Neurology - motor neurone disease

Question 1

What is motor neurone disease?

Answer 1

Umbrella term that encompasses a variety of specific diagnoses.

Motor neurone disease is a progressive, ultimately fatal condition where the motor neurones stop functioning.

Patients will not experience sensory symptoms as the sensory neurones aren’t affected

Question 2

Most common forms of MND

Answer 2

ALS (Amyotrophic lateral sclerosis) - most common

Progressive bulbar palsy - second most common

Progressive muscular atrophy
Primary lateral sclerosis

Question 3

Pathophysiology of MND

Answer 3

Progressive degeneration of both upper and lower motor neurones

There is a genetic component and many genes have been linked with an increased risk of developing the condition.

Taking a good family history is important as around 5-10% of cases are inherited.

There also seems to be an increased risk with smoking, exposure to heavy metals and certain pesticides.

Question 4

Presentation of MND

Answer 4

Typical patient is late middle aged man

Insidious progressive weakness of muscles throughout the body affecting the limbs, trunk, face and speech.

May have increased fatigue on exertion, clumsiness, dysarthria (slurred speech)

Question 5

Where is the motor weakness often first noticed?

Answer 5

The upper limbs

Question 6

Signs of lower motor neurone disease

Answer 6

Muscle wasting
Reduced tone
Fasciculations (twitches in the muscles)
Reduced reflexes

Question 7

Signs of upper motor neurone disease

Answer 7

Increased tone or spasticity
Brisk reflexes
Upgoing plantar responses

Question 8

Diagnosis

Answer 8

Made by clinical presentation and the exclusion of other conditions than can cause motor neurone symptoms

Question 9

Management of MND

Answer 9

• Riluzole can slow the progression and extend survival by a few months
• NIV used to support breathing at night (improves survival and quality of life)

The key to management of the condition is supporting the person and their family:

• Effectively breaking bad news
• Involving the multidisciplinary team (MDT) in supporting and maintaining their quality of life
• Advanced directives to document the patient’s wishes as the disease progresses
• End of life care planning

Question 10

What usually ends patient’s lives in MND?

Answer 10

Patients usually die of respiratory failure or pneumonia