Motor Cortical Control

Question 1

What are the negative affects of an upper motor neurone lesions?

Answer 1

Loss of voluntary motor function

Paresis: graded weakness of movements

Paralysis (plegia): complete loss of voluntary muscle activity

Question 2

What is meant by negative?

Answer 2

Loss of function

Question 3

What is meant by positive?

Answer 3

Unwanted gain of function

Question 4

What are the positive affects of an upper motor neurone lesions?

Answer 4

Increased abnormal motor function due to loss of inhibitory descending inputs

Spasticity: increased muscle tone

Hyper-reflexia: exaggerated reflexes

Clonus: abnormal oscillatory muscle contraction

Babinski’s sign

Question 5

What is apraxia?

Answer 5

Consequence of UMN lesion

disorder of skilled movement

Patients are not paretic but have lost information about how to perform skilled movements

Question 6

What can cause apraxia?

Answer 6

Lesion of inferior parietal lobe, the frontal lobe

e.g. stroke and dementia

Question 7

What are the symptoms of a lower motor neurone lesions?

Answer 7

Weakness

Hypotonia (reduced muscle tone)

Hyporeflexia (reduced reflexes)

Muscle atrophy

Fasciculations

Fibrillations

Question 8

What are fasciculations?

Answer 8

damaged motor units produce spontaneous action potentials, resulting in a visible twitch

Question 9

What are fibrillations?

Answer 9

spontaneous twitching of individual muscle fibres; recorded during needle electromyography examination

Question 10

What is MND?

Answer 10

Motor Neuron Disease

Question 11

What is motor neurone disease?

Answer 11

Progressive neurodegenerative disorder of the motor system

Affects UMN and LMN’s

Also known as Amyotrophic Lateral Sclerosis (ALS)

Question 12

Which muscles are particularly affected by MND?

Answer 12

Tongue
Upperlimb
Intercostal muscles
Lower limb

Question 13

What are the signs of upper motor neurone disease? in MND

Answer 13

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

Question 14

What are the signs of lower motor neurone disease? in MND

Answer 14

Weakness
Muscle wasting
Tongue fasciculations and wasting
Nasal speech
Dysphagia

Question 15

What disorders are associated with basal ganglia dysfunction?

Answer 15

Parkinson’s
Huntington’s
Ballism

Question 16

What causes Parkinson’s?

Answer 16

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

Question 17

What are the symptoms of Parkinson’s?

Answer 17

Bradykinesia
Hypomimic face
Akinesia
Rigidity
Tremor at rest

Question 18

What is bradykinesia?

Answer 18

slowness of (small) movements (doing up buttons, handling a knife)

Question 19

What is hypomimic face?

Answer 19

expressionless, mask-like (absence of movements that normally animate the face)

Question 20

What is akinesia?

Answer 20

difficulty in the initiation of movements because cannot initiate movements internally

Question 21

What is rigidity?

Answer 21

muscle tone increase, causing resistance to externally imposed joint movements

Question 22

What are the main feature of the Parkinson’s tremor?

Answer 22

4-7 Hz, starts in one hand (“pill-rolling tremor”); with time spreads to other parts of the body

Question 23

What causes Huntington’s disease?

Answer 23

Degeneration of GABAergic neurons in the striatum, caudate and then putamen

Genetic neurodegenerative disorder
Chromosome 4, autosomal dominant
CAG repeat

Question 24

What are the symptoms of Huntington’s?

Answer 24

Choreic movements 
Speech impairment
Difficulty swallowing
Unsteady gait
Later stages, cognitive decline and dementia

Question 25

What are choreic movements?

Answer 25

(chorea - dance) | rapid jerky involuntary movements of the body; hands and face affected first; then legs and rest of body

Question 26

What are the main signs of cerebellar dysfunction?

Answer 26

``` Ataxia Dysmetira Intention tremor Dysdiadochokinesia Scanning speech ```

Question 27

What is ataxia?

Answer 27

General impairments in movement coordination and accuracy. Disturbances of posture or gait: wide-based, staggering (“drunken”) gait

Question 28

What is dysmetria?

Answer 28

Inappropriate force and distance for target-directed movements (knocking over a cup rather than grabbing it)

Question 29

What is intention tremor?

Answer 29

Increasingly oscillatory trajectory of a limb in a target-directed movement (nose-finger tracking)

Question 30

What is dysdiadochokinesia?

Answer 30

Inability to perform rapidly alternating movements (rapidly pronating and supinating hands and forearms)

Question 31

What is scanning speech?

Answer 31

Staccato, due to impaired coordination of speech muscles

Question 32

How is Parkinson's diagnosed?

Answer 32

Clinical diagnosis If unclear dopaminergic agent trial can be used If symptoms improve the diagnosis can be confirmed e.g. Levodopa

Question 33

What is the primary option of mild parkinson's?

Answer 33

Levodopa

Question 34

What dopamine receptor agonists are used to treat parkinson's?

Answer 34

Ropinirole | Procyclidine

Question 35

What is important re Levodopa?

Answer 35

Reduced effectiveness with time | Cannot stop abruptly