Motor Neuron disease

Question 1

define motor neurone disease?

Answer 1

a progressive neurodegenerative disorder of cortical, brainstem and spinal motor neurons (lower and upper motor neurons)

Question 2

what are the subtypes of MND?

Answer 2

o Amyotrophic Lateral Sclerosis
o Progressive Muscular Atrophy Variant
o Progressive Bulbar Palsy Variant
o Primary Lateral Sclerosis Variant

Question 3

how does ALS present?

Answer 3

• mix of LMN and UMN signs

* Typically LMN in the arms and UMN in the legs

Question 4

how does progressive muscular atrophy variant present?

Answer 4

• Only LMN signs
• Affects distal muscles before proximal
• Best prognosis

Question 5

how does progressive bulbar palsy variant present?

Answer 5

• Palsy of the tongue, muscles of chewing, swallowing and facial muscles
• Worse prognosis

Question 6

how does the primary lateral sclerosis variant present?

Answer 6

• UMN signs only

Question 7

association of MND?

Answer 7

o Frontotemporal lobar dementia

Question 8

epidemiology of MND?

Answer 8

often presents after the age of 40

Question 9

presenting symptoms of MND?

Answer 9

• Weakness of limbs
• Speech disturbance
• Swallowing disturbance
• Behavioural changes

Question 10

signs of MND?

Answer 10

•	LMN Features 
o	Muscle wasting  
o	Fasciculations !!  
o	Flaccid weakness  
o	Hyporeflexia 
•	UMN Features 
o	Spastic weakness  
o	Extensor plantar response  
o	Hyperreflexia

Question 11

how is sensory function in MND?

Answer 11

NORMAL

Question 12

how are the eyes affected in MND?

Answer 12

• Eye movements are often spared.

Question 13

relevant investigations for MND?

Answer 13

• Bloods
• Electromyography (EMG) – shows reduced number of action potentials
• Nerve conduction studies - often normal
• MRI
• Spirometry - assess respiratory muscle weakness