Cognitive impairment in early stages of multiple sclerosis

Eye and hand motor interactions with the Symbol Digit Modalities Test in early multiple sclerosis

PURPOSE

Eye and hand motor dysfunction may be present early in the disease course of relapsing-remitting multiple sclerosis (RRMS), and can affect the results on visual and written cognitive tests. We aimed to test for differences in saccadic initiation time (SI time) between RRMS patients and healthy controls, and whether SI time and hand motor speed interacted with the written version of the Symbol Digit Modalities Test (wSDMT).

METHODS

Patients with RRMS (N = 44, age 35.1 ± 7.3 years), time since diagnosis < 3 years and matched controls (N = 41, age 33.2 ± 6.8 years) were examined with ophthalmological, neurological and neuropsychological tests, as well as structural MRI (white matter lesion load (WMLL) and brainstem lesions), visual evoked potentials (VEP) and eye-tracker examinations of saccades.

RESULTS

SI time was longer in RRMS than controls (p < 0.05). SI time was not related to the Paced Auditory Serial Addition Test (PASAT), WMLL or to the presence of brainstem lesions. 9 hole peg test (9HP) correlated significantly with WMLL (r = 0.58, p < 0.01). Both SI time and 9HP correlated negatively with the results of wSDMT (r = -0.32, p < 0.05, r = -0.47, p < 0.01), but none correlated with the results of PASAT.

CONCLUSIONS

RRMS patients have an increased SI time compared to controls. Cognitive tests results, exemplified by the wSDMT, may be confounded by eye and hand motor function.

Clinical and cognitive implications of cerebrospinal fluid oligoclonal bands in multiple sclerosis patients

The presence of cerebrospinal fluid oligoclonal bands (CSF-OCB) in Caucasian patients with multiple sclerosis (MS) is supportive of diagnosis, though the relation with patients' clinical and specifically cognitive features has never been established or thoroughly examined. Thus, we investigated the clinical and for the first time the cognitive profile of MS patients in relation to CSF-OCB. We studied 108 patients with and without OCB and recorded demographic characteristics and detailed clinical data. A comprehensive neuropsychological battery covering different cognitive domains (attention/processing speed, memory, perception/constructions, reasoning, executive functions) was administered to MS patients and 142 demographically related healthy controls (HC). We did not find any significant differences between patients with and without OCB on demographic and clinical parameters (p > 0.05), including subtype and brain neuroimaging findings. Results revealed significantly higher cognitive scores in HC compared to both OCB subgroups, with more widespread cognitive changes in patients with OCB. Analysis between OCB subgroups showed significantly worse performance in patients with OCB on visual memory (Rey's complex figure test-recall; p = 0.006). Concluding, the presence of CSF-OCB in our MS patients tends to be related to more widespread cognitive changes, specifically worse visual memory. Future longitudinal studies in different populations are warranted to better clarify the clinical and cognitive characteristics related to CSF-OCB which could serve as early biomarker in disease monitoring.

Ocular motor measures of cognitive dysfunction in multiple sclerosis I: inhibitory control

Our ability to control and inhibit behaviours that are inappropriate, unsafe, or no longer required is crucial for functioning successfully in complex environments. Here, we investigated whether a series of ocular motor (OM) inhibition tasks could dissociate deficits in patients with multiple sclerosis (MS), including patients with only a probable diagnosis (clinically isolated syndrome: CIS), from healthy individuals as well as a function of increasing disease duration. 25 patients with CIS, 25 early clinically definite MS patients (CDMS: ≤7 years of diagnosis), 24 late CDMS patients (>7 years from diagnosis), and 25 healthy controls participated. All participants completed a series of classic OM inhibition tasks [antisaccade (AS) task, memory-guided (MG) task, endogenous cue task], and a neuropsychological inhibition task [paced auditory serial addition test (PASAT)]. Clinical disability was characterised in CDMS patients using the Expanded Disability Severity Scale (EDSS). OM (latency and error) and PASAT performance were compared between patient groups and controls, as well as a function of disease duration. For CDMS patients only, results were correlated with EDSS score. All patient groups made more errors than controls on all OM tasks; error rate did not increase with increasing disease duration. In contrast, saccade latency (MG and endogenous cue tasks) was found to worsen with increasing disease duration. PASAT performance did not discriminate patient groups or disease duration. The EDSS did not correlate with any measure. These OM measures appear to dissociate deficit between patients at different disease durations. This suggests their utility as a measure of progression from the earliest inception of the disease.

