Symptom management

Respiratory

Respiratory weakness can develop at any stage of disease progression and may cause shortness of breath, fatigue, impaired quality of life and somnolence. Dyspnoea is caused by weakened respiratory muscles – intercostals, diaphragm and abdominal muscles.

The diagnosis and management of respiratory insufficiency is critical because most deaths from ALS are due to respiratory failure (Miller and others 2009a).

Swallowing

Dysphagia is difficulty in swallowing.

• caused by weakness and paralysis of the lips, facial muscles, tongue, larynx and pharynx resulting from affected trigeminal, facial, glossopharyngeal, vagus, accessory and hypoglossal nerves. 
• eventually affects about two thirds of people with motor neurone disease

Swallowing difficulties should be assessed and regularly reviewed by a speech pathologist. The goal of managing swallowing difficulties is to maintain optimal levels of nutrition and hydration and to reduce choking episodes (MND Australia 2014).

Communication

Dysarthria is impairment of speech production.

• caused by weakness and paralysis of the lips, facial muscles, tongue, larynx, and pharynx resulting from affected trigeminal, facial, glossopharyngeal, vagus, accessory and hypoglossal cranial nerves
• weakness of the muscles of respiration will also impact on speech volume
• impairment of speech production may begin with slurring, hoarseness or weak voice
• this may progress to total loss of speech (anarthria) (MND Australia 2014)

Movement and joints

The degeneration of upper motor (UMN) and lower motor (LMN) neurons, leads to progressive weakness of bulbar, limb, thoracic and abdominal muscles (Andersen and others 2007) causing muscle weakness, stiffness and immobility.

Assessment and continuing review by physiotherapist and occupational therapist for:

• management of exercise, positioning and pain
• prescription of appropriate equipment and aids to assist independence, mobility and comfort (MND Australia 2014)

Cognition

Fronto-temporal cognitive changes have been associated with MND. Fronto-temporal dementia is prominent in 5-10% of cases. Recent neuropsychological studies suggest that approximately two thirds of people with motor neurone disease may suffer from mild changes in cognitive skills and processes and/or behavioural change. (MND Australia 2014).

Emotional lability

Upper motor neurone involvement is associated with pseudobulbar affect or emotional lability. This is a troubling symptom that occurs in as many as half of all people living with motor neurone disease (MND Australia 2014).

It may involve excessive laughing or crying, or involuntary emotional expression (Miller and others 2009b).

Fatigue

Fatigue (tiredness) is a common symptom of MND. It is caused by a number of factors:

• as MND attacks motor neurones, they become unable to send commands from the brain to the muscle cells that they control-movements must then be performed by a depleted number of nerve and muscle cells. This means that muscles tire quickly
• other metabolic changes take place and the person with MND can feel very tired
• weight loss and reduced food intake due to swallowing difficulties are likely to affect the person’s energy levels
• when MND affects breathing muscles, less air is drawn into the lungs. When activity increases, it becomes more difficult for the lungs to supply enough oxygen to the body causing general fatigue (MND Australia 2014).

Insomnia

Causes of insomnia include:

• discomfort arising from immobility
• pain due to stiffness of joints or muscles
• muscle spasticity
• shortness of breath
• excessive saliva or dry mouth
• taking stimulants at bedtime.

Additionally, because breathing cannot be controlled voluntarily when sleeping, weakened muscles may lead to ineffective breathing (nocturnal hypoventilation). Sleep apnoea is the temporary cessation of breathing while sleeping. This may cause wakefulness, as the disruption of the oxygen supply wakes the person to resume normal breathing (MND Australia 2014).