Is there a case for diaphragm pacing for amyotrophic lateral sclerosis patients?

Boosting brain-computer interfaces with functional electrical stimulation: potential applications in people with locked-in syndrome

Individuals with a locked-in state live with severe whole-body paralysis that limits their ability to communicate with family and loved ones. Recent advances in brain-computer interface (BCI) technology have presented a potential alternative for these people to communicate by detecting neural activity associated with attempted hand or speech movements and translating the decoded intended movements to a control signal for a computer. A technique that could potentially enrich the communication capacity of BCIs is functional electrical stimulation (FES) of paralyzed limbs and face to restore body and facial movements of paralyzed individuals, allowing to add body language and facial expression to communication BCI utterances. Here, we review the current state of the art of existing BCI and FES work in people with paralysis of body and face and propose that a combined BCI-FES approach, which has already proved successful in several applications in stroke and spinal cord injury, can provide a novel promising mode of communication for locked-in individuals.

Considerations for Amyotrophic Lateral Sclerosis (ALS) Clinical Trial Design

Thoughtful clinical trial design is critical for efficient therapeutic development, particularly in the field of amyotrophic lateral sclerosis (ALS), where trials often aim to detect modest treatment effects among a population with heterogeneous disease progression. Appropriate outcome measure selection is necessary for trials to provide decisive and informative results. Investigators must consider the outcome measure's reliability, responsiveness to detect change when change has actually occurred, clinical relevance, and psychometric performance. ALS clinical trials can also be performed more efficiently by utilizing statistical enrichment techniques. Innovations in ALS prediction models allow for selection of participants with less heterogeneity in disease progression rates without requiring a lead-in period, or participants can be stratified according to predicted progression. Statistical enrichment can reduce the needed sample size and improve study power, but investigators must find a balance between optimizing statistical efficiency and retaining generalizability of study findings to the broader ALS population. Additional progress is still needed for biomarker development and validation to confirm target engagement in ALS treatment trials. Selection of an appropriate biofluid biomarker depends on the treatment mechanism of interest, and biomarker studies should be incorporated into early phase trials. Inclusion of patients with ALS as advisors and advocates can strengthen clinical trial design and study retention, but more engagement efforts are needed to improve diversity and equity in ALS research studies. Another challenge for ALS therapeutic development is identifying ways to respect patient autonomy and improve access to experimental treatment, something that is strongly desired by many patients with ALS and ALS advocacy organizations. Expanded access programs that run concurrently to well-designed and adequately powered randomized controlled trials may provide an opportunity to broaden access to promising therapeutics without compromising scientific integrity or rushing regulatory approval of therapies without adequate proof of efficacy.

Diaphragm pacing implantation in Japan for a patient with cervical spinal cord injury: A case report

RATIONALE

Traumatic cervical spinal cord injury (SCI) is a devastating condition leading to respiratory failure that requires permanent mechanical ventilation, which is the main driver of increased medical costs. There is a great demand for establishing therapeutic interventions to treat respiratory dysfunction following severe cervical SCI.

PATIENT CONCERNS AND DIAGNOSIS

We present a 24-year-old man who sustained a cervical displaced C2-C3 fracture with SCI due to a traffic accident. As the patient presented with tetraplegia and difficulty in spontaneous breathing following injury, he was immediately intubated and placed on a ventilator with cervical external fixation by halo orthosis. The patient then underwent open reduction and posterior fusion of the cervical spine 3 weeks after injury. Although the patient showed significant motor recovery of the upper and lower limbs over time, only a slight improvement in lung capacity was observed.

INTERVENTIONS AND OUTCOMES

At 1.5 years after injury, a diaphragmatic pacing stimulator was surgically implanted to support the patient's respiratory function. The mechanical ventilator support was successfully withdrawn from the patient 14 weeks after implantation. We observed that both the vital capacity and tidal volume of the patient were significantly promoted following implantation. The patient finally returned to daily life without any mechanical support.

