Oskarsson, Björn

ABSTRACT Introduction/Aims There are no established biomarkers of upper motor neuron degeneration to aid in the diagnosis of motor neuron disease (MND). This study examines the diagnostic value of the motor band sign as a marker of upper motor neuron degeneration and its relationship to clinical findings in MND. Methods Records of consecutive patients who underwent 7T magnetic resonance imaging (MRI) between October 2021 and April 2025 for evaluation of MND or other neurologic indications were retrospectively reviewed. Clinical variables and plasma neurofilament light chain (pNfL) levels were recorded. An upper motor neuron score (Mayo UMNS) was derived from reflex scores. Blinded MRI review assessed the degree of susceptibility‐weighted imaging (SWI) hypointensity in the hand, foot, and bulbar motor cortex regions. Results An MBS was observed in 100 of 117 (85.5%) MND patients and in 16 (15.5%) patients with non‐MND diagnoses, corresponding to a sensitivity of 85.5% (78.0%–90.7%) and 84.5% (76.2%–90.2%) specificity. The MBS in 78 MND patients (70.9%) preferentially involved the middle and deep cortical layers, giving a trilaminar appearance, while only one non‐MND patient had this finding. Mayo UMNS ( β = 0.89, p < 0.001), pNfL ( β = 0.63, p = 0.033), and age at evaluation ( β = 0.68, p = 0.027) were independently associated with the summed SWI score. Discussion The 7T MRI MBS is a sensitive and specific marker for MND that complements established clinical evaluation. Using 7T, a trilaminar appearance of the motor cortex, reflecting known histopathological changes, can be visualized and may be specific to MND.

ABSTRACT Background Primary lateral sclerosis (PLS) is an ultrarare upper motor neuron syndrome with a prognosis unique from classical ALS. The study of PLS is complicated by its rarity and the difficulty distinguishing PLS from ALS. We present data from a 1‐year prospective follow‐up study on PLS and efforts to distinguish it from ALS. Methods Seventy‐six PLS participants enrolled in this prospective natural history study. EMG studies, blood neurofilament light chain levels (NfLs), and demographic characteristics were obtained at baseline. At 1‐year follow‐up, repeat EMG studies were conducted to determine which participants fulfilled criteria for ALS. Baseline characteristics were then compared to determine features that predict reclassification. Results Seventy participants completed 1‐year follow‐up. Five of the 70 were reclassified to ALS (7.1%). Those reclassified had higher trends in baseline blood NfL levels (91.4 vs. 34.0 pg/mL, p = 0.13) and shorter symptom duration (39 vs. 69 months in the PLS group, p = 0.15). Reclassification was noted in both probable and definite PLS participants. All cases with a symptomatic duration of less than 2 years retained the PLS phenotype (5 of 5). NfL levels over 90 pg/mL predicted reclassification with 94% specificity and 60% sensitivity. No other features predicted reclassification to ALS. Conclusions In our population, reclassification of PLS to ALS occurred at a low frequency at 1 year follow‐up (7.1%). Baseline NfL was the strongest predictor in differentiating UMN dominant ALS from PLS at 1‐year follow‐up. Based on our data, we propose EMG and NfL criteria for enrollment in future PLS trials.

