Prodromes in demyelinating disorders, amyotrophic lateral sclerosis, Parkinson disease, and Alzheimer's dementia.

A prodrome is an early set of symptoms, which indicates the onset of a disease; these symptoms are often non-specific. Prodromal phases are now recognized in multiple central nervous system diseases. The depth of understanding of the prodromal phase varies across diseases, being more nascent for multiple sclerosis for example, than for Parkinson disease or Alzheimer's disease. Key challenges when identifying the prodromal phase of a disease include the lack of specificity of prodromal symptoms, and consequent need for accessible and informative biomarkers. Further, heterogeneity of the prodromal phase may be influenced by age, sex, genetics and other poorly understood factors. Nonetheless, recognition that an individual is in the prodromal phase of disease offers the opportunity for earlier diagnosis and with it the opportunity for earlier intervention.

Data harmonization for collaborative research among MS registries: A case study in employment.

OBJECTIVE: To assess the feasibility of collaboration and retrospective data harmonization among three multiple sclerosis (MS) registries by investigating employment status. METHODS: We used the Maelstrom guidelines to facilitate retrospective harmonization of data from three MS registries, including the NARCOMS (North American Research Committee on MS) Registry, German MS Register (GMSR), and United Kingdom MS (UK-MS) Register. A protocol was developed based on the guidelines, and summary-level data were used to combine results. Employment status and a limited set of factors associated with employment (age, sex, education, and disability level) were harmonized. A meta-analytic approach was used to pool estimates using a weighted average of logistic regression estimates and their variances in a random effects model. RESULTS: Employment status, age, sex, education, and disability were mapped. The overall employment rate was 57% (11,143 employed out of 19,562 persons with MS) with the GMSR having the highest proportion of participants employed (66.2%), followed by the UK-MS (55.2%) and NARCOMS (43.0%) registries. As disability level increased, the odds of not being employed increased. CONCLUSION: Harmonization across registries was feasible. The Maelstrom guidelines provide a valuable roadmap for conducting high-quality harmonization projects. The pooling of data sources has the potential to be an important mechanism for conducting research in MS.

Incidence and temporal trends of co-occurring personality disorder diagnoses in immune-mediated inflammatory diseases.

AIMS: Although immune-mediated inflammatory diseases (IMID) are associated with multiple mental health conditions, there is a paucity of literature assessing personality disorders (PDs) in these populations. We aimed to estimate and compare the incidence of any PD in IMID and matched cohorts over time, and identify sociodemographic characteristics associated with the incidence of PD. METHODS: We used population-based administrative data from Manitoba, Canada to identify persons with incident inflammatory bowel disease (IBD), multiple sclerosis (MS) and rheumatoid arthritis (RA) using validated case definitions. Unaffected controls were matched 5:1 on sex, age and region of residence. PDs were identified using hospitalisation or physician claims. We used unadjusted and covariate-adjusted negative binomial regression to compare the incidence of PDs between the IMID and matched cohorts. RESULTS: We identified 19 572 incident cases of IMID (IBD n = 6,119, MS n = 3,514, RA n = 10 206) and 97 727 matches overall. After covariate adjustment, the IMID cohort had an increased incidence of PDs (incidence rate ratio [IRR] 1.72; 95%CI: 1.47-2.01) as compared to the matched cohort, which remained consistent over time. The incidence of PDs was similarly elevated in IBD (IRR 2.19; 95%CI: 1.69-2.84), MS (IRR 1.79; 95%CI: 1.29-2.50) and RA (IRR 1.61; 95%CI: 1.29-1.99). Lower socioeconomic status and urban residence were associated with an increased incidence of PDs, whereas mid to older adulthood (age 45-64) was associated with overall decreased incidence. In a restricted sample with 5 years of data before and after IMID diagnosis, the incidence of PDs was also elevated before IMID diagnosis among all IMID groups relative to matched controls. CONCLUSIONS: IMID are associated with an increased incidence of PDs both before and after an IMID diagnosis. These results support the relevance of shared risk factors in the co-occurrence of PDs and IMID conditions.