Hippocampal function is compromised in an animal model of multiple sclerosis

Multiple sclerosis (MS) is a progressive inflammatory autoimmune disease that is characterized by demyelination and axonal damage in the nervous system. One obvious consequence is a cumulative loss of muscle control. However, cognitive dysfunction affects roughly half of MS sufferers, sometimes already early in the disease course. Although long-term (remote) memory is typically unaffected, the ability to form new declarative memories becomes compromised. A major structure for the encoding of new declarative memories is the hippocampus. Encoding is believed to be mediated by synaptic plasticity in the form of long-term potentiation (LTP) and long-term depression (LTD) of synaptic strength. Here, in an animal model of MS we explored whether disease symptoms are accompanied by a loss of functional neuronal integrity, synaptic plasticity, or hippocampus-dependent learning ability. In mice that developed MOG35-55-induced experimental autoimmune encephalomyelitis (EAE), passive properties of CA1 pyramidal neurons were unaffected, although the ability to fire action potentials became reduced in the late phase of EAE. LTP remained normal in the early phase of MOG35-55-induced EAE. However, in the late phase, LTP was impaired and LTP-related spatial memory was impaired. In contrast, LTD and hippocampus-dependent object recognition memory were unaffected. These data suggest that in an animal model of MS hippocampal function becomes compromised as the disease progresses.

Predictive value of different conventional and non-conventional MRI-parameters for specific domains of cognitive function in multiple sclerosis

Objective

While many studies correlated cognitive function with changes in brain morphology in multiple sclerosis (MS), few of them used a multi-parametric approach in a single dataset so far. We thus here assessed the predictive value of different conventional and quantitative MRI-parameters both for overall and domain-specific cognitive performance in MS patients from a single center.

Methods

69 patients (17 clinically isolated syndrome, 47 relapsing–remitting MS, 5 secondary-progressive MS) underwent the “Brief Repeatable Battery of Neuropsychological Tests” assessing overall cognition, cognitive efficiency and memory function as well as MRI at 3 Tesla to obtain T2-lesion load (T2-LL), normalized brain volume (global brain volume loss), normalized cortical volume (NCV), normalized thalamic volume (NTV), normalized hippocampal volume (NHV), normalized caudate nuclei volume (NCNV), basal ganglia R2* values (iron deposition) and magnetization transfer ratios (MTRs) for cortex and normal appearing brain tissue (NABT).

Results

Regression models including clinical, demographic variables and MRI-parameters explained 22–27% of variance of overall cognition, 17–26% of cognitive efficiency and 22–23% of memory. NCV, T2-LL and MTR of NABT were the strongest predictors of overall cognitive function. Cognitive efficiency was best predicted by NCV, T2-LL and iron deposition in the basal ganglia. NTV was the strongest predictor for memory function and NHV was particularly related to memory function.

Conclusions

The predictive value of distinct MRI-parameters differs for specific domains of cognitive function, with a greater impact of cortical volume, focal and diffuse white matter abnormalities on overall cognitive function, an additional role of basal ganglia iron deposition on cognitive efficiency, and thalamic and hippocampal volume on memory function. This suggests the usefulness of using multiparametric MRI to assess (micro)structural correlates of different cognitive constructs.

•

The predictive value of MRI-parameters for cognition was assessed in 69 MS-patients.

•

Cortical volume and focal white matter lesions predict overall cognitive function.

