Motor Neuron Disease

Question 1

Motor neuron disease is a n________ disease, causing ___ and ___ signs

Answer 1

neurodegenerative
UMN and LMN

Question 2

What is the main motor tract called?

Answer 2

Corticospinal tract

Question 3

True or false: an UMN lesion causes hypotonia

Answer 3

False
UMN causes hypertonia, rigidity and spasticity

A LMN lesion causes hypotonia (flaccid and muscle wasting)

Question 4

True or false: an UMN lesion causes hyperreflexia

Answer 4

True

Question 5

What are fasciculations?

Answer 5

Muscle twitching due to an overactive nerve resulting in involuntary muscle movement

Question 6

Are fasciculations present in an UMN or LMN lesion?

Answer 6

LMN

Question 7

True or false: an UMN lesion gives a positive Babinski sign

Answer 7

True

Question 8

What is Babinski sign?

Answer 8

Sole of foot is firmly stroked causing big toe to move upward and the other toes fan out
Normal reflex in infants (up to 2 y/o)
In adults, indicates problem with brain or spinal cord.

Question 9

In an UMN lesion are the the flexor or extensor muscles in the arm more powerful?

Answer 9

Flexors

Question 10

In an UMN lesion are the the flexor or extensor muscles in the leg more powerful?

Answer 10

Extensors

Question 11

True or false: A LMN lesion can result in hyporeflexia, no fasciculations, positive Babinski sign and less power?

Answer 11

False
In a LMN lesion, get: hyporeflexia, fasciculations, negative Babinski sign and generally less power

Question 12

If you see mixed UPN and LMN signs what could it be?

Answer 12

Motor neuron disease

Question 13

What are risk factors for MND?

Answer 13

Male
Family history
SOD-1 mutation
Age

Question 14

True or false: MND can cause paralysis of ocular muscles

Answer 14

False
Never affects eye muscles unlike in MS and MG (myasthenia gravis)

Question 15

Does MND affect sensory function?

Answer 15

No. Sensory function can be affected in MS and polyneuropathies

Question 16

After the idea of movement has begun in the association cortexes and pre-motor cortex and the UMNs have been activated in the motor cortex, where does the impulse travel next?

Answer 16

Down corticospinal tract with modulations at the cerebellum for fine tuning and basal ganglia to continue impulse.

Question 17

What are 2 classifications of MND?

Answer 17

ALS (more common) and progressive bulbar palsy

Question 18

What does ALS stand for?

Answer 18

Amyotrophic Lateral Sclerosis

Question 19

Does ALS affect UMN, LMN or both?

Answer 19

Both

Question 20

Does Progressive Muscular Atrophy occur in UMNs, LMNs or both?

Answer 20

LMN only

Is the degeneration of LMNs, generalised and progressive loss of muscle function

Question 21

What is PLS (primary lateral sclerosis)?

Answer 21

Type of motor neuron disease. Weakness in voluntary muscle movement due to nerve cells degenerating in motor regions.

Question 22

What is affected and in what order with primary lateral sclerosis?

Answer 22

Movements are slow and effortful first in legs, then body, trunk, arms, hands and bulbar muscles

Question 23

Does Primary Lateral Sclerosis occur in UMNs, LMNs or both?

Answer 23

UMNs only

Question 24

What is progressive bulbar palsy (PBP)?

Answer 24

Worst prognosis
Impaired function of lower cranial nerves that arise from brainstem
CN 9-12 affected
Difficulty chewing and swallowing, reduced gag reflex, nasal regurgitation, slurred speech, aspiration of secretions, dysphonia (hoarseness) and dysarthria

Question 25

There is an increased chance of _____ failure with progressive bulbar disease

Answer 25

respiratory

Question 26

What signs aren't present in MND to help differentiate it from other neuro conditions?

Answer 26

No eye signs No sensory signs Cerebellar function fine No Parkinson's signs

Question 27

How is MND diagnosed?

Answer 27

Mainly clinical EMG (electromyography) shows fibrillation potentials due to degeneration of muscles with LMN dysfunction

Question 28

How is MND managed?

Answer 28

Riluzole (anti-glutaminergic) Supportive physio and breathing support

Question 29

What are complications of MND?

Answer 29

Respiratory failure Aspiration pneumonia Swallowing failure

Question 30

What is PMA (progressive muscular atrophy)?

Answer 30

A type of MND whereby there is degeneration of lower motor neurons only causing progressive loss of muscle function

Question 31

What are some symptoms of Progressive Muscular Atrophy?

Answer 31

Muscle weakness and wasting in legs, arms, body and hands Flail arm syndrome Fasciculations Difficulty breathing