Prodrome in relapsing-remitting and primary progressive multiple sclerosis.

BACKGROUND AND PURPOSE: The multiple sclerosis prodrome remains poorly understood. We aimed to examine the prodrome in people with relapsing remitting multiple sclerosis at onset (RMS) and primary progressive multiple sclerosis (PPMS). METHODS: We conducted a matched cohort study using clinical and linked health administrative data in two Canadian provinces. We identified people with RMS, PPMS and age- sex- and geographically-matched population controls, and compared the number of physician encounters (total number, per International Classification of Diseases chapter, and per physician speciality) in the five years before symptom onset. Negative binomial regression models were sex, age, socioeconomic status and calendar year adjusted. RESULTS: We identified 1887 RMS, 171 PPMS cases, and 9837 matched population controls. No difference existed in the total number of encounters in the five years before index between RMS and PPMS, or between the phenotypes and their respective controls. Compared to RMS cases, PPMS cases had more nervous system-related encounters (adjusted rate ratio, 3.00; 95% confidence interval, 1.06-8.49) and fewer encounters with dermatologists (adjusted rate ratio 0.53; 95% confidence interval, 0.30-0.96). CONCLUSION: Findings suggest that people with RMS and PPMS may both experience a prodrome, although aspects may differ.

Rising incidence of psychiatric disorders before diagnosis of immune-mediated inflammatory disease.

AIMS: After the diagnosis of immune-mediated inflammatory diseases (IMID) such as inflammatory bowel disease (IBD), multiple sclerosis (MS) and rheumatoid arthritis (RA), the incidence of psychiatric comorbidity is increased relative to the general population. We aimed to determine whether the incidence of psychiatric disorders is increased in the 5 years before the diagnosis of IMID as compared with the general population. METHODS: Using population-based administrative health data from the Canadian province of Manitoba, we identified all persons with incident IBD, MS and RA between 1989 and 2012, and cohorts from the general population matched 5 : 1 on year of birth, sex and region to each disease cohort. We identified members of these groups with at least 5 years of residency before and after the IMID diagnosis date. We applied validated algorithms for depression, anxiety disorders, bipolar disorder, schizophrenia, and any psychiatric disorder to determine the annual incidence of these conditions in the 5-year periods before and after the diagnosis year. RESULTS: We identified 12 141 incident cases of IMID (3766 IBD, 2190 MS, 6350 RA) and 65 424 matched individuals. As early as 5 years before diagnosis, the incidence of depression [incidence rate ratio (IRR) 1.54; 95% CI 1.30-1.84) and anxiety disorders (IRR 1.30; 95% CI 1.12-1.51) were elevated in the IMID cohort as compared with the matched cohort. Similar results were obtained for each of the IBD, MS and RA cohorts. The incidence of bipolar disorder was elevated beginning 3 years before IMID diagnosis (IRR 1.63; 95% CI 1.10-2.40). CONCLUSION: The incidence of psychiatric comorbidity is elevated in the IMID population as compared with a matched population as early as 5 years before diagnosis. Future studies should elucidate whether this reflects shared risk factors for psychiatric disorders and IMID, a shared final common inflammatory pathway or other aetiology.

Adverse psychiatric effects of disease-modifying therapies in multiple Sclerosis: A systematic review.