LESSONS

The findings of this report suggest that diaphragmatic pacing implantation could be a promising treatment for improving respiratory function after severe cervical SCI. To our knowledge, this is the first SCI patient treated with a diaphragm pacing implantation covered by official medical insurance in Japan.

Respiratory Failure in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis is a progressive neuromuscular disease characterized by both lower motor neuron and upper motor neuron dysfunction. Although clinical presentations can vary, there is no cure for ALS, and the disease is universally terminal, with most patients dying of respiratory complications. Patients die, on average, within 3 to 5 years of diagnosis, unless they choose to undergo tracheostomy, in which case, they may live, on average, 2 additional years. Up to 95% of patients with ALS in the United States choose not to undergo tracheostomy; management of respiratory failure is therefore aimed at both prolonging survival as well as improving quality of life. Standard of care for patients with ALS includes treatment from multidisciplinary teams, but many patients do not have consistent access to a pulmonary physician who regularly sees patients with this disease. The goal of this review was to serve as an overview of respiratory considerations in the management of ALS. This article discusses noninvasive ventilation in the management of respiratory muscle weakness, mechanical insufflation/exsufflation devices for airway clearance, and treatment of aspiration, including timing of placement of a percutaneous endoscopic gastrostomy tube, as well as secretion management. In addition, it is important for physicians to consider end-of-life issues such as advanced directives, hospice referral, and ventilator withdrawal.

A practical technique in laparoscopic diaphragm pacing surgery: Retrospective analyse of 43 patients

Introduction:

Diaphragm pacing stimulation (DPS) is a treatment method used in respiratory failure occurs in diseases such as high-level cervical spinal cord injury, central hypoventilation syndrome and amyotrophic lateral sclerosis.

Materials and Methods:

A total of 43 patients, who had undergone DPS implantation surgery were evaluated retrospectively. The patients were divided into two groups according to the surgical technique (Group 1: classical surgical technic and Group 2: modified surgical technic) applied. The patients with previous abdominal surgery or percutaneous endoscopic gastrostomy were excluded from the study.

Results:

The mean operation duration was significantly shorter in modified DPS implantation technic (105.1 min in Group 1 and 87.4 min in Group 2) (P < 0.001). Capnothorax is seen 11% of the cases in classical surgery procedure. In the modified group, capnothorax was not observed. Pneumothorax rate was found similar in both groups. Post-operative atelectasis was determined 16% of the cases in classical surgery procedure and also in the modified group atelectasis was not observed. The complications were higher in classical surgery procedure group but not differed statistically in this study. Total hospitalisation duration was significantly shorter in the modified surgical technique group compared to the other group (8.0 days in Group 1 and 6.0 days in Group 2) (P = 0.03).

Conclusion:

With modification in DPS implantation surgery, shorter operation and hospitalisation durations, and less complications may be achieved.

Preoperative parameters and their prognostic value in amyotrophic lateral sclerosis patients undergoing implantation of a diaphragm pacing stimulation system

Introduction:

Amyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disease with devastating and fatal respiratory complications. Diaphragm pacing stimulation (DPS) is a treatment option in diaphragm insufficient ALS patients. Ventilatory insufficiency depending on diaphragmatic failure is treated by the present study aimed to investigate prognostic value of preoperative clinical and functional characteristics of ALS patients undergoing implantation of a DPS system and to determine appropriate indications for the DPS system.

Methods:

The study included 34 ALS patients implanted with DPS system. All patients underwent multidisciplinary and laboratory evaluations before the surgery. The laboratory examinations included pulmonary function tests and arterial blood gas analysis. Survival rates were recorded in a 2-year follow-up after the surgery.

Results:

Twenty-eight of 34 patients with ALS survived after a 2-year follow-up. These patients were younger than those who died and had the disease for a longer time; however, the differences were not significant. Both right and left hemidiaghragms were thicker in the survived patients (P < 0.0001 for each). Pulmonary function tests revealed no significant differences between the patients who survived. Arterial blood gas analysis demonstrated lower partial pressure of carbon dioxide in the survived patients (P = 0.025).

