What is MND?
Motor neurone disease (MND), also known as amyotrophic lateral sclerosis (ALS), is a progressive, debilitating neurodegenerative disease of the motor neurones.
The disease causes weakness and wasting of the muscles controlling limb movement, speech, swallowing and breathing. Death usually occurs in two to four years from the onset of symptoms and the most common cause of death is respiratory failure.
In the video below, Professor Chris McDermott, Consultant Neurologist, explains how MND affects breathing.
Respiratory failure occurs due to progressive weakness of the upper airway muscles and the respiratory muscles. Respiratory muscle weakness initially occurs at night when lying down causing insufficient exhalation of waste carbon dioxide. This causes sleep disturbance which is often the earliest indication of respiratory insufficiency. Patients might complain of unrefreshing sleep, fatigue, daytime sleepiness and breathlessness when lying flat (orthopnoea).
As respiratory failure progresses they develop daytime respiratory insufficiency causing breathlessness, initially on exertion but can become hypoxic and can experience difficulties coughing and clearing secretions. This can cause pneumonia which is a common cause of death. Bulbar weakness causes speech and swallowing difficulties which impair cough and cause oropharyngeal secretions which can further worsen respiratory symptoms.
Patients deteriorate at different speeds and some may present with respiratory failure or develop the symptoms very rapidly. Some may have respiratory failure without any symptoms. This website will explain why it is important to identify and treat respiratory failure without delay.
There is no effective treatment available for MND at present and care for patients mainly involves interventions for symptom palliation to maintain function and quality of life for as long as possible. Of all the treatment options for MND, non-invasive ventilation has been shown to have the largest survival benefit, improving survival by approximately seven months, and has been shown to sustain patients’ quality of life and improve the symptoms of respiratory insufficiency.