Week 5- Motor neurone disease

Question 1

What is motor neurone disease?

Answer 1

Progressive degeneration of motor neurones. Could be upper or lower motor neurons. This means the brain can’t tell the muscles what to do effectively.

Question 2

What is the most common type of motor neurone disease?

Answer 2

Amylotrophic lateral sclerosis.

Question 3

What problems can motor neurone disease cause?

Answer 3

Muscle weakness
Difficulty swallowing
In extreme cases difficulty breathing.

Question 4

Why is motor neurone disease considered so shocking to patients?

Answer 4

There brain works perfectly normally so they are completely aware of what is happening to them.

(NOTE- on one of the lectures it says cognitive impairment is a feature of MND but theres no evidence I can find to support that).

Question 5

Who is affected by motor neurone disease? How is it acquired?

Answer 5

Generally males and females are affected the same.

90% are sporadic and 10% are familial.

Question 6

What upper motor neurone signs are present in motor neurone disease?

Answer 6

Spasticity
Hypertone 
Brisk reflexes
Exaggerated jaw jerk
Spastic gait
Slowed movements

Question 7

What lower motor neurone signs are present in motor neurone disease?

Answer 7

Muscle weakness
Wasting
Fasciculations
Absent or reduced deep tendon reflexes.

Question 8

What does the term bulbar mean?

Answer 8

Muscles of the mouth and throat responsible for speaking and swallowing.

Question 9

Where is the most common first presentation of motor neurone disease?

Answer 9

Extremeties (arms and legs)- 70%
Bulbar- 25%
Thoracic- 2%

Question 10

Which is more likely to be presented with, upper or lower motor neurone signs?

Answer 10

Lower motor neurone.

Question 11

What other condition is amyotrophic lateral sclerosis (ALS) related to?

Answer 11

Frontotemporal dementia.

Question 12

What typical pattern of atrophy is seen in ALS?

Answer 12

Thenar muscle group wasting.

Question 13

What is the diagnostic criteria for ALS?

Answer 13

Upper and lower motor neurone signs in bulbar and atleast two spinal regions
or
Upper and lower motor neurone signs in all three spinal regions.

Question 14

When is someone diagnosed with clinically probable ALS?

Answer 14

Upper and lower motor neurone signs in atleast two regions (spinal and bulbar) with some upper motor neurone signs rostral (near the front of the body) to the lower motor neurone signs

Question 15

Case- is this motor neurone disease?
54 year old woman
Increased fatigue over 6 months; later dyspnoe at rest
Investigated by cardiology and respiratory teams, unremarkable findings
Then pneumonia, emergency intubation
Further investigations: CK 320, EMG: neurogeneic changes in paravertebral muscles, denervation

Answer 15

Diagnosis: thoracic variant (2%) of MND, rare but important presentation!
Therapeutic interventions: Early non-invasive intubation with compensation for years, but increasing risk of reflux, aspiration, pneumonia

Question 16

Describe some atypical presentations of ALS?

Answer 16

Flail arm syndrome
Flail leg syndrome
Primary lateral sclerosis

Question 17

Diagnosis of this lady :52 year old lady with right sided foot drop
6 months later right thigh weakness
6 months later left sided foot drop

…but already 18 months prior to onset of motor symptoms behavioural abnormalities: dysinhibition, decreased impulse control, increased food intake, weight gain, socially inadequate, positive mood, no insight

Answer 17

Motor weakness without sensory symptoms- MND

Frontotemporal dementia

Question 18

How would you clinically detect UMN signs?

Answer 18

Spasticity
Babinski sign
Bulbar UMN signs- exaggerated snout reflex, clonic jaw jerk, emotional lability, forced yawning
Hyperreflexia, Hoffman reflex, clonic deep tendon reflexes.

Question 19

What does the term clonic mean?

Answer 19

Uncontrolled jerking.

Question 20

What is a Hoffman reflex?

Answer 20

Tap the nail or end of the middle/ring finger. Distal pharynx of the thumb should flex.

Question 21

What does tonic mean?

Answer 21

Rigidity in the entire body.

Question 22

How would you treat a patient with motor neurone disease?

Answer 22

No treatment- just need supportive treatment.
E.g. dietician when they can’t swallow
Respiratory consultant when they need intubated.
Help with communication needs- speech and language therapist.
Riluzole- delays the onset of ventilator dependence.

Question 23

Where does amyotrophic lateral sclerosis affect to cause symptoms?

Answer 23

It affects the motor cortex causing UMN signs

It also affects the anterior horn of the spinal cord causing LMN signs

Question 24

Which cranial nerves are responsible for bulbar palsy when they are affected by motor neuron disease?

Answer 24

IX-XII.