Background: Evaluation of the structural integrity and functional excitability of the corticospinal tract (CST) is likely to be important in predicting motor recovery after stroke. Previous reports are inconsistent regarding a possible link between CST structure and CST function in this setting. This study aims to investigate the structure‒function relationship of the CST at the acute phase of stroke (<7 days).
Methods: We enrolled 70 patients who had an acute ischaemic stroke with unilateral upper extremity (UE) weakness. They underwent a multimodal assessment including clinical severity (UE Fugl Meyer at day 7 and 3 months), MRI to evaluate the CST lesion load and transcranial magnetic stimulation to measure the maximum amplitude of motor evoked potential (MEP).
Results: A cross-sectional lesion load above 87% predicted the absence of MEPs with an accuracy of 80.4%. In MEP-positive patients, the CST structure/function relationship was bimodal with a switch from a linear relationship (rho=-0.600, 95% CI -0.873; -0.039, p<0.03) for small MEP amplitudes (<0.703 mV) to a non-linear relationship for higher MEP amplitudes (p=0.72). In MEP-positive patients, recovery correlated with initial severity. In patients with a positive MEP <0.703 mV but not in patients with an MEP ≥0.703 mV, MEP amplitude was an additional independent predictor of recovery. In MEP-negative patients, we failed to identify any factor predicting recovery.
Conclusion: This large multimodal study on the structure/function of the CST and stroke recovery proposes a paradigm change for the MEP-positive patients phenotypes and refines the nature of the link between structural integrity and neurophysiological function, with implications for study design and prognostic information.
Background: Neuromyelitis optica spectrum disorder (NMOSD) can be categorised into aquaporin-4 antibody (AQP4-IgG) NMOSD or seronegative NMOSD. While our knowledge of AQP4-IgG NMOSD has evolved significantly in the past decade, seronegative NMOSD remains less understood. This study aimed to evaluate the predictors of relapses and treatment responses in AQP4-IgG NMOSD and seronegative NMOSD.
Methods: This was a multicentre, international, retrospective cohort study using the MSBase registry. Recurrent relapse risk was assessed using an Andersen-Gill model and risk of first relapse was evaluated using a Cox proportional hazards model. Covariates that putatively influence relapse risk included demographic factors, clinical characteristics and immunosuppressive therapies; the latter was assessed as a time-varying covariate.
Results: A total of 398 patients (246 AQP4-IgG NMOSD and 152 seronegative NMOSD) were included. The AQP4-IgG NMOSD and seronegative NMOSD patients did not significantly differ by age at disease onset, ethnicity or annualised relapse rate. Both low-efficacy and high-efficacy immunosuppressive therapies were associated with significant reductions in recurrent relapse risk, with notably greater protection conferred by high-efficacy therapies in both AQP4-IgG NMOSD (HR 0.27, 95% CI 0.15 to 0.49, p<0.001) and seronegative NMOSD (HR 0.21, 95% CI 0.08 to 0.51, p<0.001). Longer disease duration (HR 0.97, 95% CI 0.95 to 0.99, p<0.001) and male sex (HR 0.52, 95% CI 0.34 to 0.84, p=0.007) were additional protective variables in reducing the recurrent relapse risk for the AQP4-IgG NMOSD group.
Conclusion: Although further studies are needed to improve our understanding of seronegative NMOSD, our findings underscore the importance of aggressive treatment with high-efficacy immunotherapies in both NMOSD subtypes, regardless of serostatus.
Background: Previous natural history studies highlighted a consistent heterogeneity of disability trajectories among individuals with primary or secondary progressive multiple sclerosis (MS). However, evidence on disability progression in relapsing onset MS is scarce.The aim of this study was to investigate heterogeneity in disability accumulation over 10 years following a first clinical diagnosis of central nervous system demyelination (FCD) and identify genetic, demographic, environmental and clinical factors associated with these trajectories.
Methods: We used group-based trajectory models to measure heterogeneity in disability trajectories based on the Expanded Disability Status Scale (EDSS) in a prospectively assessed cohort of 263 participants. To capture sustained neurological impairments and avoid issues related to significant changes in EDSS associated with relapse, we did not consider EDSS points recorded within 3 months of a relapse.
Results: We identified three distinct and clinically meaningful disability trajectories: No/minimal, moderate and severe. Those in the no/minimal disability trajectory showed no appreciable progression of disability (median EDSS∼1 at 10-year review) while those in the moderate and severe disability trajectories experienced disability worsening (median time to reach EDSS 4 was 9 and 7 years, respectively). Compared with the no/minimal disability trajectory, those with older age, a higher number of relapses within the first 5 years post-FCD, and a higher number of comorbidities at baseline were more likely to be in the worse disability trajectory. Surprisingly, baseline MRI and anatomical site of initial symptoms did not influence long-term outcomes.
Conclusions: Those at higher risk of faster MS disability progression can be identified based on their early clinical characteristics with potential therapeutic implications for early intervention and treatment escalation.
Background: Total bilirubin (TBIL) has antioxidant and anti-inflammatory properties. This study aimed to determine whether elevated TBIL could modify the association between diabetes and stroke.
