities in a subset of patients at a level that is often of clinical relevance. Phase III trials demonstrate approximately 25% increase in walking speed in roughly 40% and improved muscle strength in the lower extremities. Furthermore, 4-AP might have an effect on other domains such as cognition, upper extremity function and bowel and bladder, but this warrants further investigation. Side effects are mainly mild to moderate, consisting primarily of paraesthesia, dizziness, nausea/vomiting, falls/balance disorders, insomnia, urinary tract infections and asthenia. Side effects are worse when administered intravenously and when administered as an immediate release compound. Serious adverse events are rarely seen in the marketed clinical dosages. In conclusion, 4-AP is easy and safe to use. Slow release 4-AP shows more robust clinical effects and a more beneficial side-effect profile than immediate release 4-AP.

Antibodies against interferon-beta in neuromyelitis optica patients

Neuromyelitis optica (NMO) is an antibody-mediated autoimmune inflammatory disease of the CNS. A poor response to treatment with recombinant interferon beta (IFN-ß) in NMO patients has been suggested, although the precise mechanisms remain uncertain. We analyzed occurrence and clinical consequences of IFN-neutralizing antibodies (NAbs) in 15 IFN-ß treated NMO-patients from a population-based retrospective case series cohort. NMO patients not treated with IFN-ß acted as a reference group. IFN-ß antibody determinations included binding antibodies (BAbs) measured by immunoassay and NAbs measured by a neutralization bioassay. Antibodies were determined 6-36 months after initiation of IFN-β therapy and NAbs additionally 5-10 years post-therapy. BAbs were detected in 14/15 NMO patients; 6/15 were NAbs-positive (3 at 5-10 years post-therapy) two of those anti-AQP4 antibody-positive; seven of the nine NAbs-negative patients were anti-AQP4 antibody-positive. Eleven patients (three NAbs-positive, eight NAbs-negative) developed cerebral lesions and 12 patients (four NAbs-positive, eight NAbs-negative) spinal cord lesions on magnetic resonance imaging as gadolinium positive lesions or T2-weighted lesions, at significantly higher frequencies than NMO reference group (p<0.009). Exacerbation occurred within 90 days in four and 6-36 months in eight patients. Progression of disease activity in NMO patients occurred during IFN-β treatment, irrespective of IFN-neutralizing antibody status.

[Every fifth case of multiple sclerosis is familial]

Up to 20% of all multiple sclerosis (MS) cases are familial. The concordance rates for monozygotic and dizygotic twins are 25-30% and 3-5% respectively. Certain isolated regions have a higher prevalence of MS. An estimated 30% of the disease heritability is accounted for, mostly by common risk alleles. Interpretation of risk alleles, gene-gene and gene-environment interactions is challenging, but all are believed to be important factors in the development of MS. Isolates and MS families are warranted for further research concerning these issues.

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.

Multiple sclerosis and risk of Parkinson's disease: a Danish nationwide cohort study

BACKGROUND AND PURPOSE

Case reports have observed a co-occurrence of multiple sclerosis (MS) and Parkinson's disease (PD) and it has been hypothesized that MS lesions could affect dopaminergic pathways causing parkinsonism. Our aim was to examine the association between MS and PD in a historically prospective cohort study using Danish nationwide register data.

METHODS

Multiple sclerosis patients identified in the Multiple Sclerosis Registry were followed for PD from 1977 to 2011 in the National Patient Register. As measures of relative risk, ratios of observed to expected incidence rates of first hospitalization for PD amongst persons with MS were used, i.e. standardized incidence ratios (SIRs) with 95% confidence intervals (CIs).

RESULTS

Amongst 15,557 MS patients 26 cases of PD were observed versus 26.51 expected, reflecting no overall increased risk of PD (SIR 0.98, 95% CI 0.67-1.44). Similar estimates were seen for female (SIR 0.99, 95% CI 0.58-1.67) and male MS patients (SIR 0.97, 95% CI 0.55-1.72). Likewise, no increased risk of PD amongst MS patients was observed in a robustness analysis backdating the date of diagnosis of PD by 5 years to account for the time lag between disease onset and first hospital contact with PD (SIR 0.57, 95% CI 0.32-1.00).

CONCLUSION

Our data do not suggest an increased risk of PD amongst patients with MS.

