Copy number variation in pediatric multiple sclerosis

BACKGROUND

Pediatric onset multiple sclerosis (MS) accounts for 2-4% of all MS. It is unknown whether the disease shares the same underlying pathophysiology found in adult patients or an extreme early onset phenotype triggered by distinct biological mechanisms. It has been hypothesized that copy number variations (CNVs) may result in extreme early onset diseases because CNVs can have major effects on many genes in large genomic regions.

OBJECTIVES AND METHODS

The objective of the current research was to identify CNVs, with a specific focus on de novo CNVs, potentially causing early onset MS by competitively hybridizing 30 white non-Hispanic pediatric MS patients with each of their parents via comparative genomic hybridization (CGH) analysis on the Agilent 1M CGH array.

RESULTS AND DISCUSSION

We identified 10 CNVs not overlapping with any CNV regions currently reported in the Database of Genomic Variants (DGV). Fifty-five putatively de novo CNVs were also identified: all but one common in the DGV. We found the single rare CNV was a private variation harboring the SACS gene. SACS mutations cause autosomal-recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) disease. Additional clinical review revealed that the patient with the SACS gene CNV shared some features of both MS and ARSACS.

CONCLUSIONS

This is the first reported study analyzing pediatric MS CNVs. While not yielding causal variation in our initial pediatric dataset, our approach confirmed diagnosis of an ARSACS-like disease in addition to MS in the affected individual, which led to a more complete understanding of the patient's disease course and prognosis.

Unemployment in multiple sclerosis: the contribution of personality and disease

BACKGROUND

Multiple sclerosis (MS) is the leading cause of neurological disability among young and middle-aged adults. One of the most devastating consequences of MS in this relatively young population group is unemployment. Although certain demographic and disease factors have been associated with employment, few studies have examined the contribution of person-specific factors, such as personality.

OBJECTIVE

The goal of this study was to determine the extent to which personality, demographics, and clinical measures contribute to unemployment in MS.

METHOD

A total of 101 individuals with MS who were enrolled in a clinical trial on cognition underwent a brief neuropsychological battery and completed questionnaires related to vocation, mood, fatigue, and personality. Neurological impairment was measured with the Expanded Disability Status Scale (EDSS).

RESULTS

Employment status was related with disease duration, MS subtype, level of neurological impairment, fatigue, performance on measures assessing information processing speed (Symbol Digit Modalities Test (SDMT)), learning and memory (Selective Reminding Test), and the personality characteristic of persistence. Based on a forward logistic regression analysis, EDSS, SDMT, and persistence were the strongest predictors of employment status.

CONCLUSIONS

These findings underscore the importance of personality on outcomes in MS and point to the need for more clinical attention and research in this area.

Multiple white matter tract abnormalities underlie cognitive impairment in RRMS

Diffusion tensor imaging (DTI) is a sensitive tool for detecting microstructural tissue damage in vivo. In this study, we investigated DTI abnormalities in individuals with relapsing remitting multiple sclerosis (RRMS) and examined the relations between imaging-based measures of white matter injury and cognitive impairment. DTI-derived metrics using tract-based spatial statistics (TBSS) were compared between 37 individuals with RRMS and 20 healthy controls. Cognitive impairment was assessed with three standard tests: the Symbol Digit Modalities Test (SDMT), which measures cognitive processing speed and visual working memory, the Rey Auditory Verbal Learning Test (RAVLT), which examines verbal memory, and the Paced Auditory Serial Addition Test (PASAT), which assesses sustained attention and working memory. Correlations between DTI-metrics and cognition were explored in regions demonstrating significant differences between the RRMS patients and the control group. Lower fractional anisotropy (FA) was found in RRMS participants compared to controls across the tract skeleton (0.40 ± 0.03 vs. 0.43 ± 0.01, p<0.01). In areas of reduced FA, mean diffusivity was increased and was dominated by increased radial diffusivity with no significant change in axial diffusivity, an indication of the role of damage to CNS myelin in MS pathology. In the RRMS group, voxelwise correlations were found between FA reduction and cognitive impairment in cognitively-relevant tracts, predominantly in the posterior thalamic radiation, the sagittal stratum, and the corpus callosum; the strongest correlations were with SDMT measures, with contributions to these associations from both lesion and normal-appearing white matter. Moreover, results using threshold-free cluster enhancement (TFCE) showed more widespread white matter involvement compared to cluster-based thresholding. These findings indicate the important role for DTI in delineating mechanisms underlying MS-associated cognitive impairment and suggest that DTI could play a critical role in monitoring the clinical and cognitive effects of the disease.

