Cognitive function in relapsing multiple sclerosis: Minimal changes in a 10-year clinical trial

Predicting loss of employment over three years in multiple sclerosis: clinically meaningful cognitive decline

Cognitive dysfunction is common in multiple sclerosis (MS), yet the magnitude of change on objective neuropsychological (NP) tests that is clinically meaningful is unclear. We endeavored to determine NP markers of the transition from employment to work disability in MS, as indicated by degree of decline on individual tests. Participants were 97 employed MS patients followed over 41.3 ± 17.6 months with a NP battery covering six domains of cognitive function. Deterioration at follow-up was designated as documented and paid disability benefits (conservative definition) or a reduction in hours/work responsibilities (liberal definition). Using the conservative definition, 28.9% reported deteriorated employment status and for the liberal definition, 45.4%. The Symbol Digit Modalities Test (SDMT) and California Verbal Learning Test, Total Learning (CVLT2-TL) measures distinguished employed and disabled patients at follow-up. Controlling for demographic and MS characteristics, the odds ratio of a deterioration based on a change of 2.0 on the CVLT2-TL was 3.7 (95% CI 1.2-11.4 and SDMT by 4.0 was 4.2 (95% CI 1.2-14.8), accounting for 86.7% of the area under the ROC curve. We conclude that decline on NP testing over time is predictive of deterioration in vocational status, establishing a magnitude of decline on NP tests that is clinically meaningful.

Cognitive dysfunction in multiple sclerosis: the effect of pharmacological interventions

Research has recently focused on cognitive dysfunction in multiple sclerosis (MS). Cognitive deficits are frequently encountered in patients and account for important impairment in quality of life, therefore posing a major therapeutic challenge for the disease. We presently review studies on cognitive effects of pharmacological treatments in MS. There is evidence for a possible beneficial effect of immunomodulatory treatments, particularly of interferons, and also of acetylcholinesterase inhibitors on cognition in MS, which, however, requires evaluation in larger, multi-centre, longitudinal studies. Methodological issues and future prospects regarding the investigation of this issue are also discussed.

Assessment and rehabilitation of cognitive impairment in multiple sclerosis

Patients with multiple sclerosis (MS) have a substantial risk of cognitive dysfunction, even in the earliest stages of the disease, where there is minimum physical disability. Despite the high prevalence rates and the significant impact of cognitive dysfunction on quality of life in this population, cognitive functions are not routinely assessed due to the high cost and time consumption. This article provides an overview of the current state of knowledge related to cognition in MS and on the optimal approach to neuropsychological assessment of this population. It then focuses on the pharmacological and other treatment options available for MS patients with, or at risk for developing, cognitive impairment. The available immune-modulating agents may reduce the development of new lesions and therefore prevent or minimize the progression of cognitive decline. However, there is currently insufficient evidence concerning the efficiency of symptomatic treatment in MS. There is also currently no optimal non-pharmacological treatment strategy for cognitive decline in MS, as the studies published to date report heterogeneous results. Nevertheless, non-pharmacological treatments such as cognitive rehabilitation may benefit some MS patients. As cognition is increasingly recognized as a major feature of MS, its assessment and rehabilitation will become a greater priority.

BDNF+/- mice exhibit deficits in oligodendrocyte lineage cells of the basal forebrain

Previous work indicated that brain-derived neurotrophic factor (BDNF), through the trkB receptor, increases DNA synthesis in oligodendrocyte (OLG) progenitor cells (OPCs) and differentiation of postmitotic OLGs of the basal forebrain (BF). In the present studies, BDNF knockout animals were used to investigate BDNF's effects on OLG lineage cells (OLCs) in vivo. OLCs of the BF were found to express the trkB receptor, suggesting they are responsive to BDNF. Immunohistochemistry using NG2 and CC1 antibodies was utilized to examine the numbers of NG2+ OPCs and CC1+ postmitotic BF OLGs. At embryonic day 17 (E17), BDNF-/- animals display reduced NG2+ cells. This reduction was also observed in BDNF+/- mice at E17 and at postnatal day 1 (P1), P14, and adult stage, suggesting that BDNF plays a role in OPC development. BDNF+/- mice do not exhibit deficits in numbers of CC1+ OLGs. However, myelin basic protein, myelin associated glycoprotein, and proteolipid protein are reduced in BDNF+/- mice, suggesting that BDNF plays a role in differentiation. These data indicate that progenitor cells and myelin proteins may be affected in vivo by a decrease in BDNF.

Glatiramer acetate for multiple sclerosis

BACKGROUND

This is an updated Cochrane review of the previous version published (Cochrane Database of Systematic Reviews 2004 , Issue 1 . Art. No.: CD004678. DOI: 10.1002/14651858.CD004678)Previous studies have shown that glatiramer acetate (Copaxone (R)), a synthetic amino acid polymer is effective in experimental allergic encephalomyelitis (EAE), and improve the outcome of patients with multiple sclerosis (MS).

