Higher Glycemic Index and Glycemic Load Diet Is Associated with Slower Disease Progression in Amyotrophic Lateral Sclerosis.

OBJECTIVE: High-caloric diets may slow the progression of amyotrophic lateral sclerosis; however, key macronutrients have not been identified. We examined whether dietary macronutrients are associated with the rate of progression and length of survival among the prospective cohort study participants. METHODS: Participants with a confirmed diagnosis of sporadic amyotrophic lateral sclerosis enrolled in the Multicenter Cohort Study of Oxidative Stress were included (n = 304). We evaluated baseline macronutrient intake assessed by food frequency questionnaire in relation to change in revised amyotrophic lateral sclerosis functional rating scale total-score, and tracheostomy-free survival using linear regression and Cox proportional hazard models. Baseline age, sex, disease duration, diagnostic certainty, body mass index, bulbar onset, revised amyotrophic lateral sclerosis functional rating scale total-score, and forced vital capacity were included as covariates. RESULTS: Baseline higher glycemic index and load were associated with less decline of revised amyotrophic lateral sclerosis functional rating scale total score at 3-month follow-up (ß = -0.13, 95% CI -0.2, -0.01, p = 0.03) and (ß = -0.01, 95% CI -0.03, -0.0007, p = 0.04), respectively. Glycemic index second-quartile, third-quartile, and fourth-quartile groups were associated with less decline at 3 months by 1.9 (95% CI -3.3, -0.5, p = 0.008), 2.0 (95% CI -3.3, -0.6, p = 0.006), and 1.6 (95% CI -3.0, -0.2, p = 0.03) points compared with the first-quartile group; the glycemic load fourth-quartile group had 1.4 points less decline compared with the first-quartile group (95% CI -2.8, 0.1, p = 0.07). Higher glycemic index was associated with a trend toward longer tracheostomy-free survival (HR 0.97, 95% CI 0.93, 1.00, p = 0.07). INTERPRETATION: Higher dietary glycemic index and load are associated with slower disease progression in amyotrophic lateral sclerosis. ANN NEUROL 2024;95:217-229.

Rare variant analyses validate known ALS genes in a multi-ethnic population and identifies ANTXR2 as a candidate in PLS.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting over 300,000 people worldwide. It is characterized by the progressive decline of the nervous system that leads to the weakening of muscles which impacts physical function. Approximately, 15% of individuals diagnosed with ALS have a known genetic variant that contributes to their disease. As therapies that slow or prevent symptoms continue to develop, such as antisense oligonucleotides, it is important to discover novel genes that could be targets for treatment. Additionally, as cohorts continue to grow, performing analyses in ALS subtypes, such as primary lateral sclerosis (PLS), becomes possible due to an increase in power. These analyses could highlight novel pathways in disease manifestation. METHODS: Building on our previous discoveries using rare variant association analyses, we conducted rare variant burden testing on a substantially larger multi-ethnic cohort of 6,970 ALS patients, 166 PLS patients, and 22,524 controls. We used intolerant domain percentiles based on sub-region Residual Variation Intolerance Score (subRVIS) that have been described previously in conjunction with gene based collapsing approaches to conduct burden testing to identify genes that associate with ALS and PLS. RESULTS: A gene based collapsing model showed significant associations with SOD1, TARDBP, and TBK1 (OR = 19.18, p = 3.67 × 10-39; OR = 4.73, p = 2 × 10-10; OR = 2.3, p = 7.49 × 10-9, respectively). These genes have been previously associated with ALS. Additionally, a significant novel control enriched gene, ALKBH3 (p = 4.88 × 10-7), was protective for ALS in this model. An intolerant domain-based collapsing model showed a significant improvement in identifying regions in TARDBP that associated with ALS (OR = 10.08, p = 3.62 × 10-16). Our PLS protein truncating variant collapsing analysis demonstrated significant case enrichment in ANTXR2 (p = 8.38 × 10-6). CONCLUSIONS: In a large multi-ethnic cohort of 6,970 ALS patients, collapsing analyses validated known ALS genes and identified a novel potentially protective gene, ALKBH3. A first-ever analysis in 166 patients with PLS found a candidate association with loss-of-function mutations in ANTXR2.

