Motor Control 2

Question 1

what are the features of an upper motor neurone lesion

Answer 1

weakness
hypertonia
increased reflexes
abnormal reflexes

Question 2

what are the features of lower motor neurone lesions

Answer 2

hypotonia
paralysis
fasciculations 
reduced reflexes 
atrophy

Question 3

describe some features of ALS/ MND

Answer 3

affects both upper and lower MNs

lower: anterior horn and brainstem nuclei
upper: cerebral cortex

neurones die at the periphery and move inwards

muscles atrophy
scar tissue forms around axons

sacral parasympathetics spared

Question 4

what is the most common cause of upper motor neurone lesions

Answer 4

infarcts due to CVAs

Question 5

which artery is particularly susceptible to CVAs causing corticospinal lesions

Answer 5

middle cerebral artery supplying the lateral surface of the hemispheres and internal capsule

Question 6

where does the rubrospinal pathway originate

Answer 6

brainstem red nucleus

projects to the upper limbs affecting flexor activity

receives information from corticospinal collaterals and directly from the cerebellum

Question 7

what 3 phases of a voluntary movement

Answer 7

sensory integration
planning
execution

Question 8

basal ganglia

Answer 8

structures linked to the thalamus in the base of the brain and involved in coordination of movement.

Question 9

describe the premotor area

Answer 9

mediates actions through the primary motor cortex

involved in establishing an appropriate postural set before a movement and plasticity of complex sequences of movements

Question 10

what can damage to the premotor area cause

Answer 10

apraxia

Question 11

what is the area in front of the primary motor area known as

Answer 11

area 6

made up of premotor cortex, supplementary or secondary motor cortex

Question 12

what is the supplementary motor cortex involved in

Answer 12

rehearsal of a sequence of finger movements

Question 13

describe the functions of the parietal cortex

Answer 13

spatial processing of a visual stimuli

planning of a sequence of motor outputs

Question 14

where does the parietal cortex recieve information from

Answer 14

somatic sensory area 
vestibular system 
premotor areas
visual system 
limbic cortex (motivational state)

Question 15

how does the impulse frequency of neurons in the primary motor cortex affect the movement

Answer 15

relates to the force required

Question 16

what 3 inputs are involved in fine tuning movement

Answer 16

sensory receptors
impulses from the cerebellum
impulses from the basal ganglia

Question 17

corticospinal tracts

Answer 17

contain nerve fibres which come from the primary motor cortex, pre motor areas and association areas

mostly decussates in the pyramids (lateral path)

some remain ipsilateral until they innervate bilaterally at the ventral root (axial muscles- medial path)

controls distal muscles (lateral corticospinal path)

Question 18

where does the rubrospinal pathway initiate

Answer 18

red nucleus in the brainstem

UL flexor activity

Question 19

what is the most common cause of corticospinal lesion

Answer 19

cerebrovascular accidents leading to infarction

Question 20

which artery is particulary vulnerable to cerebrovascular accidents causing UMN damage

Answer 20

middle cerebral artery

Question 21

why are corticospinal lesions common (aka upper motor neurons)

Answer 21

axons are very long so are vulnerable

Question 22

what is an extensor plantar reflex caused by

Answer 22

corticospinal lesion