Multicenter randomized clinical trial of donepezil for memory impairment in multiple sclerosis

OBJECTIVES

The goal of this study was to determine if memory would be improved by donepezil as compared to placebo in a multicenter, double-blind, randomized clinical trial (RCT).

METHODS

Donepezil 10 mg daily was compared to placebo to treat memory impairment. Eligibility criteria included the following: age 18-59 years, clinically definite multiple sclerosis (MS), and performance ≤ ½ SD below published norms on the Rey Auditory Verbal Learning Test (RAVLT). Neuropsychological assessments were performed at baseline and 24 weeks. Primary outcomes were change on the Selective Reminding Test (SRT) of verbal memory and the participant's impression of memory change. Secondary outcomes included changes on other neuropsychological tests and the evaluating clinician's impression of memory change.

RESULTS

A total of 120 participants were enrolled and randomized to either donepezil or placebo. No significant treatment effects were found between groups on either primary outcome of memory or any secondary cognitive outcomes. A trend was noted for the clinician's impression of memory change in favor of donepezil (37.7%) vs placebo (23.7%) (p = 0.097). No serious or unanticipated adverse events attributed to study medication developed.

CONCLUSIONS

Donepezil did not improve memory as compared to placebo on either of the primary outcomes in this study.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence which does not support the hypothesis that 10 mg of donepezil daily for 24 weeks is superior to placebo in improving cognition as measured by the SRT in people with MS whose baseline RAVLT score was 0.5 SD or more below average.

Regression-based pediatric norms for the brief visuospatial memory test: revised and the symbol digit modalities test

The Brief Visuospatial Memory Test - Revised (BVMTR) and the Symbol Digit Modalities Test (SDMT) oral-only administration are known to be sensitive to cerebral disease in adult samples, but pediatric norms are not available. A demographically balanced sample of healthy control children (N = 92) ages 6-17 was tested with the BVMTR and SDMT. Multiple regression analysis (MRA) was used to develop demographically controlled normative equations. This analysis provided equations that were then used to construct demographically adjusted z-scores for the BVMTR Trial 1, Trial 2, Trial 3, Total Learning, and Delayed Recall indices, as well as the SDMT total correct score. To demonstrate the utility of this approach, a comparison group of children with acute disseminated encephalomyelitis (ADEM) or multiple sclerosis (MS) were also assessed. We find that these visual processing tests discriminate neurological patients from controls. As the tests are validated in adult multiple sclerosis, they are likely to be useful in monitoring pediatric onset multiple sclerosis patients as they transition into adulthood.

Visual-cognitive processing deficits in pediatric multiple sclerosis

Background: Children with multiple sclerosis (MS) can suffer significant cognitive deficits. This study investigates the sensitivity and validity in pediatric MS of two visual processing tests borrowed from the adult literature, the Brief Visuospatial Memory Test-Revised (BVMTR) and the Symbol Digit Modalities Test (SDMT).

Objective: To test the hypothesis that visual processing is disproportionately impacted in pediatric MS by comparing performance with that of healthy controls on the BVMTR and SDMT.

Methods: We studied 88 participants (43 MS, 45 controls) using a neuropsychological assessment battery including measures of intelligence, language, visual memory, and processing speed. Patients and demographically matched controls were compared to determine which tests are most sensitive in pediatric MS.

Results: Statistically significant differences were found between the MS and control groups on BVMTR Total Learning ( t (84) = 4.04, p < 0.001, d = 0.87), BVMTR Delayed Recall ( t (84) = 4.45, p < 0.001, d = 0.96), and SDMT ( t (38) = 2.19, p = 0.035, d = 0.69). No significant differences were found between groups on confrontation naming or general intellectual ability. Validity coefficients exploring correlation between BVMTR, SDMT, and disease characteristics were consistent with the adult literature.

Conclusions: This study found that BVMTR and SDMT may be useful in assessing children and adolescents with MS.