BACKGROUND: Psychiatric comorbidity is prevalent in persons with multiple sclerosis (MS). Few studies have assessed whether second-generation disease-modifying therapies (DMT) are associated with adverse psychiatric effects. OBJECTIVE: We aimed to systematically review the literature regarding the APEs associated with natalizumab, fingolimod, dimethyl fumarate, teriflunomide and alemtuzumab in MS. As a secondary objective, we evaluated changes in anxiety or depression scores following treatment with the aforementioned DMTs. METHODS: We searched MEDLINE, EMBASE, International Pharmaceutical Abstracts, PsychINFO, Central Register of Controlled Trials & Cochrane database of systematic reviews for published studies, and clinicaltrials.gov and regulatory documents from the US and Canada for unpublished studies. Data sources were searched from inception to September 2017. Studies reporting adverse psychiatric effects involving any DMT of interest were included. We report the incidence proportions of the adverse psychiatric effects and, where applicable, risk differences between DMT-exposed and unexposed individuals along with the corresponding 95% confidence intervals. We calculated the standardized mean differences (SMD) of changes in anxiety and depression scores if reported as study outcomes, and pooled the data using random effects meta-analysis. RESULTS: Of 4389 abstracts screened, 78 met the inclusion criteria, including 48 clinical trials, 28 observational studies and 2 case reports. Depression was the most commonly reported adverse psychiatric effect. Incidence proportions for all adverse psychiatric effects ranged from 0 to 24.7%. None of the DMT studied were associated with a statistically significant increased risk of any adverse psychiatric effect (range of risk difference: -7.69% [95%CI: -16.06%, 5.56%] to 6.67 [-8.56, 15.59]). Eighteen studies examined changes in depression or anxiety following fingolimod, natalizumab or dimethyl fumarate treatment; depression symptoms improved in fingolimod-treated groups (SMD [95%CI]: 1.18 [0.17, 2.19]). We did not identify studies examining changes in these outcomes following treatment with any of the other DMTs. CONCLUSION: The DMTs reviewed were not associated with an increased risk of adverse psychiatric effect in MS, and some may reduce the incidence of depressive symptoms. This may reflect either a positive direct effect (e.g. immune modulation) or an indirect effect arising due to a positive impact on disease activity or course.

Validation of the PHQ-9 for Suicidal Ideation in Persons with Inflammatory Bowel Disease.

Background: Suicide is a leading cause of death worldwide. Transition from suicidal ideation (SI) to suicide attempt is high within a year of SI onset. The risk of suicide and SI is elevated in persons with inflammatory bowel disease (IBD) versus the general population. We aimed to validate the Patient Heath Questionnaire (PHQ)-9 as a screening tool for SI in IBD and to determine factors associated with SI in IBD. Methods: IBD participants (n = 247) recruited from the community and clinics completed the PHQ-9 and participated in the Structured Clinical Interview for DSM-IV (SCID). We determined the sensitivity, specificity, and positive and negative predictive value (PPV and NPV) of the PHQ-9 in identifying SI as compared to the SCID. Using logistic regression we examined the association of SI with demographic and clinical factors. Results: SI was endorsed by 24 (9.7%) participants on the PHQ-9 and 5 (2.0%) based on the SCID. The PHQ-9 had good sensitivity (100%), specificity (92.2%), and NPV (100%) but low PPV (20.8%) for SI. On univariate analysis, factors strongly associated with SI were depression (OR 13.1; 95%CI: 4.46, 40.5), anxiety (OR 11.3; 95%CI: 4.46, 28.6), and active disease (OR 3.87; 95%CI: 1.54, 9.71). On multivariable analysis, depression (OR 5.54; 95%CI: 1.67, 18.4) and pain (OR 1.14; 95%CI: 1.03, 1.25) were associated with SI. Conclusions: Overall the PHQ-9 is a valid screening tool for SI in IBD patients, and routine implementation of this tool would support screening for depression and SI effectively and efficiently in clinical practice.

National estimates of self-reported sitting time in adults with multiple sclerosis.

