Measuring disability in multiple sclerosis: the WHODAS 2.0.

INTRODUCTION: Reliable measurement of disability in multiple sclerosis (MS) using a comprehensive, patient self-reported scale, such as the World Health Organization Disability Assessment Schedule (WHODAS) 2.0, would be of clinical and research benefit. METHODS: In the Trajectories of Outcome in Neurological Conditions-MS study, WHODAS 2.0 (WHODAS-36 items for working, WHODAS-32 items if not working, WHODAS-12 items short-form) was examined using Rasch analysis in 5809 people with MS. RESULTS: The 36- and 32-item parallel forms, and the cognitive and physical domains, showed reliability consistent with individual or group use. The 12-item short-form is valid for group use only. Interval level measurement for parametric statistics can be derived from all three scales which showed medium to strong effect sizes for discrimination across characteristics such as age, subtype, and disease duration. Smallest detectable difference for each scale was < 6 on the standardised metric of 0-100 so < 6% of the total range. There was no substantial differential item functioning (DIF) by age, gender, education, working full/part-time, or disease duration; the finding of no DIF for time or sample supports the use of WHODAS 2.0 for longitudinal studies, with the 36- and 32-item versions and the physical and cognitive domains valid for individual patient follow-up. CONCLUSIONS: Disability in MS can be comprehensively measured at interval level by the WHODAS 2.0, and validly monitored over time. Routine use of this self-reported measure in clinical and research practice would give valuable information on the trajectories of disability of individuals and groups.

Measuring coping in multiple sclerosis: The Coping Index-MS.

BACKGROUND: Coping in multiple sclerosis (MS) refers to cognitive and behavioural efforts to manage stresses imposed by the illness. Existing generic and disease-specific coping scales do not meet modern guidelines for scale development and cannot produce interval-level metrics to allow for change scores. OBJECTIVE: The main aim of this study was to develop a brief patient-reported outcome measure for coping in MS, capable of interval-level measurement. METHODS: Qualitative work in 43 people with MS leads to a draft scale which was administered to 5747 participants, with longitudinal collection in 2290. A calibration sample of 1000 subjects split into development and validation sets was used to generate three scales consistent with Rasch model expectations. RESULTS: The total Coping Index-MS (CI-MS-T), CI-MS-Internal (CI-MS-I) and CI-MS-External (CI-MS-E) cover total, internal and externally focused coping. All three scales are capable of interval-level measurement. Trajectory analysis of 9000 questionnaires showed two trajectories in CI-MS-T: Group 1 showed a low level of coping with slight decline over 40 months, while Group 2 had a better and stable level of coping due to improving CI-MS-I which compensated for the deteriorating CI-MS-E over time. CI-MS-T < 30 identified group membership at baseline. CONCLUSION: The CI-MS-T, CI-MS-I and CI-MS-E, comprising 20 items, provide interval-level measurement and are free-for-use in not-for-profit settings.

The four self-efficacy trajectories among people with multiple sclerosis: Clinical associations and implications.

BACKGROUND: Longitudinal studies among people with Multiple Sclerosis (pwMS) have shown that self-efficacy is linked to physical, cognitive and psychological functioning. OBJECTIVES: To determine the distribution of self-efficacy in a large sample of pwMS, examining whether there are distinct groups which show different self-efficacy trajectories over time, and the health status characteristics of any groups identified. METHODS: Participants completed serial questionnaire packs, including Unidimensional Self-efficacy-MS (USE-MS) scale, for the Trajectories of Outcome in Neurological Conditions-MS (TONiC-MS) study over an average 46-month period. The resulting longitudinal data were analysed by a group-based trajectory model. RESULTS: 5887 pwMS were studied: mean age 50.2 years (SD 12.0); 73.6% female; Relapsing Remitting MS (61.8%), Secondary Progressive (22.9%), Primary Progressive (11.1%), Rapidly Evolving Relapsing Remitting MS (4.2%). Four distinct self-efficacy trajectories emerged, with declining, slightly declining, stable or improving self-efficacy, each showing different patterns of health status indicators such as EQ-5D-5L, disability and depression. USE-MS ≤ 18 at baseline detected all participants in the two declining groups. CONCLUSION: Future trials on interventions for self-efficacy should assume a priori that those with low levels of self-efficacy (USE-MS ≤ 18 at baseline) are likely to be on a declining trajectory and may need different interventions from those with stable self-efficacy.

A case of voltage-gated potassium channel antibody-related limbic encephalitis.

BACKGROUND: A 56-year-old man presented to hospital with a 6-month history of recurrent episodes of altered behavior and 'odd' episodes. He had become apathetic and uninterested in his family. He had no relevant past medical or family history. General and physical neurological examinations were unremarkable, as was bedside cognitive testing. INVESTIGATIONS: Brain MRI scan, 24-h electroencephalogram, serum and cerebrospinal fluid testing for voltage-gated potassium channel antibodies, blood screening for tumors, CT scans of the chest, abdomen and pelvis, whole-body PET scan, neuropsychological examination, brain 18F-fluorodeoxyglucose-PET scan. DIAGNOSIS: Voltage-gated potassium channel antibody-related limbic encephalitis. MANAGEMENT: Antiepileptic drugs, immunomodulatory therapy, oral steroids, plasma exchange.

LHON/MELAS overlap syndrome associated with a mitochondrial MTND1 gene mutation.

Pathogenic point mutations in the mitochondrial MTND1 gene have previously been described in association with two distinct clinical phenotypes -- Leber hereditary optic neuropathy (LHON) and mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Here we report the first heteroplasmic mitochondrial DNA (mtDNA) point mutation (3376G>A) in the MTND1 gene associated with an overlap syndrome comprising the clinical features of both LHON and MELAS. Muscle histochemistry revealed subtle mitochondrial abnormalities, while biochemical analysis showed an isolated complex I deficiency. Our findings serve to highlight the growing importance of mutations in mitochondrial complex I structural genes in MELAS and its associated overlap syndromes.