Age at onset of amyotrophic lateral sclerosis in China

Clinical and genetic characteristics of 1672 cases of amyotrophic lateral sclerosis in China: a single-center retrospective study

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. In recent years, continuous discoveries of new ALS-causing genes have enhanced the understanding of the genotype-phenotype relationship in ALS, aiding in disease progression prediction and providing a more comprehensive basis for genetic diagnosis.

METHODS

A total of 1672 ALS patients who visited the Neurology Department of Peking Union Medical College Hospital between January 2014 and December 2022 and met the revised El Escorial diagnostic criteria were included. Clinical data were collected, whole exome sequencing and dynamic mutation screening of the C9ORF72 gene were performed, and the clinical phenotypes and genotypes of the patients were analyzed.

RESULTS

The average age of onset for the 1672 ALS patients was 52.6 ± 11.2 years (range 17-85 years), with a median disease duration of 14 months at the time of visit (interquartile range 9-24 months, range 2-204 months). The male to female ratio was 833:839. The patients included 297 (17.8%) with bulbar onset, 198 (11.8%) with flail arm/leg syndrome, 89 (5.3%) with familial ALS, and 52 (3.1%) with concomitant frontotemporal dementia (FTD). Pathogenic variants associated with ALS were detected in 175 patients (10.5% of the cohort), with the most common mutations being SOD1, FUS, and ANXA11. Among patients with familial ALS, 56.2% (50/89) had genetic mutations, compared to 7.9% (125/1583) in sporadic ALS cases. From the perspective of phenotype-genotype correlation, (1) In ALS-FTD patients, the most common genetic mutations were ANXA11 and C9ORF72 repeat expansions. Patients with flail arm/leg syndrome more frequently carried mutations in SOD1, ANXA11, and hnRNPA1; (2) Despite genetic heterogeneity, it was observed that mutations in FUS and NEK1 were more common in males, and patients with FUS mutations had a younger age of onset; mutations in SOD1 and SQSTM1 were more likely to present with lower limb onset.

CONCLUSION

This study provides comprehensive data on the genetic characteristics of ALS patients in China through large-scale clinical data and genetic analysis of 1672 cases. Differences in age of onset, onset site, and clinical phenotype among ALS patients with different genotypes can help clinicians better predict disease progression and provide a basis for precise diagnosis and individualized treatment.

Whole-Genome Sequencing Identified a Novel Mutation in the N-Terminal Domain of KIF5A in Chinese Patients with Familial Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by progressive damage to both upper and lower motor neurons. Genetic factors are known to play a crucial role in ALS, as genetic studies not only advance our comprehension of disease mechanisms but also help unravel the complex phenotypes exhibited by patients. To gain further insights into the genetic landscape of ALS in the Chinese population and explore genotype-phenotype correlations among individuals, we conducted whole-genome sequencing to screen genes in 34 Chinese familial ALS (FALS) probands lacking the most common ALS-associated genes. Within this cohort, we identified a rare heterozygous missense mutation in the N-terminal domain of KIF5A (c.86A>G) in one of the probands. This finding is significant as mutations in the KIF5A gene have been implicated in ALS in European cohorts since 2018, predominantly characterized by C-terminal mutations. Analysis of the clinical phenotype within this familial lineage revealed a delayed onset of symptoms, an extended survival duration, and initial manifestations in both upper limbs. These observations underscore the clinical heterogeneity observed in ALS patients harboring KIF5A mutations. In conclusion, our study contributes to the growing body of evidence linking KIF5A to ALS and enhances our understanding of the intricate genetic landscape of this disease.

Sex biology in amyotrophic lateral sclerosis

Although sex differences in amyotrophic lateral sclerosis (ALS) have not been studied systematically, numerous clinical and preclinical studies have shown sex to be influential in disease prognosis. Moreover, with the development of advanced imaging tools, the difference between male and female brain in structure and function and their response to neurodegeneration are more definitive. As discussed in this review, ALS patients exhibit a sex bias pertaining to the features of the disease, and their clinical, pathological, (and pathophysiological) phenotypes. Several epidemiological studies have indicated that this sex disparity stems from various aetiologies, including sex-specific brain structure and neural functioning, genetic predisposition, age, gonadal hormones, susceptibility to traumatic brain injury (TBI)/head trauma and lifestyle factors.

Genome-wide analyses identify NEAT1 as genetic modifier of age at onset of amyotrophic lateral sclerosis

BACKGROUND

Patients with amyotrophic lateral sclerosis (ALS) demonstrate great heterogeneity in the age at onset (AAO), which is closely related to the course of disease. However, most genetic studies focused on the risk of ALS, while the genetic background underlying AAO of ALS is still unknown.

METHODS

To identify genetic determinants influencing AAO of ALS, we performed genome-wide association analysis using a Cox proportional hazards model in 2,841 patients with ALS (Ndiscovery = 2,272, Nreplication = 569) in the Chinese population. We further conducted colocalization analysis using public cis-eQTL dataset, and Mendelian randomization analysis to identify risk factors for AAO of ALS. Finally, functional experiments including dual-luciferase reporter assay and RT-qPCR were performed to explore the regulatory effect of the target variant.

RESULTS

The total heritability of AAO of ALS was ~ 0.24. One novel locus rs10128627 (FRMD8) was significantly associated with earlier AAO by ~ 3.15 years (P = 1.54E-08, beta = 0.31, SE = 0.05). This locus was cis-eQTL of NEAT1 in multiple brain tissues and blood. Colocalization analysis detected association signals at this locus between AAO of ALS and expression of NEAT1. Furthermore, functional exploration supported the variant rs10128627 was associated with upregulated expression of NEAT1 in cell models and patients with ALS. Causal inference suggested higher total cholesterol, low-density lipoprotein, and eosinophil were nominally associated with earlier AAO of ALS, while monocyte might delay the AAO.

CONCLUSIONS

Collective evidence from genetic, bioinformatic, and functional results suggested NEAT1 as a key player in the disease progression of ALS. These findings improve the current understanding of the genetic role in AAO of ALS, and provide a novel target for further research on the pathogenesis and therapeutic options to delay the disease onset.

