Medicine (RMH) - Research Publications
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ItemNo Preview AvailableThe Patient-Determined Disease Steps scale is not interchangeable with the Expanded Disease Status Scale in mild to moderate multiple sclerosis(WILEY, 2024-01)BACKGROUND AND PURPOSE: The validity, reliability, and longitudinal performance of the Patient-Determined Disease Steps (PDDS) scale is unknown in people with multiple sclerosis (MS) with mild to moderate disability. We aimed to examine the psychometric properties and longitudinal performance of the PDDS. METHODS: We included relapsing-remitting MS patients with an Expanded Disability Status Scale (EDSS) score of less than 4. Validity and test-retest reliability was examined. Longitudinal data were analysed with mixed-effect modelling and Cohen's kappa for concordance in confirmed disability progression (CDP). RESULTS: We recruited a total of 1093 participants, of whom 904 had complete baseline data. The baseline correlation between PDDS and EDSS was weak (ρ = 0.45, p < 0.001). PDDS had stronger correlations with patient-reported outcomes (PROs). Conversely, EDSS had stronger correlations with age, disease duration, Kurtzke's functional systems and processing speed test. PDDS test-retest reliability was good to excellent (concordance correlation coefficient = 0.73-0.89). Longitudinally, PDDS was associated with EDSS, age and depression. A higher EDSS score was associated with greater PDSS progression. The magnitude of these associations was small. There was no concordance in CDP as assessed by PDDS and EDSS. CONCLUSION: The PDDS has greater correlation with other PROs but less correlation with other MS-related outcome measures compared to the EDSS. There was little correlation between PDDS and EDSS longitudinally. Our findings suggest that the PDDS scale is not interchangeable with the EDSS.
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ItemGait and balance deterioration over a 12-month period in multiple sclerosis patients with EDSS scores ≤ 3.0(IOS PRESS, 2017)BACKGROUND AND PURPOSE: It is not currently known whether gait and balance measures are responsive to deterioration of motor function in multiple sclerosis (MS) patients with low EDSS scores (≤3.0). The aim of this study was to quantify MS-related gait and balance deterioration over a 12-month period. METHODS: Thirty-eight participants with MS (33 female, mean age: 41.1 ± 8.3 years), mean time since diagnosis 2.2 ± 4.1 years, EDSS score ≤3.0 and without clinical evidence of gait deterioration, were recruited. Participants performed walking trials and Functional and Lateral Reach Tests. Kinematics of the ankle and knee, and electromyography of the tibialis anterior and medial gastrocnemius muscles were also measured. RESULTS: Three participants reported relapses with worsening EDSS scores and 4 non-relapsing participants had worse EDSS scores at 12 months. There were significant decreases in mean gait speed, stride length and balance scores, and a significant increase in double support. Marked changes in ankle kinematics, with decreased medial gastrocnemius activity were observed. CONCLUSION: Gait and balance performance of non-disabled RRMS participants may progressively decline, even in the absence of both acute clinical relapse and change in clinical status measured by the EDSS.
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ItemGait stability reflects motor tracts damage at early stages of multiple sclerosis(SAGE PUBLICATIONS LTD, 2022-10)BACKGROUND: Gait in people with multiple sclerosis (PwMS) is affected even when no changes can be observed on clinical examination. A sensitive measure of gait deterioration is stability; however, its correlation with motor tract damage has not yet been established. OBJECTIVE: To compare stability between PwMS and healthy controls (HCs) and determine associations between stability and diffusion magnetic resonance image (MRI) measures of axonal damage in selected sensorimotor tracts. METHODS: Twenty-five PwMS (Expanded Disability Status Scale (EDSS) < 2.5) and 15 HCs walked on a treadmill. Stability from sacrum (LDESAC), shoulder (LDESHO) and cervical (LDECER) was calculated using the local divergence exponent (LDE). Participants underwent a 7T-MRI brain scan to obtain fibre-specific measures of axonal loss within the corticospinal tract (CST), interhemispheric sensorimotor tract (IHST) and cerebellothalamic tract (CTT). Correlation analyses between LDE and fibre density (FD) within tracts, fibre cross-section (FC) and FD modulated by FC (FDC) were conducted. Between-groups LDE differences were analysed using analysis of variance (ANOVA). RESULTS: Correlations between all stability measures with CSTFD, between CSTFDC with LDESAC and LDECER, and LDECER with IHSTFD and IHSTFDC were significant yet moderate (R < -0.4). Stability was significantly different between groups. CONCLUSIONS: Poorer gait stability is associated with corticospinal tract (CST) axonal loss in PwMS with no-to-low disability and is a sensitive indicator of neurodegeneration.
