Motor Neurone Lesions

Question 0

List some of the main causes of LMN lesions

Answer 0

Trauma
Viral infection (e.g. Polio)

Question 1

What are the classic signs of LMN lesions?

Answer 1

1) Muscle weakness and atrophy
2) Reduced muscle tone
3) Hyporeflexia
4) Paralysis

Question 2

What are the 3 main inhibitory effects UMNs have on the nerves below them?

Answer 2

1) dampen down reflex arc
2) prevent muscle overactivity and spasm
3) suppress primitive reflexes such as the plantar response (Babinski)

Question 3

What are the keys signs of UMN lesions?

Answer 3

• Hyper-reflexia
• Hypertonia and Spasticity (stiffness - resistant to passive movement in single direction)
• Up-going plantars (positive Babinski)

Question 4

If an individual suffered a lesion at C6 what would the consequence be?

Answer 4

Quadriplegia

Question 5

If an individual suffered a lesion at T7 what would the consequence be?

Answer 5

Paraplegia