Age of Onset and Length of Survival of Queensland Patients with Amyotrophic Lateral Sclerosis: Details of Subjects with Early Onset and Subjects with Long Survival

INTRODUCTION

The aims of the study were to document the characteristics of amyotrophic lateral sclerosis (ALS) patients in Queensland, to examine factors influencing age of onset, and survival, and to study those with early-onset (<45 years) disease and those with long (>5 years) survival.

METHODS

We studied subjects seen at the ALS Clinic at the Royal Brisbane and Women's Hospital. We recorded sex, age of onset, region of onset, length of survival, presence of family history, type of disease, and evidence of cognitive involvement. We analysed the influence of these features on age of onset and survival. We analysed the features of patients with early onset of disease and patients with long survival.

RESULTS

There were 855 ALS patients (505 males) in the cohort. The age of onset was lower in males than females, in patients with a family history of ALS compared to those without, and in patients with spinal onset compared to bulbar onset. Early-onset disease was seen in 10% of patients, and had a greater proportion of males, spinal onset, and classical ALS phenotype compared to late-onset disease. Survival was shorter in females, in patients with bulbar onset, and in patients with classical ALS. Long survival was seen in 18% of patients. Patients with long survival had younger age of onset, greater proportion of males, spinal onset, and fewer patients with classical ALS.

CONCLUSION

Our study confirms that ALS is more prevalent in males and that spinal onset is more common than bulbar onset. Males have earlier onset but longer survival. We found that overall, patients with classical ALS have worse survival than ALS variants, but some patients who were considered to have classical ALS had long survival. This study confirms the similarity of ALS in our region to ALS in other geographical regions.

"Walking a tightrope": A grounded theory approach to informal caregiving for amyotrophic lateral sclerosis

Informal caregivers, mainly family members and friends, provide supportive and palliative care for people with amyotrophic lateral sclerosis (ALS) during their terminal disease course. Informal caregiving for people with ALS continues towards palliative care and end-of-life care with the progression of the disease. In this study, we provide a theoretical understanding of informal caregiving in ALS utilising 23 semi-structured interviews conducted with informal caregivers of people with ALS (pwALS) in Switzerland. Due to the expected death of the care recipient, our grounded theory approach outlines informal caregivers' caregiving work as an effort to secure a balance amongst different caregiving activities, which feed into the final stage of providing palliative care. Overall, our theoretical understanding of ALS informal caregiving work encompasses the core category 'holding the balance' and four secondary categories: 'Organising support', 'being present', 'managing everyday life' and 'keeping up with ALS'. The core category of holding the balance underlines the significance of ensuring care and normalcy even as disease progresses and until the end of life. For the informal caregivers, this balancing act is the key element of care provision to pwALS and therefore guides decisions surrounding caregiving. On this understanding, those caregivers that succeed in holding the balance can provide care at home until death. The balance is heavily influenced by contextual factors of caregiving, for example relating to personal characteristics of the caregiver, or activities of caregiving where the goal is to ensure the quality of life of the pwALS. As there is a heterogeneity of speed and subtype of progression of ALS, our work accounts for multiple caregiving trajectories.

Natural history and remarkable psychiatric state of late-onset amyotrophic lateral sclerosis in China

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neurons. The proportion of late-onset ALS in China were low and may have distinct clinical and genetic manifestations. We aimed to investigate the natural history and remarkable psychiatric state of ALS with age at onset over 60 years in China.

MATERIALS AND METHODS

We collected all ALS cases from 2017 to 2020 in our center and focused on late-onset ALS patients particularly, by analyzing the clinical data, including the ALS onset and disease progression. Anxiety, depression, cognitive function, and sleep quality were assessed to reflect the psychiatric state.

RESULTS

A total of 193 late-onset ALS patients were included in this study. The median age at onset of late-onset ALS was 65 years with the quartile from 62 to 68 years. When compared with 446 non-late-onset ALS, late-onset ALS showed distinct clinical presentation, with lower ALS Functional Rating Scale-Revised at diagnosis and faster rate of progression. Remarkably, late-onset ALS were suffering from worse psychiatric state, including serious anxiety and depression, as well as worse cognitive function with sleep quality. The abnormal psychiatric state was more pronounced in female patients of late-onset.

CONCLUSIONS

In the current study, ALS patients with late-onset showed unique clinical features. Severe psychiatric conditions and faster progression in the early stage of the disease of late-onset ALS indicated the need for more social and psychiatric support in this population.

China amyotrophic lateral sclerosis registry of patients with Traditional Chinese Medicine (CARE-TCM): Rationale and design

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine (TCM) has become popular interventional treatment for amyotrophic lateral sclerosis (ALS). However, lack of knowledge about the general characteristics and long-term clinical outcomes hampers the development of herbal drugs for ALS.

AIM OF THE STUDY

The China Amyotrophic Lateral Sclerosis Registry of Patients with Traditional Chinese Medicine (CARE-TCM) provides an opportunity to better understand which TCM interventions patients with ALS are receiving, what the characteristics of patients with ALS are, and how these interventions impact clinical measures.

MATERIALS AND METHODS

This study includes a voluntary nationwide registry, and data will be collected prospectively using an electronic data system. Detailed data collection will be performed every 3 months for 5 years. Baseline characteristics and 5-year survival will be collected. This registry was initiated in March 2021. The number of participating medical centers will be about 30 hospitals, and the target procedure number will be 2000. We will also compare the results with those of other registries in China and other countries.

DISCUSSION

The CARE-TCM registry will first provide real-world data regarding TCM and ALS in China, focusing on the clinical characteristics of ALS patients with TCM, disease phenotypes that respond best to TCM, and correlating clinical response with other parameters. The CARE-TCM can be very helpful to improve the efficiency and quality of TCM clinical trial design.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04885374 (registered on May 8, 2021).

Characteristics of Late-Onset Amyotrophic Lateral Sclerosis in a Chinese Cohort

OBJECTIVE

This retrospective study analyzed the clinical characteristics and prognosis of the elderly amyotrophic lateral sclerosis (ALS) population in a large sample.

METHODS

The study included 1,005 patients with sporadic ALS admitted to Chinese PLA General Hospital between March 2011 and March 2021. We stratified the ALS patients into young and old groups using 2 cutoffs for the age at disease onset (≥65 or ≥70 years old) and compared their demographic, clinical, and survival data.

