Neuro: Motor neuron disease

Question 1

What is meant by ‘motor neuron disease’?

Answer 1

Umbrella term for a range of neurological conditions in which the motor neurons stop functioning. It is progressive and ultimatley fatal.

Question 2

What are the most common types of motor neuron disease?

Answer 2

ALS: Amyotrophic lateral sclerosis (ALS) - most common specific motor neurone disease
Progressive bulbar palsy: second most common and well-known specific motor neurone disease.

Question 3

Specific types of motor neurone disease?

Answer 3

ALS (amyotrophic lateral sclerosis)
Progressive bulbar palsy
Progressive muscular atrophy
Primary lateral scelrosis

Question 4

What muscles are primarily affected by progressive bulbar palsy?

Answer 4

Muscles of talking and swallowing

Question 5

What is the very basic pathophysiology of motor neurone disease?

Answer 5

Progressive degeneration of both upper and lower motor neurones.
Sensory neurones are spared.

Question 6

Risk factors for motor neurone disease?

Answer 6

Family history - genetics. Many genes linked with increased risk and 5-10% cases are inherited.
Smoking
Exposure to heavy metals
Exposure to cetrain pesticides

Question 7

How does motor neurone disease typically present?

Answer 7

Typical patient: middle aged male (+/- affected relative)
Incidious, progressive
Weakness first noticed in upper limbs but progressive to trunk face and speech
Increased fatigue when exercising
Clumsiness, tripping, dropping things
Dysarthria (slurred speech)
Signs of motor neuron disease

Question 8

Signs of LOWER motor neurone disease?

Answer 8

Muscle wasting
Reduced tone
Fasiculations
Reduced reflexes

Question 9

Signs of UPPER motor neurone disease

Answer 9

Increased tone or spasticity
Hyperreflexia
Upgoing plantar responses

Question 10

How is motor neuron disease diagnosed?

Answer 10

The diagnosis of motor neurone disease needs to be made very carefully. It is based on the clinical presentation and excluding other conditions that can cause motor neurone symptoms. It should only be made by a specialist when there is certainty. Unfortunately, the diagnosis is often delayed, which causes considerable anxiety and stress.

Question 11

Pharmacological management of ALS?

Answer 11

Riluzole can slow progression and extend survival by a few months (initiated by specilists)
(Edaravone licesnced in US but not UK)

Question 12

Non pharmacological management of motor neurone disease?

Answer 12

NIV at home to support breathing at night - improves survival and QOL
MDT involvement
End of life care planning
Advanced directives to anticipate disease progression

Question 13

What is the most common cause of mortality in motor neurone disease patients?

Answer 13

Respiratory failure or pneumonia

Question 14

What is the only liscenced treatment for motor neuron disease?

Answer 14

Riluzole

Question 15

ALS presenting symptoms?

Answer 15

Weakness in muscles of the hands, arms or legs
Impairment in the use of arms and legs
Twitching and cramping of muscles, especially those in the hands and feet
Weakness in the muscles that control speech, swallowing or breathing
Slow or slurred speech (called dysarthria or “thick speech”) and difficulty in projecting the voice

Question 16

ALS prognosis?

Answer 16

Life expectancy 2-5 years following onset of symptoms

Question 17

Progressive Bulbar Palsy presenting symptoms?

Answer 17

Patients with progressive bulbar palsy initially develop symptoms restricted to the bulbar muscles. They usually present with a several-month history of progressive dysarthria with gagging, choking, and weight loss. The speech disturbance may lead to complete anarthria.

Question 18

Progressive bulbar palsy prognosis?

Answer 18

Life expectancy 6 months to 3 years of onset of symptoms?

Question 19

Between what ages does ALS typically present?

Answer 19

40-70 years

Question 20

Between what ages are the typical onset of symptoms in progressive bulbar palsy?

Answer 20

50-70 years

Question 21

First line treatments for muscle cramps in MND?

Answer 21

Quinine

Question 22

Management of sialorrhoea in MND?

Answer 22

Consider a trial of antimuscarinic medicine as the first‑line treatment for sialorrhoea in people with MND

Consider glycopyrrolate as the first‑line treatment for sialorrhoea in people with MND who have cognitive impairment

Question 23

Management of dysphaGIA in MND?

Answer 23

Modify diet and fluids
Involve salt
Reduce risks of aspirations
Reduce excess secretions
Early gastronomy

Question 24

Management of respiratory failure in MND?

Answer 24

Address excessive secretions
NIV
CHest physio
Opioids
Consider benzos

Question 25

What does hyperreflexia indicate?

Answer 25

Upper motor neurone lesion at a spinal level above that responsible for the reflex

Question 26

What motor neurone signs occur in ALS and why

Answer 26

disease affecting the motor cortex and the anterior horn of the spinal cord, and thus characterised by the presence of both upper and lower motor neuron signs and symptoms