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ItemImplementing education: Personal communication with a healthcare professional is a critical step to address vaccine hesitancy for people with multiple sclerosis(ELSEVIER SCI LTD, 2022-07)BACKGROUND: People with Multiple Sclerosis (PwMS) were first able to access COVID-19 vaccines in Australia from March 2021, when vaccine hesitancy in the general population was high (14-43%). High uptake of vaccination is important globally and critical to protect this vulnerable population. We conducted an on-line survey to examine factors influencing COVID-19 vaccination willingness among PwMS in Australia. METHODS: 149 PwMS living in Australia completed the on-line survey (April-September 2021) examining demographic, environmental and clinical factors with respect to vaccine willingness, including attitudes towards COVID-19 illness and vaccines. Additional items explored the influence of different information sources on vaccination decisions. Continuous and ordinal data were compared using the Mann-Whitney U test. All tests were two-tailed, with alpha set at 0.5. RESULTS: A majority of the respondents were female (87.2%) with relapsing-remitting MS (77.5%) treated by a neurologist (94.0%). A majority were on high efficacy disease-modifying therapies (DMTs) (64.9%), while 19.9% were on no DMTs. About one third of respondents (32.9%) had had two doses, 20.8% had received their first dose, and 22.1% were unvaccinated, while 24.2% of responses were missing. When asked about vaccine intentions, 60.6% of the unvaccinated indicated they were likely to extremely likely to get vaccinated, while 15.2% were very unlikely or extremely unlikely to do so and 24.2% were undecided. Unvaccinated people were significantly more concerned about vaccine side effects (mean 5.3 versus 3.1/10; p < .001). Only 53.3% of people on DMTs were vaccinated, compared to 75% of those who were not. People on ocrelizumab therapy (n = 35) had a lower vaccination rate (39%) than those on other medications (n = 86, 59%). Vaccine willingness in the unvaccinated was most highly correlated with knowledge regarding the vaccine (rs2=.709), agreement with the statement that COVID-19 vaccination is "too new for me to be confident about getting vaccinated" (rs2= -.709), anticipation of regret due to side effects of vaccination (rs2= -.642), and lack of knowledge regarding interactions between COVID-19 vaccines and DMTs (rs2= -.570). Almost two thirds had read MS-specific information about COVID-19 vaccinations and found it easy to understand (67.6%) and applicable to their situation (53.6%). However, less than half (47.8%) reported the information helped them make a personal vaccination decision. Over two-thirds (64.9%) had discussed vaccinations with their healthcare professional and 31.1% had not. Those who had not, were significantly more uninformed about the interactions of the vaccine with MS medications (mean 3.9 versus 2.9/10; p = .044) and significantly lower intention of vaccine uptake than those who had (mean 5.8 versus 7.9/10; p = .009). CONCLUSION: Our study highlights that vaccination efforts should be delivered by healthcare professionals, focus on educating those who are managed with DMTs, and include individual recommendations related to specific DMTs, how the vaccines work, expectations regarding potential side-effects, potential exacerbation of MS symptoms, likelihood of recovery from any exacerbation, and the relative risks of side effects versus COVID-19 infection. Specific recommendations are provided.
