Lecture 6 - Motor Planning

Question 1

What is the hierarchy of of controls in motor planning

Answer 1

higher - strategy - TERTIARY
middle - tactics - SECONDARY
lowest - execution - PRIMARY

Question 2

What level of the motor system uses sensory information

Answer 2

all levels use sensory information - for sensorimotor

Question 3

what is the premotor cortex

Answer 3

secondary area for motor planning…

Question 4

what are the secondary areas for motor cortex

Answer 4

premotor cortex

supplementary motor area

Question 5

What is schema theory?

Answer 5

• there are a set of general rules, concepts and relationships to guide performance
• learnable
• modifiable at a level that is not conscious
• goes back to procedural memory

Question 6

What are the important areas for planning movement?

Answer 6

Area 4 - PRIMARY MOTOR CORTEX

Area 6 - High Motor Cortex

• -> laterally is the premotor area
• –> medially is the supplementary motor area

Question 7

What is the “high motor area”

Answer 7

important for motor planning

laterally - premotor area - complex processing of movement

medially - supplementary motor area - programs complex sequences of movement

somatotopic maps are in these areas. they both have similar functions but innervate different areas

Question 8

What happens when you stimulate area 4

Answer 8

muscle contraction

Question 9

What are betz cells?

Answer 9

UMN found in Primary motor cortex
axon all the way down to spinal cord - synapse onto anterior horn

other cortical areas and thalamus input into the betz cells, which then sends info out

Question 10

What area controls the drive to create motor action

Answer 10

DLPFC

lesion would cause avolitional state, discoordination or repetitve and perseveration

Question 11

what area regulates control of motor actions

Answer 11

orbito and ventromedial PFC

lesion would make peopel do random and impulsive things disinhibited

Question 12

What are the contributions of the posterior parietal and prefrontal cortex to the

Answer 12

area 5, which gets info from 3,1,2,

area 7, which gets visual input from middle temporal

anterior frontal lobes - abstract thought, decision making and anticipating consequences of action

area 6 - converts signals specificying how actiosn will be performed

SHOWS HIGHER ORDER MOTOR PLANNING

Question 13

what happens if you get a lesion in the anterior frontal lobes?

Answer 13

• problems in abstract thought and anticipating consequences of action

IDEATIONAL APRAXIA

Question 14

What areas would be activated for doing a complex finger tapping sequence

Answer 14

primary motor cortex
primary somatosensory
supplementary motor area
dorsolateral pfc

Question 15

What would be activated by just thinking about performing a complex finger tapping sequence

Answer 15

supplmentary motor area

Question 16

What area would be activated by making forceful finger movements

Answer 16

PMC

PSC

Question 17

what areas would be activated by performing finger maze test with right hand

Answer 17

PMC
PSC
supplementary motor area
premotor
and more..

Question 18

How is the basal ganglia involved in motor movement

Answer 18

selection and initiation of willed movement

Question 19

How does the basal ganglia interact with the motor areas?

Answer 19

projects to the ventral lateral (VLo) nucleus of the thalamus

provides major input into area 6 (supplemetary and premotor areas)

cortex projects back to basal ganglia to form a loop

Question 20

explain the motor loop between basal ganglia and motor cortex

Answer 20

• excitatory connection from cortex to putamen

cortical activation will

• excite putamen
• inhibit global palladis
• uninhibit VLo of thalamus

VLo activity influences SMA activity

Question 21

How does the cerebellum influence motor movement

Answer 21

controls the sequence of muscle contractions, calibration and coordination.

also has a role in learning new motor programs to ensure smooth movement

Question 22

What can happen in cerebellar lesions?

Answer 22

ataxia - uncoordinted or innaccurate movements

dysynergia - decomposition of synergistic multijoint movements

dysmetria - overshooting or undershooting target

Question 23

What is the cerebellar motor loop?

Answer 23

sensorimotor cortex –> pons (pontine nuclei) –> lateral cerebellum –> VL in thalamus –> PMC

execution of smooth voluntary multi-joint movements

Question 24

What is apraxia

Answer 24

Disorders of the execution of skilled movements

 Many forms; limb kinetic, ideomotor, ideational, dissconnection,
buccofacial, constructional, dressing, gait and apraxic
agraphia

It is not due to:
 deafness or aphasia
 primary sensory weakness (blindness or tactile
anaesthesia) or agnosia (visual or tactile)
 paresis, tremor, ataxia, hypokinesis (Parkinson’s) or
hyperkinesis (Huntington’s)
 impaired spatial orientation
 impaired body schema
 frontal inertia or dementia

Question 25

What is ideomotor apraxia

Answer 25

impairment in the performance of skilled pantomime movements on verbal command or in imitation

• parietal damage in LHS - causes bilateral apraxia
• disconnect from premotor and motor regions, so they can conceptualise it but not execute the action

tends to use body parts as objects

Question 26

What are some errors associated with ideomotor apraxia

Answer 26

• imitating transitive movements (tool use)
• ipsilesional limb better
• body parts as imagined tool
• perseverative errors
• sequencing
• spatial errors - not knowing hOW to do it rather than WHAT to do - wrong grip, wrong area in space, worng movement (arm not wrist etc)

Question 27

What is ideational apraxia

Answer 27

 Inability to produce a coherent action sequence
 Impairment in the concept of an action

• can imitate

 Thought to occur when the motor programming area is destroyed by damage to the supramarginal gyrus, impairing the conceptual representation of an action and leading to deficits in using tools or performing an action to verbal command while imitation is spared

Question 28

bucco-facial apraxia?

Answer 28

This affects the muscles of mouth, tongue, pharynx and larynx.

• Difficulties in protruding the tongue, whistling, protruding the lips (kissing), swallowing etc.
• cant do it on demand but can do it spontaneously (voluntary-autonomic dissociation)

ASSOCIATED WITH SPEECH APRAXIA

lesions of LEFT ANTERIOR INSULA

Question 29

Truncal apraxia?

Answer 29

• dissociation between limb movements and those that executed by the axial musculature (e.g. trunk), preserved in patients with limb apraxia.
• only a hypo
• bilateral frontal lesions that can also cause gait apraxia.

Question 30

Limb apraxia

Answer 30

apraxia of both upper limbs - in RH patients, due to lesion on LHS

• lower limbs can be affected but rarely tested

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