Motor function in multiple sclerosis assessed by navigated transcranial magnetic stimulation mapping.

INTRODUCTION: Impaired motor function is a major cause of disability in multiple sclerosis (MS), involving various neuroplasticity processes typically assessed by neuroimaging. This study aimed to determine whether navigated transcranial magnetic stimulation (nTMS) could also provide biomarkers of motor cortex plasticity in patients with MS (pwMS). METHODS: nTMS motor mapping was performed for hand and leg muscles bilaterally. nTMS variables included the amplitude and latency of motor evoked potentials (MEPs), corticospinal excitability measures, and the size of cortical motor maps (CMMs). Clinical assessment included disability (Expanded Disability Status Scale, EDSS), strength (MRC scale, pinch and grip), and dexterity (9-hole Pegboard Test). RESULTS: nTMS motor mapping was performed in 68 pwMS. PwMS with high disability (EDSS ≥ 3) had enlarged CMMs with less dense distribution of MEPs and various MEP parameter changes compared to pwMS with low disability (EDSS < 3). Patients with progressive MS had also various MEP parameter changes compared to pwMS with relapsing remitting form. MRC score correlated positively with MEP amplitude and negatively with MEP latency, pinch strength correlated negatively with CMM volume and dexterity with MEP latency. CONCLUSIONS: This is the first study to perform 4-limb cortical motor mapping in pwMS using a dedicated nTMS procedure. By quantifying the cortical surface representation of a given muscle and the variability of MEP within this representation, nTMS can provide new biomarkers of motor function impairment in pwMS. Our study opens perspectives for the use of nTMS as an objective method for assessing pwMS disability in clinical practice.

COVID-19 outcomes in patients with multiple sclerosis: Understanding changes from 2020 to 2022.

BACKGROUND: Epidemiologic studies on coronavirus disease 2019 (COVID-19) in patients with multiple sclerosis (pwMS) have focused on the first waves of the pandemic until early 2021. OBJECTIVES: We aimed to extend these data from the onset of the pandemic to the global coverage by vaccination in summer 2022. METHODS: This retrospective, multicenter observational study analyzed COVISEP registry data on reported COVID-19 cases in pwMS between January 2020 and July 2022. Severe COVID-19 was defined as hospitalization or higher severity. RESULTS: Among 2584 pwMS with confirmed/highly suspected COVID-19, severe infection rates declined from 14.6% preomicron wave to 5.7% during omicron wave (p < 0.001). Multivariate analysis identified age (odds ratio (OR) = 1.43, 95% confidence interval (CI) = [1.25-1.64] per 10 years), male sex (OR = 2.01, 95% CI = [1.51-2.67]), obesity (OR = 2.36, 95% CI = [1.52-3.68]), cardiac comorbidities (OR = 2.36, 95% CI = [1.46-3.83]), higher Expanded Disability Status Scale (EDSS) scores (OR = 2.09, 95% CI = [1.43-3.06] for EDSS 3-5.5 and OR = 4.53, 95% CI = [3.04-6.75] for EDSS ⩾6), and anti-CD20 therapies (OR = 2.67, 95% CI = [1.85-3.87]) as risk factors for COVID-19 severity. Vaccinated individuals experienced less severe COVID-19, whether on (risk ratio (RR) = 0.64, 95% CI = [0.60-0.69]) or off (RR = 0.32, 95% CI = [0.30-0.33]) anti-CD20. DISCUSSION: In pwMS, consistent risk factors were anti-CD20 therapies and neurological disability, emerging as vital drivers of COVID-19 severity regardless of wave, period, or vaccination status.

Optic Nerve Lesion Length at the Acute Phase of Optic Neuritis Is Predictive of Retinal Neuronal Loss.

