17 research outputs found
Cursive Eye-Writing With Smooth-Pursuit Eye-Movement Is Possible in Subjects With Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder causing a progressive motor weakness of all voluntary muscles, whose progression challenges communication modalities such as handwriting or speech. The current study investigated whether ALS subjects can use Eye-On-Line (EOL), a novel eye-operated communication device allowing, after training, to voluntarily control smooth-pursuit eye-movements (SPEM) so as to eye-write in cursive. To that aim, ALS participants (n = 12) with preserved eye-movements but impaired handwriting were trained during six on-site visits. The primary outcome of the study was the recognition of eye-written digits (0–9) from ALS and healthy control subjects by naïve “readers.” Changes in oculomotor performance and the safety of EOL were also evaluated. At the end of the program, 69.4% of the eye-written digits from 11 ALS subjects were recognized by naïve readers, similar to the 67.3% found for eye-written digits from controls participants, with however, large inter-individual differences in both groups of “writers.” Training with EOL was associated with a transient fatigue leading one ALS subject to drop out the study at the fifth visit. Otherwise, itching eyes was the most common adverse event (3 subjects). This study shows that, despite the impact of ALS on the motor system, most ALS participants could improve their mastering of eye-movements, so as to produce recognizable eye-written digits, although the eye-traces sometimes needed smoothing to ease digit legibility from both ALS subjects and control participants. The capability to endogenously and voluntarily generate eye-traces using EOL brings a novel way to communicate for disabled individuals, allowing creative personal and emotional expression
Muscle cells of sporadic amyotrophic lateral sclerosis patients secrete neurotoxic vesicles
BACKGROUND: The cause of the motor neuron (MN) death that drives terminal pathology in amyotrophic lateral sclerosis (ALS) remains unknown, and it is thought that the cellular environment of the MN may play a key role in MN survival. Several lines of evidence implicate vesicles in ALS, including that extracellular vesicles may carry toxic elements from astrocytes towards MNs, and that pathological proteins have been identified in circulating extracellular vesicles of sporadic ALS patients. Because MN degeneration at the neuromuscular junction is a feature of ALS, and muscle is a vesicle-secretory tissue, we hypothesized that muscle vesicles may be involved in ALS pathology. METHODS: Sporadic ALS patients were confirmed to be ALS according to El Escorial criteria and were genotyped to test for classic gene mutations associated with ALS, and physical function was assessed using the ALSFRS-R score. Muscle biopsies of either mildly affected deltoids of ALS patients (n = 27) or deltoids of aged-matched healthy subjects (n = 30) were used for extraction of muscle stem cells, to perform immunohistology, or for electron microscopy. Muscle stem cells were characterized by immunostaining, RT-qPCR, and transcriptomic analysis. Secreted muscle vesicles were characterized by proteomic analysis, Western blot, NanoSight, and electron microscopy. The effects of muscle vesicles isolated from the culture medium of ALS and healthy myotubes were tested on healthy human-derived iPSC MNs and on healthy human myotubes, with untreated cells used as controls. RESULTS: An accumulation of multivesicular bodies was observed in muscle biopsies of sporadic ALS patients by immunostaining and electron microscopy. Study of muscle biopsies and biopsy-derived denervation-naïve differentiated muscle stem cells (myotubes) revealed a consistent disease signature in ALS myotubes, including intracellular accumulation of exosome-like vesicles and disruption of RNA-processing. Compared with vesicles from healthy control myotubes, when administered to healthy MNs the vesicles of ALS myotubes induced shortened, less branched neurites, cell death, and disrupted localization of RNA and RNA-processing proteins. The RNA-processing protein FUS and a majority of its binding partners were present in ALS muscle vesicles, and toxicity was dependent on the expression level of FUS in recipient cells. Toxicity to recipient MNs was abolished by anti-CD63 immuno-blocking of vesicle uptake. CONCLUSIONS: ALS muscle vesicles are shown to be toxic to MNs, which establishes the skeletal muscle as a potential source of vesicle-mediated toxicity in ALS
Muscle cells of sporadic amyotrophic lateral sclerosis patients secrete neurotoxic vesicles