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ItemEarly predictors of visual and axonal outcomes after acute optic neuritis(FRONTIERS MEDIA SA, 2022-09-08)BACKGROUND: Predicting long-term visual outcomes and axonal loss following acute optic neuritis (ON) is critical for choosing treatment. Predictive models including all clinical and paraclinical measures of optic nerve dysfunction following ON are lacking. OBJECTIVES: Using a prospective study method, to identify 1 and 3 months predictors of 6 and 12 months visual outcome (low contrast letter acuity 2.5%) and axonal loss [retinal nerve fiber layer thickness and multifocal evoked potential (mfVEP) amplitude] following acute ON. METHODS: In total, 37 patients of acute ON onset were evaluated within 14 days using between-eye asymmetry of visual acuity, color vision (Ishihara plates), optical coherence tomography, mfVEP, and optic nerve magnetic resonance imaging [magnetic transfer ratio (MTR) and diffusion tensor imaging (DTI)]. RESULTS: Visual outcome at 6 and 12 months was best predicted by Ishihara asymmetry at 1 and 3 months following ON onset. Axonal loss at 6 and 12 months was reliably predicted by Ishihara asymmetry at 1 month. Optic nerve MTR and DTI at 3 months post-acute ON could predict axonal loss at 6 and 12 months. CONCLUSIONS: Simple Ishihara asymmetry testing 1 month after acute ON onset can best predict visual outcome and axonal loss at 6 and 12 months in a clinical or research setting.
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ItemImpact of telehealth on health care in a multiple sclerosis outpatient clinic during the COVID-19 pandemic(ELSEVIER SCI LTD, 2022-07)BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has precipitated expansion of telemedicine in outpatient management of chronic diseases including multiple sclerosis (MS). Studies conducted pre-pandemic, when telehealth was an alternative to in-person consultations, represent a different setting to current practice. The aim of this study was to assess the impact of telehealth on MS outpatient care in a tertiary metropolitan hospital in Melbourne, Australia during the COVID-19 pandemic. METHOD: From March-December 2020, patients and clinicians in the MS outpatient clinic were surveyed regarding their attitudes towards telehealth. Scores on the Expanded Disability Status Scale (EDSS) from telehealth and face-to-face appointments during the study period were compared to scores from face-to-face consultations before and after this period. Medical records were reviewed to compare management decisions made during telehealth versus face-to-face consultations. Diagnoses and treatment of MS relapses were compared to 2019. RESULTS: Telehealth was used in 73% of outpatient appointments. Patient satisfaction was generally high. Patients and clinicians preferred face-to-face consultations but were willing to use telehealth longer term. Overall, there were no significant delays in identifying patients experiencing disability worsening via telehealth, but EDSS increase was recorded in more face-to-face than telehealth appointments particularly for those with lower baseline disability. Disease-modifying therapy commencement rates were similar, but symptomatic therapy initiation and investigation requests occurred more frequently in face-to-face visits. Comparable numbers of MS relapses were diagnosed and treated with corticosteroids in 2019 and 2020. CONCLUSIONS: Patient satisfaction with telehealth was high, but both clinicians and patients preferred in-person appointments. Telehealth implementation did not lead to high rates of undetected disability worsening or undiagnosed acute relapses, but telehealth-based EDSS assessment may underestimate lower scores. Treatment inertia may affect some management decisions during telehealth consultations. Telehealth will likely play a role in outpatient settings beyond the COVID-19 pandemic with further studies on its long-term impact on clinical outcomes required.