BACKGROUND: Limited data exist on the prevalence and distribution of sedentary behavior (SB) in multiple sclerosis (MS). OBJECTIVE: The objective of this paper is to describe sitting time as a metric of SB in a large national sample of people with MS. METHODS: A total of 8004 individuals from the North American Research Committee on MS (NARCOMS) Registry completed the sitting time question from the International Physical Activity Questionnaire in spring 2015. We present descriptive data on sitting time for the total sample and across sociodemographic, clinical, and behavioral characteristics. RESULTS: The final sample included 6483 individuals. Of these, 36.7% were classified with mild disability, 24.7% with moderate disability, and 38.6% with severe disability. Median sitting time for the total sample was 480 min/day (P25 = 310 min/day, P75 = 720 min/day). Sitting time was highest for individuals with MS who were male (540 min/day), not married (540 min/day), had a disease duration >30 years (540 min/day), were underweight (540.5 min/day), had an annual income of < $15,000 (585 min/day), presented with a progressive form of MS (600 min/day), were classified as insufficiently active (600 min/day), or presented with severe disability (661 min/day). CONCLUSION: Sitting time is twice as high in individuals with MS compared to the general population (240 min/day).

Markedly increased incidence of critical illness in adults with Type 1 diabetes.

AIMS: To compare the incidence of and mortality after intensive care unit admission in adults with paediatric-onset Type 1 diabetes vs the general population. METHODS: Using population-based administrative data from Manitoba, Canada, we identified 814 cases of paediatric-onset Type 1 diabetes, and 3579 general population controls matched on age, sex and region of residence. We estimated the incidence of intensive care unit admission in adulthood, and compared the findings between populations using incidence rate ratios and multivariable Cox proportional hazards regression, adjusting for age, sex, comorbidity and socio-economic status. We estimated age- and sex-standardized mortality rates after intensive care unit admission. RESULTS: Between January 2000 and October 2009, the average annual incidence of intensive care unit admission among prevalent cohorts was 910 per 100 000 in the Type 1 diabetes population, and 106 per 100 000 in matched controls, an eightfold increased risk (incidence rate ratio 8.6; 95% CI 5.5, 14.0). The adjusted risk of intensive care unit admission was elevated to a greater extent among women with Type 1 diabetes compared with matched women (hazard ratio 14.7; 95% CI 7.2, 29.4) than among men with Type 1 diabetes compared with matched men (hazard ratio 4.92; 95% CI 10.3, 2.36) The most common reasons for admission in the diabetes cohort were diabetic ketoacidosis, infection and ischaemic heart disease. At 30%, 5-year mortality was higher in the diabetes cohort than in the matched cohort (relative risk 5.7; 95% CI 1.2, 8.9). CONCLUSIONS: Compared with the general population, the risk of intensive care unit admission was higher in adults with paediatric-onset Type 1 diabetes, and mortality after admission was also higher.

The computer-based Symbol Digit Modalities Test: establishing age-expected performance in healthy controls and evaluation of pediatric MS patients.

Decreased information processing speed (IPS) is frequently reported in pediatric multiple sclerosis (MS) patients. The computerized version of the Symbol Digit Modalities Test (c-SDMT) measures IPS over eight consecutive trials per session and additionally captures changes in performance within the session. Here, we establish normative c-SDMT performance and test-retest reliability in healthy children (HC) and explore differences in the overall c-SDMT-performance between HC and MS patients. This cross-sectional study included 478 HC (237 female, 49.5%) divided into five age groups (2 years each), and 27 MS patients (22 female, 81.5%) aged 8-18 years. The average time to complete the c-SDMT increased with age (|r| 0.70, 95% CI -0.74, -0.64). Test-retest reliability was high (ICC = 0.91) in HC. The total time to complete the c-SDMT did not differ between children with MS and sex- and age- matched HC (p = 0.23). However, MS patients were less likely to show faster performance across all the successive eight trials compared to HC (p = 0.0001). Healthy children demonstrate faster IPS with increasing age, as well as during successive trials of the c-SDMT. The inability of pediatric MS patients to maintain the increase in processing speed over successive trials suggests a reduced capacity for procedural learning, possibly resulting from cognitive fatigue.

A population-based study comparing multiple sclerosis clinic users and non-users in British Columbia, Canada.