OBJECTIVES

To verify the clinical efficacy of glatiramer acetate in the treatment of MS patients with relapsing remitting (RR) and progressive (P) course.

SEARCH STRATEGY

We searched the Cochrane MS Group Trials Register (26 March 2009), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2009), MEDLINE (PubMed) (January 1966 to 26 March 2009), EMBASE (January 1988 to 26 March 2009) and hand searching of symposia reports (1990-2009).

SELECTION CRITERIA

All randomised controlled trials (RCTs) comparing glatiramer acetate and placebo in patients with definite MS, whatever the administration schedule and disease course, were eligible for this review.

DATA COLLECTION AND ANALYSIS

Both patients with RR and P MS were analysed. Study protocols were comparable across trials. No major flaws were found in methodological quality. However, efficacy of blinding should be balanced against side effects, including injection-site reactions.

MAIN RESULTS

Among 409 retrieved references, we identified 16 RCTs; six of them, published between 1987 and 2007, met the selection criteria and were included in this review. Five hundred and forty RR patients and 1049 PMS contributed to the analysis. In RR MS, a decrease in the mean EDSS score (-0.33 and -0.45), was found respectively at 2 years and 35 months without any significant effect on sustained disease progression. The reduction of mean number of relapse was evident at 1 year (-0.35 ) 2 years (-0.51 ) and 35 months (-0.64), but significant studies ' heterogeneity was found. The number of hospitalisations and steroid courses were significantly reduced. No benefit was shown in P MS patients. No major toxicity was found. The most common systemic adverse event was a transient and self-limiting patterned reaction of flushing, chest tightness, sweating, palpitations, anxiety. Local injection-site reactions were observed in up to a half of patients treated with glatiramer acetate, thus making a blind assessment of outcomes questionable.

AUTHORS' CONCLUSIONS

Glatiramer acetate did show a partial efficacy in RR MS in term of relapse -related clinical outcomes, without any significant effect on clinical progression of disease measured as sustained disability. The drug is not effective in progressive MS patients.

Effects of immunomodulatory treatment with subcutaneous interferon beta-1a oncognitive decline in mildly disabled patients with relapsing—remitting multiple sclerosis

The objective of this study was to assess the effects of subcutaneous (sc) interferon beta-1a (IFNβ-1a) on cognition in mildly disabled patients with relapsing—remitting multiple sclerosis (RRMS). Patients aged 18—50 years with RRMS (McDonald criteria; Expanded Disability Status Scale score ≤4.0) were assigned IFNβ therapy at the physician’s discretion and underwent standardized magnetic resonance imaging, neurological examination and neuropsychological testing at the baseline and regular intervals for up to three years.

This analysis included 459 patients who received sc IFNβ-1a (44 mcg: n = 236; 22 mcg: n = 223; three-year follow up was available for 318 patients). The hazard ratio for cognitive impairment over three years (44 mcg versus 22 mcg) was 0.68 (95% confidence interval [CI]: 0.480—0.972), suggesting a 32% lower risk with the higher dose treatment. At year 3, the proportion of patients who were cognitively impaired increased slightly from 23.5% at the baseline to 24.8% in the IFNβ-1a 22 mcg treatment group, but remained stable at 15.2% in the IFNβ-1a 44 mcg treatment group. The proportion of patients with cognitive impairment at year 3 was significantly higher in the 22 mcg group than in the 44 mcg group (P = 0.03), although a trend was also seen at the baseline (P = 0.058). Multivariate logistic regression (corrected for baseline cognitive deficits) indicated that treatment with the higher dose of IFNβ-1a was predictive of lower cognitive impairment at three years (odds ratio: 0.51, 95% CI: 0.26—0.99) compared with the lower dose of IFNβ-1a.

These findings suggest that sc IFNβ-1a may have dose-dependent cognitive benefits in mildly disabled patients with RRMS, and may support early initiation of high-dose IFNβ-1a treatment.

Cognitive impairment in multiple sclerosis

Multiple sclerosis (MS) is a progressive disease of the CNS that is characterised by widespread lesions in the brain and spinal cord. MS results in motor, cognitive, and neuropsychiatric symptoms, all of which can occur independently of one another. The common cognitive symptoms include deficits in complex attention, efficiency of information processing, executive functioning, processing speed, and long-term memory. These deficits detrimentally affect many aspects of daily life, such as the ability to run a household, participate fully in society, and maintain employment--factors that can all affect the overall quality of life of the patient. The increased use of neuroimaging techniques in patients with MS has advanced our understanding of structural and functional changes in the brain that are characteristic of this disease, although much remains to be learned. Moreover, examination of efforts to treat the cognitive deficits in MS is still in the early stages.