RESULTS

The mean onset age of all patients was 52.79 ± 10.55 years, with 123 (12.24%) having a disease onset ≥65 years and 44 (4.38%) having an onset ≥70 years. There were 624 (62.1%) male patients. More bulbar-onset cases were in the late-onset group (p = 0.001). The sex distribution, time from onset to diagnosis, and the time of symptom spread from spinal or bulbar localization to a generalized localization did not differ between groups. Late-onset patients progressed more rapidly and had a significantly shorter survival.

CONCLUSIONS

Chinese ALS patients have an earlier age at onset and a relatively smaller proportion of old onset than European and Japanese patients. Elderly patients are more likely to have bulbar onset, which is related to rapid progression and a shorter survival.

The Gold Coast criteria increases the diagnostic sensitivity for amyotrophic lateral sclerosis in a Chinese population

OBJECTIVES

The aim of this study was to assess and compare the diagnostic utility of a new diagnostic criteria for amyotrophic lateral sclerosis (ALS), abbreviated as the 'Gold Coast Criteria', with the revised El Escorial (rEEC) and Awaji criteria.

METHODS

Clinical and electrophysiological data of 1185 patients from January 2014 to December 2019 in the Peking Union Medical College Hospital ALS database were reviewed. The sensitivity of the Gold Coast criteria was compared to that of the possible rEEC and Awaji criteria (defined by the proportion of patients categorized as definite, probable, or possible ALS).

RESULTS

A final diagnosis of ALS was recorded in 1162 patients. The sensitivity of the Gold Coast criteria (96.6%, 95% confidence interval [CI] = 95.3%-97.5%) was greater than that of the rEEC (85.1%, 95%CI = 82.9%-87.1%) and Awaji (85.3%, 95%CI = 83.2%-87.3%). In addition, the sensitivity of the novel criteria maintained robust across subgroups, and the advantage was more prominent in limb-onset ALS patients and those who completed electromyographic tests. In those who did not achieve any of the rEEC diagnostic categories, the sensitivity of Gold Coast criteria was 84.4%.

CONCLUSIONS

The current study demonstrated that the Gold Coast criteria exhibited greater diagnostic sensitivity than the rEEC and Awaji criteria in a Chinese ALS population. The application of the Gold Coast criteria should be considered in clinical practice and future therapeutic trials.

Hypermetabolism associated with worse prognosis of amyotrophic lateral sclerosis

BACKGROUND AND OBJECTIVE

Exploration of hypermetabolism in amyotrophic lateral sclerosis (ALS) with different ethnicities is needed to understand its metabolic implications for clinical management. We aimed to evaluate the features of hypermetabolism and investigate its association with clinical characteristics and prognosis of ALS in a prospective Chinese cohort.

METHODS

This prospective study was conducted at Peking University Third Hospital, China from 2017 to 2020. 343 participants were enrolled initially. After strict screening, 147 matched health controls and 93 patients with ALS were eligible and underwent detailed clinical assessments. Disease severity and progression were evaluated using recognized scales. Metabolic assessments included body composition and metabolic index (MI) [hypermetabolism if MI ≥ 120.0%]. Patients were followed up every 6 months for survival analysis.

RESULTS

Compared with controls, hypermetabolism was significantly more prevalent in ALS (p = 0.009). MI was consistently higher in ALS than controls (p = 0.009). Further correlation analysis showed that MI significantly decreased with disease progression, as graded by King's College staging system (p < 0.001). MI was significantly correlated with fat-free mass and fat mass (p = 0.005 and 0.007). Survival analysis showed that hypermetabolism independently indicated a worse prognosis for ALS (HR = 1.020, CI = 1.004-1.036, p = 0.013).

CONCLUSION

A significant increase in the prevalence and degree of hypermetabolism was identified in ALS compared with strictly matched controls. Metabolic index, which is significantly associated with disease progression and body composition, is an independent prognostic indicator for a worse survival of ALS.

GLT8D1 may not be significant in Chinese sporadic amyotrophic lateral sclerosis patients

To detect the mutation frequency of exon 4 of amyotrophic lateral sclerosis (ALS) in a new disease-causing gene, GLT8D1 (NM_018446), in Chinese patients, we used whole-exome sequencing technology to screen the full-length GLT8D1 gene in 539 Chinese sporadic ALS patients and 176 controls without a history of neurological diseases. Then, we sequenced the coding region of exon 4 in the GLT8D1 gene in a cohort consisting of 256 sporadic ALS patients. Our current results did not find an association between GLT8D1 and ALS in Chinese patients, and further studies will be required.

Medical cost and healthcare utilization of amyotrophic lateral sclerosis in China: A cohort study based on hospital data from 2015 to 2018

Amyotrophic lateral sclerosis (ALS), a specific neurodegenerative disease, imposed increased economic and utilizations burden on the healthcare system, especially with the progress of the diseases severity. However, the economic burden on Chinese ALS patients remained unclear. This study therefore was aimed to investigate medical cost and healthcare utilization for Chinese ALS patients.Longitudinal health data of over 20 million individuals, including military personnel and civilians, was collected from all Chinese military hospitals. We identified 480 patients with a first major diagnosis for ALS from 2015 to 2018, while matched 400 controlled patients on age, gender, ethnic group, geographic region, length of stay, year of diagnosis and comorbidity. Their medical cost and healthcare utilizations were then measured 1 year before, and 1 year after ALS diagnosis.The median annual medical cost of ALS patients was about 2-fold higher, 17,087 CNY during the index year than 1 year before, 7859 CNY. The highest increase in utilizations may account for medical costs on ALS patients, which was represented by hospitalizations (Odd Ratio (OR) = 4.26, 95% confidence interval (CI) 3.52, 5.15), electromyography (OR = 4.14, 95% CI 2.37, 7.22), nerve conduction velocity (OR = 3.26, 95% CI 2.23, 4.77).This study is the first one reporting direct economic burden on Chinese ALS patients. Efforts should be made to develop cost-effective diagnostic tools in order that sources of medical cost were more effectively allocated, and this disease was detected earlier.