Conclusions:

DPS implantation was more efficacious in ALS patients with mild respiratory failure and thicker diaphragm. Predictors of long-term effectiveness of DPS system are needed to be addressed by large-scale studies.

Early diaphragm pacing in patients with amyotrophic lateral sclerosis (RespiStimALS): a randomised controlled triple-blind trial

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder associated with respiratory muscle weakness and respiratory failure. Non-invasive ventilation alleviates respiratory symptoms and prolongs life, but is a palliative intervention. Slowing the deterioration of diaphragm function before respiratory failure would be desirable. We aimed to assess whether early diaphragm pacing could slow down diaphragm deterioration and would therefore delay the need for non-invasive ventilation.

METHODS

We did a multicentre, randomised, controlled, triple-blind trial in patients with probable or definite ALS in 12 ALS centres in France. The main inclusion criterion was moderate respiratory involvement (forced vital capacity 60-80% predicted). Other key eligibility criteria were age older than 18 years and bilateral responses of the diaphragm to diagnostic phrenic stimulation. All patients were operated laparoscopically and received phrenic stimulators. Clinicians randomly assigned patients (1:1) to receive either active or sham stimulation with a central web-based randomisation system (computer-generated list). Investigators, patients, and an external outcome allocation committee were masked to treatment. The primary outcome was non-invasive ventilation-free survival, analysed in the intention-to-treat population. Safety outcomes were also assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01583088.

FINDINGS

Between Sept 27, 2012, and July 8, 2015, 74 participants were randomly assigned to receive either active (n=37) or sham (n=37) stimulation. On July 16, 2015, an unplanned masked analysis was done after another trial showed excess mortality with diaphragm pacing in patients with hypoventilation (DiPALS, ISRCTN 53817913). In view of this finding, we analysed mortality in our study and found excess mortality (death from any cause) in our active stimulation group. We therefore terminated the study on July, 16, 2015. Median non-invasive ventilation-free survival was 6·0 months (95% CI 3·6-8·7) in the active stimulation group versus 8·8 months (4·2-not reached) in the control (sham stimulation) group (hazard ratio 1·96 [95% CI 1·08-3·56], p=0·02). Serious adverse events (mainly capnothorax or pneumothorax, acute respiratory failure, venous thromboembolism, and gastrostomy) were frequent (24 [65%] patients in the active stimulation group vs 22 [59%] patients in the control group). No treatment-related death was reported.

INTERPRETATION

Early diaphragm pacing in patients with ALS and incipient respiratory involvement did not delay non-invasive ventilation and was associated with decreased survival. Diaphragm pacing is not indicated at the early stage of the ALS-related respiratory involvement.

FUNDING

Hospital Program for Clinical Research, French Ministry of Health; French Patients' Association for ALS Research (Association pour la Recherche sur la Sclérose Latérale Amyotrophique); and Thierry de Latran Foundation.

DiPALS: Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis - a randomised controlled trial

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease resulting in death, usually from respiratory failure, within 2-3 years of symptom onset. Non-invasive ventilation (NIV) is a treatment that when given to patients in respiratory failure leads to improved survival and quality of life. Diaphragm pacing (DP), using the NeuRx/4(®) diaphragm pacing system (DPS)™ (Synapse Biomedical, Oberlin, OH, USA), is a new technique that may offer additional or alternative benefits to patients with ALS who are in respiratory failure.

OBJECTIVE

The Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis (DiPALS) trial evaluated the effect of DP on survival over the study duration in patients with ALS with respiratory failure.

DESIGN

The DiPALS trial was a multicentre, parallel-group, open-label, randomised controlled trial incorporating health economic analyses and a qualitative longitudinal substudy.

PARTICIPANTS

Eligible participants had a diagnosis of ALS (ALS laboratory-supported probable, clinically probable or clinically definite according to the World Federation of Neurology revised El Escorial criteria), had been stabilised on riluzole for 30 days, were aged ≥ 18 years and were in respiratory failure. We planned to recruit 108 patients from seven UK-based specialist ALS or respiratory centres. Allocation was performed using 1 : 1 non-deterministic minimisation.