Utilizing machine learning and lipidomics to distinguish primary lateral sclerosis from amyotrophic lateral sclerosis.

INTRODUCTION/AIMS: There are currently no imaging or blood diagnostic biomarkers that can differentiate amyotrophic lateral sclerosis (ALS) from primary lateral sclerosis (PLS) patients early in their disease courses. Our objective is to examine whether patients with PLS can be differentiated from ALS reliably by using plasma lipidome profile and supervised machine learning. METHODS: 40 ALS and 28 PLS patients derived from the Multicenter Cohort study of Oxidative Stress (COSMOS) and 28 healthy control volunteers (CTR) were included. ALS, PLS, and CTR were matched by age and sex. Plasma samples were obtained after overnight fasting. Lipids were extracted from the plasma samples and analyzed using liquid chromatography/mass spectrometry to obtain relative concentrations of 392 lipid species. The lipid data were partitioned into training and testing datasets randomly. An elastic net algorithm was trained using cross-validation to classify PLS vs ALS and PLS vs CTR. Final accuracy was evaluated in the testing dataset. RESULTS: The elastic net model trained with labeled PLS and ALS training lipid dataset demonstrated accuracy (number classified correctly/total number), sensitivity, and specificity of 100% in classifying PLS vs ALS in the unlabeled testing lipid dataset. Similarly, the elastic net model trained with labeled PLS and CTR training lipid datasets demonstrated accuracy, sensitivity, and specificity of 88% in classifying PLS vs CTR in the unlabeled testing lipid dataset. DISCUSSION: Our study suggests PLS patients can be accurately distinguished from ALS and CTR by combining lipidome profile and supervised machine learning without clinical information.

Early initiation of riluzole may improve absolute survival in amyotrophic lateral sclerosis.

INTRODUCTION/AIMS: Riluzole improves survival in amyotrophic lateral sclerosis (ALS), but optimal time and duration of treatment are unknown. The aim of this study was to examine if timing of riluzole initiation and duration of treatment modified its effect on survival. METHODS: Patients from the PRO-ACT dataset with information on ALS Functional Rating Scale, time from onset to enrollment (TFOE), and riluzole use were selected for analysis. Survival from enrollment was the outcome. Multivariable Cox proportional hazard models were examined for interactions between riluzole and TFOE. Inverse probability of treatment weighting (IPTW) was used to assess average treatment effect. RESULTS: Of 4778 patients, 3446 (72.1%) had received riluzole. In unadjusted analyses, riluzole improved median survival significantly (22.6 vs. 20.2 months, log-rank p < 0.001). In multivariable analyses, no significant interaction between TFOE and riluzole was found. Riluzole effect was uniform during follow-up. By IPTW, estimated riluzole hazard ratio was 0.798 (95% confidence interval 0.686-0.927). Delaying riluzole initiation by 1 y (6 to 18 months from onset) may translate to reducing median survival from onset by 1.9 months (40.1 to 38.2 months). DISCUSSION: Riluzole appears to reduce risk of death uniformly, regardless of time from onset to treatment, and duration of treatment. Earlier treatment with riluzole may be associated with greater absolute survival gain from onset. Early diagnosis of ALS will facilitate early treatment and is expected to improve survival.

Phase 2B randomized controlled trial of NP001 in amyotrophic lateral sclerosis: Pre-specified and post hoc analyses.

INTRODUCTION/AIMS: ALS is a heterogeneous disease that may be complicated or in part driven by inflammation. NP001, a regulator of macrophage activation, was associated with slowing disease progression in those with higher levels of the plasma inflammatory marker C-reactive protein (CRP) in phase 2A studies in ALS. Here, we evaluate the effects of NP001 in a phase 2B trial, and perform a post hoc analysis with combined data from the preceding phase 2A trial. METHODS: The phase 2B trial enrolled 138 participants within 3 y of symptom onset and with plasma hs-CRP values >1.13 mg/L. They were randomized 1:1 to receive either placebo or NP001 for 6 mo. Change from baseline ALSFRS-R scores was the primary efficacy endpoint. Secondary endpoints included vital capacity (VC) change from baseline and percentage of participants showing no decline of ALSFRS-R score over 6 mo (non-progressor). RESULTS: The phase 2B study did not show significant differences between placebo and active treatment with respect to change in ALSFRS-R scores, or VC. The drug was safe and well tolerated. A post hoc analysis identified a 40- to 65-y-old subset in which NP001-treated patients demonstrated slower declines in ALSFRS-R score by 36% and VC loss by 51% compared with placebo. A greater number of non-progressors were NP001-treated compared with placebo (p = .004). DISCUSSION: Although the phase 2B trial failed to meet its primary endpoints, post hoc analyses identified a subgroup whose decline in ALSFRS-R and VC scores were significantly slower than placebo. Further studies will be required to validate these findings.