Background: The cause of the motor neuron (MN) death that drives terminal pathology in amyotrophic lateral sclerosis (ALS) remains unknown, and it is thought that the cellular environment of the MN may play a key role in MN survival. Several lines of evidence implicate vesicles in ALS, including that extracellular vesicles may carry toxic elements from astrocytes towards MNs, and that pathological proteins have been identified in circulating extracellular vesicles of sporadic ALS patients. Because MN degeneration at the neuromuscular junction is a feature of ALS, and muscle is a vesicle-secretory tissue, we hypothesized that muscle vesicles may be involved in ALS pathology. Methods: Sporadic ALS patients were confirmed to be ALS according to El Escorial criteria and were genotyped to test for classic gene mutations associated with ALS, and physical function was assessed using the ALSFRS-R score. Muscle biopsies of either mildly affected deltoids of ALS patients (n = 27) or deltoids of aged-matched healthy subjects (n = 30) were used for extraction of muscle stem cells, to perform immunohistology, or for electron microscopy. Muscle stem cells were characterized by immunostaining, RT-qPCR, and transcriptomic analysis. Secreted muscle vesicles were characterized by proteomic analysis, Western blot, NanoSight, and electron microscopy. The effects of muscle vesicles isolated from the culture medium of ALS and healthy myotubes were tested on healthy human-derived iPSC MNs and on healthy human myotubes, with untreated cells used as controls. Results: An accumulation of multivesicular bodies was observed in muscle biopsies of sporadic ALS patients by immunostaining and electron microscopy. Study of muscle biopsies and biopsy-derived denervation-naïve differentiated muscle stem cells (myotubes) revealed a consistent disease signature in ALS myotubes, including intracellular accumulation of exosome-like vesicles and disruption of RNA-processing. Compared with vesicles from healthy control myotubes, when administered to healthy MNs the vesicles of ALS myotubes induced shortened, less branched neurites, cell death, and disrupted localization of RNA and RNA-processing proteins. The RNA-processing protein FUS and a majority of its binding partners were present in ALS muscle vesicles, and toxicity was dependent on the expression level of FUS in recipient cells. Toxicity to recipient MNs was abolished by anti-CD63 immuno-blocking of vesicle uptake. Conclusions: ALS muscle vesicles are shown to be toxic to MNs, which establishes the skeletal muscle as a potential source of vesicle-mediated toxicity in ALS
Analysis of shared common genetic risk between amyotrophic lateral sclerosis and epilepsy
Because hyper-excitability has been shown to be a shared pathophysiological mechanism, we used the latest and largest genome-wide studies in amyotrophic lateral sclerosis (n = 36,052) and epilepsy (n = 38,349) to determine genetic overlap between these conditions. First, we showed no significant genetic correlation, also when binned on minor allele frequency. Second, we confirmed the absence of polygenic overlap using genomic risk score analysis. Finally, we did not identify pleiotropic variants in meta-analyses of the 2 diseases. Our findings indicate that amyotrophic lateral sclerosis and epilepsy do not share common genetic risk, showing that hyper-excitability in both disorders has distinct origins
Abnormalities of satellite cells function in amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis (ALS) is characterized by progressive denervation leading to muscle atrophy prevented, during the early phase, by compensatory reinnervation. Little is known about muscle fibre regeneration capacity in ALS. We have carried out in vivo and in vitro investigation of skeletal muscle in ALS. Seven ALS patients underwent a deltoid muscle biopsy. Immunohistochemical analysis revealed various degrees of denervation- and reinnervation-related changes in the ALS muscle biopsies including satellite cells (SCs) activation and regenerating fibres. Only 3/7 primary cultures of ALS muscle cells were successfully established and had sufficient myogenicity, as assessed by desmin positivity, to be used without further purification. This was in contrast with the cultures derived from control muscles, predominantly desmin-positive cells. Although capable to proliferate in vitro, ALS-derived SCs presented an abnormal senescent-like morphology. Markers of senescence, including senescent-associated (SA)-βGal activity and p16 expression, were increased. Furthermore, ALS-derived SCs were also unable to fully differentiate in vitro as shown by abnormal myotubes morphology and reduced MHC isoform expression, compared to control myotubes. Our study suggests that SC function is altered in ALS. This could limit the efficacy of compensatory processes and therefore could contribute to the progression of muscle atrophy and weakness
Anosognosia in amyotrophic lateral sclerosis: a cross-sectional study of 85 individuals and their relatives
Ce manuscrit est mis à disposition sous la licence d'utilisation Elsevier https://www.elsevier.com/open-access/userlicense/1.0/International audienceAnosognosia in amyotrophic lateral sclerosis: a cross-sectional study of 85 individuals and their relatives. Background. Amyotrophic lateral sclerosis (ALS) has long been considered a pure motor neurodegenerative disease. However, now, extra-motor manifestations such as cognitive- behavioral disorders are considered not rare and are even a severity factor of the disease. Experiencing anosognosia (i.e., the inability to recognize neurological symptoms) might affect care and treatment compliance in ALS. Regardless, this pivotal feature has been little investigated. Objectives. By comparing patients’ and caregivers’ reports, we analysed whether patients