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ItemMRI Patterns Distinguish AQP4 Antibody Positive Neuromyelitis Optica Spectrum Disorder From Multiple Sclerosis(FRONTIERS MEDIA SA, 2021-09-09)Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are inflammatory diseases of the CNS. Overlap in the clinical and MRI features of NMOSD and MS means that distinguishing these conditions can be difficult. With the aim of evaluating the diagnostic utility of MRI features in distinguishing NMOSD from MS, we have conducted a cross-sectional analysis of imaging data and developed predictive models to distinguish the two conditions. NMOSD and MS MRI lesions were identified and defined through a literature search. Aquaporin-4 (AQP4) antibody positive NMOSD cases and age- and sex-matched MS cases were collected. MRI of orbits, brain and spine were reported by at least two blinded reviewers. MRI brain or spine was available for 166/168 (99%) of cases. Longitudinally extensive (OR = 203), "bright spotty" (OR = 93.8), whole (axial; OR = 57.8) or gadolinium (Gd) enhancing (OR = 28.6) spinal cord lesions, bilateral (OR = 31.3) or Gd-enhancing (OR = 15.4) optic nerve lesions, and nucleus tractus solitarius (OR = 19.2), periaqueductal (OR = 16.8) or hypothalamic (OR = 7.2) brain lesions were associated with NMOSD. Ovoid (OR = 0.029), Dawson's fingers (OR = 0.031), pyramidal corpus callosum (OR = 0.058), periventricular (OR = 0.136), temporal lobe (OR = 0.137) and T1 black holes (OR = 0.154) brain lesions were associated with MS. A score-based algorithm and a decision tree determined by machine learning accurately predicted more than 85% of both diagnoses using first available imaging alone. We have confirmed NMOSD and MS specific MRI features and combined these in predictive models that can accurately identify more than 85% of cases as either AQP4 seropositive NMOSD or MS.
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ItemAxonal loss in major sensorimotor tracts is associated with impaired motor performance in minimally disabled multiple sclerosis patients(OXFORD UNIV PRESS, 2021)Multiple sclerosis is a neuroinflammatory disease of the CNS that is associated with significant irreversible neuro-axonal loss, leading to permanent disability. There is thus an urgent need for in vivo markers of axonal loss for use in patient monitoring or as end-points for trials of neuroprotective agents. Advanced diffusion MRI can provide markers of diffuse loss of axonal fibre density or atrophy within specific white matter pathways. These markers can be interrogated in specific white matter tracts that underpin important functional domains such as sensorimotor function. This study aimed to evaluate advanced diffusion MRI markers of axonal loss within the major sensorimotor tracts of the brain, and to correlate the degree of axonal loss in these tracts to precise kinematic measures of hand and foot motor control and gait in minimally disabled people with multiple sclerosis. Twenty-eight patients (Expanded Disability Status Scale < 4, and Kurtzke Functional System Scores for pyramidal and cerebellar function ≤ 2) and 18 healthy subjects underwent ultra-high field 7 Tesla diffusion MRI for calculation of fibre-specific measures of axonal loss (fibre density, reflecting diffuse axonal loss and fibre cross-section reflecting tract atrophy) within three tracts: cortico-spinal tract, interhemispheric sensorimotor tract and cerebello-thalamic tracts. A visually guided force-matching task involving either the hand or foot was used to assess visuomotor control, and three-dimensional marker-based video tracking was used to assess gait. Fibre-specific axonal markers for each tract were compared between groups and correlated with visuomotor task performance (force error and lag) and gait parameters (stance, stride length, step width, single and double support) in patients. Patients displayed significant regional loss of fibre cross-section with minimal loss of fibre density in all tracts of interest compared to healthy subjects (family-wise error corrected p-value < 0.05), despite relatively few focal lesions within these tracts. In patients, reduced axonal fibre density and cross-section within the corticospinal tracts and interhemispheric sensorimotor tracts were associated with larger force tracking error and gait impairments (shorter stance, smaller step width and longer double support) (family-wise error corrected p-value < 0.05). In conclusion, significant gait and motor control impairments can be detected in minimally disabled people with multiple sclerosis that correlated with axonal loss in major sensorimotor pathways of the brain. Given that axonal loss is irreversible, the combined use of advanced imaging and kinematic markers could be used to identify patients at risk of more severe motor impairments as they emerge for more aggressive therapeutic interventions.