Vitamin D status and antibody levels to common viruses in pediatric-onset multiple sclerosis

BACKGROUND

The relative contribution and interaction of risk factors for multiple sclerosis (MS) have not been evaluated.

OBJECTIVES

To determine whether vitamin D status is associated with antibody levels to common viruses in pediatric-onset MS or clinically isolated syndrome (CIS) patients and controls.

METHODS

We assessed whether vitamin D status was associated with viral antibody levels to Epstein-Barr virus, cytomegalovirus (CMV), and herpes simplex virus (HSV)-1 or -2 in subjects who demonstrated evidence of remote infection with these viruses and whether these associations differed depending on disease status.

RESULTS

In 140 subjects, vitamin D status was weakly associated with antibody levels to CMV but not to the other viruses. However, there were some interactions between vitamin D status and disease state. Among those with vitamin D sufficiency (≥30 ng/ml), MS/CIS patients had higher antibody levels to Epstein-Barr nuclear antigen-1 than controls. Vitamin D sufficiency was associated with higher CMV antibody levels in MS/CIS subjects but lower CMV antibody levels in controls. Higher vitamin D levels appeared to be associated with higher titers to HSV-2 in MS/CIS patients but not controls.

CONCLUSIONS

Vitamin D status may be differentially associated with antibody levels to common childhood viruses among seropositive subjects.

Vitamin D status is associated with relapse rate in pediatric-onset multiple sclerosis

OBJECTIVE

We sought to determine if vitamin D status, a risk factor for multiple sclerosis, is associated with the rate of subsequent clinical relapses in pediatric-onset multiple sclerosis.

METHODS

This is a retrospective study of patients with pediatric-onset multiple sclerosis or clinically isolated syndrome who were consecutively recruited into a prospective cohort at their clinical visit at the pediatric multiple sclerosis center of University of California, San Francisco or State University of New York at Stony Brook. Of 171 eligible patients, 134 (78%) with multiple sclerosis/clinically isolated syndrome were included in the cohort; a further 24 were excluded from this analysis due to lack of available serum (n = 7) or lack of follow-up (n = 17). Serum 25-hydroxyvitamin D(3) levels were measured and were adjusted to reflect a deseasonalized value. The adjusted serum 25-hydroxyvitamin D(3) level was the primary predictor in a multivariate negative binomial regression model in which the main outcome measure was the number of subsequent relapses.

RESULTS

Among the 110 subjects, the mean unadjusted 25-hydroxyvitamin D(3) level was 22 +/- 9 ng/ml. After adjustment for age, gender, race, ethnicity, disease duration, disease-modifying therapy, and length of follow-up, every 10 ng/ml increase in the adjusted 25-hydroxyvitamin D(3) level was associated with a 34% decrease in the rate of subsequent relapses (incidence rate ratio, 0.66; 95% confidence interval, 0.46-0.95; p = 0.024).

INTERPRETATION

Lower serum 25-hydroxyvitamin D(3) levels are associated with a substantially increased subsequent relapse rate in pediatric-onset multiple sclerosis or clinically isolated syndrome, providing rationale for a randomized controlled trial of vitamin D supplementation.

Younger children with MS have a distinct CSF inflammatory profile at disease onset

BACKGROUND

The clinical and MRI presentation differs between earlier- and later-onset pediatric multiple sclerosis (MS), whereas the effect of age on the CSF inflammatory profile is unknown and may contribute to delayed diagnosis.

OBJECTIVES

To compare the CSF cellular and immunoglobulin G (IgG) profiles between earlier- and later-onset pediatric MS.

METHODS

We queried the databases of 6 pediatric MS centers for earlier-onset (onset <11 years) and later-onset (> or = 11 and <18 years) patients with MS or clinically isolated syndrome who underwent CSF analysis within the first 3 months of presentation (observational study). We compared CSF white blood cell (WBC) differential count, IgG index, and IgG oligoclonal bands between age groups.