Method: Data were obtained from the National Health and Nutrition Examination Survey 2011-2016. TBIL was stratified by median (10.3 µmol/L). The association between diabetes and stroke was quantified using multivariable logistic regression models. The cut-off concentration for the presence of TBIL modification effects was identified by Johnson-Neyman analyses. Mediation analyses were performed to determine the influence of TBIL on mediating factors that mediate the relationship between diabetes and stroke.
Results: This cross-sectional study included 16 130 participants, with the mean age of 46.8±0.4 years and 48.5% of men. Diabetes was associated with the presence of stroke at TBIL <10.3 µmol/L (OR=2.19, 95% CI 1.58 to 3.05) but not at TBIL ≥10.3 µmol/L (OR=1.27, 95% CI 0.85 to 1.88) after adjustment for confounders. Above associations were significantly different between the two TBIL concentrations (P for interaction=0.03). Moreover, the modification effect of TBIL specifically occurred in men (P for interaction=0.02) rather than in women (P for interaction=0.08). The cut-off concentration for the presence of TBIL modification effects was 17.05 µmol/L. Additionally, the TBIL of ≥10.3 µmol/L inhibited mediating effects of hypersensitive C reactive protein (mediating effect=0.03, 95% CI -0.15 to 0.22, P=0.72) and systemic immune-inflammation index (mediating effect=0.01, 95% CI -0.01 to 0.04, P=0.29) as compared with the TBIL of <10.3 µmol/L.
Conclusions: Elevated TBIL modified the association between diabetes and stroke through inhibiting mediating effects of inflammatory factors.
Background: Cryptogenic new-onset refractory status epilepticus (cNORSE) currently lacks comprehensive knowledge regarding its clinical dynamics, prognostic factors and treatment guidance. Here we present the longitudinal clinical profiles, predictive factors for outcomes and the optimal duration of immunotherapy in patients with cNORSE.
Methods: This retrospective secondary endpoint analysis investigated patients with cNORSE identified from a prospective autoimmune encephalitis cohort at a national referral centre in Korea. The main outcomes included longitudinal functional scales, seizure frequency and the number of antiseizure medications. Measures encompassed NORSE-related clinical parameters such as the duration of unconsciousness, immunotherapy profiles, cytokine/chemokine analysis, and serial MRI scans.
Results: A total of 74 patients with cNORSE were finally analysed (mean age: 38.0±18.2; 36 (48.6%) male). All patients received first-line immunotherapy, and 91.9% (68/74) received second-line immunotherapy. A total of 83.8% (62/74) regained consciousness within a median duration of 30 days (14-56), and 50% (31/62) achieved good outcome (mRS ≤2) at 2 years. Poor 1-year outcomes (mRS ≥3) were predicted by the presence of mesial temporal lobe (mTL) and extra-mTL lesions at 3-month MRI, and prolonged unconsciousness (≥60 days). Those with mTL atrophy exhibited a higher seizure burden post-NORSE. The optimal duration of immunotherapy appeared to be between 18 weeks and 1-year post-NORSE onset.
Conclusions: This study elucidates longitudinal clinical dynamics, functional outcomes, prognostic factors and immunotherapy response in patients with cNORSE. These findings might contribute to a more standardised understanding and clinical decision-making for cNORSE.
Background: The cognitive effects of sports-related concussion (SRC) have been the subject of vigorous debate but there has been little research into long-term outcomes in non-athlete populations.
Methods: This cohort study of UK community-dwelling adults (aged 50-90 years) was conducted between November 2015 and November 2020, with up to 4 years annual follow-up (n=15 214). Lifetime history of concussions was collected at baseline using the Brain Injury Screening Questionnaire. The first analysis grouped participants by type of concussion (no concussion, only SRC, only non-SRC (nSRC), mixed concussions (both SRC and nSRC)) and the second grouped the participants by number (0, 1, 2 or 3+ SRC or nSRC). Mixed models were used to assess the effect of concussion on outcomes including four cognitive domains and one behavioural measure (Mild Behavioural Impairment-C).
Results: Analysis of the included participants (24% male, mean age=64) at baseline found that the SRC group had significantly better working memory (B=0.113, 95% CI 0.038, 0.188) and verbal reasoning (B=0.199, 95% CI 0.092, 0.306) compared with those without concussion. Those who had suffered one SRC had significantly better verbal reasoning (B=0.111, 95% CI 0.031, 0.19) and attention (B=0.115, 95% CI 0.028, 0.203) compared with those with no SRC at baseline. Those with 3+ nSRCs had significantly worse processing speed (B=-0.082, 95% CI -0.144 to -0.019) and attention (B=-0.156, 95% CI -0.248 to -0.063). Those with 3+ nSRCs had a significantly worse trajectory of verbal reasoning with increasing age (B=-0.088, 95% CI -0.149 to -0.026).
Conclusions: Compared with those reporting no previous concussions, those with SRC had no cognitive or behavioural deficits and seemed to perform better in some tasks. As indicated by previous studies, sports participation may confer long-term cognitive benefits.