Recruitment of Patients With Amyotrophic Lateral Sclerosis for Clinical Trials and Epidemiological Studies: Descriptive Study of the National ALS Registry's Research Notification Mechanism.

BACKGROUND: Researchers face challenges in patient recruitment, especially for rare, fatal diseases such as amyotrophic lateral sclerosis (ALS). These challenges include obtaining sufficient statistical power as well as meeting eligibility requirements such as age, sex, and study proximity. Similarly, persons with ALS (PALS) face difficulty finding and enrolling in research studies for which they are eligible. OBJECTIVE: The aim of this study was to describe how the federal Agency for Toxic Substances and Disease Registry's (ATSDR) National ALS Registry is linking PALS to scientists who are conducting research, clinical trials, and epidemiological studies. METHODS: Through the Registry's online research notification mechanism (RNM), PALS can elect to be notified about new research opportunities. This mechanism allows researchers to upload a standardized application outlining their study design and objectives, and proof of Institutional Review Board approval. If the application is approved, ATSDR queries the Registry for PALS meeting the study's specific eligibility criteria, and then distributes the researcher's study material and contact information to PALS via email. PALS then need to contact the researcher directly to take part in any research. Such an approach allows ATSDR to protect the confidentiality of Registry enrollees. RESULTS: From 2013 to 2019, a total of 46 institutions around the United States and abroad have leveraged this tool and over 600,000 emails have been sent, resulting in over 2000 patients conservatively recruited for clinical trials and epidemiological studies. Patients between the ages of 60 and 69 had the highest level of participation, whereas those between the ages of 18 and 39 and aged over 80 had the lowest. More males participated (4170/7030, 59.32%) than females (2860/7030, 40.68%). CONCLUSIONS: The National ALS Registry's RNM benefits PALS by connecting them to appropriate ALS research. Simultaneously, the system benefits researchers by expediting recruitment, increasing sample size, and efficiently identifying PALS meeting specific eligibility requirements. As more researchers learn about and use this mechanism, both PALS and researchers can hasten research and expand trial options for PALS.

Primary lateral sclerosis: consensus diagnostic criteria.

Primary lateral sclerosis (PLS) is a neurodegenerative disorder of the adult motor system. Characterised by a slowly progressive upper motor neuron syndrome, the diagnosis is clinical, after exclusion of structural, neurodegenerative and metabolic mimics. Differentiation of PLS from upper motor neuron-predominant forms of amyotrophic lateral sclerosis remains a significant challenge in the early symptomatic phase of both disorders, with ongoing debate as to whether they form a clinical and histopathological continuum. Current diagnostic criteria for PLS may be a barrier to therapeutic development, requiring long delays between symptom onset and formal diagnosis. While new technologies sensitive to both upper and lower motor neuron involvement may ultimately resolve controversies in the diagnosis of PLS, we present updated consensus diagnostic criteria with the aim of reducing diagnostic delay, optimising therapeutic trial design and catalysing the development of disease-modifying therapy.

Primary lateral sclerosis (PLS) functional rating scale: PLS-specific clinimetric scale.