Mendelian randomization implies no direct causal association between leukocyte telomere length and amyotrophic lateral sclerosis

We employed Mendelian randomization (MR) to evaluate the causal relationship between leukocyte telomere length (LTL) and amyotrophic lateral sclerosis (ALS) with summary statistics from genome-wide association studies (n = ~ 38,000 for LTL and ~ 81,000 for ALS in the European population; n = ~ 23,000 for LTL and ~ 4,100 for ALS in the Asian population). We further evaluated mediation roles of lipids in the pathway from LTL to ALS. The odds ratio per standard deviation decrease of LTL on ALS was 1.10 (95% CI 0.93–1.31, p = 0.274) in the European population and 0.75 (95% CI 0.53–1.07, p = 0.116) in the Asian population. This null association was also detected between LTL and frontotemporal dementia in the European population. However, we found that an indirect effect of LTL on ALS might be mediated by low density lipoprotein (LDL) or total cholesterol (TC) in the European population. These results were robust against extensive sensitivity analyses. Overall, our MR study did not support the direct causal association between LTL and the ALS risk in neither population, but provided suggestive evidence for the mediation role of LDL or TC on the influence of LTL and ALS in the European population.

Characteristics of amyotrophic lateral sclerosis in Lebanon-a chart review

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder primarily manifesting as motor deficits. It is caused by motor neuron death and leads to progressive disability and demise. It can present at any age, manifest as several phenotypes, and may have a variable progression pattern. Methods: This retrospective study is based on chart review of subjects presenting to the American University of Beirut Medical Center from June 2015 till March 2020. It aims to describe the characteristics of ALS in Lebanon. Results: Out of 140 subjects identified, 113 had classical ALS. The mean age in classical and atypical ALS were 55.5 and 55.6 years, male gender was predominant in both groups, and the mean duration from disease onset to diagnosis was 10 months in classic ALS compared to 22 months in atypical ALS. The median survival in subjects with classical ALS was 31 months which was significantly lower than atypical ALS phenotypes of 41.5 months. Additionally, more than half of patients (57%) were found to have a moderate ALSFRS-R progression rate. Conclusions: The study is the first to report the characteristics of amyotrophic lateral sclerosis in Lebanon. Moreover, we were able to categorize patients with classical phenotype according to disease progression using the ALSFRS-R score which can be a useful tool in determining disease prognosis at an early stage.

The protective role of pre-morbid type 2 diabetes in patients with amyotrophic lateral sclerosis: a center-based survey in China

Objective: To assess the role of premorbid type 2 diabetes in patients with amyotrophic lateral sclerosis (ALS) in China.Methods: We compared data from ALS patients with premorbid type 2 diabetes (T2D) and ALS patients without T2D with regard to the age of onset of ALS. In addition, survival was compared between these two groups of patients using propensity score matching (PSM). Results: Among 1331 consecutive sporadic ALS patients, 100 (7.5%) were labeled as ALS-T2D and 1231 were labeled as ALS-control according to the presence or absence of premorbid T2D. The mean age of onset in patients in the ALS-T2D group was 57.0 years, with a 4.4-year delay compared to that in the ALS-control group [57.0 (SD, 9.6) years vs 52.6 (SD, 10.3) years, respectively; p = 0.000]. This 4.4-year delay was significant after adjusting for sex and the site of onset in a multiple linear regression model. Additionally, after comparison with matched pairs, a nonsignificant increase in survival was observed among the ALS patients with premorbid T2D. Conclusions: The results support the protective role of diabetes in ALS. It is possible to infer that these beneficial effects occur mainly in the preclinical and early stages of the disease course.

Causal association of type 2 diabetes with amyotrophic lateral sclerosis: new evidence from Mendelian randomization using GWAS summary statistics

BACKGROUND

Associations between type 2 diabetes (T2D) and amyotrophic lateral sclerosis (ALS) were discovered in observational studies in both European and East Asian populations. However, whether such associations are causal remains largely unknown.

METHODS

We employed a two-sample Mendelian randomization approach to evaluate the causal relationship of T2D with the risk of ALS in both European and East Asian populations. Our analysis was implemented using summary statistics obtained from large-scale genome-wide association studies with ~660,000 individuals for T2D and ~81,000 individuals for ALS in the European population, and ~191,000 individuals for T2D and ~4100 individuals for ALS in the East Asian population. The causal relationship between T2D and ALS in both populations was estimated using the inverse-variance-weighted methods and was further validated through extensive complementary and sensitivity analyses.

RESULTS

Using multiple instruments that were strongly associated with T2D, a negative association between T2D and ALS was identified in the European population with the odds ratio (OR) estimated to be 0.93 (95% CI 0.88-0.99, p = 0.023), while a positive association between T2D and ALS was observed in the East Asian population with OR = 1.28 (95% CI 0.99-1.62, p = 0.058). These results were robust against instrument selection, various modeling misspecifications, and estimation biases, with the Egger regression and MR-PRESSO ruling out the possibility of horizontal pleiotropic effects of instruments. However, no causal association was found between T2D-related exposures (including glycemic traits) and ALS in the European population.

CONCLUSION

Our results provide new evidence supporting the causal neuroprotective role of T2D on ALS in the European population and provide empirically suggestive evidence of increasing risk of T2D on ALS in the East Asian population. Our results have an important implication on ALS pathology, paving ways for developing therapeutic strategies across multiple populations.

Comparison of the clinical and genetic features of amyotrophic lateral sclerosis across Cuban, Uruguayan and Irish clinic-based populations

OBJECTIVES

This study compares the clinical characteristics of patients with amyotrophic lateral sclerosis (ALS) within three clinic-based populations from Cuba, Uruguay and Ireland and determines the impact of known ALS-associated genetic variants on phenotypic manifestations within the Cuban population.

METHODS

Demographic and clinical information was collected on 115 Cuban, 220 Uruguayan and 1038 Irish patients with ALS attending national specialist clinics through 1996-2017. All Cuban patients and 676 Irish patients underwent next-generation DNA sequencing and were screened for the pathogenic C9orf72 repeat expansion.

RESULTS

The mean age of onset was younger in the Cuban (53.0 years, 95% CI 50.4 to 55.6) and Uruguayan (58.2 years, 95% CI 56.5 to 60.0) populations compared with the Irish population (61.6 years, 95% CI 60.9 to 62.4). No differences in survival between populations were observed. 1.7 % (95% CI 0.6 to 4.1) of Cubans with ALS carried the C9orf72 repeat expansion compared with 9.9% (95% CI 7.8 to 12.0) of Irish patients with ALS (p=0.004). Other known variants identified in the Cuban population included ANG (one patient), CHCHD10 (one patient) and DCTN1 (three patients).