•

T2-lesion load is a strong predictor for cognition (overall and specific domains).

•

Cortical volume and basal ganglia iron deposition predict cognitive efficiency.

•

Thalamic volume, MTR of NABT and hippocampal volume predict memory function.

A randomized, controlled, single-blind, 6-month pilot study to evaluate the efficacy of MS-Line!: a cognitive rehabilitation programme for patients with multiple sclerosis

Background:

MS-Line! was created to provide an effective treatment for cognitive impairment in multiple sclerosis (MS) patients.

Objective:

To assess the efficacy of MS-Line!.

Methods:

A randomized, controlled, single-blind, 6-month pilot study. Patients were randomly assigned to an experimental group (cognitive rehabilitation with the programme) or to a control group (no cognitive rehabilitation). Randomization was stratified by cognitive impairment level. Cognitive assessment included: selective reminding test, 10/36 spatial recall test (10/36 SPART), symbol digit modalities test, paced auditory serial addition test, word list generation (WLG), FAS test, subtests of WAIS-III, Boston naming test (BNT), and trail making test (TMT).

Results:

Forty-three patients (22 in the experimental group, 21 in the control group) were analyzed. Covariance analysis showed significant differences in 10/36 SPART ( P=0.0002), 10/36 SPART delayed recall ( P=0.0021), WLG ( P=0.0123), LNS ( P=0.0413), BNT ( P=0.0007) and TMT-A ( P=0.010) scores between groups.

Conclusions:

The study showed a significant improvement related to learning and visual memory, executive functions, attention and information processing speed, and naming ability in those patients who received cognitive rehabilitation. The results suggest that MS-Line! is effective in improving cognitive impairment in MS patients.

School performance as a marker of cognitive decline prior to diagnosis of multiple sclerosis

Background:

For many years, cognitive impairment has been established as a well-known symptom of multiple sclerosis. Moreover, we know that it was present even at the beginning of the disease.

Objective:

In this case-control study, we decided to evaluate whether there is an impairment of cognitive functions even before onset in those patients who will eventually suffer from multiple sclerosis.

Methods:

We evaluated the overall school performance, and particularly school performance in math and language in a group of patients who would later develop the disease and we compared our findings with a control group.

Results:

We found that school performance was poorer in subjects who were to become patients. And we found that the later the start of the first symptom, the better the qualifications.

Conclusion:

Testing a premorbid cognitive deficit by a validated indirect evaluation method allowed us to verify that there was evidence of neurological compromise even before a clinical diagnosis or the completion of the first magnetic resonance imaging in patients who would then suffer from multiple sclerosis.

The impact of dynamic balance measures on walking performance in multiple sclerosis

BACKGROUND

Static posture imbalance and gait dysfunction are common in individuals with multiple sclerosis (MS). Although the impact of strength and static balance on walking has been examined, the impact of dynamic standing balance on walking in MS remains unclear.

OBJECTIVE

To determine the impact of dynamic balance, static balance, sensation, and strength measures on walking in individuals with MS.

METHODS

Fifty-two individuals with MS (27 women; 26 relapsing-remitting; mean age = 45.6 ± 10.3 years; median Expanded Disability Status Scale score = 3.5) participated in posturography testing (Kistler-9281 force plate), hip flexion, hip extension, ankle dorsiflexion strength (Microfet2 hand-held dynamometer), sensation (Vibratron II), and walk velocity (Optotrak Motion Analysis System). Analyses included, Mann-Whitney, Spearman correlation coefficients, and multiple regression.

RESULTS

All measures were abnormal in individuals with MS when compared with norms (P < .05). Static balance (eyes open, feet together [EOFT]), anterior-posterior (AP) dynamic sway, and hip extension strength were strongly correlated with walking velocity (AP sway r = 0.68; hip extension strength r = 0.73; EOFT r = -0.40). Together, AP dynamic sway (ρr = 0.71; P < .001), hip extension strength (ρr = 0.54; P < .001), and EOFT static balance (ρr = -0.41; P = .01) explained more than 70% of the variance in walking velocity (P < .001).