RESULTS

We identified 40 earlier-onset (mean age at onset = 7.2 +/- 2.7 years, 60% females) and 67 later-onset pediatric MS patients (15.1 +/- 1.7 years, 63% females). Although WBC count tended to be higher in earlier-onset patients (median = 9/mm(3) [0-343] vs 6 [0-140], p = 0.15), they had a lower proportion of lymphocytes (70% [0-100] vs 93% [0-100] of WBCs, p = 0.0085; difference = +3% per 1-year increase of age, p = 0.0011) and higher proportion of neutrophils than later-onset patients (0.5% [0-75] vs 0% [0-50] of WBCs, p = 0.16; difference = -1% per 1-year increase of age, p = 0.033). In earlier-onset disease, fewer patients had an elevated IgG index than in the later-onset group (35% vs 68% of patients, p = 0.031).

CONCLUSION

Age modifies the CSF profile at pediatric multiple sclerosis (MS) onset, which may mislead the diagnosis. Our findings suggest an activation of the innate rather than the adaptive immune system in the earlier stages of MS or an immature immune response.

Psychiatric comorbidity in pediatric patients with demyelinating disorders

Little is known about psychiatric aspects of pediatric demyelinating conditions. A total of 23 youths (6-17 years) with demyelinating conditions underwent semistructured psychiatric interviews using the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version. Adolescents and parents completed the Child Symptom Inventory-4 and the Youth's Inventory-4. Fears and conceptions of their neurological problems were elicited. In all, 48% (n = 11) met criteria for current psychiatric diagnoses, including 27% (n = 3) with depressive disorders and 64% (n = 7) with anxiety disorders. Fears and conceptions of the illness were severe and diverse. Depressive and anxiety disorders are common in pediatric demyelinating disease. Clinicians should therefore screen for psychiatric comorbidity symptoms as part of the routine evaluation of such patients.

Fatigue and quality of life in pediatric multiple sclerosis

Fatigue and quality of life are significant concerns in adult multiple sclerosis (MS) but little is known about these factors in pediatric MS. The present investigation evaluates fatigue and quality of life in 51 pediatric MS patients to determine the rate of fatigue and reduced quality of life and assesses the relations between these variables and clinical factors. Fatigue and quality of life were assessed by self- and parent-report via the PedsQL Multidimensional Fatigue Scale and the PedsQL Quality of Life Scale. One-sample t-tests determined if scores were below published data for healthy individuals. Moreover, scores falling one standard deviation from norms were considered mildly affected, with severe difficulties being defined as scores falling two or more standard deviations from norms. Associations between self- and parent-reported difficulties and clinical factors were examined via Pearson correlation analyses. In comparison with healthy samples, pediatric MS patients reported greater difficulties with respect to fatigue, sleep, cognition, physical limitations, and academics. In addition to significant difficulties on these factors, parents reported problems with respect to emotional functioning, and tended to report greater fatigue, sleep, and cognitive difficulties than were self-reported. Expanded Disability Status Scale score was the only neurologic variable significantly related to fatigue or quality of life scores. Fatigue was significantly correlated with reports of sleep difficulties, cognitive problems, and quality of life variables. These findings suggest that fatigue and poorer quality of life is a clear concern in pediatric MS, and is related to overall physical disability.

Protein expression profiles in pediatric multiple sclerosis: potential biomarkers

The diagnosis of pediatric multiple sclerosis (MS) is challenging due to its low frequency and the overlap with other acquired childhood demyelinating disorders of the central nervous system. To identify potential protein biomarkers which could facilitate the diagnosis, we used two-dimensional gel electrophoresis (2-DE) in combination with mass spectrometry to identify proteins associated with pediatric MS. Plasma samples from nine children with MS and nine healthy subjects, matched in aggregate by age and gender, were analyzed for differences in their patterns of protein expression. We found 12 proteins that were significantly up regulated in the pediatric MS group: alpha-1-acid-glycoprotein 1, alpha-1-B-glycoprotein, transthyretin, apoliprotein-C-III, serum amyloid P component, complement factor-I, clusterin, gelsolin, hemopexin, kininogen-1, hCG1993037-isoform, and vitamin D-binding protein. These results show that 2-DE in combination with mass spectrometry is a highly sensitive technique for the identification of blood-based biomarkers. This proteomic approach could lead to a new panel of diagnostic and prognostic markers in pediatric MS.

Sustained-release oral fampridine in multiple sclerosis: a randomised, double-blind, controlled trial

BACKGROUND

Clinical studies suggested that fampridine (4-aminopyridine) improves motor function in people with multiple sclerosis. This phase III study assessed efficacy and safety of oral, sustained-release fampridine in people with ambulatory deficits due to multiple sclerosis.