CONCLUSIONS AND RELEVANCE

This study is the first to describe the clinical characteristics of ALS in Cuban and Uruguayan populations and report differences between the Cuban and Irish genetic signature in terms of known ALS-associated genetic variants. These novel clinical and genetic data add to our understanding of ALS across different and understudied populations.

The epidemiology and genetics of Amyotrophic lateral sclerosis in China

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder associated with loss of motor neurons. Previous knowledge of the disease has been mainly based on studies from Caucasian ALS patients of European descent. Here we review the epidemiological characteristics of ALS among the Chinese population in order to compare the similarities and differences between Chinese ALS cases and those from other countries. We describe a potential lower incidence and prevalence of ALS, a younger age of onset and a lower proportion of familial ALS cases in the Chinese population. Additionally, we highlight potential genetic differences between Chinese and Caucasian ALS patients. Most notably, the frequency of GGGGCC repeat expansions in C9ORF72 in Chinese ALS is significantly lower than in Caucasians. Since some conclusions might not be consistent across all of the studies around China to date, we suggest that it is necessary to carry out a prospective population-based study and large-scale gene sequencing around to better define epidemiological and genetic features of Chinese ALS patients.

Mutation analysis of KIF5A in Chinese amyotrophic lateral sclerosis patients

Amyotrophic lateral sclerosis (ALS) is an age-related fatal neurodegenerative orphan disorder that is characterized by progressive injury of both the upper and lower motor neurons. Recently, loss-of-function mutations predominately disrupting the C-terminal amino acid sequence of KIF5A via aberrant exon 27 splicing have been reported in European ALS cohorts. However, the contributions of KIF5A mutations in Asian patients with ALS remain unclear. KIF5A sequences, including exons 26 and 27, were analyzed in a large Chinese ALS cohort comprising 33 unrelated familial ALS probands, 645 sporadic ALS (SALS) patients, 15 ALS patients presenting with concomitant frontotemporal dementia, 400 in-house controls, and 12,951 East Asian individuals from the Exome Aggregation Consortium and Genome Aggregation Database databases. As a result, the previously reported canonical splicing site mutation c.2993-1G>A was found in 1 SALS patient, while no mutations were detected in familial ALS case or ALS patients presenting with concomitant frontotemporal dementia. The frequency of KIF5A mutations accounts for 0.16% (1/645) of Chinese SALS patients, implying that it is an uncommon genetic determinant of ALS in Chinese patients.

Brain Structural and Perfusion Signature of Amyotrophic Lateral Sclerosis With Varying Levels of Cognitive Deficit

Objective

To characterize the patterns of brain atrophy and perfusion as measured by arterial spin labeling (ASL)-MRI, in amyotrophic lateral sclerosis (ALS) patients with varying levels of cognitive deficit, including ALS with frontotemporal dementia (FTD).

Methods

A total of 55 ALS patients and 20 healthy controls (HCs) were included, and all participants underwent neuropsychological assessments and MRI scans. According to their cognitive performance, ALS patients were further subclassified into ALS with normal cognition (ALS-Cn, n = 27), ALS with cognitive impairment (ALS-Ci, n = 17), and ALS-FTD (n = 11). Voxel-based comparisons of gray matter (GM) changes and cerebral blood flow (CBF) were conducted among the subgroups.

Results

The whole-brain comparisons of GM changes and CBF among ALS-Ci, ALS-Cn, and HCs were not significantly different. However, the ALS-FTD patients demonstrated a similar pattern of GM loss and hypoperfusion with more significant alterations in the left frontal and temporal lobe compared with the HCs, ALS-Cn, and ALS-Ci patients. Decreased CBF was found in many of the same brain areas wherein structural alterations occurred, although isolated GM loss and hypoperfusion were also observed. In addition, for both GM and CBF abnormalities, a similar pattern of changes was found in the comparisons of ALS-FTD vs. ALS-Ci, ALS-FTD vs. ALS-Cn, and ALS-FTD vs. HCs, with the differences being most significant between ALS-FTD and HCs.

Conclusion

The cognitive status of ALS patients is associated with different patterns of GM changes and cerebral perfusion. ASL-MRI might be a useful tool with which to investigate the pathological burden of ALS and to disclose the early signature of possible cognitive impairment.

Referral bias in ALS epidemiological studies

Background

Despite concerns about the representativeness of patients from ALS tertiary centers as compared to the ALS general population, the extent of referral bias in clinical studies remains largely unknown. Using data from EURALS consortium we aimed to assess nature, extent and impact of referral bias.

Methods

Four European ALS population-based registries located in Ireland, Piedmont, Puglia, Italy, and Limousin, France, covering 50 million person-years, participated. Demographic and clinic characteristics of ALS patients diagnosed in tertiary referral centers were contrasted with the whole ALS populations enrolled in registries in the same geographical areas.

Results

Patients referred to ALS centers were younger (with difference ranging from 1.1 years to 2.4 years), less likely to present a bulbar onset, with a higher proportion of familial antecedents and a longer survival (ranging from 11% to 15%) when compared to the entire ALS population in the same geographic area.

Conclusions

A trend for referral bias is present in cohorts drawn from ALS referral centers. The magnitude of the possible referral bias in a particular tertiary center can be estimated through a comparison with ALS patients drawn from registry in the same geographic area. Studies based on clinical cohorts should be cautiously interpreted. The presence of a registry in the same area may improve the complete ascertainment in the referral center.

Using the Capture-Recapture Method to Estimate the Incidence of Amyotrophic Lateral Sclerosis in Beijing, China

BACKGROUND

To assess the total, gender-related and ageing process-related incidence rates of amyotrophic lateral sclerosis (ALS) in Beijing, China. Determine whether the decreased male to female ratio among postmenopausal age groups.

METHODS

We used the 2-source capture-recapture method to estimate the incidence of ALS in Beijing. The primary and secondary data sources were from diagnostic hospitals and assisted care institutions in the same area from 2010 to 2015.

RESULTS

A total of 562 cases and 283 cases were extracted from 2 data sources, and a total of 962 patients diagnosed with ALS within the 6-year period were estimated (95% CI 883-1041). The average yearly incidence was 0.77/100,000 persons (95% CI 0.71-0.83). The female to male ratio was 1.63. The incidence was associated with age and peaked in the 55-64 year age group. There was no obvious decline in the male:female ratio among postmenopausal age groups.

