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Objective: To evaluate progressive cerebral degeneration in amyotrophic lateral sclerosis (ALS) by assessing alterations in N -acetylaspartate (NAA) ratios in the motor and prefrontal cortex within clinical subgroups of ALS., Methods: Seventy-six patients with ALS and 59 healthy controls were enrolled in a prospective, longitudinal, multicenter study in the Canadian ALS Neuroimaging Consortium. Participants underwent serial clinical evaluations and magnetic resonance spectroscopy at baseline and 4 and 8 months using a harmonized protocol across 5 centers. NAA ratios were quantified in the motor cortex and prefrontal cortex. Patients were stratified into subgroups based on disease progression rate, upper motor neuron (UMN) signs, and cognitive status. Linear mixed models were used for baseline and longitudinal comparisons of NAA metabolite ratios., Results: Patients with ALS had reduced NAA ratios in the motor cortex at baseline ( p < 0.001). Ratios were lower in those with more rapid disease progression and greater UMN signs ( p < 0.05). A longitudinal decline in NAA ratios was observed in the motor cortex in the rapidly progressing ( p < 0.01) and high UMN burden ( p < 0.01) cohorts. The severity of UMN signs did not change significantly over time. NAA ratios were reduced in the prefrontal cortex only in cognitively impaired patients ( p < 0.05 ) ; prefrontal cortex metabolites did not change over time., Conclusions: Progressive degeneration of the motor cortex in ALS is associated with more aggressive clinical presentations. These findings provide biological evidence of variable spatial and temporal cerebral degeneration linked to the disease heterogeneity of ALS. The use of standardized imaging protocols may have a role in clinical trials for patient selection or subgrouping., Classification of Evidence: This study provides Class II evidence that MRS NAA metabolite ratios of the motor cortex are associated with more rapid disease progression and greater UMN signs in patients with ALS., Trial Registration Information: ClinicalTrials.gov Identifier: NCT02405182., (© 2021 American Academy of Neurology.)

Objective: To evaluate progressive white matter (WM) degeneration in amyotrophic lateral sclerosis (ALS)., Methods: Sixty-six patients with ALS and 43 healthy controls were enrolled in a prospective, longitudinal, multicenter study in the Canadian ALS Neuroimaging Consortium (CALSNIC). Participants underwent a harmonized neuroimaging protocol across 4 centers that included diffusion tensor imaging (DTI) for assessment of WM integrity. Three visits were accompanied by clinical assessments of disability (ALS Functional Rating Scale-Revised [ALSFRS-R]) and upper motor neuron (UMN) function. Voxel-wise whole-brain and quantitative tract-wise DTI assessments were done at baseline and longitudinally. Correction for site variance incorporated data from healthy controls and from healthy volunteers who underwent the DTI protocol at each center., Results: Patients with ALS had a mean progressive decline in fractional anisotropy (FA) of the corticospinal tract (CST) and frontal lobes. Tract-wise analysis revealed reduced FA in the CST, corticopontine/corticorubral tract, and corticostriatal tract. CST FA correlated with UMN function, and frontal lobe FA correlated with the ALSFRS-R score. A progressive decline in CST FA correlated with a decline in the ALSFRS-R score and worsening UMN signs. Patients with fast vs slow progression had a greater reduction in FA of the CST and upper frontal lobe., Conclusions: Progressive WM degeneration in ALS is most prominent in the CST and frontal lobes and, to a lesser degree, in the corticopontine/corticorubral tracts and corticostriatal pathways. With the use of a harmonized imaging protocol and incorporation of analytic methods to address site-related variances, this study is an important milestone toward developing DTI biomarkers for cerebral degeneration in ALS., Clinicaltrialsgov Identifier: NCT02405182., (© 2020 American Academy of Neurology.)

Objective: Suggested C9orf72 disease mechanisms for amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration include C9orf72 haploinsufficiency, G 4 C 2 /C 4 G 2 RNA foci, and dipeptide repeat (DPR) proteins translated from the G 4 C 2 expansion; however, the role of small expansions (e.g., 30-90 repeats) is unknown and was investigated here., Methods: We conducted a molecular and pathology study of a family in which the father (unaffected at age 90) carried a 70-repeat allele in blood DNA that expanded to ≈1,750 repeats in his children, causing ALS., Results: Southern blotting revealed different degrees of mosaicism of small and large expansions in the father's tissues from the CNS. Surprisingly, in each mosaic tissue, C9orf72 mRNA levels were significantly increased compared to an ALS-affected daughter with a large expansion. Increased expression correlated with higher levels of the 70-repeat allele (the upregulation was also evident at the protein level). Remarkably, RNA foci and DPR burdens were similar or even significantly increased (in cerebellum) in the unaffected father compared to the daughter with ALS. However, the father did not display TDP-43 pathology and signs of neurodegeneration., Conclusion: The presence of RNA foci and DPR pathology was insufficient for disease manifestation and TDP-43 pathology in the mosaic C9orf72 carrier with upregulated C9orf72 expression. It is important to conduct an investigation of similar cases, which could be found among unaffected parents of sporadic C9orf72 patients (e.g., 21% among Finnish patients with ALS). Caution should be taken when consulting carriers of small expansions because disease manifestation could be dependent on the extent of the somatic instability in disease-relevant tissues., (Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: To survey amyotrophic lateral sclerosis (ALS) health care providers to determine attitudes regarding physician-assisted death (PAD) after the Supreme Court of Canada (SCC) invalidated the Criminal Code provisions that prohibit PAD in February 2015., Methods: We conducted a Canada-wide survey of physicians and allied health professionals (AHP) involved in the care of patients with ALS on their opinions regarding (1) the SCC ruling, (2) their willingness to participate in PAD, and (3) the PAD implementation process for patients with ALS., Results: We received 231 responses from ALS health care providers representing all 15 academic ALS centers in Canada, with an overall response rate for invited participants of 74%. The majority of physicians and AHP agreed with the SCC ruling and believed that patients with moderate and severe stage ALS should have access to PAD; however, most physicians would not provide a lethal prescription or injection to an eligible patient. They preferred the patient obtain a second opinion to confirm eligibility, have a psychiatric assessment, and then be referred to a third party to administer PAD. The majority of respondents felt unprepared for the initiation of this program and favored the development of PAD training modules and guidelines., Conclusions: ALS health care providers support the SCC decision and the majority believe PAD should be available to patients with moderate to severe ALS with physical or emotional suffering. However, few clinicians are willing to directly provide PAD and additional training and guidelines are required before implementation in Canada., (© 2016 American Academy of Neurology.)