INTRODUCTION: Our research aim was to develop a novel clinimetric scale sensitive enough to detect disease progression in primary lateral sclerosis (PLS). METHODS: A prototype of the PLS Functional Rating Scale (PLSFRS) was generated. Seventy-seven participants with PLS were enrolled and evaluated at 21 sites that comprised the PLSFRS study group. Participants were assessed using the PLSFRS, Neuro-Quality of Life (QoL), Schwab-England Activities of Daily Living (ADL), and the Clinical Global Impression of Change scales. Participants completed telephone assessments at 12, 24, and 48 weeks after enrollment. RESULTS: The PLSFRS demonstrated internal consistency as well as intrarater, interrater, telephone test-retest reliability, and construct validity. Significant changes in disease progression were detected at 6 and 12 months; changes measured by the PLSFRS vs the ALSFRS-R were significantly higher. DISCUSSION: The PLSFRS is a valid tool to assess the natural history of PLS in a shorter study period.

Sexuality and intimacy in ALS: systematic literature review and future perspectives.

Several features of amyotrophic lateral sclerosis (ALS) impact on sexuality and intimate relationship; however, the issue has received poor attention so far. We performed a systematic literature review in order to provide an up-to-date account of sexuality in ALS. References were identified by searches of PubMed, Web of Science, Scopus and PsycINFO (1970-2017, English literature). The following were the key terms: 'sexual' OR 'sexuality' OR 'intimacy' OR 'marital' AND 'ALS' OR 'Amyotrophic Lateral Sclerosis' OR 'Motor Neuron Disease' OR 'MND'. Titles and abstracts were screened for relevance and a full-text analysis was performed on the selected articles. Studies were included if they referred to sexual well-being/activities/functions or intimate relationship between patients and their partners and management of such topic by clinicians. Eligibility assessment was performed independently by two reviewers. A thematic and level of evidence classification of studies was performed. Studies' design, objectives, measurements and outcomes were summarised. Thirty articles were included and four topics were identified: intimacy in the dyads; sexual activities in patients and with their partners; sexual function disturbances; and sexuality and cognitive-behavioural alterations. The quality of the studies varies, with globally poor level of evidence. Some sexuality issues have been only sparsely addressed, such as gender-related differences, same-sex relationships and sexual activities other than intercourse. Sexuality in ALS is still not adequately considered by clinicians and researchers. We present preliminary recommendations for improving sexuality and intimacy at any ALS multidisciplinary clinics.

Rasagiline for amyotrophic lateral sclerosis: A randomized, controlled trial.

INTRODUCTION: Rasagiline is a monoamine oxidase B (MAO-B) inhibitor with possible neuroprotective effects in patients with amyotrophic lateral sclerosis (ALS). METHODS: We performed a randomized, double-blind, placebo-controlled trial of 80 ALS participants with enrichment of the placebo group with historical controls (n = 177) at 10 centers in the United States. Participants were randomized in a 3:1 ratio to 2 mg/day rasagiline or placebo. The primary outcome was average slope of decline on the ALS Functional Rating Scale-Revised (ALSFRS-R). Secondary measures included slow vital capacity, survival, mitochondrial and molecular biomarkers, and adverse-event reporting. RESULTS: There was no difference in the average 12-month ALSFRS-R slope between rasagiline and the mixed placebo and historical control cohorts. Rasagiline did not show signs of drug-target engagement in urine and blood biomarkers. Rasagiline was well tolerated with no serious adverse events. DISCUSSION: Rasagiline did not alter disease progression compared with controls over 12 months of treatment. Muscle Nerve 59:201-207, 2019.

Improving symptom management for people with amyotrophic lateral sclerosis.

INTRODUCTION: Symptomatic management is the main focus of ALS clinical care. We aim to report the prevalence of ALS-related symptoms and characterize self-reported symptomatic management. METHODS: A symptom management survey developed by the Muscular Dystrophy Association Clinical Research Network was completed by ALS registrants. Logistic regression identified potential predictors of symptom prevalence, severity, and treatment. RESULTS: A total of 567 ALS participants reported fatigue (90%), muscle stiffness (84%), and muscle cramps (74%) as most prevalent symptoms. Fatigue (18%), muscle stiffness (14%), and shortness of breath (12%) were most bothersome. Although fatigue was the most prevalent symptom, it was also least treated (10%). Neither location of care nor disease duration was associated with symptom prevalence, severity, or probability of receiving treatment. DISCUSSION: This large patient-reported symptom survey suggests that fatigue is the most prevalent, bothersome, and undertreated ALS symptom. Improving ALS symptom management is an unmet medical need and clinical trials of symptomatic treatments are needed. Muscle Nerve 57: 20-24, 2018.