CONCLUSIONS

The total incidence of ALS in Beijing is similar to international reports. The onset of ALS is not merely the result of ageing.

Complete hazard ranking to analyze right-censored data: An ALS survival study

Survival analysis represents an important outcome measure in clinical research and clinical trials; further, survival ranking may offer additional advantages in clinical trials. In this study, we developed GuanRank, a non-parametric ranking-based technique to transform patients' survival data into a linear space of hazard ranks. The transformation enables the utilization of machine learning base-learners including Gaussian process regression, Lasso, and random forest on survival data. The method was submitted to the DREAM Amyotrophic Lateral Sclerosis (ALS) Stratification Challenge. Ranked first place, the model gave more accurate ranking predictions on the PRO-ACT ALS dataset in comparison to Cox proportional hazard model. By utilizing right-censored data in its training process, the method demonstrated its state-of-the-art predictive power in ALS survival ranking. Its feature selection identified multiple important factors, some of which conflicts with previous studies.

Whole-exome sequencing in amyotrophic lateral sclerosis suggests NEK1 is a risk gene in Chinese

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive neurological disease characterised by the degeneration of motor neurons, which are responsible for voluntary movement. There remains limited understanding of disease aetiology, with median survival of ALS of three years and no effective treatment. Identifying genes that contribute to ALS susceptibility is an important step towards understanding aetiology. The vast majority of published human genetic studies, including for ALS, have used samples of European ancestry. The importance of trans-ethnic studies in human genetic studies is widely recognised, yet a dearth of studies of non-European ancestries remains. Here, we report analyses of novel whole-exome sequencing (WES) data from Chinese ALS and control individuals.

METHODS

WES data were generated for 610 ALS cases and 460 controls drawn from Chinese populations. We assessed evidence for an excess of rare damaging mutations at the gene level and the gene set level, considering only singleton variants filtered to have allele frequency less than 5 × 10-5 in reference databases. To meta-analyse our results with a published study of European ancestry, we used a Cochran-Mantel-Haenszel test to compare gene-level variant counts in cases vs controls.

RESULTS

No gene passed the genome-wide significance threshold with ALS in Chinese samples alone. Combining rare variant counts in Chinese with those from the largest WES study of European ancestry resulted in three genes surpassing genome-wide significance: TBK1 (p = 8.3 × 10-12), SOD1 (p = 8.9 × 10-9) and NEK1 (p = 1.1 × 10-9). In the Chinese data alone, SOD1 and NEK1 were nominally significantly associated with ALS (p = 0.04 and p = 7 × 10-3, respectively) and the case/control frequencies of rare coding variants in these genes were similar in Chinese and Europeans (SOD1: 1.5%/0.2% vs 0.9%/0.1%, NEK1 1.8%/0.4% vs 1.9%/0.8%). This was also true for TBK1 (1.2%/0.2% vs 1.4%/0.4%), but the association with ALS in Chinese was not significant (p = 0.14).

CONCLUSIONS

While SOD1 is already recognised as an ALS-associated gene in Chinese, we provide novel evidence for association of NEK1 with ALS in Chinese, reporting variants in these genes not previously found in Europeans.

Cross-ethnic meta-analysis identifies association of the GPX3-TNIP1 locus with amyotrophic lateral sclerosis

Cross-ethnic genetic studies can leverage power from differences in disease epidemiology and population-specific genetic architecture. In particular, the differences in linkage disequilibrium and allele frequency patterns across ethnic groups may increase gene-mapping resolution. Here we use cross-ethnic genetic data in sporadic amyotrophic lateral sclerosis (ALS), an adult-onset, rapidly progressing neurodegenerative disease. We report analyses of novel genome-wide association study data of 1,234 ALS cases and 2,850 controls. We find a significant association of rs10463311 spanning GPX3-TNIP1 with ALS (p = 1.3 × 10⁻⁸), with replication support from two independent Australian samples (combined 576 cases and 683 controls, p = 1.7 × 10⁻³). Both GPX3 and TNIP1 interact with other known ALS genes (SOD1 and OPTN, respectively). In addition, GGNBP2 was identified using gene-based analysis and summary statistics-based Mendelian randomization analysis, although further replication is needed to confirm this result. Our results increase our understanding of genetic aetiology of ALS.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease. Here, Wray and colleagues identify association of the GPX3-TNIP1 locus with ALS using cross-ethnic meta-analyses.

The Awaji criteria increases the diagnostic sensitivity of the revised El Escorial criteria for amyotrophic lateral sclerosis diagnosis in a Chinese population

OBJECTIVES

The accurate and early diagnosis of amyotrophic lateral sclerosis (ALS) is important for extending the life expectancy of patients. However, previous studies that have assessed the diagnostic sensitivities of the Awaji criteria (AC) and the revised El Escorial criteria (rEEC) in patients with ALS have been inconsistent, most of them were consensual regarding the advantage of Awaji over conventional criteria. Our study sought to compare the roles of AC and rEEC in the diagnosis of ALS.

METHODS

Data from a total of 294 consecutive patients with ALS were collected between January 2014 and August 2015 in the Peking Union Medical College Hospital. The clinical and electrophysiological records of 247 patients were eventually analyzed. The primary outcome measures were the sensitivities of the AC and rEEC for the diagnosis of ALS.

RESULTS

The sensitivity of probable or definite ALS as diagnosed with the AC (78%) was greater than that of the rEEC (36%, P <0.001). Following the application of the AC, 103 of the 147 patients categorized as probable ALS-laboratory supported from the rEEC were upgraded to probable or definite ALS, and 44 were downgraded to possible ALS.

CONCLUSIONS

Our data demonstrated that the AC exhibited greater diagnostic sensitivity than the rEEC in a Chinese ALS population. The use of the AC should be considered in clinical practice.

Neurofilaments in CSF As Diagnostic Biomarkers in Motor Neuron Disease: A Meta-Analysis

Objective: Neurofilaments in CSF are promising biomarkers which might help in the diagnosis of motor neuron disease (MND). We aim to assess the diagnostic value of neurofilaments in CSF for MND.

