Sleep in Patients with ALS
I try to start my blogs in a lighthearted way, but there is nothing lighthearted about amyotrophic lateral sclerosis, more commonly known as ALS. ALS is a group of progressive diseases of upper and lower motor neurons, resulting in weakness of muscles. The course is often rapid, with most people dying from respiratory failure within three to five years from the onset of symptoms. Patients have difficulty breathing due to weakness of respiratory muscles. As the disease progresses, patients may require tracheostomy and ventilation. There is no known treatment.
You may be asking what the role of sleep medicine might be in the management of patients with ALS, and the role is admittedly limited. Many patients complain of trouble sleeping, and the complaints most often involve difficulty breathing during sleep. Sleeping supine often leads to shortness of breath. When severe, mechanical ventilation is required. But prior to the initiation of mechanical ventilation, noninvasive ventilation may be helpful. In most patients, the window between unassisted breathing and mechanical ventilation is short.
A recent review article1 highlights treatment modalities for sleep related hypoventilation disorders, including those related to neuromuscular disorders such as ALS. The preferred mode is bi-level PAP with a backup rate. Volume assured pressure support (VAPS) is also recommended, as it requires a lower median inspiratory pressure to resolve apnea and hypopnea. For more on PAP titration in a patient with ALS, see the February Journal Club. Studies of the effects of these treatments on breathing during sleep are mixed. Most show an improvement in nocturnal oxygen saturation, but minimal effect on sleep stage durations and number of arousals during sleep2. Further, compliance with treatment is low as patients have trouble with mask fitting, pressure sores and synchronizing breathing with treatments that use a backup rate.
Therefore, there are three reasons not to treat sleep-related breathing disorders in patients with ALS:
- The duration of treatment efficacy (the time between the need for PAP therapy and progression to the need for mechanical ventilation) may be relatively short.
- Treatment may not achieve the goals we usually set for other patient populations. The outcomes of reduced blood pressure, reduction in stroke risk, and prevention of cardiovascular events may not occur and may not be relevant to ALS patients.
- Adherence to treatment may be poor in this population.
Nevertheless, we persist in treating these patients. Why? The answer is that we are providing palliative care. Palliative care is defined as providing relief from suffering associated with diseases. Studies show that treatment of sleep-related breathing disorders in ALS patients results in improved quality of life. Even in the absence of sleep stage improvements or prolongation of life, treatments result in reductions in fatigue and improved mood. The “work of breathing” associated with progressive weakness of the diaphragm muscles takes a toll on patients — one that is alleviated to some extent through PAP therapy.
This means we should recalibrate our “cheerleading” to encourage treatment adherence. If there are mask problems or difficulty matching the backup rate for breathing, adjustments should be made. But the “hard sell” we give to OSA patients about adherence reducing long-term risk should be avoided.
Given that we have nothing to offer in terms of treatment of ALS, reducing suffering with any effective means seem appropriate. As Boentert and colleagues2 state, “We consider this meaningful in both clinical and ethical terms.” The benefits of treatment extend to the patient’s family and caretakers. Reductions in awakenings during the night aid the family as well as the patient. Sleep is important, not only for the patients but also for those family members dealing with the stresses and emotions associated with a progressive, untreatable illness.
- Selim BJ, Wolfe L, Coleman JM, Dewan NA. Initiation of noninvasive ventilation for sleep related hypoventilation disorders. CHEST 2018;153(1):251-265.
- Boentert M, Brenscheidt I, Glatz C, Young P. Effects of non-invasive ventilation on objective sleep and nocturnal respiration in patients with amyotrophic lateral sclerosis. J Neurol 2015;262:2073-2082.