CONCLUSIONS

AP dynamic sway affects walking performance in MS. A combined evaluation of dynamic balance, static balance, and strength may lead to a better understanding of walking mechanisms and the development of strategies to improve walking.

Assessment of early cognitive impairment in patients with clinically isolated syndromes and multiple sclerosis

Objective. The aim of our study was to investigate the frequency and pattern of cognitive impairment in patients with clinically isolated syndromes and definite diagnosis of multiple sclerosis within the last 2 years. Methods. We assessed the cognitive status of 46 patients aged 18–49 years with clinically isolated syndromes or definite diagnosis of multiple sclerosis who have onset of their symptoms within the last 2 years. Patients were matched with 40 healthy participants for age, sex, and educational level. Neuropsychological assessment was performed by stroop test, paced auditory serial addition test (PASAT), controlled oral word association test (COWAT), clock drawing test, trail making test (TMT), faces symbol test (FST). Hamilton Depression Scale and Modified Fatigue Impact Scale were used to quantify the severity of any depression and fatigue the subjects might suffer. Results. 19.6% of early MS/CIS group failed at 4 and more tests and had significant cognitive impairment focused on attention, executive functions, memory, and learning. No significant relationship was found between cognitive impairment and disability and fatigue scores. Discussion. Cognitive impairment can be present from the earliest stage of multiple sclerosis. It should be considered among the main manifestations of MS even in the earliest stages of the disease.

Brain networks disconnection in early multiple sclerosis cognitive deficits: an anatomofunctional study

Severe cognitive impairment involving multiple cognitive domains can occur early during the course of multiple sclerosis (MS). We investigated resting state functional connectivity changes in large-scale brain networks and related structural damage underlying cognitive dysfunction in patients with early MS. Patients with relapsing MS (3-5 years disease duration) were prospectively assigned to two groups based on a standardized neuropsychological evaluation: (1) cognitively impaired group (CI group, n = 15), with abnormal performances in at least 3 tests; (2) cognitively preserved group (CP group, n = 20) with normal performances in all tests. Patients and age-matched healthy controls underwent a multimodal 3T magnetic resonance imaging (MRI) including anatomical T1 and T2 images, diffusion imaging and resting state functional MRI. Structural MRI analysis revealed that CI patients had a higher white matter lesion load compared to CP and a more severe atrophy in gray matter regions highly connected to networks involved in cognition. Functional connectivity measured by integration was increased in CP patients versus controls in attentional networks (ATT), while integration was decreased in CI patients compared to CP both in the default mode network (DMN) and ATT. An anatomofunctional study within the DMN revealed that functional connectivity was mostly altered between the medial prefrontal cortex (MPFC) and the posterior cingulate cortex (PCC) in CI patients compared to CP and controls. In a multilinear regression model, functional correlation between MPFC and PCC was best predicted by PCC atrophy. Disconnection in the DMN and ATT networks may deprive the brain of compensatory mechanisms required to face widespread structural damage.

Comparing long-term results of PASAT and SDMT scores in relation to neuropsychological testing in multiple sclerosis

Background and objectives:

The Symbol Digit Modalities Test (SDMT) shows advantages over the Paced Auditory Serial Addition Test (PASAT) as a cognitive test in patients with multiple sclerosis (MS). To determine which of these tests is most valid and reliable over time as an indicator of the cognitive state of MS patients, long-term test results of both tests were compared in relation to scores of the Brief Repeatable Battery of Neuropsychological tests (BRBN).

Methods:

For 485 MS patients visiting the VU University Medical Center Amsterdam for different research projects, a total number of 1078 visits with BRBN (including PASAT and SDMT) was planned. Observed and model-based correlations were used to calculate the construct validity of the SDMT and PASAT 3 seconds test (PASAT3) by comparing correlations with the BRBN-sumscore. The test-retest reliability of each test was also computed.