Abstract Background G 4 C 2 repeat expansions in C9orf72 gene are the most common genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Mounting evidence indicates that dipeptide repeat (DPR) proteins translated from the expanded repeats, in particular poly(GR) and poly(PR), play a significant role. We and others have shown that these positively‐charged arginine‐rich DPR proteins induce the assembly of stress granules (SGs) and impair their disassembly. While distinct from SGs, processing bodies (PBs) are also cytoplasmic messenger ribonucleoprotein condensates that assemble upon stress. However, the impacts of arginine‐rich DPR proteins on PB assembly and dynamics have yet to be investigated. Method We conducted immunofluorescence staining for arginine‐rich DPR proteins, SG‐ and PB‐associated markers in cultured cells and mouse brain. Additionally, we performed in vitro liquid‐liquid phase separation (LLPS) using recombinant proteins and assessed molecular dynamics of SG and PB through fluorescence recovery (FRAP) after photobleaching in living cells. Result Here, we observed that both GFP‐(GR) 100 and GFP‐(PR) 100 formed cytosolic inclusions immunopositive PB proteins. Unlike GFP‐(GR) 100 and GFP‐(PR) 100 inclusions, cellular cytoplasmic GFP‐(GA) 100 inclusions did not contain PB proteins. We subsequently examined whether the phenomena observed in cultured cells occur in vivo. We observed that PB proteins were recruited to poly(GR) inclusions in cells with aggregated poly(GR). Next, we examined the dynamics of poly(GR)‐induced PBs in cultured cells using the FRAP technique. We observed that the recovery of stress‐induced PBs was more rapid than that of PBs in HEK293T cells expressing GFP‐(GR) 100 . Lastly, mechanistic studies revealed that poly(GR) interacts with PB proteins to form condensates in vitro via LLPS. Conclusion Our results provide both in vitro and in vivo evidence that arginine‐rich DPRs induce the spontaneous formation of PBs via LLPS. Our results also indicate that poly(GR)‐induced PBs are more stable than the transient and dynamic conventional PBs. Given that PBs uniquely enriched with mRNA degradation and decay factors, the consequences of impairing these processes are expected to contribute to abnormal RNA metabolism in c9FTD/ALS.

Background/Objectives: Overall survival in patients with amyotrophic lateral sclerosis (ALS) is linked to the rate of predicted respiratory vital capacity (PVC) loss. The objective of this study was to test whether changes in quantitative PVC measures over time linked to survival would define an immunopathogenic subset of ALS responsive to NP001, a regulator of innate immunity. Methods: In a retrospective study, data from intent-to-treat (ITT) population of two phase 2 trials of NP001 were evaluated for over time changes in PVC, time-to-event (TTE) loss of 15% PVC and PVC change from baseline, as linked to survival outcomes in patients treated with NP001 vs placebo. Results: Treatment with NP001 was associated with a significantly lower risk compared to placebo in the loss of 15% PVC over six months (p = 0.01; HR = 0.60, 95% CI: 0.39, 0.90). Data from the two trials were subsequently divided by a disease progression rate (DPR) value of 0.50 units of ALSFRS-R score lost per month for analysis of slow vs. rapid disease. In ALS patients with slowly progressive disease (DPR < 0.50), TTE PVC changes from baseline were slowed (p < 0.0005) and overall survival extended significantly (18.5 months) in NP001-treated vs. placebo groups. The rapidly progressive ALS patients (DPR ≥ 0.50) treated with NP001 showed no significant difference in PVC change or survival from the placebo group. Conclusions: These hypothesis-generating observations suggest that inflammation might play a significant role in the loss of respiratory function in a major subset of ALS patients.

Objective The primary lateral sclerosis ( PLS ) consensus diagnostic criteria and functional rating scale ( PLSFRS ) were recently established to facilitate and optimize future PLS clinical trials. We examined the trajectory of the PLSFRS and other functional outcome measures and biomarkers in the PLS Natural History Study ( PLS NHS ) to understand their performance in this prospective cohort. Methods The PLS NHS is a prospective, longitudinal, multicenter study of people living with PLS in different diagnostic categories: early (disease duration <2 years); probable (2–4 years); and definite PLS (4–15 years). PLSFRS scores and other functional outcome measures were collected at baseline, 3‐, 6‐, 9‐, and 12‐month follow‐up visits. Baseline characteristics were compared between the groups. The slopes of the PLSFRS and other functional outcome measures over 12 months were examined in the overall cohort and subgroups using linear mixed‐effect models. The associations between baseline characteristics and the rate of PLSFRS decline were analyzed with linear regression models. Results A total of 76 participants were included: early (n = 6); probable (n = 26); and definite (n = 44) PLS . Baseline PLSFRS total scores were highest in the early PLS group, followed by the probable and definite PLS groups. In the overall cohort, the PLSFRS total score declined by 0.33 points/month (95% confidence interval [0.27–0.39], adjusted p < 0.05). The rate of decline was steepest in the early PLS group, followed by the probable and definite PLS groups. Baseline neurofilament light chain level was associated with the rate of PLSFRS decline over 1 year ( p = 0.001). Interpretation In PLS, the rate of functional decline, as measured by the PLSFRS total score, is faster during the early phase of the disease. Neurofilament light might serve as a prognostic biomarker in PLS. ANN NEUROL 2026;99:418–428