Risk factors related to cardiovascular diseases and the metabolic syndrome in multiple sclerosis - a systematic review

Despite many epidemiological studies examining comorbidity in people with multiple sclerosis (pMS), there are conflicting opinions on whether pMS are at more or less risk of cardiovascular disease (CVD) and the metabolic syndrome compared with the general population. As pMS can now expect longer survival, this as an important question both at an individual and public health level. This study aimed to systematically review the literature linking MS to CVD risks and to the risk factors constituting the metabolic syndrome. This systematic review is based on a comprehensive literature search of six databases (Swemed+, Pubmed, Embase, Cochrane, PEDro and CINAHL). In total 34 studies were identified. Despite the high number of identified papers, only limited and inconsistent data exist on the risk factors of the metabolic syndrome and MS. Overall, the data suggest an increased CVD risk in pMS. From the existing studies it is not clear whether the increased risk of CVD is related to an increased risk of obesity or changes in body composition, hypertension, dyslipidemia or type II diabetes in pMS, indicating the need for future research in the field, if we are to advise pMS adequately in avoiding preventable comorbidity.

The use of epidemiological multiple sclerosis registers in research: the Danish MS Registry

INTRODUCTION

The claim of detection of several environmental risk factors for multiple sclerosis (MS), some of them new, makes the research of population-based MS registers for critical review or confirmation of alleged associations more relevant than ever before.

AIMS

To present examples of the use and important contributions from the Danish MS Registry (DMSR) over decades.

METHODS

The DMSR has through more than six decades registered virtually all patients with MS in Denmark, using multiple sources of notification and has been used for descriptive epidemiology, follow-up studies, studies of comorbidity and 'historical prospective' studies of proposed risk factors for MS.

RESULTS

Based on research from DMSR, we have found that female incidence of multiple sclerosis in Denmark has increased considerably; that patients with MS loose their working ability and their spouses/partners at a much higher rate than the background population; that patients with MS have a considerable excess mortality which seem to have decreased over several centuries decades - not centuries, also before the era of disease modifying treatment; that fewer patients with MS than expected from the population get diagnosed with or die from cancer; that infectious mononucleosis increases the risk of MS; that head trauma and a number of occupational exposures, for example, nurses, utility workers, exposure to solvents do not carry an enhanced risk of MS.

CONCLUSION

The DMSR has, as an example of long-lasting population-based registers, proven to be an effective tool for studying MS epidemiology. In future, the need for this kind of registers will continue, as biology or immunology cannot stand alone.

Socioeconomic factors in childhood and the risk of multiple sclerosis

In a national cohort comprising 1.5 million Danes born from 1966 to 1992, we studied the association between childhood socioeconomic status (SES) and the risk of multiple sclerosis (MS) from 1981 to 2007 using information about household income and parental educational levels at the person's 15th birthday. The association between childhood SES and MS was evaluated using MS incidence rate ratios with 95% confidence intervals obtained in log-linear Poisson regression analyses. We found no strong association between childhood SES and MS but did observe a tendency toward a reduced risk of MS among children from households with more highly educated parents, particularly mothers. Children whose mothers had a secondary (rate ratio = 0.95, 95% confidence interval: 0.86, 1.04) or higher (rate ratio = 0.86, 95% confidence interval: 0.76, 0.97) education had reduced risks of MS (5% and 14%, respectively) compared with children of mothers with a basic education (P for trend = 0.02). Results were practically unchanged in an analysis restricted to persons aged 15-29 years, among whom the possible effect of own SES on MS risk is considered limited. Overall, SES in childhood seems of no major importance for the subsequent risk of MS; however, offspring of well-educated mothers may be at a slightly reduced risk of MS.

[Neuromyelitis optica is a frequently seen inflammatory demyelinating disease]

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system with autoimmune characteristics. Serum immunoglobulin G autoantibodies have been identified in the majority of NMO patients with the water channel aquaporin-4 (AQP4) as their main target autoantigen. Clinical criteria have defined NMO and NMO-spectrum disease. The clinical features include inflammation of the optic nerve.

Childhood body mass index and multiple sclerosis risk: a long-term cohort study

BACKGROUND

Obesity in late adolescence has been associated with an increased risk of multiple sclerosis (MS); however, it is not known if body size in childhood is associated with MS risk.

METHODS

Using a prospective design we examined whether body mass index (BMI) at ages 7-13 years was associated with MS risk among 302,043 individuals in the Copenhagen School Health Records Register (CSHRR). Linking the CSHRR with the Danish MS registry yielded 774 MS cases (501 girls, 273 boys). We used Cox proportional hazards models to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Among girls, at each age 7-13 years, a one-unit increase in BMI z-score was associated with an increased risk of MS (HR(age 7)=1.20, 95% CI: 1.10-1.30; HR(age 13)=1.18, 95% CI: 1.08-1.28). Girls who were ≥95(th) percentile for BMI had a 1.61-1.95-fold increased risk of MS as compared to girls <85(th) percentile. The associations were attenuated in boys. The pooled HR for a one-unit increase in BMI z-score at age 7 years was 1.17 (95% CI: 1.09-1.26) and at age 13 years was 1.15 (95% CI: 1.07-1.24).

