Motor neurone disease
Motor neurone disease (the most common form of which is amyotrophic lateral sclerosis) is a progressive neurodegenerative disorder of the upper and lower motor neurones. It presents with limb, bulbar and/or respiratory muscle weakness. The disease is fatal, usually within 3 to 4 years of onset. A small percentage of patients survive much longer—often these patients have pure upper (primary lateral sclerosis) or pure lower (progressive muscular atrophy) motor neurone variants of the disease.
Multidisciplinary care improves quality of life and survival in patients with motor neurone disease, and is an effective way to manage symptoms (eg limb weakness; difficulty walking, speaking, breathing and swallowing). Other management options include noninvasive ventilation, which can improve survival and quality of life, and a gastrostomy tube.
Motor neurone disease has no cure. Riluzole slows the disease modestly (ie improves survival by 3 to 6 months). The usual dosage is:
riluzole 50 mg orally, twice daily. motor neurone disease riluzole
Hepatic disturbance and neutropenia are uncommon adverse effects.
Symptoms of motor neurone disease that often need treating are muscle cramps, spasticity, sialorrhoea, musculoskeletal pain and emotional lability. There is no high-quality evidence on which to base choice of therapy, and the following advice is based on expert opinion.
Muscle cramps are common, and may respond to baclofen, gabapentin, carbamazepine or magnesium.
Spasticity can be treated with stretching and drug therapy (eg baclofen, dantrolene). Be aware when treating spasticity that some patients with limb weakness rely on the spasticity to maintain mobility.
Sialorrhoea usually occurs when patients have significant bulbar weakness and lose the ability to swallow their saliva. This can be distressing for the patient and family. First-line therapy is oral drugs that have anticholinergic effects (eg propantheline, amitriptyline, atropine [drops applied sublingually]). For example, use:
propantheline 15 mg orally, 1 to 3 times daily. Review efficacy after 2 weeks. sialorrhoea (motor neurone disease) propantheline
Try one oral anticholinergic drug for 2 weeks, and if it is not effective, consider subcutaneous glycopyrronium (glycopyrrolate). Use:
glycopyrronium (glycopyrrolate) 20 to 30 micrograms subcutaneously, twice daily. Increase dose slowly to avoid thick sticky secretions (maximum dose 100 micrograms subcutaneously, 3 times daily). sialorrhoea (motor neurone disease)
Subcutaneous glycopyrronium (glycopyrrolate) is usually so effective that third-line treatment (eg botulinum toxin type A injection into the salivary glands) is not needed.
Mild to moderate musculoskeletal pain can be treated with paracetamol, nonsteroidal anti-inflammatory drugs, physiotherapy and corticosteroid injections in local joints. When pain is severe, consider transdermal buprenorphine or oral oxycodone.
Emotional lability may be treated with an antidepressant. Psychological support can help the patient and their family.
Another aspect of managing patients with motor neurone disease is to discuss advanced health care directives. See also advice on managing the disease in patients receiving palliative care.