BACKGROUND AND PURPOSE: Much clinical knowledge about multiple sclerosis (MS) has been gained from patients who attend MS specialty clinics. However, there is limited information about whether these patients are representative of the wider MS population. The objective of this study was to compare incident MS cases who were MS clinic users to non-users of the specialty MS clinics in British Columbia, Canada. METHODS: This was a retrospective record-linkage cohort study using prospectively collected data from the British Columbia Multiple Sclerosis database and province-wide health administrative databases. RESULTS: There were 2841 incident MS cases between 1996 and 2004 including 1648 (58%) that had registered at an MS clinic ('clinic cases') and 1193 (42%) that had not ('non-clinic cases'). Gender and socioeconomic status distributions were similar; however, non-clinic cases were older, accessed health services more frequently and had a higher burden of comorbidity than clinic cases. Only 1% of the non-clinic cases had filled a prescription for an MS-specific disease-modifying therapy, compared to 51% of the clinic cases. CONCLUSIONS: Our findings have several important implications: even within a publicly funded healthcare system, a high proportion of individuals with MS may not access a specialty MS clinic; the needs of MS patients managed in the community may differ from those referred to an MS clinic; findings from studies involving clinic-based MS cohorts may not always be generalizable to the wider MS population; and access to population-based health administrative data offers the opportunity to gain a broader understanding of MS.

Systematic review and meta-analysis of interventions for depression and anxiety in persons with multiple sclerosis.

BACKGROUND: Depression and anxiety are common in persons with multiple sclerosis (MS), and adversely affect fatigue, medication adherence, and quality of life. Though effective treatments for depression and anxiety exist in the general population, their applicability in the MS population has not been definitively established. OBJECTIVE: To determine the overall effect of psychological and pharmacological treatments for depression or anxiety in persons with MS. METHODS: We searched the Medline, EMBASE, PsycINFO, PsycARTICLES Full Text, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, and Scopus databases using systematic review methodology from database inception until March 25, 2015. Two independent reviewers screened abstracts, extracted data, and assessed risk of bias and strength of evidence. We included controlled clinical trials reporting on the effect of pharmacological or psychological interventions for depression or anxiety in a sample of persons with MS. We calculated standardized mean differences (SMD) and pooled using random effects meta-analysis. RESULTS: Of 1753 abstracts screened, 21 articles reporting on 13 unique clinical trials met the inclusion criteria. Depression severity improved in nine psychological trials of depression treatment (N=307; SMD: -0.45 (95%CI: -0.74, -0.16)). The severity of depression also improved in three pharmacological trials of depression treatment (SMD: -0.63 (N=165; 95%CI: -1.07, -0.20)). For anxiety, only a single trial examined psychological therapy for injection phobia and reported no statistically significant improvement. CONCLUSION: Pharmacological and psychological treatments for depression were effective in reducing depressive symptoms in MS. The data are insufficient to determine the effectiveness of treatments for anxiety.

Comorbidity is associated with pain-related activity limitations in multiple sclerosis.

BACKGROUND: Comorbidities are common in multiple sclerosis (MS). The high prevalence of pain in MS is well-established but the influence of comorbidities on pain, specifically, pain-related interference in activity is not. OBJECTIVE: To examine the relationship between comorbidity and pain in MS. METHODS: We recruited 949 consecutive patients with definite MS from four Canadian centres. Participants completed the Health Utilities Index (HUI-Mark III) and a validated comorbidity questionnaire at 3 visits over 2 years. The HUI's pain scale was dichotomized into two groups: those with/without pain that disrupts normal activities. We used logistic regression to assess the association of pain with each comorbidity individually at baseline and over time. RESULTS: The incidence of disruptive pain over two years was 31.1 per 100 persons. Fibromyalgia, rheumatoid arthritis, irritable bowel syndrome, migraine, chronic lung disease, depression, anxiety, hypertension, and hypercholesterolemia were associated with disruptive pain (p<0.006). Individual-level effects on the presence of worsening pain were seen for chronic obstructive pulmonary disease (odds ratio [OR]: 1.50 95% CI: 1.08-2.09), anxiety (OR: 1.49 95% CI: 1.07-2.08), and autoimmune thyroid disease (OR: 1.40 95% CI: 1.00-1.97). CONCLUSION: Comorbidity is associated with pain in persons with MS. Closer examination of these associations may provide guidance for better management of this disabling symptom in MS.

