NS: Motor neurone disease

Question 1

What is motor neurone disease?

Answer 1

Motor neurone disease is a neurodegenerative condition affecting the brain and spinal cord. Degeneration of motor neurones leads to progressive muscle weakness; resulting symptoms include muscle cramps, wasting and stiffness, loss of dexterity, reduced respiratory function and cognitive dysfunction. The most common form is amyotrophic lateral sclerosis.

Question 2

What are the symptoms of motor neurone disease?

Answer 2

1. Muscle cramps
2. Wasting and stiffness
3. Loss of dexterity
4. Reduce respiratory function
5. Cognitive dysfunction

Question 3

What is the most common form of motor neurone disease?

Answer 3

Motor neurone disease is a neurodegenerative condition affecting the brain and spinal cord. Degeneration of motor neurones leads to progressive muscle weakness; resulting symptoms include muscle cramps, wasting and stiffness, loss of dexterity, reduced respiratory function and cognitive dysfunction. The most common form is amyotrophic lateral sclerosis.

Question 4

What is recommended as the first line treatment for muscle cramps in motor neurone disease?

Answer 4

Quinine

Question 5

If quinine is ineffective, not tolerated or contra-indicated what should be considered as second line treatment of muscle cramps in motor neurone disease?

Answer 5

Baclofen.

Subsequent treatment options include tizanidine, dantrolene sodium or gabapentin.

Question 6

A trial of what type of drug can be considered for excessive drooling of saliva in motor neurone disease?

Answer 6

A trial of an antimuscarinic drug.

Glycopyrronium bromide is recommended in patients who have cognitive impairment as it has fewer central nervous system side-effects.

Question 7

If initial treatment of excessive drooling of saliva in motor neurone disease using a trial of an antimuscarinic drug (with glycopyrronium being the drug of choice due to fewer CNS side-effects) fails, what can be tried next?

Answer 7

A trial of an antimuscarinic drug [unlicensed indication] can be considered for excessive drooling of saliva. Glycopyrronium bromide is recommended in patients who have cognitive impairment as it has fewer central nervous system side-effects. If initial treatment is ineffective, not tolerated or contra-indicated, referral for specialist administration of botulinum toxin type A [unlicensed indication] may be required.

Question 8

What can be used to treat motor neurone patients with thick, tenacious saliva?

Answer 8

Humidification, nebulisers and carbocisteine.

Question 9

What drug is licensed for use in patients with amyotrophic lateral sclerosis to extend life or to extend the time to mechanical ventilation?

Answer 9

Riluzole

Question 10

How does Riluzole work?

Answer 10

Riluzole preferentially blocks TTX-sensitive sodium channels, which are associated with damaged neurones.

Riluzole has also been reported to directly inhibit the kainate and NMDA receptors.

The drug has also been shown to postsynaptically potentiate GABAa receptors via an allosteric binding site.