Advanced statistical methods to study the effects of gastric tube and non-invasive ventilation on functional decline and survival in amyotrophic lateral sclerosis

Giving Breath to Motor Neurons: Noninvasive Mechanical Ventilation Slows Disease Progression in Amyotrophic Lateral Sclerosis

OBJECTIVE

Noninvasive mechanical ventilation (NIMV) improves amyotrophic lateral sclerosis (ALS) quality of life and survival. However, data about its effect on disease progression are still lacking. Here, we test whether NIMV use changed the rate of functional decline among ALS patients.

METHODS

In this retrospective observational study, we included 448 ALS patients followed up at the ALS Center in Turin, Italy, who underwent NIMV during the disease course. The primary outcome was the change in functional decline after NIMV initiation adjusting for covariates. Functional decline was based on the nonrespiratory items of the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R).

RESULTS

NIMV initiation resulted in a slower functional decline (mean improvement = 0.16 points per month, 95% confidence interval = 0.12-0.19, p < 0.001), with consistent effects observed across various demographic factors, including sex, age at diagnosis, and disease duration before NIMV initiation. This finding was replicated using the PRO-ACT (Pooled Resource Open-Access ALS Clinical Trials) dataset. The favorable impact of NIMV on ALSFRS-R progression was evident independently of disease stages. Notably, NIMV benefits were not dose-dependent but were particularly prominent for nighttime respiratory support.

INTERPRETATION

NIMV significantly influences the rate of motor progression in ALS, and this effect is not determined by the nonlinearity of ALSFRS-R trajectory. The functional decline slowed following NIMV initiation, independently of the site of disease onset or disease severity at the time of NIMV initiation. Our findings underscore the importance of timely NIMV initiation for all ALS patients and highlight the need to consider NIMV-induced slowing of disease progression when evaluating clinical trial outcomes. ANN NEUROL 2024;95:817-822.

Enteral tube feeding for amyotrophic lateral sclerosis/motor neuron disease

BACKGROUND

Maintaining adequate nutrition is critical for people with amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND). Enteral tube feeding is offered to people experiencing difficulty swallowing (dysphagia) to prevent weight loss and aspiration pneumonia. Among the types of enteral tube feeding, percutaneous endoscopic gastrostomy (PEG) is the typical procedure offered to people with ALS and will be mainly discussed here.

OBJECTIVES

To examine the effectiveness of percutaneous endoscopic gastrostomy or other enteral tube feeding in people with ALS, compared to oral feeds without enteral tube feeding on: 1. survival; 2. nutritional status; 3. quality of life. To examine the incidence of minor and major complications of percutaneous endoscopic gastrostomy (PEG) and other enteral tube feeding procedures in people with ALS.

SEARCH METHODS

On 3 January 2020 and 6 February 2021, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE. Embase, ClinicalTrials.gov and WHO ICTRP. We screened the results to identify randomized controlled studies on enteral tube feeding in ALS. We reviewed all references from the search in published articles to identify any additional references.

SELECTION CRITERIA

We included randomized controlled trials (RCTs), quasi-RCTs, and cross-over trials evaluating the effectiveness and complications of PEG or other enteral tube feeding placement in ALS.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We found no RCTs or quasi-RCTs comparing the effectiveness of enteral tube feeding versus oral feeds without enteral tube feeding.

AUTHORS' CONCLUSIONS

There are no RCTs or quasi-RCTs to indicate whether enteral tube feeding is effective compared to continuation of oral feeding for any of the outcome measures. Such RCTs are very unlikely to be performed for ethical reasons. RCTs evaluating the effect of different enteral tube insertion techniques and timings of tube placement on survival and quality of life of people with ALS dysphagia are feasible and warranted.

Stress load and neurodegeneration after gastrostomy tube placement in amyotrophic lateral sclerosis patients