Cognitive impairment in multiple sclerosis

BACKGROUND

Cognitive impairment is increasingly being recognized as a common and disabling symptom of multiple sclerosis (MS) that contributes to poor quality of life in affected patients. Despite the high prevalence of cognitive impairment in MS, cognitive function is not assessed routinely in clinical practice or in clinical trials. The perception that cognitive assessments are costly, time-consuming, complicated, and difficult to administer and interpret has contributed, at least in part, to the failure to incorporate cognitive testing into standard clinical evaluation of patients with MS. Detailed studies of cognitive impairment in MS are rare and guidelines for the assessment of cognitive function in MS are lacking.

TREATMENT

How to manage cognitive decline in MS also requires further study. Licensed disease-modifying drug (DMD) treatments for MS reduce brain lesion development, and associations between brain lesions and cognitive performance have been reported, providing a rationale for DMD treatment of MS-associated cognitive impairment. There is some evidence for cognitive benefits of DMDs, but as few pivotal DMD trials included cognitive assessments, the effects of these agents on cognition are not fully understood and more studies are needed.

CONCLUSIONS

It is only through further studies that it will be possible to identify patients with, or at risk of, cognitive impairment and to provide appropriate therapy to limit the effects of this potentially devastating symptom.

Should SDMT substitute for PASAT in MSFC? A 5-year longitudinal study

BACKGROUND

The multiple sclerosis functional composite (MSFC) includes the Paced Auditory Serial Addition test (PASAT) as a measure of cognition.

OBJECTIVES AND METHODS

We compared the MSFC incorporating the Symbol Digit Modalities test (SDMT) (MSFC [sdmt]) to the usually applied MSFC (MSFC [pasat]) in a sample of 46 ptients with relapsing-remitting MS who were followed over a five-year period. Magnetic resonance imaging was performed at baseline.

RESULTS

The Expanded Disability Status scale (EDSS) deteriorated significantly over 5 years (P < 0.01), but MSFC scores remained stable. MSFC [sdmt] correlated with EDSS at all time points of evaluation, but MSFC [pasat] correlated with EDSS only at baseline, 1, and 5 years. The 5-year EDSS correlated significantly with baseline MSFC [sdmt] and MSFC [pasat] but did not correlate after adjustment for baseline EDSS. No significant correlation was found at baseline between MSFC and imaging parameters (lesion load, brain parenchymal fraction [BPF], ventricular fraction, mean magnetization transfer ratio of lesions and normal-appearing brain tissue), but baseline BPF correlated significantly with changes of SDMT z score (P = 0.0003), MSFC [pasat] (P = 0.006), and MSFC [sdmt] (P = 0.0002) over 5 years.

CONCLUSION

We propose not to substitute PASAT by SDMT in the MSFC but to consider SDMT as a complementary useful approach to evaluate overall MS disease.

Memory decline evolves independently of disease activity in MS

Background

The natural history of cognitive impairment in multiple sclerosis (MS) and its relationship with disease activity is not well known. In this study, we evaluate a prospective cohort of 44 MS patients who were followed every 3 months for 2 years. Cognitive evaluation was done at baseline and by the end of the study using the Brief Repeatable Battery-Neuropsychology. Clinical evaluation included assessment of new relapses and changes in disability (Extended Disability Status Scale (EDSS)) confirmed at 6 months.

Results

We found that verbal memory performance deteriorates after 2 years in patients with MS. These changes were observed in stable and active patients both in terms of relapses and disability progression, even at the beginning of the disease, and in patients with or without cognitive impairment at study entry. Attention and executive functions measured with the symbol digit modality test (SDMT) declined after 2 years in patients with confirmed disability progression. Furthermore, SDMT performance correlated with the EDSS change.

Conclusions

Our findings indicate that verbal memory steadily declines in patients with MS from the beginning of the disease and independently of other parameters of disease activity.

Prise en charge thérapeutique des troubles cognitifs dans la sclérose en plaques : données et perspectives

Taking in charge cognitive disorders is a new concept in the global care of MS patients. Cognitive disorders are observed in the all forms of the disease, sometimes early on in the evolution. These disorders can be evaluated in details even detected despite any complain in the patient. Because of the lack of clear demonstration that disease-modifying treatments could act on cognition, new specific therapeutic issues have emerged during last years. This article first discusses relationships between disease-modifying treatments and cognition for the different forms of the disease, then analyse the effects of symptomatic drug therapy especially the use of anticholinesterasics. In the last part of the article new issues about antagonists of excitatory amino-acids and individual or group cognitive training are discussed. Recent functional imaging data concerning cerebral adaptation and their modifications by drug or non-drug procedures in MS patients suggest interesting therapeutic development in a next future.