Methods: Pubmed, Emabase, and Web of Science were searched for relevant studies systematically. Articles in English that evaluated the utility of neurofilaments in CSF in the diagnosis of MND were included. Data were extracted by two independent investigators. Diagnostic indexes for neurofilament light chain (NFL) and phosphorylated neurofilament heavy chain (pNFH) were calculated separately. Stata 12.0 software with a bivariate mixed-effects model was used to summarize the diagnostic indexes from eligible studies.

Results: Five studies on NFL and eight studies on pNFH met inclusion criteria. For NFL, the pooled sensitivity and specificity were 81% (95% confidence interval [CI], 72–88%) and 85% (95% CI, 76–91%), respectively; the positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 5.5 (95% CI, 3.1–9.8) and 0.22 (95% CI, 0.14–0.35), respectively; the summary diagnostic odds ratio (DOR) was 25 (95% CI, 9–70), and the area under summary receiver operator characteristic curve (AUC) was 0.90 (95% CI, 0.87–0.92). For pNFH, the pooled sensitivity, specificity, PLR and NLR were 85% (95% CI, 80–88%), 85% (95% CI, 77–90%), 5.5 (95% CI, 3.6–8.4), and 0.18 (95% CI, 0.13–0.25), respectively; the DOR was 30 (95% CI, 16–58), and the AUC was 0.91 (95% CI, 0.88–0.93).

Conclusion: Neurofilaments in CSF have a high value in the diagnosis of MND, though the optimal cutoff value remains to be further investigated.

Amyotrophic lateral sclerosis and motor neuron syndromes in Asia

While the past 2 decades have witnessed an increasing understanding of amyotrophic lateral sclerosis (ALS) arising from East Asia, particularly Japan, South Korea, Taiwan and China, knowledge of ALS throughout the whole of Asia remains limited. Asia represents >50% of the world population, making it host to the largest patient cohort of ALS. Furthermore, Asia represents a diverse population in terms of ethnic, social and cultural backgrounds. In this review, an overview is presented that covers what is currently known of ALS in Asia from basic epidemiology and genetic influences, through to disease characteristics including atypical phenotypes which manifest a predilection for Asians. With the recent establishment of the Pan-Asian Consortium for Treatment and Research in ALS to facilitate collaborations between clinicians and researchers across the region, it is anticipated that Asia and the Pacific will contribute to unravelling the uncertainties in ALS.

Behavioral Symptoms in Motor Neuron Disease and Their Negative Impact on Caregiver Burden

Background:

The spectrum of abnormal behaviors in amyotrophic lateral sclerosis/motor neuron disease (ALS/MND) has been described, but its practical meaning, namely its impact on caregiver burden, has not been clearly documented in Chinese population. This study aimed to assess the distribution of abnormal behaviors in Chinese population, and to analyze the relationship between behavior changes and caregiver burden.

Methods:

Sixty-five patients with ALS/MND have been consecutively enrolled into registry platform of Peking Union Medical College Hospital. An investigation was performed to these patients and their caregivers using the revised ALS function rating scale, Frontal Behavioral Inventory-ALS version, the Frontal Assessment Battery, and the Caregiver Burden Inventory.

Results:

Twenty-eight (43.1%) patients displayed abnormal behaviors of varying degrees, with one fulfilling the diagnostic criteria of frontotemporal lobe degeneration. Irritability, logopenia, and inflexibility ranked top 3 of abnormal behavior list. Correlation analysis revealed that the degree of behavioral change and frontal cognitive status were significantly associated with caregiver burden, with more extensive impact from disinhibitive behaviors. Analysis of covariance analysis showed that after associated factors were corrected, caregivers of patients with moderate to severe behavior change reported significantly heavier developmental burden, physical burden, and total burden than those with no behavioral change.

Conclusions:

Neurobehavioral symptoms could present in around 40% of Chinese patients with ALS/MND, and the distribution of these behaviors was also unique. Besides, abnormal behaviors were highly related to caregivers’ burden.

Single-nucleotide Polymorphism rs2275294 in ZNF512B is not Associated with Susceptibility to Amyotrophic Lateral Sclerosis in a Large Chinese Cohort

Background:

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that primarily affects motor neurons and has no effective treatment. Recently, Iida et al. identified a single-nucleotide polymorphism (SNP) rs2275294 in the ZNF512B gene that is significantly associated with susceptibility to ALS in the Japanese population. Here, we performed a case–control study examining the possible association of rs2275294 with risk of sporadic ALS (SALS) in a large Chinese cohort.

Methods:

To assess this association, we performed a replication study in 953 SALS patients and 1039 age- and gender-matched healthy control subjects, who were recruited from Peking University Third Hospital and the First Affiliated Hospital of Anhui Medical University from January 2004 to December 2013 throughout China. We genotyped the rs2275294 SNP using polymerase chain reaction and direct sequencing.

Results:

The allele frequency of rs2275294 in ZNF512B was different between Japanese and Chinese. The association in Chinese between ALS patients and controls did not reach statistical significance (P = 0.54; odds ratio = 0.94; 95% confidence interval = 0.76–1.15).

Conclusions:

The SNP rs2275294 in ZNF512B is not considered to be associated with ALS susceptibility in the Chinese population. Our study highlights genetic heterogeneity in ALS susceptibility in different population. Given our negative results, further replication study involving larger and more homogeneous samples in different ethnicities should be performed in the future.

TUBA4A may not be a significant genetic factor in Chinese ALS patients

TUBA4A gene has recently been identified as a potential candidate amyotrophic lateral sclerosis(ALS)-associated gene using exome-wide rare variant burden analysis. The identification of novel TUBA4A variants in Italian ALS patients further support the role of TUBA4A in ALS. We sequenced the coding region of exon 4 in the TUBA4A gene in a cohort consisting of 80 familial ALS probands, 500 sporadic ALS patients and 500 healthy control individuals. No TUBA4A causative variants were identified in the ALS patients. In conclusion, our current results did not find an association between TUBA4A and ALS in Chinese patients, and further studies will be required.

Natural history and clinical features of sporadic amyotrophic lateral sclerosis in China

OBJECTIVES

To describe the natural history and clinical features of sporadic amyotrophic lateral sclerosis (ALS) in Chinese patients, and to report data on the prognostic factors for survival.

METHODS

All patients referred to our ALS centre between 2003 and 2012 were followed up every 3 months. Survival and tracheotomy were predefined as primary outcome measures. Group differences were analysed using parametric and non-parametric tests as appropriate. Survival was analysed using the Kaplan-Meier method and Cox regression analysis.