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ItemNo Preview AvailablePredicting Infection Risk in Multiple Sclerosis Patients Treated with Ocrelizumab: A Retrospective Cohort Study(ADIS INT LTD, 2021-08)BACKGROUND: Ocrelizumab safety outcomes have been well evaluated in clinical trials and open-label extension (OLE) studies. However, risk factors for infection in patients with multiple sclerosis (MS) receiving ocrelizumab have not been extensively studied in the real-world setting. OBJECTIVE: The aim of this study was to examine factors determining risk of self-reported infections and antimicrobial use in patients receiving ocrelizumab for MS. METHODS: A retrospective, observational cohort study was conducted in patients receiving ocrelizumab at the Royal Melbourne Hospital. Infection type and number were reported by patients, and the associations of potential clinical and laboratory risk factors with self-reported infection and antimicrobial use were estimated using univariate and multivariable logistic regression models. RESULTS: A total of 185 patients were included in the study; a total of 176 infections were reported in 89 patients (46.1%), and antimicrobial use was identified in 47 patients (25.3%). In univariate analyses, a higher serum IgA was associated with reduced odds of infection (OR 0.44, 95% CI 0.25-0.76). In multivariable analyses, older age (OR 0.94, 95% CI 0.88-0.99), higher serum IgA (OR 0.37, 95% CI 0.17-0.80) and higher serum IgG (OR 0.81, 95% CI 0.67-0.99) were associated with reduced odds of infection. Older age (OR 0.85, 95% CI 0.75-0.96) and higher serum IgA (OR 0.23, 95% CI 0.07-0.79) were associated with reduced odds of antimicrobial use, whilst longer MS disease duration (OR 1.22, 95% CI 1.06-1.41) and higher Expanded Disability Status Scale (EDSS) score (OR 1.99, 95% CI 1.02-3.86) were associated with increased odds of antimicrobial use. CONCLUSIONS: Higher serum IgA and IgG and older age were associated with reduced odds of infection. Our findings highlight that infection risk is not uniform in patients with MS receiving ocrelizumab and substantiate the need to monitor immunoglobulin levels pre-treatment and whilst on therapy.
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ItemFunctional correlates of motor control impairments in multiple sclerosis: A 7 Tesla task functional MRI study(WILEY, 2021-06-01)Upper and lower limb impairments are common in people with multiple sclerosis (pwMS), yet difficult to clinically identify in early stages of disease progression. Tasks involving complex motor control can potentially reveal more subtle deficits in early stages, and can be performed during functional MRI (fMRI) acquisition, to investigate underlying neural mechanisms, providing markers for early motor progression. We investigated brain activation during visually guided force matching of hand or foot in 28 minimally disabled pwMS (Expanded Disability Status Scale (EDSS) < 4 and pyramidal and cerebellar Kurtzke Functional Systems Scores ≤ 2) and 17 healthy controls (HC) using ultra-high field 7-Tesla fMRI, allowing us to visualise sensorimotor network activity in high detail. Task activations and performance (tracking lag and error) were compared between groups, and correlations were performed. PwMS showed delayed (+124 s, p = .002) and more erroneous (+0.15 N, p = .001) lower limb tracking, together with lower cerebellar, occipital and superior parietal cortical activation compared to HC. Lower activity within these regions correlated with worse EDSS (p = .034), lower force error (p = .006) and higher lesion load (p < .05). Despite no differences in upper limb task performance, pwMS displayed lower inferior occipital cortical activation. These results demonstrate that ultra-high field fMRI during complex hand and foot tracking can identify subtle impairments in lower limb movements and upper and lower limb brain activity, and differentiates upper and lower limb impairments in minimally disabled pwMS.