METHODS

We undertook a randomised, multicentre, double-blind, controlled phase III trial. We randomly assigned 301 patients with any type of multiple sclerosis to 14 weeks of treatment with either fampridine (10 mg twice daily; n=229) or placebo (n=72), using a computer-generated sequence stratified by centre. We used consistent improvement on timed 25-foot walk to define response, with proportion of timed walk responders in each treatment group as the primary outcome. We used the 12-item multiple sclerosis walking scale to validate the clinical significance of the response criterion. Efficacy analyses were based on a modified intention-to-treat population (n=296), which included all patients with any post-treatment efficacy data. The study is registered with ClinicalTrials.gov, number NCT00127530.

FINDINGS

The proportion of timed walk responders was higher in the fampridine group (78/224 or 35%) than in the placebo group (6/72 or 8%; p<0.0001). Improvement in walking speed in fampridine-treated timed walk responders, which was maintained throughout the treatment period, was 25.2% (95% CI 21.5% to 28.8%) and 4.7% (1.0% to 8.4%) in the placebo group. Timed walk responders showed greater improvement in 12-item multiple sclerosis walking scale scores (-6.84, 95% CI -9.65 to -4.02) than timed walk non-responders (0.05, -1.48 to 1.57; p=0.0002). Safety data were consistent with previous studies.

INTERPRETATION

Fampridine improved walking ability in some people with multiple sclerosis. This improvement was associated with a reduction of patients' reported ambulatory disability, and is a clinically meaningful therapeutic benefit.

Longitudinal correlates of fatigue in multiple sclerosis

Objective

To determine the predictors of longitudinal changes in fatigue based on pain, mood, and neurological impairment across multiple sclerosis (MS) subtypes.

Background

Fatigue is the most common symptom of MS but remains poorly understood. The New York State Multiple Sclerosis Consortium (NYSMSC) database offers a unique opportunity to longitudinally assess a variety of potential fatigue correlates in a very large and diverse MS sample.

Design/Methods

This study examined baseline and 1-year follow-up data on 2768 patients drawn from the NYSMSC database regarding fatigability, pain, depressive symptoms, MS subtype, and expanded disability status scale (EDSS). Correlates and predictors of fatigue were assessed in correlational and multiple regression analyses.

Results

Baseline fatigue, pain, and depression accounted for 34.6% of the variance in 1-year follow-up fatigue scores. Fatigue was lower in relapsing–remitting subjects than in other MS subtypes. Fatigue consistently correlated at baseline and follow-up with depressive symptoms, pain severity, and EDSS. Changes in fatigue correlated with changes in other variables.

Conclusions

Predictors of fatigue at 1 year include baseline fatigue, pain, mood, and EDSS. These symptoms are also correlated at baseline, follow-up, and in change scores. Identifying predictors of fatigue may facilitate patient management.

Dose comparison trial of sustained-release fampridine in multiple sclerosis

OBJECTIVE

To examine the efficacy and safety of three different doses of sustained-release fampridine in people with multiple sclerosis (MS).

METHOD

This multicenter, randomized, double-blind, placebo-controlled, parallel-group study recruited 206 participants at 24 centers in the United States and Canada. After a single-blind, 2-week placebo run-in, participants were randomly assigned to receive fampridine (10, 15, or 20 mg twice daily) or placebo for 15 weeks. The primary efficacy variable was percent change in walking speed based on the timed 25-foot walk.

RESULTS

Trends for increased walking speed were consistent across dose groups vs placebo, but not significant, on the prospective analysis. An increase from baseline in lower extremity strength during the 12-week stable-dose period was seen in the groups receiving 10- and 15-mg doses, compared with placebo (p = 0.018 and 0.003). There were no significant changes in other secondary assessments. Post hoc analysis revealed subsets of participants in each dose group with walking speeds during the treatment period that were consistently faster than during the nontreatment period. There were significantly more "consistent responders" in the drug-treated groups than in the placebo group (36.7% compared with 8.5%). Consistent responders showed significantly greater improvement in self-assessed ambulation on the 12-Item MS Walking Scale than did nonresponders. Fampridine was generally well tolerated. Severe and serious adverse events were more frequent at the highest dose.