RESULTS

Of the 1624 patients with ALS, 75.1% had limb-onset, 14.0% had bulbar-onset, 7.8% had flail-arm syndrome (FAS), 2.6% had progressive muscular atrophy and 0.5% had primary lateral sclerosis. The male:female ratio was 1.7:1, and the mean age at onset was 49.8 years. The median diagnostic delay was 14 months, and the median survival time after symptom onset was 71 months. Male gender, older age at symptom onset, lower body mass index, shorter diagnostic delay, bulbar-onset ALS phenotype, higher Airlie House category at presentation, rural place of residence, use of traditional Chinese medicine and a history of contact with pesticides were associated with poorer survival, whereas female gender or an FAS phenotype may have a better prognosis.

CONCLUSIONS

The clinical characteristics and outcomes of Chinese patients with sporadic ALS were different compared with patients from other countries. Compared with other studies, the age at onset of Chinese patients was earlier, the percentage of bulbar-onset ALS was lower and the prognosis was better. This study substantially advances the understanding of the clinical features and epidemiology of this rare disease.

Cognitive Impairment in Chinese Patients with Sporadic Amyotrophic Lateral Sclerosis

Background

It has reached a consensus that patients with amyotrophic lateral sclerosis (ALS) could display cognitive impairment characterized by executive dysfunction or even dementia, but cognitive spectrum of Chinese patients with ALS still waits to be documented.

Methods

A total of 106 incident patients with sporadic ALS were enrolled and comprehensive neuropsychological tests covering memory, executive function, attention, language, and visuospatial function were administered to them. Neuropsychological performances of 76 age- and education- matched healthy controls were used for the purpose of classification and comparison.

Results

106 patients were categorized into 4 subtypes:84 (79.2%) ALS with normal cognition (ALS-NC), 12 (11.3%) ALS with executive cognitive impairment (ALS-ECI), 5 (4.7%) ALS with non-executive cognitive impairment (ALS-NECI), and 5 (4.7%) ALS with frontotemporal lobe degeneration (ALS-FTLD). Under the same criteria, 2 (2.6%) and 1 (1.3%) healthy controls were diagnosed as ECI and NECI, respectively. The proportion of ECI was significantly higher in non-demented ALS than that in healthy controls, but it was not for NECI. Patients with ALS-FTLD had significantly severer bulbar function and older age than those with ALS-NC.

Conclusion

Comorbid FTLD occurred in around 5% of Chinese sporadic ALS cases. Different genetic background and unique age distribution of Chinese ALS patients might be the reasons for the relatively low rate of comorbid FTLD. Cognitive dysfunction, predominant but not exclusive in executive area, was present in around 16% of non-demented ALS patients.

Clinical features of amyotrophic lateral sclerosis in south-west China

Our objective was to profile clinical features of amyotrophic lateral sclerosis (ALS); we performed a large sample, cross-sectional study based on a hospital registry of ALS in south-west China. Patients were coded in our tertiary referral centre from May 2006 to September 2014. Demographic data and disease-related parameters were collected. A total of 1131 patients were included. Mean age of onset was 54.3 ± 11.6 years and the highest proportion of onset age (30.6%) was between 51 and 60 years. Male:female ratio was 1.45:1. Nearly 30% of the patients were young onset, and 20.3% of the patients were bulbar onset; only 35% received riluzole treatment. The young-onset patients had a higher educational level with a higher proportion performing manual labour and living in rural areas, and a lower proportion with bulbar onset than those who were older at onset. The bulbar-onset patients were older at age of onset, with a lower proportion of males than spinal-onset patients. In conclusion, Chinese ALS patients may be younger at age of onset than Caucasian patients. Environmental and geographical factors are related to the occurrence of ALS. The large treatment gap indicated a pressing need for medical and financial support for Chinese ALS patients.

Neuropsychological investigation in Chinese patients with progressive muscular atrophy

Background

Progressive muscular atrophy (PMA) is a rare type of degenerative motor neuron disease (MND) of which the onset happens in adult period. Despite its well-defined clinical characteristics, its neuropsychological profile has remained poorly understood, considering the consensus of cognitive and behavioral impairment reached in amyotrophic lateral sclerosis (ALS).

Methods

We conducted a cross-sectional evaluation of Chinese PMA patients with a series of comprehensive batteries emphasizing the executive and attention function, and covering other domains of memory, language, visuospatial function, calculation and behavior as well. Their performances were compared with those of age- and education-matched ALS and healthy controls (HC).

Results

21 patients newly diagnosed with PMA were consecutively enrolled into our ALS and other MND registry platform, accounting for 14.7% of all the incident MND cases registered during the same period. 20 patients who completed the neuropsychological batteries were included into analysis. Compared with HC, PMA performed significantly worse in maintenance function of attention, while they exhibited quantitative similarity to ALS in all behavioral inventories and neuropsychological tests except the time for Stroop interference effect.

Conclusion

PMA could display mild cognitive dysfunction in the same frontal-mediated territory of ALS but in a lesser degree, whereas they did not differ from ALS behaviorally.

Epidemiological characteristics of motor neuron disease in Chinese patients

BACKGROUND

The epidemiology, diagnosis, and treatment of motor neuron disease (MND) in Chinese patients are ill known.

METHODS

A registered study of 461 MND patients was conducted across 10 facilities in 7 Chinese cities from February 2009 to March 2010.

RESULTS

Patients were classified as amyotrophic lateral sclerosis (ALS) (84.4%), progressive bulbar palsy (PBP) (4.1%), progressive muscular atrophy (PMA) (10.4%), or primary lateral sclerosis (PLS) (0.9%). MND was predominant in men (men/women; 1.6:1.0). Mean onset age was 52.6 years, with the highest incidence being observed between 51 and 60 years. Notably, 26.0% of MND patients were employed in forestry, fishery, or animal husbandry industries. Ten cases (2.7%) reported family history of MND, and 54.2% exhibited cervical onset. MND was also associated with head/neck trauma. Non-invasive positive pressure ventilation was the most common supportive therapy.

CONCLUSION

As a novel comprehensive report of a Chinese population, this study reveals that epidemiological characteristics of MND patients were similar to those observed in international populations. MND is age-related, male gender predominant, and may be associated with both environmental and genetic risk factors.