INTERVENTIONS

Participants were randomised to either standard care (NIV alone) or standard care (NIV) plus DP using the NeuRX/4 DPS.

MAIN OUTCOME MEASURES

The primary outcome was overall survival, defined as the time from randomisation to death from any cause. Secondary outcomes were patient quality of life [assessed by European Quality of Life-5 Dimensions, three levels (EQ-5D-3L), Short Form questionnaire-36 items and Sleep Apnoea Quality of Life Index questionnaire]; carer quality of life (EQ-5D-3L and Caregiver Burden Inventory); cost-utility analysis and health-care resource use; tolerability and adverse events. Acceptability and attitudes to DP were assessed in a qualitative substudy.

RESULTS

In total, 74 participants were randomised into the trial and analysed, 37 participants to NIV plus pacing and 37 to standard care, before the Data Monitoring and Ethics Committee advised initial suspension of recruitment (December 2013) and subsequent discontinuation of pacing (on safety grounds) in all patients (June 2014). Follow-up assessments continued until the planned end of the study in December 2014. The median survival (interquartile range) was 22.5 months (lower quartile 11.8 months; upper quartile not reached) in the NIV arm and 11.0 months (6.7 to 17.0 months) in the NIV plus pacing arm, with an adjusted hazard ratio of 2.27 (95% confidence interval 1.22 to 4.25; p = 0.01).

CONCLUSIONS

Diaphragmatic pacing should not be used as a routine treatment for patients with ALS in respiratory failure.

FUTURE WORK

It may be that certain population subgroups benefit from DP. We are unable to explain the mechanism behind the excess mortality in the pacing arm, something the small trial size cannot help address. Future research should investigate the mechanism by which harm or benefit occurs further.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN53817913.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 45. See the HTA programme website for further project information. Additional funding was provided by the Motor Neurone Disease Association of England, Wales and Northern Ireland.

Safety and efficacy of diaphragm pacing in patients with respiratory insufficiency due to amyotrophic lateral sclerosis (DiPALS): a multicentre, open-label, randomised controlled trial

BACKGROUND

Non-invasive ventilation is part of the standard of care for treatment of respiratory failure in patients with amyotrophic lateral sclerosis (ALS). The NeuRx RA/4 Diaphragm Pacing System has received Humanitarian Device Exemption approval from the US Food and Drug Administration for treatment of respiratory failure in patients with ALS. We aimed to establish the safety and efficacy of diaphragm pacing with this system in patients with respiratory muscle weakness due to ALS.

METHODS

We undertook a multicentre, open-label, randomised controlled trial at seven specialist ALS and respiratory centres in the UK. Eligible participants were aged 18 years or older with laboratory supported probable, clinically probable, or clinically definite ALS; stable riluzole treatment for at least 30 days; and respiratory insufficiency. We randomly assigned participants (1:1), via a centralised web-based randomisation system with minimisation that balanced patients for age, sex, forced vital capacity, and bulbar function, to receive either non-invasive ventilation plus pacing with the NeuRx RA/4 Diaphragm Pacing System or non-invasive ventilation alone. Patients, carers, and outcome assessors were not masked to treatment allocation. The primary outcome was overall survival, defined as the time from randomisation to death from any cause. Analysis was by intention to treat. This trial is registered, ISRCTN number 53817913.

FINDINGS

Between Dec 5, 2011, and Dec 18, 2013, we randomly assigned 74 participants to receive either non-invasive ventilation alone (n=37) or non-invasive ventilation plus diaphragm pacing (n=37). On Dec 18, 2013, the Data Monitoring and Ethics Committee (DMEC) recommended suspension of recruitment on the basis of overall survival figures. Randomly assigned participants continued as per the study protocol until June 23, 2014, when the DMEC advised discontinuation of pacing in all patients. Follow-up assessments continued until the planned end of the study in December, 2014. Survival was shorter in the non-invasive ventilation plus pacing group than in the non-invasive ventilation alone group (median 11·0 months [95% CI 8·3-13·6] vs 22·5 months [13·6-not reached]; adjusted hazard ratio 2·27, 95% CI 1·22-4·25; p=0·009). 28 (76%) patients died in the pacing group and 19 (51%) patients died in the non-invasive ventilation alone group. We recorded 162 adverse events (5·9 events per person-year) in the pacing group, of which 46 events were serious, compared with 81 events (2·5 events per person-year) in the non-invasive ventilation alone group, of which 31 events were serious.