CONCLUSION

Having a high BMI in early life is a risk factor for MS, but the mechanisms underlying the association remain to be elucidated.

Cesarean section and offspring's risk of multiple sclerosis: a Danish nationwide cohort study

BACKGROUND

Apart from a recent study reporting a 2- to 3-fold increased risk of multiple sclerosis (MS) among women and men who were delivered by Cesarean section (C-section), little attention has been given to the possible association between mode of delivery and the risk of MS.

OBJECTIVES

We studied the association between C-section and risk of MS, in a cohort of 1.7 million Danes born from 1973 to 2005.

METHODS

Information on C-section and MS was obtained from the Danish Medical Birth Register and the Danish MS Register, respectively. The association between C-section and MS was evaluated by means of MS incidence rate ratios (RR) with 95% confidence intervals (CI) obtained in log-linear Poisson regression analyses.

RESULTS

There were 930 cases of MS in the study cohort, of whom 80 (9%) were delivered by C-section. Overall, we found there was no significant association between C-section and risk of MS (RR = 1.17; 0.92-1.46). Analyses stratified by sex revealed no unusual risk of MS for women (RR = 1.08: 0.80-1.42) nor men (RR = 1.37: 0.91-1.98). A supplementary sibling-matched Cox regression analysis likewise suggested there was no excess risk of MS in persons delivered by C-section (HR = 1.03; 0.63-1.69).

CONCLUSIONS

Mode of delivery appears to be unimportant in relation to MS development in the offspring.

Heat sensitive persons with multiple sclerosis are more tolerant to resistance exercise than to endurance exercise

Background:

Heat sensitivity (HS) is reported by 58% of all persons with multiple sclerosis (MS), causing symptom exacerbation possibly limiting exercise participation.

Objective:

The purpose of this study was to test the hypotheses that (a) a relationship between exercise-induced changes in core–temperature (Ctemp) and changes in symptom intensity exists, and (b) that resistance exercise (RE), as a consequence of a minor increase in core temperature, will induce a lesser worsening of symptoms than endurance exercise (EE) in HS persons with MS.

Methods:

On two separate days, 16 HS persons with MS randomly completed a session of RE and EE, or EE and RE, respectively. Testing was conducted pre, post and one hour after exercise and consisted of Visual Analogue Scale (VAS) scoring (fatigue, spasticity, pain, strength, walking and balance), the 5-time sit-to-stand (5STS), the Multiple Sclerosis Functional Composite (MSFC) and Body Sway. Composite scores describing average subjective symptom intensity (SI) and total number of symptoms (SN) were calculated from VAS scores.

Results:

Ctemp (0.9±0.4°C vs 0.3±0.1°C, p<0.001), SI (1.7±1.9 cm vs 0.6±1.5 cm, p<0.05) and SN (1.6±1.9 vs 0.6±2.1, p<0.05) increased significantly more during EE than RE. Changes in Ctemp correlated to changes in SI ( r=0.50, p<0.01). No differences were observed in 5STS, MSFC and Body Sway scores after EE when compared to RE.

Conclusion:

An exercise-induced increase in Ctemp is associated with increased number and severity of perceived symptoms in HS persons with MS. Based on these findings it is expected that HS persons with MS do tolerate RE better than EE.

A wireless body measurement system to study fatigue in multiple sclerosis

Fatigue is reported as the most common symptom by patients with multiple sclerosis (MS). The physiological and functional parameters related to fatigue in MS patients are currently not well established. A new wearable wireless body measurement system, named Fatigue Monitoring System (FAMOS), was developed to study fatigue in MS. It can continuously measure electrocardiogram, body-skin temperature, electromyogram and motions of feet. The goal of this study is to test the ability of distinguishing fatigued MS patients from healthy subjects by the use of FAMOS. This paper presents the realization of the measurement system including the design of both hardware and dedicated signal processing algorithms. Twenty-six participants including 17 MS patients with fatigue and 9 sex- and age-matched healthy controls were included in the study for continuous 24 h monitoring. The preliminary results show significant differences between fatigued MS patients and healthy controls. In conclusion, the FAMOS enables continuous data acquisition and estimation of multiple physiological and functional parameters. It provides a new, flexible and objective approach to study fatigue in MS, which can distinguish between fatigued MS patients and healthy controls. The usability and reliability of the FAMOS should however be further improved and validated through larger clinical trials.

Validity and variability of the 5-repetition sit-to-stand test in patients with multiple sclerosis

PURPOSE

To investigate; (i) the relationship between the 5STS-test and lower extremity muscle strength and balance, and (ii) the variability of the 5STS-test in multiple sclerosis (MS) patients.