Dysphagia and progressive swallowing problems due to motoneuron death is one of amyotrophic lateral sclerosis (ALS) symptoms. Malnutrition and body weight loss result in immunological disturbances, fatigability and increase risk of secondary complications in ALS patients, percutaneous endoscopic gastrostomy tube (PEG) placement representing a well-recognized method for malnutrition correction and potentially increasing life expectancy. However, despite nutritional correction, occasional rapid neurological deterioration may develop after PEG placement. We have hypothesized that this decline can be a result of exteroceptive stress during PEG placement and promote neurodegeneration in ALS patients. Intravenous sedation may decrease stress during invasive procedures and it is safe during PEG placement in ALS patients. The aim of the study was comparing different PEG placement protocols of anesthesia (local anesthesia or local anesthesia plus intravenous sedation) in ALS from perspectives of stress load and neurological deterioration profile. During 1.5 years 94 ALS patients were admitted; gastrostomy was performed in 79 patients. After screening according to inclusion and exclusion criteria, 30 patients were included in the prospective consecutive study. All patients were divided in two groups, with local anesthesia and with combination of local anesthesia and intravenous sedation. Routine biochemical indices, neurodegeneration and stress markers were measured. The age of ALS patients was 61 ± 10 years; 20 patients were included at stage 4A and 10 at stage 4B (King's College staging). PEG was placed at average14 months after the diagnosis and 2.2 years after first symptoms. Mean ALS Functional Rating Scale-Revised was 27.8, mean forced vital capacity of lung 46.3% (19-91%). After one year of observation only 8 patients survived. Mean life duration after PEG was 5 months (5 days-20 months). Comparison of two PEG placement protocols did not reveal differences in survival time, stress load and inflammation level. Higher saliva cortisol levels, serum cortisol, glucose, C-reactive protein and interleukin-6 were detected after PEG placement, confirming considerable stress response. PEG is a stressful factor for ALS patients, PEG placement representing a natural model of exteroceptive stress. Stress response was detected as increased cortisol, C-reactive protein, interleukin-6, and glucose levels. Intravenous sedation did not increase the risk of PEG placement procedure, however, sedation protocol did not affect stress load.

Percutaneous gastrostomy in amyotrophic lateral sclerosis: a review

Amyotrophic lateral sclerosis (ALS) causes dysphagia and consequent poor nutrition. Sometimes enteral feeding is offered. Percutaneous endoscopic gastrostomy (PEG) is currently the technique of choice for enteral nutrition of these patients. This systematic review addresses the role of PEG and other enteral feeding techniques in maintaining ALS patients' survival and quality of life and in identifying prognostic factors for survival, in order to optimize their usefulness. We also evaluated the mortality of enteral feeding in the first 30 days after each procedure and its complications. Studies were retrieved from Pubmed, Google Scholar, and Cochrane databases, using the relevant keywords, and by hand search. The inclusion criteria were prospective and retrospective designs of studies of people with clinically diagnosed ALS in whom gastrostomy or nasogastric enteral feeding were used in management, published in English. Studies with sample sizes <40, or which focused on a specific gastrostomy technique utilizing less than 30 subjects were excluded in order to avoid small sample bias. We conclude that PEG is safe and probably prolongs survival in non-malnourished ALS patients. However, older age at onset, marked loss of weight or reduced body mass index from symptomatic onset, and marked respiratory dysfunction negatively influence the outcome after PEG insertion. The currently available evidence does not meaningfully address the impact of PEG on quality of life in ALS. The literature about other enteral feeding techniques is insufficient for reliable conclusions. The optimum time for PEG insertion and preferences for specific gastrostomy techniques also require more investigation.

Improvements in the multidisciplinary care are beneficial for survival in amyotrophic lateral sclerosis (ALS): experience from a tertiary ALS center

Objective: The Ljubljana ALS Centre, established in 2002, is the only tertiary center for amyotrophic lateral sclerosis (ALS) in Slovenia. The aim of our study was to evaluate the impact of therapeutic interventions and improvements in the multidisciplinary care on the survival of our patients.Methods: All patients diagnosed with ALS at our center during years 2003-2005 (early group) and 2011-2012 (late group) were included in this retrospective cohort study (n = 124). Kaplan-Meier survival analysis and multiple regression analysis with Cox proportional hazards model were performed to compare survival and to evaluate the differences between the two cohorts.Results: Median survival from the time of diagnosis was 13.0 (95% CI 10.2-15.8) months in the early group and 21.8 (95% CI 17.2-26.4) months in the late group (p = 0.005). In the Cox proportional hazards analysis, the late group of patients was associated with better survival independently of all other prognostic factors (hazard ratio (HR)=0.51, 95% CI = 0.32-0.81, p = 0.004). Survival was also associated with patients' age, use of noninvasive ventilation (NIV) and gastrostomy. The model fit significantly improved when the interaction between the NIV use and the observed time period was added to the model (HR = 0.34, 95% CI = 0.12-0.96, p = 0.041).Conclusions: Our findings suggest that improvements in the multidisciplinary care were beneficial for survival of our patients with ALS. The survival benefit in the late group of our patients could be partially explained by the improvements in the NIV use at our center.