Non-invasive measurement of abnormal ventilatory mechanics in amyotrophic lateral sclerosis.

INTRODUCTION: In this study we investigated non-invasive, effort-independent measurement of ventilatory mechanics in patients with amyotrophic lateral sclerosis (ALS). METHODS: Ventilatory mechanics were measured by optoelectronic plethysmography (OEP) in ALS patients and matched controls. Analysis determined whether OEP measurements correlated with standard clinical measures. RESULTS: ALS patients (N = 18) had lower forced vital capacity percent predicted (55.2 ± 22.0 L) compared with controls (N = 15; 104.7 ± 16.2 L) and higher ventilatory inefficiency (49.2 ± 9.0 vs. 40.0 ± 3.5, respectively; P < 0.001 for both measures). Lower tidal volumes within the diaphragm area correlated with the dyspnea subscore calculated from the ALS Functional Rating Scale-revised (P = 0.031), and paradoxical movement of the ribcage compared with the abdominal compartment was seen in the most severe cases. CONCLUSIONS: Evaluation of ventilatory mechanics in mild to severe ALS reveals dysfunction that is not readily detected by standard testing and ALS functional severity assessment measures. Muscle Nerve 54: 270-276, 2016.

Hypercaloric enteral nutrition in patients with amyotrophic lateral sclerosis: a randomised, double-blind, placebo-controlled phase 2 trial.

BACKGROUND: Amyotrophic lateral sclerosis is a fatal neurodegenerative disease with few therapeutic options. Mild obesity is associated with greater survival in patients with the disease, and calorie-dense diets increased survival in a mouse model. We aimed to assess the safety and tolerability of two hypercaloric diets in patients with amyotrophic lateral sclerosis receiving enteral nutrition. METHODS: In this double-blind, placebo-controlled, randomised phase 2 clinical trial, we enrolled adults with amyotrophic lateral sclerosis from participating centres in the USA. Eligible participants were aged 18 years or older with no history of diabetes or liver or cardiovascular disease, and who were already receiving percutaneous enteral nutrition. We randomly assigned participants (1:1:1) using a computer-generated list of random numbers to one of three dietary interventions: replacement calories using an isocaloric tube-fed diet (control), a high-carbohydrate hypercaloric tube-fed diet (HC/HC), or a high-fat hypercaloric tube-fed diet (HF/HC). Participants received the intervention diets for 4 months and were followed up for 5 months. The primary outcomes were safety and tolerability, analysed in all patients who began their study diet. This trial is registered with ClinicalTrials.gov, number NCT00983983. FINDINGS: Between Dec 14, 2009, and Nov 2, 2012, we enrolled 24 participants, of whom 20 started their study diet (six in the control group, eight in the HC/HC group, and six in the HF/HC group). One patient in the control group, one in the HC/HC group, and two in the HF/HC group withdrew consent before receiving the intervention. Participants who received the HC/HC diet had a smaller total number of adverse events than did those in the other groups (23 in the HC/HC group vs 42 in the control group vs 48 in the HF/HC group; overall, p=0.06; HC/HC vs control, p=0.06) and significantly fewer serious adverse events than did those on the control diet (none vs nine; p=0.0005). Fewer patients in the HC/HC group discontinued their study diet due to adverse events (none [0%] of eight in the HC/HC group vs three [50%] of six in the control group). During the 5 month follow-up, no deaths occurred in the nine patients assigned to the HC/HC diet compared with three deaths (43%) in the seven patients assigned to the control diet (log-rank p=0.03). Adverse events, tolerability, deaths, and disease progression did not differ significantly between the HF/HC group and the control group. INTERPRETATION: Our results provide preliminary evidence that hypercaloric enteral nutrition is safe and tolerable in patients with amyotrophic lateral sclerosis, and support the study of nutritional interventions in larger randomised controlled trials at earlier stages of the disease. FUNDING: Muscular Dystrophy Association, National Center for Research Resources, National Institutes of Health, and Harvard NeuroDiscovery Center.

Bioenergetic markers in skin fibroblasts of sporadic amyotrophic lateral sclerosis and progressive lateral sclerosis patients.