CONCLUSIONS

This phase 2 study suggests that a subgroup of patients, when treated with fampridine, experiences a clinically relevant improvement in walking ability, which is sustained for at least 14 weeks.

Treatment of cognitive impairment in multiple sclerosis: is the use of acetylcholinesterase inhibitors a viable option?

Approximately half of all patients with multiple sclerosis (MS) experience cognitive impairment, most commonly with regard to new learning and memory. Cognitive dysfunction is a leading cause of disability in MS and it can have profound social and economic consequences for patients and their families. Research on treatment for cognitive impairment in MS is still in the early stages, as it is for most neurological conditions. The available disease-modifying therapies in MS may provide some modest benefit to cognition, but patients with MS clearly need better treatment for cognitive dysfunction. A number of studies have assessed symptomatic treatments of cognition in MS, and the results of these small, underpowered studies have been mixed. Regardless, acetylcholinesterase inhibitors (AChEIs) have been the most promising class of medications tested in MS to date. Seven of eight studies on AChEIs have shown positive results, although it is difficult to assess their adequacy since only three of the studies have been published in peer reviewed journals, with the rest appearing only as abstracts. The earliest AChEI studies in MS examined physostigmine, but the short half-life and prominent adverse effects of this medication may have limited its use compared with other AChEIs. All of the more recent AChEI studies have used donepezil, which, from the limited data available to date, appears to have been relatively well tolerated among MS patients. The largest randomized controlled trial of donepezil included 69 subjects and found that donepezil improved verbal learning and memory compared with placebo during neuropsychological testing. That study also found that patients receiving donepezil were more likely to report memory improvement than those receiving placebo, and the study clinician also noted a cognitive benefit among those on donepezil as opposed to placebo. There are still many unanswered questions regarding the use of AChEIs in MS, including the effects of their long-term use in a chronic disease such as MS. On the whole, to date the research on AChEIs in MS must be considered preliminary, and it is premature to recommend the clinical use of this class of medications at the present time.

Fatigue in Parkinson's disease: a review

Fatigue is a common problem in Parkinson's disease (PD), often the most troubling of all symptoms. It is poorly understood, generally under-recognized, and has no known treatment. This article reviews what is known about the symptom, putting it into the context of fatigue in other disorders, and outlines a program for developing better understanding and therapy.

Consensus definitions proposed for pediatric multiple sclerosis and related disorders

BACKGROUND

The CNS inflammatory demyelinating disorders of childhood include both self-limited and lifelong conditions, which can be indistinguishable at the time of initial presentation. Clinical, biologic, and radiographic delineation of the various monophasic and chronic childhood demyelinating disorders requires an operational classification system to facilitate prospective research studies.

METHODS

The National Multiple Sclerosis Society (NMSS) organized an International Pediatric MS Study Group (Study Group) composed of adult and pediatric neurologists and experts in genetics, epidemiology, neuropsychology, nursing, and immunology. The group met several times to develop consensus definitions regarding the major CNS inflammatory demyelinating disorders of children and adolescents.

RESULTS

Clinical definitions are proposed for pediatric multiple sclerosis (MS), acute disseminated encephalomyelitis (ADEM), recurrent ADEM, multiphasic ADEM, neuromyelitis optica, and clinically isolated syndrome. These definitions are considered operational and need to be tested in future research and modified accordingly.

CONCLUSION

CNS inflammatory demyelinating disorders presenting in children and adolescents can be defined and distinguished. However, prospective research is necessary to determine the validity and utility of the proposed diagnostic categories.

The psychosocial consequences of pediatric multiple sclerosis

Although psychological distress and cognitive dysfunction are well documented in adults with multiple sclerosis (MS), they are poorly understood in children with the disease. Psychosocial difficulty experienced by children and adolescents with MS involves factors common to all chronic illnesses in children, as well as MS-specific factors. The psychosocial manifestations of the disease may affect the patient's self-image, role functioning, mood, and cognition to adversely affect schooling, interpersonal relationships, and treatment compliance. Furthermore, the impact of having a family member with MS may affect overall family functioning. Assessment and interventions for psychosocial and cognitive problems in pediatric MS should be multidisciplinary in nature and address the child's functioning at home, school, and among peers, as well as the effect on the family.