BACKGROUND AND OBJECTIVES: Acute optic neuritis (ON) is a classical presenting symptom of multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and anti-MOG-associated disorders. The resulting visual impairment is variable and can be severe. Clinicians are in need of predictive biomarkers to optimize the management of acute ON. In this longitudinal study (IRMANO, NCT03651662), we evaluated the ability of optic nerve lesion length measured on MRI at the acute phase of ON to predict retinal neuro-axonal loss and visual impairment at a chronic stage. METHODS: We conducted a longitudinal study (IRMANO, NCT03651662) of patients who presented a clinical episode of ON (≤8 weeks). All patients underwent a retinal optical coherence tomography (OCT) and a brain/optic nerve MRI, including 3D double-inversion recovery (DIR) sequence at the acute phase of ON and 12 months later. Primary outcomes were optic nerve DIR hypersignal lesion length, macular ganglion cell-inner plexiform layer (GCIPL) volume measured on OCT, and low-contrast monocular visual acuity (LCMVA). RESULTS: The study group included 51 patients (33 women, mean age of 32.4 years ± 7.9). We recruited patients with a clinically isolated syndrome (n = 20), a relapsing-remitting MS (n = 23), an isolated ON (n = 6), and a first clinical episode of NMOSD (n = 2). Optic nerve DIR hypersignal was observed in all but 1 symptomatic optic nerves. At inclusion, the mean optic nerve lesion length (in mm) was 12.35 ± 5.98. The mean GCIPL volume (in mm3) significantly decreased between inclusion (1.90 ± 0.18) and M12 (1.67 ± 0.21; p < 0.0001). Optic nerve lesion length at inclusion was significantly associated with GCIPL thinning (estimate ± SD; -0.012 ± 0.004; p = 0.0016) and LCMVA at M12 (0.016 ± 0.003; p < 0.001). Optic nerve lesion length significantly increased at M12 (15.76 ± 8.70; p = 0.0007). The increase in optic nerve lesion length was significantly associated with the GCIPL thinning between inclusion and M12 (-0.012 ± 0.003; p = 0.0011). DISCUSSION: At the acute phase of ON, optic nerve lesion length is an imaging biomarker predictive of retinal neuro-axonal loss and chronic visual impairment, which can help to stratify future therapeutic strategies in acute ON. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that optic nerve lesion length measured on MRI during the acute phase of a first episode of ON is associated with long-term retinal neuro-axonal loss and visual impairment.

Outcomes of coronavirus disease 2019 in patients with neuromyelitis optica and associated disorders.

BACKGROUND: Outcomes of coronavirus disease 2019 (COVID-19) in patients with neuromyelitis optica spectrum disorders (NMOSD) or myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), often treated with immunosuppressive therapies, are still unknown. METHODS: We conducted a multicenter, retrospective, observational cohort study among all French expert centers for neuromyelitis optica and related disorders. Patients with NMOSD or MOGAD included in the study received a confirmed or highly suspected diagnosis of COVID-19 between 1 March 2020 and 30 June 2020. Main outcome was COVID-19 severity score assessed on a seven-point ordinal scale ranging from 1 (not hospitalized with no limitations on activities) to 7 (death). RESULTS: Fifteen cases (mean [SD] age: 39.3 [14.3] years, 11 female) were included. Five patients (33.3%) were hospitalized, all receiving rituximab. A 24-year-old patient with positive aquaporine-4 antibody, with obesity as comorbidity, needed mechanical ventilation. Outpatients were receiving anti-CD20 (5), mycophenolate mofetil (3) or azathioprine (3). They were younger (mean [SD] age: 37.0 [13.4] years), with a longer disease duration (mean [SD]: 8.3 [6.3] years) and had a lower expanded disability severity score (EDSS) score (median [range] EDSS: 2.5 [0-4]) relative to patients requiring hospitalization (mean [SD] age: 44.0 [16.4] years, mean [SD] disease duration: 5.8 [5.5] years, median [range] EDSS: 4 [0-6.5]). CONCLUSIONS: COVID-19 outcome was overall favorable in this cohort. Larger international studies are needed to identify risk factors of severe COVID-19; however, we recommend personal protective measures to reduce risk of SARS-CoV-2 infection in this immunocompromised population.