INTERPRETATION

Addition of diaphragm pacing to standard care with non-invasive ventilation was associated with decreased survival in patients with ALS. Our results suggest that diaphragmatic pacing should not be used as a routine treatment for patients with ALS in respiratory failure.

FUNDING

The National Institute for Health Research Health Technology Assessment Programme; the Motor Neurone Disease Association of England, Wales, and Northern Ireland.

Sleep disorders and respiratory function in amyotrophic lateral sclerosis

Sleep disorders in amyotrophic lateral sclerosis (ALS) present a significant challenge to the management of patients. Issues include the maintenance of adequate ventilatory status through techniques such as non-invasive ventilation, which has the ability to modulate survival and improve patient quality of life. Here, a multidisciplinary approach to the management of these disorders is reviewed, from concepts about the underlying neurobiological basis, through to current management approaches and future directions for research.

Breathing new life into treatment advances for respiratory failure in amyotrophic lateral sclerosis patients

SUMMARY In the last three decades, improvements in respiratory management are responsible for increasing survival and improving quality of life for amyotrophic lateral sclerosis (ALS) patients. Nowadays, ALS patients with respiratory involvement are offered a support treatment other than the traditional respiratory palliative care. Knowledge about available respiratory support potentialities is essential for appropriate, customized and effective treatment of ALS, which should probably be started sooner than the conventional approach. There is evidence supporting that respiratory support has a larger impact than riluzole on survival. Noninvasive ventilation is essential in the treatment of ALS patients with respiratory involvement. In this article methods to determine respiratory failure in ALS, mechanical invasive and noninvasive ventilation, telemetry, diaphragm pacing, cough aids and respiratory exercise are reviewed, after a brief overlook of respiratory insufficiency in ALS.

Amyotrophic Lateral Sclerosis: An update for 2013 Clinical Features, Pathophysiology, Management and Therapeutic Trials

Amyotrophic lateral sclerosis (ALS), first described by Jean-Martin Charcot in the 1870s, is an age-related disorder that leads to degeneration of motor neurons. The disease begins focally in the central nervous system and then spreads relentlessly. The clinical diagnosis, defined by progressive signs and symptoms of upper and lower motor neuron dysfunction, is confirmed by electromyography. Additional testing excludes other conditions. The disease is heterogeneous, but most patients die of respiratory muscle weakness less than 3 years from symptom-onset. Like other age-related neurodegenerative diseases, ALS has genetic and environmental triggers. Of the five to 10% of cases that are inherited, mutations have been discovered for a high proportion. In addition to genetic factors, age, tobacco use, and athleticism may contribute to sporadic ALS, but important etiologies are unidentified for most patients. Complex pathophysiological processes, including mitochondrial dysfunction, aggregation of misfolded protein, oxidative stress, excitotoxicity, inflammation and apoptosis, involve both motor neurons and surrounding glial cells. There is clinical and pathological overlap with other neurodegenerative diseases, particularly frontotemporal dementia. The mechanisms leading to disease propagation in the brain are a current focus of research. To date, one medication, riluzole, licensed in 1996, has been proved to prolong survival in ALS. Numerous clinical trials have so far been unable to identify another neuroprotective agent. Researchers now aim to slow disease progression by targeting known pathophysiological pathways or genetic defects. Current approaches are directed at muscle proteins such as Nogo, energetic balance, cell replacement, and abnormal gene products resulting from mutations. Until better understanding of the causes and mechanisms underlying progression lead to more robust neuroprotective agents, symptomatic therapies can extend life and improve quality of life. Palliative care programs such as hospice give emotional and physical support to patients and families throughout much of the disease course.