Results:

For the construct validity, higher correlations were found between SDMT and BRBN compared to PASAT3 and BRBN, especially for the model-based correlations at baseline. The reliability of the measurements was good for all instruments, with the highest coefficients for the SDMT.

Conclusion:

As a single assessment tool for cognition in MS, the SDMT is more valid and reliable compared to PASAT3.

Cognition in early relapsing-remitting multiple sclerosis: consequences may be relative to working memory

The Relative Consequence Model proposes multiple sclerosis (MS) patients have a fundamental deficit in processing speed that compromises other cognitive functions. The present study examined the mediating role of processing speed,as well as working memory, in the MS-related effects on other cognitive functions for early relapsing-remitting patients. Seventy relapsing-remitting MS patients with disease duration not greater than 10 years and 72 controls completed tasks assessing processing speed, working memory, learning, and executive functioning. The possible mediating roles of speed and working memory in the MS-related effects on other cognitive functions were evaluated using structural equation modeling. Processing speed was not significantly related to group membership and could not have a mediating role. Working memory was related to group membership and functioned as a mediating/intervening factor. The results do not support the Relative Consequence Model in this sample and they challenge the notion that working memory impairment only emerges at later disease stages. The results do support a mediating/intervening role of working memory. These results were obtained for early relapsing-remitting MS patients and should not be generalized to the broader MS population. Instead, future research should examine the relations that exist at other disease stages.

General fluid-type intelligence is related to indices of white matter structure in middle-aged and old adults

General fluid-type intelligence (gF) reflects abstract reasoning and problem solving abilities, and is an important predictor for lifetime trajectories of cognition, and physical and mental health. Structural and functional neuroimaging studies have demonstrated the role of parieto-frontal gray matter, but the white matter (WM) underpinnings of gF and the contribution of individual gF components to gF-WM relationship still need to be explored. The aim of this study was to characterize, in a sample of 100 healthy middle-aged and old subjects (mean=63.8 years), the relationship between gF and indices of WM structure obtained from diffusion tensor magnetic resonance imaging (DT-MRI) (fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD)). gF was estimated by principal component analysis including measures of episodic memory, reasoning, and processing speed. Tract-based spatial statistics and permutation-based inference statistics were used to test the association between gF and WM indices, while controlling for the effect of age and sex. We hypothesized a positive relationship between gF and WM structure. Based on previous studies, we further hypothesized that this relationship was heavily influenced by the processing speed component of gF. We found a robust relationship between gF and DT-MRI measures of FA, RD and MD in all major WM tracts. Higher gF score was related to higher degree of WM integrity, in middle-aged as well as old individuals. Thus, the distributed relationship between gF and indices of WM microstructure is consistent with the notion that gF reflects efficient signaling between cortical areas. Furthermore, analysis of relationships between WM measures and gF components revealed an association with information processing speed and reasoning ability, but not with episodic memory. Thus, although all subcomponents loaded high on gF factor, the speed-related components were most strongly associated with DT-MRI-derived measures. These results suggest that DT-MRI can be used to parse gF.

Cognitive impairment and its relation to imaging measures in multiple sclerosis: a study using a computerized battery

BACKGROUND AND PURPOSE

Cognitive impairment (CI) is an important component of multiple sclerosis (MS) disability. A complex biological interplay between white matter (WM) and gray matter (GM) disease likely sustains CI. This study aims to address this issue by exploring the association between the extent of normal WM and GM disease and CI.

METHODS

Cognitive function of 24 MS patients and 24 healthy volunteers (HVs) was studied using the Automated Neuropsychological Assessment Metrics (ANAM) battery. WM focal lesions and normal appearing WM (NAWM) volume in patients, cortical thickness (CTh) and deep GM structure volumes in both patients and HVs were measured by high field strength (3.0-Tesla; 3T) imaging.