Energy metabolism could influence amyotrophic lateral sclerosis (ALS) and progressive lateral sclerosis (PLS) pathogenesis and the response to therapy. We developed a novel assay to simultaneously assess mitochondrial content and membrane potential in patients' skin fibroblasts. In ALS and PLS fibroblasts, membrane potential was increased and mitochondrial content decreased, relative to healthy controls. In ALS higher mitochondrial membrane potential correlated with age at diagnosis, and in PLS it correlated with disease severity. These unprecedented findings in ALS and PLS fibroblasts could shed new light onto disease pathogenesis and help in developing biomarkers to predict disease evolution and the individual response to therapy in motor neuron diseases.

Amyotrophic lateral sclerosis: a long preclinical period?

The onset of amyotrophic lateral sclerosis (ALS) is conventionally considered as commencing with the recognition of clinical symptoms. We propose that, in common with other neurodegenerations, the pathogenic mechanisms culminating in ALS phenotypes begin much earlier in life. Animal models of genetically determined ALS exhibit pathological abnormalities long predating clinical deficits. The overt clinical ALS phenotype may develop when safety margins are exceeded subsequent to years of mitochondrial dysfunction, neuroinflammation or an imbalanced environment of excitation and inhibition in the neuropil. Somatic mutations, the epigenome and external environmental influences may interact to trigger a metabolic cascade that in the adult eventually exceeds functional threshold. A long preclinical and subsequent presymptomatic period pose a challenge for recognition, since it offers an opportunity for protective and perhaps even preventive therapeutic intervention to rescue dysfunctional neurons. We suggest, by analogy with other neurodegenerations and from SOD1 ALS mouse studies, that vulnerability might be induced in the perinatal period.

History of ALS and the competing theories on pathogenesis: IFCN handbook chapter.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder of the human motor system, first described in the 19th Century. The etiology of ALS appears to be multifactorial, with a complex interaction of genetic, epigenetic, and environmental factors underlying the onset of disease. Importantly, there are no known naturally occurring animal models, and transgenic mouse models fail to faithfully reproduce ALS as it manifests in patients. Debate as to the site of onset of ALS remain, with three competing theories proposed, including (i) the dying-forward hypothesis, whereby motor neuron degeneration is mediated by hyperexcitable corticomotoneurons via an anterograde transsynaptic excitotoxic mechanism, (ii) dying-back hypothesis, proposing the ALS begins in the peripheral nervous system with a toxic factor(s) retrogradely transported into the central nervous system and mediating upper motor neuron dysfunction, and (iii) independent hypothesis, suggesting that upper and lower motor neuron degenerated independently. Transcranial magnetic stimulation studies, along with pathological and genetic findings have supported the dying forward hypothesis theory, although the science is yet to be settled. The review provides a historical overview of ALS, discusses phenotypes and likely pathogenic mechanisms.

Clinical evolution of pure upper motor neuron disease/dysfunction (PUMMD).

INTRODUCTION: PLS is defined as pure upper motor neuron disease/dysfunction (PUMND) beyond 48 months after symptom onset. We know little about its early stages, but such knowledge would help to identify the mechanisms underlying PLS and ALS and determine why PLS patients seem to be protected against lower MND (LMND). METHODS: We reviewed 622 MND cases during a 4-year period and identified 34 patients with PUMND (5.4%). RESULTS: Among 23 cases with follow-up data/electromyograms (EMGs; 2 had only 1 EMG), 13 (57%) remained classified as PUMND, and 8 (35%) developed LMND (mean, 51.4 months after onset). Of these 8, LMND developed in 3 after 48 months from symptom onset. Patients with PUMND and LMND were more functionally impaired (P = 0.02). Separately, we identified 5 patients with PUMND who developed LMND long after 48 months (range, 50-127 months). CONCLUSIONS: PLS belongs to the ALS spectrum, and perhaps all cases eventually develop LMND.

Rare variant analyses validate known ALS genes in a multi-ethnic population and identifies ANTXR2 as a candidate in PLS.