Performance of administrative case definitions for comorbidity in multiple sclerosis in Manitoba and Nova Scotia.

INTRODUCTION: As the population ages and the prevalence of comorbid conditions increases, the need for feasible, validated methods of comorbidity surveillance in chronic diseases such as multiple sclerosis (MS) increases. METHODS: Using kappa (k) statistics, we evaluated the performance of administrative case definitions for comorbidities commonly observed in MS by comparing agreement between Manitoba (MB) administrative data and self-report (n = 606) and Nova Scotia (NS) administrative data and self-report (n = 1923). RESULTS: Agreement between the administrative definitions and self-report was substantial for hypertension (k = 0.69 [NS], 0.76 [MB]) and diabetes (k = 0.70 [NS], 0.66 [MB]); moderate for hyperlipidemia (k = 0.53 [NS], 0.51 [MB]) and heart disease (k = 0.42 [NS], 0.51 [MB]) and fair for anxiety (k = 0.27 [NS], 0.26 [MB]). In NS, agreement was substantial for inflammatory bowel disease (k = 0.71) and moderate for epilepsy (k = 0.48). CONCLUSION: Administrative definitions for commonly observed comorbidities in MS performed well in 2 distinct jurisdictions. This suggests that they could be used more broadly across Canada and in national studies.

TITRE: Performance des définitions administratives de cas pour les affections concomitantes de la sclérose en plaques au Manitoba et en Nouvelle-Écosse. INTRODUCTION: Au fur et à mesure du vieillissement de la population et de l'augmentation de la prévalence d'affections concomitantes, le recours à des méthodes fiables et efficaces de surveillance des affections concomitantes de maladies chroniques telles que la sclérose en plaques (SP) s'avère de plus en plus nécessaire. MÉTHODOLOGIE: Nous avons évalué, au moyen de la statistique kappa (k), la performance des définitions administratives de cas pour les affections concomitantes fréquemment observées en lien avec la SP en comparant les concordances entre les données administratives et les données provenant d'autodéclarations au Manitoba (MB) (n = 606) et en Nouvelle-Écosse (NS) (n = 1 923). RÉSULTATS: Les concordances entre les définitions administratives et les autodéclarations étaient bonnes pour l'hypertension (k = 0,69 [NS] et 0,76 [MB]) et le diabète (k = 0,70 [NS] et 0,66 [MB]), modérées pour l'hyperlipidémie (k = 0,53 [NS] et 0,51 [MB]) et la cardiopathie (k = 0,42 [NS] et 0,51 [MB]) et médiocres pour l'anxiété (k = 0,27 [NS] et 0,26 [MB]). La concordance était bonne en Nouvelle-Écosse pour la maladie inflammatoire chronique de l'intestin (k = 0,71) et modérée pour l'épilepsie (k = 0,48). CONCLUSION: Les définitions administratives étaient performantes dans les deux provinces pour plusieurs affections concomitantes fréquemment observées en lien avec la SP. À la lumière de ces résultats, il semble que ces définitions puissent être utilisées plus largement au Canada et dans les études nationales.

MS incidence and prevalence in Africa, Asia, Australia and New Zealand: A systematic review.