ABSTRACTIntroduction/AimsMuscle cramps are a common symptom in amyotrophic lateral sclerosis (ALS). Ameliorating muscle cramps may improve quality of life in devastating diseases like ALS. A traditional Japanese medicine (Kampo, TJ‐68) is widely prescribed in Japan for muscle cramps. However, it is not available in the USA. This study evaluated the safety, tolerability, and efficacy of TJ‐68 in ALS.MethodsThis study was a double‐blind, randomized, placebo‐controlled crossover trial, consisting of four periods, conducted at three centers in the USA. Safety was evaluated using multiple measures. The primary efficacy outcome was the Visual Analog Scale for Muscle Cramps Affecting Overall Daily Activity (item #5 of the Muscle Cramp Scale (MCS)). The secondary outcomes included the remaining items of the MCS and the Clinical Global Impression of Changes (CGIC), among others. The study was planned to enroll 22 participants with ALS within 2 years.ResultsThe enrollment was slow and was completed with 11 participants. There were no serious safety issues and TJ‐68 was well tolerated. Although the primary outcome measure did not reach statistical significance (p = 0.35), several secondary measures showed significant results: MCS #1 triggering of cramps (p = 0.01), MCS #2 cramp frequency (p = 0.03), MCS Additional 1 change of motor behaviors (p = 0.02), and CGIC assessed by the evaluator (p = 0.009). Other outcome measures did not reach statistical significance.DiscussionThe study revealed that N‐of‐1 trial design can detect changes in a small sample size, and TJ‐68 appeared to be safe. Larger studies are needed to confirm the efficacy of TJ‐68.

Objective Motor neuron disease (MND) is a progressive neurological disorder with no known cure that damages motor neurons. The purpose of this analysis is to examine the place of death for MND patients in the United States during the coronavirus disease 2019 (COVID-19) pandemic and to investigate the extent of specific comorbidities. Methods We obtained death certificate and associated comorbidities data for all U.S. MND deaths from 2018 to 2021 and conducted a population-based cross-sectional analysis of the deaths pre-COVID-19 (2018-2019) and during COVID-19 (2020-2021). We hypothesized that place of death and comorbidities associated with place of death for MND patients in the United States were altered during the COVID-19 pandemic in comparison to the 2 years period before the pandemic. Results We analyzed 30 066 MND deaths (14 562 pre-COVID-19 and 15 504 during COVID-19) aged 20 years and older. During COVID-19, MND deaths at home increased (54.4% vs 45.5% pre-COVID). Hispanic individuals had an increased likelihood of dying at home compared to a nursing home or hospice (OR = 1.57, 95%CI: 1.22-2.02), but a decreased likelihood compared to a hospital (OR = 0.61, 95% CI: 0.51-0.72). Among the top comorbidities listed, there was a 27.8% increase in diabetes mellitus and a 20.2% increase in essential hypertension during COVID-19. During COVID-19, diabetes mellitus was more commonly reported as a comorbidity for deaths occurring in hospitals (OR = 1.40, 95%CI: 1.03-1.89) or at home (OR = 1.26, 95%CI: 1.03-1.55), while essential hypertension was more commonly reported with deaths at home (OR = 1.17, 95%CI: 1.01-1.36). Conclusion Our analysis showed an increase in at-home MND deaths as well as certain comorbidities during the COVID-19 pandemic, suggesting MND patients had a higher likelihood of death from non-COVID-19 comorbidities.