RESULTS

An analysis of covariance showed that patients performed worse than HVs on Code Substitution Delayed Memory (P = .04) and Procedural Reaction Time (P = .05) indicative of reduced performance in memory, cognitive flexibility, and processing speed. A summary score (Index of Cognitive Efficiency) indicating global test battery performance was also lower for the patient group (P = .04). Significant associations, as determined by the Spearman rank correlation tests, were noted between each of these 3 cognitive scores and measures of NAWM volume [CDD-TP1(r = .609; P = .0035), PRO-TP1 (r = .456; P = .029) and ICE (r = .489; P = .0129)], CTh (r = .5; P ≤ .05) and volume of subcortical normal appearing GM (NAGM) structures (r = .4; P≤ .04), but not WM lesions.

CONCLUSIONS

Both NAWM and NAGM volumes are related to CI in MS. The results highlight once again the urgent need to develop pharmacological strategies protecting patients from widespread neurodegeneration as possible preventive strategies of CI development.

Therapeutic testosterone administration preserves excitatory synaptic transmission in the hippocampus during autoimmune demyelinating disease

Over 50% of multiple sclerosis (MS) patients experience cognitive deficits, and hippocampal-dependent memory impairment has been reported in >30% of these patients. While postmortem pathology studies and in vivo magnetic resonance imaging demonstrate that the hippocampus is targeted in MS, the neuropathology underlying hippocampal dysfunction remains unknown. Furthermore, there are no treatments available to date to effectively prevent neurodegeneration and associated cognitive dysfunction in MS. We have recently demonstrated that the hippocampus is also targeted in experimental autoimmune encephalomyelitis (EAE), the most widely used animal model of MS. The objective of this study was to assess whether a candidate treatment (testosterone) could prevent hippocampal synaptic dysfunction and underlying pathology when administered in either a preventative or a therapeutic (postdisease induction) manner. Electrophysiological studies revealed impairments in basal excitatory synaptic transmission that involved both AMPA receptor-mediated changes in synaptic currents, and faster decay rates of NMDA receptor-mediated currents in mice with EAE. Neuropathology revealed atrophy of the pyramidal and dendritic layers of hippocampal CA1, decreased presynaptic (Synapsin-1) and postsynaptic (postsynaptic density 95; PSD-95) staining, diffuse demyelination, and microglial activation. Testosterone treatment administered either before or after disease induction restores excitatory synaptic transmission as well as presynaptic and postsynaptic protein levels within the hippocampus. Furthermore, cross-modality correlations demonstrate that fluctuations in EPSPs are significantly correlated to changes in postsynaptic protein levels and suggest that PSD-95 is a neuropathological substrate to impaired synaptic transmission in the hippocampus during EAE. This is the first report demonstrating that testosterone is a viable therapeutic treatment option that can restore both hippocampal function and disease-associated pathology that occur during autoimmune disease.

Pediatric multiple sclerosis

Pediatric multiple sclerosis has been increasingly recognized in the past 10 to 15 years; 3% to 5% of all multiple sclerosis patients experience their first attack in childhood. Childhood multiple sclerosis has a relapsing-remitting disease course. The first attack, or "acquired demyelinating syndrome," consists of optic neuritis, transverse myelitis, acute disseminated encephalomyelitis, and monofocal or polyfocal neurological deficits. The diagnosis of multiple sclerosis necessitates the clinical or magnetic resonance imaging confirmation of dissemination in space and time and exclusion of other disorders. The morbidity of childhood multiple sclerosis is significant; within the first 2 years from onset, 30% of children have significant cognitive impairment, 50% show signs of depression, and 75% are fatigued. The relapse rate in children with multiple sclerosis is higher than in adult-onset disease. Following acute treatment, recovery after the first attacks is usually excellent, but patients with childhood-onset multiple sclerosis reach permanent disability or enter the secondary progressive disease course 10 years younger than patients with adult-onset multiple sclerosis.