OBJECTIVES: Studies of multiple sclerosis (MS) incidence and prevalence from Africa, Asia, Australia and New Zealand are relatively scarce. We systematically reviewed MS incidence and prevalence in these regions including a standardized evaluation of study quality. METHODS: We searched MEDLINE and EMBASE databases for studies of MS prevalence or incidence in Africa, Asia, Australia and New Zealand published in English or French between January 1, 1985 and January 31, 2011. Study quality was assessed using a standardized tool. All steps of the review were performed in duplicate. RESULTS: Of 3925 citations identified, 28 studies met inclusion criteria and 21 of these were from Asia. Quality scores ranged from 1/8 to 8/8; the lowest scores were observed in studies from Asia (median 4/8, IQR 3,6). Prevalence was lowest in South African Blacks (0.22/100,000) and highest amongst Australian-born individuals in Australia (125/100,000). Prevalence increased over time in many countries. MS prevalence increased with increasing latitude only in some regions, and prevalence varied significantly with ethnicity. Eight studies reported incidence, which ranged from 0.67/100,000/year in Taiwan to 3.67/100,00/year in Australia. CONCLUSIONS: This comprehensive study provides an update of MS epidemiology in Africa, Asia, Australia, and New Zealand. Incidence and prevalence were lowest in Africa and Asia and highest in Australia, but many Asian studies were of poor quality. Use of consistent case ascertainment methods, standardized data collection tools, and similar outcomes would all improve study quality and comparability. The underlying basis of observed ethnic differences is an important area for future study.

No evidence for impairment of venous hemodynamics in children or young adults with pediatric-onset multiple sclerosis.

BACKGROUND AND PURPOSE: Chronic cerebrospinal venous insufficiency is a postulated etiologic factor for multiple sclerosis, but the higher frequency with longer disease duration and progressive disability suggests that chronic cerebrospinal venous insufficiency is secondary to chronic disease. We evaluated the presence of chronic cerebrospinal venous insufficiency in pediatric-onset MS. MATERIALS AND METHODS: Twenty-six pediatric patients with MS (18 years of age or younger), 26 age-matched healthy controls, and 13 young adults with pediatric-onset MS underwent sonography of the internal jugular, vertebral, and deep cerebral veins. Five venous hemodynamic criteria were assessed, with 2 criteria required for chronic cerebrospinal venous insufficiency. MR imaging studies, performed in the pediatric patients with MS and healthy control groups, included intracranial 2D time-of-flight MR venography and velocity-sensitive phase-contrast sequences. Contrast-enhanced brain MR images were obtained in pediatric patients with MS to further evaluate venous patency. We used paired t tests, Wilcoxon matched pairs, McNemar tests, and exact conditional logistic regression to estimate the association of chronic cerebrospinal venous insufficiency with MS. RESULTS: Fifty participants (73.5%) had normal ultrasound findings, 15 (23.1%) met 1 venous hemodynamic criterion, and 2 pediatric patients with MS and 1 young adult with pediatric-onset MS met chronic cerebrospinal venous insufficiency criteria. Chronic cerebrospinal venous insufficiency was not associated with MS (odds ratio, 2.41; 95% CI, 0.19-infinity). Demographic and disease characteristics did not differ between the patients with MS meeting chronic cerebrospinal venous insufficiency criteria (n = 3) and those who did not (n = 36; all, P > .05). The mean (SD) MR imaging measures of intracerebral flow did not differ between the 2 pediatric patients with MS meeting chronic cerebrospinal venous insufficiency criteria (0.85 ± 0.11) and healthy controls (0.87 ± 0.16, P = .50); no child demonstrated venous obstruction. CONCLUSIONS: Chronic cerebrospinal venous insufficiency is rarely observed in children or young adults with pediatric-onset MS. Venous anatomy and flow rates indicate that venous outflow is intact in pediatric patients with MS. Our findings argue against chronic cerebrospinal venous insufficiency as a component of MS etiology.

Cumulative impact of comorbidity on quality of life in MS.