ImportanceMyeloperoxidase is one of the most abundant peroxidase enzymes in activated myeloid cells. Myeloperoxidase inhibitors may have a clinical benefit in amyotrophic lateral sclerosis (ALS) by slowing neurodegeneration via reduced neuroinflammation and oxidative stress.ObjectiveTo determine the safety, tolerability, and efficacy of verdiperstat, a selective myeloperoxidase inhibitor, in ALS.Design, Settings, and ParticipantsVerdiperstat was tested as a regimen of the HEALEY ALS Platform Trial, a multicenter, double-blind, perpetual platform design, randomized clinical trial, with sharing of trial infrastructure and placebo data across multiple regimens. The study was conducted at 54 ALS referral centers across the US from July 2020 to April 2022. Adult participants with a diagnosis of clinically possible, probable, laboratory-supported probable, or definite ALS defined by the revised El Escorial criteria were randomized to verdiperstat or regimen-specific placebo. An additional group of participants concurrently randomized to placebo from other regimens was included in the analyses.InterventionsEligible participants were randomized in a 3:1 ratio to receive oral verdiperstat, 600 mg, twice daily or matching placebo for a planned placebo-controlled duration of 24 weeks.Main Outcomes and MeasuresThe primary efficacy outcome was change from baseline through week 24 in disease severity, as measured by a joint model of ALS Functional Rating Scale–Revised and survival, with the treatment effect quantified by the disease rate ratio (DRR), with DRR less than 1 indicating a slowing in disease progression of verdiperstat relative to placebo.ResultsA total of 167 participants (mean [SD] age, 58.5 [11.4] years; 59 [35.3%] female; 108 [64.6%] male) were randomized to either verdiperstat (126 [75.4%]) or to placebo (41 [25.6%]). Among the participants randomized to the verdiperstat regimen, 130 (78%) completed the trial. The estimated DRR was 0.98 (95% credible interval, 0.77-1.24; posterior probability = 0.57 for slowing of disease progression [DRR &amp;lt;1]). Verdiperstat was estimated to slow progression by 2% vs placebo (95% credible interval, −23% to 24%; posterior probability 0.57). Verdiperstat was overall safe and well tolerated. Common adverse events in the verdiperstat group were nausea, insomnia, and elevated thyrotropin levels.Conclusions and RelevanceResults demonstrate that treatment with verdiperstat was unlikely to alter disease progression in ALS.Trial RegistrationClinical Trial Identifiers: NCT04297683 and NCT04436510

ImportanceAmyotrophic lateral sclerosis (ALS) is a fatal disease. The sigma-1 (σ1) receptor emerged as a target for intervention.ObjectiveTo determine the effects of pridopidine, a σ1-receptor agonist, in ALS.Design, Settings, and ParticipantsPridopidine was tested as a regimen of the HEALEY ALS Platform Trial, a phase 2/3, multicenter, randomized, double-blind, platform trial. The study was conducted at 54 sites in the US from January 2021 to July 2022 (final follow-up, July 14, 2022). A total of 163 participants with ALS were randomized to receive pridopidine or placebo. An additional 122 concurrently randomized participants were assigned to receive placebo in other regimens and included in the analyses.InterventionsEligible participants were randomized 3:1 to receive oral pridopidine 45 mg twice daily (n = 121) or matching oral placebo (n = 42) for a planned duration of 24 weeks.Main Outcomes and MeasuresThe primary efficacy outcome was change from baseline through week 24 in ALS disease severity, analyzed using a bayesian shared parameter model, which has components for function (Revised Amyotrophic Lateral Sclerosis Functional Rating Scale [ALSFRS-R]) and survival that were linked through an integrated estimate of treatment-dependent disease slowing across these 2 components. This was denoted as the disease rate ratio (DRR), with DRR less than 1 indicating a slowing in disease progression on pridopidine relative to placebo. There were 5 key secondary end points: time to 2-point or greater reduction in ALSFRS-R total score among participants with bulbar dysfunction at baseline, rate of decline in slow vital capacity among participants with bulbar dysfunction at baseline, percentage of participants with no worsening in the ALSFRS-R bulbar domain score, time to 1-point or greater change in the ALSFRS-R bulbar domain score, and time to death or permanent assisted ventilation.ResultsAmong 162 patients (mean age, 57.5 years; 35% female) who were randomized to receive the pridopidine regimen and included in the primary efficacy analysis, 136 (84%) completed the trial. In the primary analysis comparing pridopidine vs the combined placebo groups, there was no significant difference between pridopidine and placebo in the primary end point (DRR, 0.99 [95% credible interval, 0.80-1.21]; probability of DRR &amp;lt;1, 0.55) and no differences were seen in the components of ALSFRS-R or survival. There was no benefit of pridopidine on the secondary end points. In the safety dataset (pridopidine, n = 121; placebo, n = 163), the most common adverse events were falls (28.1% vs 29.3%, respectively) and muscular weakness (24.0% vs 31.7%, respectively).Conclusions and RelevanceIn this 24-week study, pridopidine did not impact the progression of ALS.Trial RegistrationClinicalTrials.gov Identifiers: NCT04297683, NCT04615923