Objective: To prospectively assess the incidence of both symptomatic and asymptomatic venous thromboembolism (VTE) in patients with amyotrophic lateral sclerosis (ALS) and to identify risk factors., Methods: Fifty outpatients with ALS were recruited consecutively and prospectively evaluated with bilateral venous duplex ultrasonography (VDU) of the proximal leg veins at enrollment and 6 and 12 months. The primary outcome measure was clinically important VTE, defined as asymptomatic proximal deep vein thrombosis (DVT) by screening VDU, symptomatically proven DVT or pulmonary embolism (PE), or fatal PE. For each patient, person-days of follow-up were recorded from enrollment until the date of VTE, death, loss to follow-up, or final 12-month visit., Results: During the 1-year follow-up period, VTE was detected in 4 patients (1 symptomatic DVT, 1 symptomatic PE, and 2 asymptomatic DVTs) over 13,011 person-days of follow-up, representing an 11.2% 1-year incidence. Subjects with leg-onset ALS or significant leg weakness had a 1-year VTE incidence rate of 35.8% and 35.5%, respectively. VTE risk was significantly increased for those patients with decreased lower extremity Revised ALS Functional Rating Scale subscore (p = 0.03), decreased Lower Extremity Activity Scale score (p = 0.02), and decreased average lower limb Medical Research Council scale strength score (p = 0.03)., Conclusions: Our data suggest that clinically important VTE is common in patients with ALS, particularly those with leg weakness and reduced mobility. Given these results, the potential benefits of routine VTE screening and primary prophylaxis in high-risk patients with ALS with leg weakness should be explored in future studies. In the meantime, physicians should have a low threshold for considering VTE in patients with ALS with leg weakness.

Background: About 20% of familial amyotrophic lateral sclerosis (ALS) is caused by mutations in SOD1 and is typically transmitted as an autosomal dominant trait. However, due to reduced mutation penetrance, the disease may present in a recessive or sporadic manner., Objective: To determine the factors responsible for the low penetrance of the SOD1 mutation., Methods: Twelve members of a Canadian ALS family of Filipino origin were recruited for the study. SOD1 was sequenced in the proband. SOD1 expression was assessed by real-time-PCR and immunoblotting., Results: The proband was a homozygous carrier of a novel 6 bp deletion in exon 2 (DeltaG27/P28), the pathologic significance of which was confirmed by immunohistochemistry. Eight living family members are heterozygotes and remain unaffected at ages ranging between 48 and 85 years. Haplotype analysis showed that the deletion is a single founder mutation likely common in the Cagayan province (Philippines). The low penetrance of the mutation is explained by the fact that it enhances the naturally occurring alternative splicing of exon 2 of the SOD1 mRNA, leading to reduced transcription of the mutant allele. Indeed, Western blot analysis demonstrated the low level of SOD1 protein in carriers of the DeltaG27/P28 compared to wild-type individuals or a carrier of the A4V SOD1 mutation., Conclusion: The enhanced splicing of exon 2 acts as a natural knock-down of the mutant SOD1 allele in the Filipino amyotrophic lateral sclerosis (ALS) family. There is a need for careful investigation of splicing isoforms of SOD1 and other ALS genes as factors influencing the severity of disease.

Objective: We aimed to determine the effectiveness of IV immunoglobulin (IVIG) in the treatment of patients with myasthenia gravis (MG) and worsening weakness in a randomized, placebo-controlled, masked study., Methods: Fifty-one patients with worsening weakness due to MG were randomized to infusion with 2 g/kg of IVIG or an equivalent volume of IV dextrose 5% in water. The Quantitative Myasthenia Gravis (QMG) Score for Disease Severity, a validated clinical composite scale, was calculated by a masked observer at baseline and days 14 and 28., Results: In IVIG-treated patients, a clinically meaningful improvement in QMG Score for Disease Severity was observed at day 14 and persisted at day 28. The greatest improvement occurred in patients with more severe disease as defined by a QMG Score for Disease Severity greater than 10.5., Conclusion: This study provides level 1 evidence for the effectiveness of IV immunoglobulin in patients with worsening weakness due to myasthenia gravis.