BACKGROUND: Little is known about the impact of comorbidity on health-related quality of life (HRQOL) in multiple sclerosis (MS). We investigated the association of comorbidity and health-related HRQOL among participants in the North American Research Committee on Multiple Sclerosis (NARCOMS). MATERIALS AND METHODS: In 2006, we queried NARCOMS participants regarding physical and mental comorbidities and HRQOL, using the Short-Form 12. We summarized physical HRQOL using the aggregate Physical Component Scale (PCS-12) score and mental HRQOL using the aggregate Mental Component Scale (MCS-12) score. We assessed multivariable associations between comorbidity and HRQOL using a general linear model, adjusting for potential confounders. RESULTS: Among 8983 respondents, the mean (SD) PCS-12 was 36.9 (11.8) and MCS-12 was 45.6 (11.6). After adjustment for sociodemographic and clinical factors, participants with any physical comorbidity had a lower PCS-12 (37.2; 95% CI: 36.4-38.1) than those without any physical comorbidity (40.1; 95% CI: 39.0-41.1). As the number of physical comorbidities increased, PCS-12 scores decreased (r = -0.25; 95% CI: -0.23 to -0.27) indicating lower reported HRQOL. Participants with any mental comorbidity had a lower MCS-12 (40.7; 95% CI: 39.8-41.6) than those without any mental comorbidity (48.5; 95% CI: 47.7-49.4). CONCLUSIONS: Comorbidity is associated with reduced HRQOL in MS. Further research should evaluate whether more aggressive treatment of comorbidities improves the HRQOL of MS patients.

Design, methodological issues and participation in a multiple sclerosis case-control study.

OBJECTIVES: This study was conducted to determine whether the risk of developing multiple sclerosis (MS) was associated with certain environmental exposures or genetic factors previously reported to influence MS risk. This paper describes the methodological issues, study design and characteristics of the study population. MATERIALS AND METHODS: Individuals with definite MS were identified from a prevalence study conducted in three geographic areas. The target number of cases was not reached, so an additional study area was added. Identifying clinic controls was inefficient, so controls were recruited using random digit dialing. All study participants completed a detailed questionnaire regarding environmental exposures using computer-assisted telephone interviewing, and blood was collected for genetic analysis. RESULTS: In total, 276 cases and 590 controls participated, but participation rates were low, ranging from 28.4% to 38.9%. Only one-third (33.6%) of individuals identified in the prevalence study agreed to participate in the case-control study. Cases were more likely to be non-Hispanic white and older than their source populations as identified in the preceding prevalence study (P < 0.05). Most participants provided a blood sample for genotyping (91%; n = 789). CONCLUSIONS: Epidemiological studies play a key role in identifying genetic and environmental factors that are associated with complex diseases like MS. Methodological issues arise in every study, and investigators need to be able to detect, respond to and correct problems in a timely and scientifically valid manner.

Association between comorbidity and clinical characteristics of MS.

BACKGROUND: Comorbidity may be associated with the clinical phenotype of disease and may affect prognostication and treatment decisions. Using the North American Research Committee on Multiple Sclerosis Registry, we described comorbidities present at onset and diagnosis of multiple sclerosis (MS) and examined whether comorbidities present at onset were associated with clinical course or age of MS symptom onset. METHODS: In 2006, 8983 participants reported their physical and mental comorbidities; smoking status; height; and past and present weight. We compared clinical course at onset and age of symptom onset by comorbidity status. RESULTS: At MS onset, a substantial proportion of participants had physical (24%) or mental (8.4%) comorbidities. The mean (SD) age of MS onset was 31.2 (9.0) years. Vascular, autoimmune, cancer, visual, and musculoskeletal comorbidities were associated with a later age of symptom onset. Among men and women, the odds of a relapsing course at onset were increased if mental comorbidities (OR 1.48; 1.08-2.01) were present at symptom onset. In women, gastrointestinal comorbidities (OR 1.78; 1.25-2.52) and obesity (OR 2.08 1.53-2.82) at MS onset were also associated with a relapsing course at onset. CONCLUSIONS: Comorbidity is frequently present at onset of MS and is associated with differences in clinical characteristics.