Background: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting over 30,000 people in the United States. It is characterized by the progressive decline of the nervous system that leads to the weakening of muscles which impacts physical function. Approximately, 15% of individuals diagnosed with ALS have a known genetic variant that contributes to their disease. As therapies that slow or prevent symptoms, such as antisense oligonucleotides, continue to develop, it is important to discover novel genes that could be targets for treatment. Additionally, as cohorts continue to grow, performing analyses in ALS subtypes, such as primary lateral sclerosis (PLS), becomes possible due to an increase in power. These analyses could highlight novel pathways in disease manifestation. Methods: Building on our previous discoveries using rare variant association analyses, we conducted rare variant burden testing on a substantially larger cohort of 6,970 ALS patients from a large multi-ethnic cohort as well as 166 PLS patients, and 22,524 controls. We used intolerant domain percentiles based on sub-region Residual Variation Intolerance Score (subRVIS) that have been described previously in conjunction with gene based collapsing approaches to conduct burden testing to identify genes that associate with ALS and PLS. Results: A gene based collapsing model showed significant associations with SOD1, TARDBP, and TBK1 (OR=19.18, p = 3.67 × 10-39; OR=4.73, p = 2 × 10-10; OR=2.3, p = 7.49 × 10-9, respectively). These genes have been previously associated with ALS. Additionally, a significant novel control enriched gene, ALKBH3 (p = 4.88 × 10-7), was protective for ALS in this model. An intolerant domain based collapsing model showed a significant improvement in identifying regions in TARDBP that associated with ALS (OR=10.08, p = 3.62 × 10-16). Our PLS protein truncating variant collapsing analysis demonstrated significant case enrichment in ANTXR2 (p=8.38 × 10-6). Conclusions: In a large multi-ethnic cohort of 6,970 ALS patients, rare variant burden testing validated known ALS genes and identified a novel potentially protective gene, ALKBH3. A first-ever analysis in 166 patients with PLS found a candidate association with loss-of-function mutations in ANTXR2.

Randomized double-blind personalized N-of-1 clinical trial to test the safety and potential efficacy of TJ-68 for treating muscle cramps in amyotrophic lateral sclerosis (ALS): study protocol for a TJ-68 trial.

INTRODUCTION/AIMS: Muscle cramps are a common and often disabling symptom in amyotrophic lateral sclerosis (ALS), a devastating and incurable neurodegenerative disorder. To date, there are no medications specifically approved for the treatment of muscle cramps. Ameliorating muscle cramps in ALS may improve and sustain quality of life. A widely prescribed traditional Japanese (Kampo) medicine against muscle cramps, shakuyakukanzoto (TJ-68), has been studied in advanced liver disease, spinal stenosis, kidney failure, and diabetic neuropathy. The Japanese ALS Management Guideline mentions TJ-68 for difficult muscle cramps in ALS. Therefore, the rationale of our trial is to investigate the safety and effectiveness of TJ-68 in treating painful and disabling muscle cramps in people with ALS outside of Japan. Accordingly, we are conducting a randomized clinical trial to test the safety and efficacy of TJ-68 in participants with ALS reporting frequent muscle cramps using an innovative, personalized N-of-1 design. If successful, TJ-68 may be used for muscle cramps in a broader population of people with ALS. METHODS: This is a two-site, double-blind, randomized personalized N-of-1 early clinical trial with TJ-68. At least 22 participants with ALS and daily muscle cramps will receive drug or placebo for 2 weeks (one treatment period) followed by a 1-week washout in a four-period cross-over design. While the primary objective is to evaluate the safety of TJ-68, the study has 85% power to detect a one-point shift on the Visual Analog Scale for Muscle Cramps Affecting Overall Daily Activity of the Columbia Muscle Cramp Scale (MCS). Secondary outcomes include the full MCS score, a Cramp Diary, Clinical Global Impression of Changes, Goal Attainment Scale, quality of life scale and ALS functional rating scale-revised (ALSFRS-R). DISCUSSION: The study is underway. A personalized N-of-1 trial design is an efficient approach to testing medications that alleviate muscle cramps in rare disorders. If TJ-68 proves safe and efficacious then it may be used to treat cramps in ALS, and help to improve and sustain quality of life. TRIAL REGISTRATION: This clinical trial has been registered with ClinicalTrials.gov (NCT04998305), 8/9/2021.