Injuries to the motor pathways

Question 1

What is complete loss of the ability to contract a muscle/muscle group fro purposeful voluntary movement?

Answer 1

Paralysis

Interruption of the pathway between the primary motor cortex and the muscle

Question 2

What is partial loss of voluntary control?

Answer 2

Paresis

Question 3

What is associated with LMN injuries?

Answer 3

Paresis/ paralysis
Hypotonia
Hyporeflexia
Rapid onset pronounced atrophy
Fasciculations - quick twitches

Question 4

Associated with UMN injuries?

Answer 4

Paresis/ paralysis
hypertonia
hyperreflexia
Typically less atrophy initially

Question 5

What is clonus?

Answer 5

Involuntary, repeated and rhythmical contractions of a single muscle group
Activated by muscle stretch, a noxious stimulus or attempting to voluntary move
Soleus often presents with clonus

Question 6

Lesions of corticospinal neurons have more pronounced effect on voluntary movement of?

Answer 6

paresis/paralysis than tone and reflexes

Question 7

Lesions of non-corticosprinal upper motor neuron have more pronounced?

Answer 7

effects on tone and reflexes than voluntary movement

Question 8

Brainstem and spinal cord lesions often affect?

Answer 8

Both corticospinal and non-corticospinal tracts

Ex: If LCST damaged, expect damage to lateral reticulospinal tract due to proximity