with ALS would experience a lack of awareness about their executive disorders and their apathy symptoms. Methods. From the ALS reference center in Paris, we included 85 patients (47 men, mean [SD] age 60.5 [12] years and ALS-Functional Rating Scale-revised score 8 to 46) and their primary family caregivers who all completed the Dysexecutive Questionnaire (DEX) and the Apathy Evaluation Scale (AES). Overall scores and answers were compared by agreement/disagreement statistical methods. Results. Caregivers reported higher levels of cognitive-behavioral disorders than did patients, but reports matched when cognitive-behavioral disorders were absent or mild. With published DEX and AES cutoffs, 32% and 51% of patients had executive disorders and apathy, respectively. In these patients with significant impairment, Bland-Altman plots (i.e., visual display agreement that represents the difference between the patient’s and caregiver’s scores as a function of their average) showed a strong discrepancy between joint reports: patients underestimated their symptoms by a mean bias of -6.81 DEX points (95% confidence interval 2 -11.88, -1.75) and -8.85 AES points (95% confidence interval -11.72, -5.98). We found no clear relationship between bulbar or spinal ALS subtypes and anosognosia. Conclusions. ALS patients with a cognitive-behavioral phenotype show anosognosia by a mismatch between self and proxy reports, which warrants further investigation in neuroimaging. Systematic longitudinal screening of anosognosia is needed to propose targeted psychoeducation in patient–caregiver dyads showing disagreement
Impact of a frequent nearsplice SOD1 variant in Amyotrophic Lateral Sclerosis: optimizing SOD1 genetic screening for gene therapy opportunities
International audienceObjective Mutations in superoxide dismutase 1 gene ( SOD1) , encoding copper/zinc superoxide dismutase protein, are the second most frequent high penetrant genetic cause for amyotrophic lateral sclerosis (ALS) motor neuron disease in populations of European descent. More than 200 missense variants are reported along the SOD1 protein. To limit the production of these aberrant and deleterious SOD1 species, antisense oligonucleotide approaches have recently emerged and showed promising effects in clinical trials. To offer the possibility to any patient with SOD1-ALS to benefit of such a gene therapy, it is necessary to ascertain whether any variant of unknown significance (VUS), detected for example in SOD1 non-coding sequences, is pathogenic. Methods We analysed SOD1 mutation distribution after SOD1 sequencing in a large cohort of 470 French familial ALS (fALS) index cases. Results We identified a total of 27 SOD1 variants in 38 families including two SOD1 variants located in nearsplice or intronic regions of the gene. The pathogenicity of the c.358–10T>G nearsplice SOD1 variant was corroborated based on its high frequency (as the second most frequent SOD1 variant) in French fALS, the segregation analysis confirmed in eight affected members of a large pedigree, the typical SOD1-related phenotype observed (with lower limb onset and prominent lower motor neuron involvement), and findings on postmortem tissues showing SOD1 misaccumulation. Conclusions Our results highlighted nearsplice/intronic mutations in SOD1 are responsible for a significant portion of French fALS and suggested the systematic analysis of the SOD1 mRNA sequence could become the method of choice for SOD1 screening, not to miss these specific cases
Effect of familial clustering in the genetic screening of 235 French ALS families
International audienceObjectives To determine whether the familial clustering of amyotrophic lateral sclerosis (ALS) cases and the phenotype of the disease may help identify the pathogenic genes involved. Methods We conducted a targeted next-generation sequencing analysis on 235 French familial ALS (FALS), unrelated probands to identify mutations in 30 genes linked to the disease. The genealogy, that is, number of cases and generations with ALS, gender, age, site of onset and the duration of the disease were analysed. Results Regarding the number of generations, 49 pedigrees had only one affected generation, 152 had two affected generations and 34 had at least three affected generations. Among the 149 pedigrees (63.4%) for which a deleterious variant was found, an abnormal G4C2 expansion in C9orf72 was found in 98 cases as well as SOD1 , TARBP or FUS mutations in 30, 9 and 7 cases, respectively. Considering pedigrees from the number of generations, abnormal G4C2 expansion in C9orf72 was more frequent in pedigrees with pairs of affected ALS cases, which represented 65.2% of our cohort. SOD1 mutation involved all types of pedigrees. No TARDBP nor FUS mutation was present in monogenerational pedigrees. TARDBP mutation predominated in bigenerational pedigrees with at least three cases and FUS mutation in multigenerational pedigrees with more than seven cases, on average, and with an age of onset younger than 45 years. Conclusion Our results suggest that familial clustering, phenotypes and genotypes are interconnected in FALS, and thus it might be possible to target the genetic screening from the familial architecture and the phenotype of ALS cases