A Comprehensive Examination of Percutaneous Endoscopic Gastrostomy and Its Association with Amyotrophic Lateral Sclerosis Patient Outcomes

There is literature discord regarding the impact of percutaneous endoscopic gastrostomy (PEG), or “feeding tube”, on amyotrophic lateral sclerosis (ALS) outcomes. We assess one of the largest retrospective ALS cohorts to date (278 PEG users, 679 non-users). Kruskal–Wallis and Kaplan–Meier analysis compared cohort medians and survival duration trends. A meta-analysis determined the aggregate associative effect of PEG on survival duration by combining primary results with 7 published studies. Primary results (p < 0.001) and meta-analysis (p < 0.05) showed PEG usage is associated with an overall significant increase in ALS survival duration, regardless of onset type. Percent predicted forced vital capacity (FVC %predict) ≥50 at PEG insertion significantly increases survival duration (p < 0.001); FVC %predict ≥60 has the largest associative benefit (+6.7 months, p < 0.05). Time elapsed from ALS onset until PEG placement is not predictive (p > 0.05). ALSFRS-R survey assessment illustrates PEG usage does not slow functional ALS pathology (p > 0.05), but does stabilize weight and/or body mass index (BMI) (p < 0.05). Observed clinical impression of mood (CIM), was not impacted by PEG usage (p > 0.05). Overall results support PEG as a palliative intervention for ALS patients with ≥50 FVC %predict at PEG insertion.

Variation in noninvasive ventilation use in amyotrophic lateral sclerosis

Objective

We sought to examine prevalence and predictors of noninvasive ventilation (NIV) in a composite cohort of patients with amyotrophic lateral sclerosis (ALS) followed in a clinical trials setting (Pooled Resource Open-Access ALS Clinical Trials database).

Methods

NIV initiation and status were ascertained from response to question 12 of the revised ALS Functional Rating Scale (ALSFRS-R). Factors affecting NIV use in patients with forced vital capacity (FVC) ≤50% of predicted were examined. Predictors of NIV were evaluated by Cox proportional hazard models and generalized linear mixed models.

Results

Among 1,784 patients with 8,417 simultaneous ALSFRS-R and FVC% measures, NIV was used by 604 (33.9%). Of 918 encounters when FVC% ≤50%, NIV was reported in 482 (52.5%). Independent predictors of NIV initiation were lower FVC% (hazard ratio [HR] 1.27, 95% confidence interval [CI] 1.17–1.37 for 10% drop), dyspnea (HR 2.62, 95% CI 1.87–3.69), orthopnea (HR 4.09, 95% CI 3.02–5.55), lower bulbar and gross motor subscores of ALSFRS-R (HRs 1.09 [95% CI 1.03–1.14] and 1.13 [95% CI 1.07–1.20], respectively, per point), and male sex (HR 1.73, 95% CI 1.31–2.28). Adjusted for other variables, bulbar onset did not significantly influence time to NIV (HR 0.72, 95% CI 0.47–1.08). Considerable unexplained variability in NIV use was found.

Conclusion

NIV use was lower than expected in this ALS cohort that was likely to be optimally managed. Absence of respiratory symptoms and female sex may be barriers to NIV use. Prospective exploration of factors affecting adoption of NIV may help bridge this gap and improve care in ALS.

Maximizing the Survival of Amyotrophic Lateral Sclerosis Patients: Current Perspectives

Amyotrophic lateral sclerosis is a neurodegenerative disease that leads to loss of the upper and lower motor neurons. Almost 90% of all cases occur in the sporadic form, with the rest occurring in the familial form. The disease has a poor prognosis, with only two disease-modifying drugs approved by the United States Food and Drug Administration (FDA). The approved drugs for the disease have very limited survival benefits. Edaravone is a new FDA-approved medication that may slow the disease progression by 33% in a selected subgroup of ALS patients. This paper covers the various interventions that may provide survival benefits, such as early diagnosis, medications, gene therapy, stem cell therapy, diet, nutritional supplements, multidisciplinary clinics, and mechanical invasive and noninvasive ventilation. The recent data on masitinib, the role of enteral feeding, gene therapy, and stem cell therapy is discussed.

Causal inference methods to study gastric tube use in amyotrophic lateral sclerosis

OBJECTIVE

To estimate effects of gastric tube (G-tube) on survival and quality of life (QOL) in people with amyotrophic lateral sclerosis (ALS) correcting for confounding by indication inherent in nonrandomized observational data.

METHODS

To complement a recent causal inference analysis, which concluded that G-tube placement increases the hazard of death, permanent assisted ventilation, or tracheostomy by 28%, we fit causal inference models on a different sample of 481 patients with ALS enrolled in a recent clinical trial of ceftriaxone. Forward selection identified predictors of G-tube placement. Effects of G-tube on survival and QOL were estimated using structural nested models and marginal structural models, accounting for predictors of G-tube treatment.