Optical coherence tomography for detection of asymptomatic optic nerve lesions in clinically isolated syndrome.

OBJECTIVE: To evaluate the ability of intereye retinal thickness difference (IETD) measured by optical coherence tomography (OCT) to detect asymptomatic optic nerve involvement in clinically isolated syndrome (CIS). METHODS: We conducted a cross-sectional study of patients who recently presented a CIS (≤4.5 months). All patients underwent OCT and brain/optic nerve MRI. Optic nerve involvement was defined clinically (episode of optic neuritis [ON] or not) and radiologically (optic nerve hypersignal on 3D double inversion recovery [3D-DIR]). We evaluated the sensitivity and specificity of previously published IETD thresholds and report the observed optimal thresholds for identifying symptomatic optic nerve involvement but also for identifying asymptomatic optic nerve involvement (optic nerve hypersignal without ON history). Primary outcomes were ganglion cell-inner plexiform layer (GC-IPL) and peripapillary retinal nerve fiber layer IETD. RESULTS: The study group consisted of 130 patients. In the CIS with ON group, 3D-DIR showed a hypersignal in all 41 symptomatic optic nerves and in 11 asymptomatic optic nerves. In the CIS without ON group, 3D-DIR showed a unilateral optic nerve hypersignal in 22 patients and a bilateral optic nerve hypersignal in 7 patients. For the detection of symptomatic and asymptomatic optic nerve lesion, GC-IPL IETD had better performance. We found an optimal GC-IPL IETD threshold ≥2.83 µm (sensitivity 88.2, specificity 83.3%) for the detection of symptomatic lesions and an optimal GC-IPL IETD ≥1.42 µm (sensitivity 89.3%, specificity 72.6%) for the detection of asymptomatic lesions. CONCLUSIONS: Detection of asymptomatic optic nerve lesions in CIS requires lower IETD thresholds than previously reported. GC-IPL IETD represents an alternative biomarker to MRI for the detection of asymptomatic optic nerve lesions. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that OCT accurately identifies asymptomatic optic nerve involvement in patients with CIS.

Outcomes of Nonagenarians with Acute Ischemic Stroke Treated with Intravenous Thrombolytics.

BACKGROUND: Nonagenarians are under-represented in thrombolytic trials for acute ischemic stroke (AIS). The effectiveness of intravenous thrombolytics in nonagenarians in terms of safety and outcome is not well established. MATERIALS AND METHODS: We used a multinational registry to identify patients aged 90 years or older with good baseline functional status who presented with AIS. Differences in outcomes-disability level at 90 days, frequency of symptomatic intracerebral hemorrhage (sICH), and mortality-between patients who did and did not receive thrombolytics were assessed using multivariable logistic regression, adjusted for prespecified prognostic factors. Coarsened exact matching (CEM) was utilized before evaluating outcome by balancing both groups in the sensitivity analysis. RESULTS: We identified 227 previously independent nonagenarians with AIS; 122 received intravenous thrombolytics and 105 did not. In the unmatched cohort, ordinal analysis showed a significant treatment effect (adjusted common odds ratio [OR]: .61, 95% confidence interval [CI]: .39-.96). There was an absolute difference of 8.1% in the rate of excellent outcome in favor of thrombolysis (17.4% versus 9.3%; adjusted ratio: .30, 95% CI: .12-.77). Rates of sICH and in-hospital mortality were not different. Similarly, in the matched cohort, CEM analysis showed a shift in the primary outcome distribution in favor of thrombolysis (adjusted common OR: .45, 95% CI: .26-.76). CONCLUSIONS: Nonagenarians treated with thrombolytics showed lower stroke-related disability at 90 days than those not treated, without significant difference in sICH and in-hospital mortality rates. These observations cannot exclude a residual confounding effect, but provide evidence that thrombolytics should not be withheld from nonagenarians because of age alone.