METHOD

22 MS patients were divided into two groups (Group A and Group B) who completed one 5STS familiarization test session and two testing sessions. In Group A, session 1 also included assessment of lower extremity muscle strength. Session 2 and 3 involved completion of two 5STS-tests and assessment of balance. In Group B, session 2 and 3 involved completion of two rounds of two 5STS-tests separated by a 30 min break.

RESULTS

Significant correlations were found between the 5STS-test and isometric and isokinetic knee flexor and extensor muscle strength of the most affected leg (R = -0.60 to -0.77), and between the 5STS-test and balance performance (R = 0.69). Intra-assessor day-to-day variability, intra-assessor test-retest variability and intra-assessor variability within test were 25.5, 22.3, and 23.1%, respectively. Inter-assessor variability within test and inter-assessor variability were 23.4 and 5.9%, respectively.

CONCLUSIONS

The 5STS-test is related to lower extremity muscle strength and to balance performance in MS patients. For interventional purposes, a change of >25% can be regarded as a real change.

Mobile phones and multiple sclerosis--a nationwide cohort study in Denmark

We investigated the risk of, prognosis of and symptoms of multiple sclerosis (MS) among all Danish residents who owned a mobile phone subscription before 1996. Using the Danish Multiple Sclerosis Registry and Civil Registration System, study subjects were followed up for MS through 2004. Poisson models were used to calculate incidence rate ratios (IRR, age range: 18–64 years) and mortality rate ratios (MRR, age range: 18+) and to compare presenting symptoms among subscribers and all non-subscribers. A total of 405 971 subscription holders accrued four million years of follow up, with men accounting for 86% of the observation time. Among subscription holding men, the IRR of MS was close to unity, overall as well as 13+ years after first subscription (IRR 1.02, 95% CI: 0.48–2.16). Among women, the IRR was 3.43 (95% CI: 0.86–13.72) 13+ years after first subscription, however, based on only two cases. Presenting symptoms of MS differed between subscribers and non-subscribers (p = 0.03), with slightly increased risk of diplopia in both genders (IRR: 1.38, 95% CI: 1.02–1.86), an increased risk of fatigue among women (IRR: 3.02, 95% CI: 1.45–6.28), and of optic neuritis among men (IRR: 1.38, 95% CI: 1.03–1.86). Overall the MRR was close to one (MRR: 0.91, 95%CI 0.70–1.19) among MS-patients with a subscription and although we observed some increased MRR estimates among women, these were based on small numbers. In conclusion, we found little evidence for a pronounced association between mobile phone use and risk of MS or mortality rate among MS patients. Symptoms of MS differed between subscribers and nonsubscribers for symptoms previously suggested to be associated with mobile phone use. This deserves further attention, as does the increased long-term risk of MS among female subscribers, although small numbers and lack of consistency between genders prevent causal interpretation.

The risk of fracture in incident multiple sclerosis patients: The Danish National Health Registers

Background:

Patients with multiple sclerosis (MS) may be at increased risk of fractures owing to osteoporosis and falling.

Objective:

To evaluate the risk of fracture in incident MS patients drawn from a dedicated MS registry compared with population-based controls.

Methods:

We conducted a population-based cohort study (1996–2007) utilising the Danish National Health Registers that were linked to the Danish MS Registry and the Danish MS Treatment Registry. Incident MS patients (2963 cases) were 1:6 matched by year of birth, gender, calendar time and region to persons without MS (controls). Cox proportional hazards models and logistic regression were used to estimate the risk of fracture in MS. Time-dependent adjustments were made for age, history of diseases and drug use.

Results:

Compared with controls, patients with MS had no overall increased risk of fracture (adjusted hazard ratio (adj. HR): 1.0, 95% CI: 0.9–1.2). However, the risk of femur/hip fracture (adj. HR: 1.9, 95% CI: 1.1–3.4) was significantly increased compared to controls. As compared with unexposed patients, MS patients who had been exposed to a short course of methylprednisolone in the prior year had no significantly increased risk of osteoporotic fracture (adj. HR: 1.2, 95% CI: 0.5–2.9). Disabled MS patients with Expanded Disability Status Scale [EDSS] scores between 6 and 10, had a 2.6-fold increased risk of osteoporotic fracture (adjusted odds ratio (adj. OR): 2.6, 95% CI: 1.0–6.6) compared to patients with an EDSS score between 0 and 3.

Conclusion:

Patients with MS had a higher risk of femur/hip fracture than controls. Disability status is probably more important than glucocorticoid use in the aetiology of MS and osteoporotic fracture.