RESULTS

Forced vital capacity and the total score and bulbar subscale of the revised ALS Functional Rating Scale best predicted G-tube placement. Correcting for these confounders, G-tube placement decreased survival time by 46% (p < 0.001) and had no effect on QOL (p = 0.078). Sensitivity survival analyses varied in significance, but none revealed a survival benefit.

CONCLUSIONS

In the absence of randomization, causal inference methods are necessary to correct for time-varying confounding. G-tube placement may have a negative effect on survival with no QOL-related benefit for people with ALS. A randomized controlled trial is warranted to further evaluate the efficacy of this widely used intervention.

CLINICALTRIALSGOV IDENTIFIER

NCT00349622.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with ALS, G-tube placement decreases survival time and does not affect QOL.

What causes amyotrophic lateral sclerosis?

Amyotrophic lateral sclerosis is a neurodegenerative disease predominantly affecting upper and lower motor neurons, resulting in progressive paralysis and death from respiratory failure within 2 to 3 years. The peak age of onset is 55 to 70 years, with a male predominance. The causes of amyotrophic lateral sclerosis are only partly known, but they include some environmental risk factors as well as several genes that have been identified as harbouring disease-associated variation. Here we review the nature, epidemiology, genetic associations, and environmental exposures associated with amyotrophic lateral sclerosis.

Gastrostomy tube placement is safe in advanced amyotrophic lateral sclerosis

OBJECTIVES

To evaluate the safety and effect on survival of insertion of a gastrostomy tube (G-tube) in patients with amyotrophic lateral sclerosis (ALS) who have upright forced vital capacity (uFVC) ≤ 50% predicted. Current guidelines, which are based on higher rates of post-procedure complications in ALS patients with advanced respiratory dysfunction, have led to a recommendation to perform G-tube insertion before the FVC drops to <50% predicted, even when the patient has no significant dysphagia.

METHODS

We assessed 41 ALS patients who received a G-tube, mostly by insertion of a percutaneous endoscopic gastrostomy (PEG) tube by a dedicated team that included a gastroenterologist and one of two anesthesiologists using Monitored Anesthesia Care with deep sedation, and 61 patients who did not receive a G-tube. uFVC was ≤50% predicted in 12 of 41 patients who received a G-tube and in 18 of 61 who did not.

RESULTS

The procedure was safe regardless of FVC status, with low rates of post-operative complications in both low and high FVC groups. There was no survival benefit for patients who received a G-tube when compared with those who did not.

DISCUSSION

PEG insertion is safe in ALS patients with significant respiratory muscle weakness when performed by a dedicated team, which suggests that the recommendation for G-tube placement should not be based on the patient's respiratory status.

Comprehensive rehabilitative care across the spectrum of amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease) is a neurodegenerative disease that results in progressive muscle weakness and wasting. There is no known cure and the disease is uniformly fatal.

PURPOSE

This review discusses current concepts in ALS care, from breaking the diagnosis to end-of-life care. People with ALS have several multidisciplinary needs due to a complex and dynamic disease process. They benefit from rehabilitation interventions that are individualized and have the goal of optimizing independence, function, and safety. These strategies also help minimize symptomatic burden and maximize quality of life.

CONCLUSION

Patient-centered, multidisciplinary care has a significant impact on the life of people with ALS and is the current standard of care for this patient population.

Homozygous SMN2 deletion is a protective factor in the Swedish ALS population

Abnormal survival motor neuron 1 (SMN1)-copy number has been associated with an increased risk of amyotrophic lateral sclerosis (ALS) in French and Dutch population studies. The aim of this study was to determine whether SMN gene copy number increases the risk of ALS or modulates its phenotype in a cohort of Swedish sporadic ALS (SALS) patients. In all, 502 Swedes with SALS and 502 Swedish controls matched for gender and age were enrolled. SMN1 and SMN2 gene copy numbers were studied by a semi-quantitative PCR method. A genotype-phenotype comparison was performed in order to determine whether SMN genes modulate the phenotype of ALS. The results were also compared with our previously reported French cohort of ALS patients. There was no difference between Swedish patients and controls in the frequency of SMN1 and SMN2 copy numbers. The frequency of SMN1 gene copies differed significantly between the French and Swedish ALS populations. The duration of the disease was significantly longer in the Swedish cohort with homozygous deletions of SMN2 when compared with the French cohort. Abnormal SMN1 gene copy number cannot be considered as a universal genetic susceptibility factor for SALS and this result underlines the importance of reproducing association gene studies in groups from different origins. We also suggest that SMN2 gene copy number might have different effects on ALS progression in disparate human populations.