Cortical Motor Control

Question 1

What is hierarchial organisation?

Answer 1

Areas of higher order are involved in more complex tasks

Question 2

What are the 2 types of descending tracts?

Answer 2

Pyramidal

Non-pyramidal

Question 3

What are the 2 pyramidal tracts?

Answer 3

Corticospinal

Corticobulbar

Question 4

What are the 4 non pyramidal tracts

Answer 4

Tectospinal
Rubrospinal
Reticulospinal
Vestibulospinal

Question 5

What are pyramidal tracts for?

Answer 5

Voluntary movement of the head and face

Question 6

What are non-pyramidal tracts for?

Answer 6

Non voluntary movements for balance locomotion etc

Question 7

Describe how pyramidal tracts decend

Answer 7

Through pyramidal cells pf medulla

From the motor cortex to the spinal chord or cranial nerve nuclei in the brainstem

Question 8

Describe how non-pyramidal tracts decend

Answer 8

Not through the pyramidal cells of the medulla

From brainstem nuclei to spinal chord

Question 9

What is the vestibulospinal tract for?

Answer 9

Stabilises head during body movements

Coordinates head movements with eye movements

Question 10

What is the reticulospinal tract for?

Answer 10

Changes muscle tone associated with voluntary movement and postural stability

Question 11

What is the rubrospinal tract for?

Answer 11

Innervate lower motor neurons of flexors of the upper limb

Question 12

What is the tectospinal tract for?

Answer 12

Orientation of the head and neck during eye movements

Question 13

What is the role of the primary motor cortex?

Answer 13

Controls fine, discrete, precise voluntary movements

Question 14

What is the role of the supplementary area?

Answer 14

Involved in planning complex movements (e.g. internally cued, speech), is active prior to voluntary movement

Question 15

What is the role of the premotor area?

Answer 15

Involved in planning externally cued movements

Question 16

Where does the corticospinal tract decussate?

Answer 16

Pyramidal cells of the medulla

Question 17

What symptoms are associated with an upper motor neuron lesion?

Answer 17

Loss of voluntary motor function
Graded weakness of movement
Paralysis
Increased abnormal motor function (due to loss if inhibition)
Increased muscle tone
Hyper reflexia
Babinskis sign
Apraxia

Question 18

What is Babinski’s sign?

Answer 18

Big toe curls upwards instead of down when sole of the foot is stroked (note this is normal for babies but in anyone older they should curl down)

Question 19

What is apraxia?

Answer 19

Patients have lost information about how to perform skilled movements.

Question 20

What symptoms are associated with a lower motor neuron lesion?

Answer 20

Weakness
Hypotonia
Hyporeflexia
Muscle atrophy
Fasciculations
Fibrillations

Question 21

In MND, what upper motor neuron lesion symptoms do patients have?

Answer 21

Spasticity (increased tone of limbs and tongue)
Brisk limbs and jaw reflexes 
Babinski’s sign
Loss of dexterity
Dysarthria (difficulty speaking)
Dysphagia (difficulty swallowing)

Question 22

In MND, what lower motor neuron lesion symptoms do patients have?

Answer 22

Weakness
Muscle wasting
Tongue fasciculations and wasting
Nasal speech
Dysphagia

Question 23

Where is the basal ganglia located?

Answer 23

Caudate nucleus

Question 24

What are the functions of the basal ganglia?

Answer 24

Decision to move, elaborating associated movements, moderating and coordinating movement, performing movements in order

Question 25

What happens in Parkinsons?

Answer 25

Degeneration of the dopaminergic neurons that originate in the substantia nigra and project to the striatum

Question 26

How does Parkinson's present?

Answer 26

``` Bradykinesia Hyponomic (expressionless face) Akinesia Rigidity Tremor at rest (starts in one hand) ```

Question 27

What happens in Huntingtons?

Answer 27

Degeneration of GABAergic neurons in the striatum, caudate and then putamen due to chromosome 4 CAG repeat (autonomic dominant)

Question 28

How does Huntington's present?

Answer 28

Choreic movements Speech impairment Dysphagia Unsteady gait

Question 29

What is ballism?

Answer 29

Sudden flinging of extremities, happens contralaterally

Question 30

Why does ballism arise?

Answer 30

Due to stroke in subthalamic nucleus

Question 31

Where is the cerebellum located?

Answer 31

Posterior cranial fossa

Question 32

What is the role of the cerebellum?

Answer 32

Coordinator and predictor of movements

Question 33

What are the 3 subparts of the cerebellum?

Answer 33

Vestibulocerebellum Spinocerebellum Cerebrocerebellum

Question 34

How does damage to the vestibulocerebellum usually occour?

Answer 34

Tumor

Question 35

How does damage to the spinocerebellum usually occour?

Answer 35

Chronic alcoholism causes degeneration and atrophy

Question 36

How does damage to the vestibulocerebellum present?

Answer 36

Gait ataxia and tendency to fall

Question 37

How does damage to the spinocerebellum present?

Answer 37

Affects mainly legs, causes abnormal gait and stance

Question 38

How does damage to the cerebrocerebellum present?

Answer 38

Affects mainly arms/skilled coordinated movements (tremor) and speech

Question 39

What are the main signs of cerebellar dysfunction? When do they present?

Answer 39

``` Only apparent on movement: Ataxia Dysmetria Intention tremor Dysdiadochokinesia Scanning speech ```