The puzzle of multiple sclerosis: gray matter finds its place

The way we think of multiple sclerosis (MS) pathology has significantly changed over the last 10 years. Several studies clearly indicate that MS has to be considered a gray and white matter disease, where gray matter pathology probably plays a relevant role in determining physical and cognitive disability. The reviewed article presents new cross-sectional data on gray matter and white matter volumes across different MS phenotypes in a very large group of MS patients. In their study, the authors confirm an early and substantial deterioration of gray matter in MS and the evidence of a primary role of gray matter atrophy in the progression of clinical and cognitive disability. Another preliminary exciting step has therefore been taken toward the comprehension of the MS puzzle.

Functional adaptive changes within the hippocampal memory system of patients with multiple sclerosis

Memory deficits are highly prevalent in multiple sclerosis (MS). As the hippocampus is crucial to memory processing, a functional magnetic resonance imaging (fMRI) task was used to investigate changes in hippocampal function in MS patients with and without cognitive decline. Fifty patients with MS, (34 cognitively preserved (CP) and 16 cognitively impaired (CI)) and 30 healthy controls completed an episodic memory fMRI task (encoding and retrieval) that was used to specifically activate the hippocampus. During encoding of correctly remembered items, increased brain activation was seen in the parahippocampal areas bilaterally and in the left anterior cingulate gyrus in the CP patients compared to the controls (unclustered, Z ≥ 3.1, P ≤ 0.001). No brain areas showed less activation. In CI patients the right (para)hippocampal areas and the prefrontal cortex showed less brain activation compared to controls (cluster-corrected, P < 0.05). The posterior cingulate gyrus and the left precuneus showed increased activation in CI patients when compared to controls (unclustered Z ≥ 3.1, P ≤ 0.001). No significant differences were found on structural MRI measures between the CP and CI patients. These results suggest the presence of functional adaptation in the memory network before cognitive decline becomes evident in MS, as displayed by the increased brain activation in the hippocampal-cingulate memory system in CP patients. Interestingly, CI patients showed less activation in the hippocampal network during correct encoding. These findings are important for future cognitive therapeutic studies, since cognitive intervention might be most effective before cognitive impairment is present and when adaptive changes of the brain are most prominent.

Symptomatic management in multiple sclerosis

The development of immunomodulatory therapies for multiple sclerosis (MS) has had significant impact in altering the natural history of the disease. Although these agents reduce relapse rate and MRI-associated disease activity, they are only partially effective and do not ameliorate irreversible axonal injury, which produces much of the symptomatic burden of MS. Treatment of MS-associated symptoms remains an essential cornerstone of comprehensive care of patients with MS and, arguably, more favorably enhances quality of life than do the disease-modifying medications. This article reviews strategies of symptom management in patients with MS.

New methods for multiple sclerosis drug discovery

INTRODUCTION

MS is a heterogeneous disorder that requires the development of better diagnostics to identify disease subtypes enabling appropriate therapeutic intervention at an early stage of the disease. Accumulating evidence indicates that members of the inhibitor of apoptosis (IAP) family play an important role in the pathogenesis of MS by reducing the apoptotic elimination of autoreactive immune cells.

AREAS COVERED

The authors describe improved animal modeling strategies to identify compounds that have immunomodulatory, neurorestorative and neuroprotective properties. In addition, the authors propose new approaches to better model cognitive dysfunction in MS, which will aid the development of novel therapeutics for this complex disorder. The paper provides the reader with an appreciation for the diagnostic and therapeutic potential of apoptosis-related proteins for MS.

EXPERT OPINION

Recent evidence suggests that increased resistance of autoreactive immune cells to apoptotic elimination is a contributing factor to both disease susceptibility and progression in MS. This occurs, at least in part, because of elevated levels of the IAP family of anti-apoptotic genes that display distinct expression profiles associated with different subtypes of MS. The authors believe that the detection and targeting of members of the IAP family can provide better drugs for MS. Particularly, the authors feel that the overexpression of IAPs in animal models can provide novel insights into MS for both its pathogenesis and the discovery of new lead compounds.