Clinical signs and Patterns of Motor Control Impairment

Question 1

Where are motor movements controlled in the cortex

Answer 1

Frontal lobe executes movement.

Question 2

What areas are involved in frontal love execution of movement and what is each area responsible for

Answer 2

1- Primary motor cortex ( M1 ) : large pyramidal neurons that travel down spinal cord and synapse with motor neurons

2- premotor cortes : organizes and sequences movements

3- Prefrontal and orbitofrontal : abstract planning and selecting a goal to tell premotor cortex the steps required to reach that goal

Question 3

What are the lower motor neurons

Answer 3

Cell bodies within the anterior horn of spinal cord / brainstem.
Alpha motor neurons : voluntary muscle contraction, myosatic stretch reflex

OR

Gamma motor neurons: regulate muscle tone , maintain proprioception

Question 4

The descending motor pathway can be divided into which two groups

Answer 4

1- Pyramidal tracts ( Direct )

2- Extrapyramidal tracts ( Indirect )

Question 5

Explain the descending Pyramidal Corticospinal motor pathway ( 6 steps )

Answer 5

1- Corticospinal tract begins at cortex and receives input from primary , premotor and supplementary areas

2- Neurones descend through internal capsule ( between he thalamus and basal ganglia )

3- Neurone then passes through the crus cerebra of midbrain, the pons and into the medulla

4- in the inferior part ( caudal ) of the medulla and then divides into 2 tracts

5- Lateral corticospinal tract crosses over at the medulla and then descends into spinal cord.
Anterior corticospinal tract stays ipsilateral and descends in the spinal cord.

6- Lateral tracts terminates at ventral horn and then synapses with lower motor neurons. Anterior tract terminates at ventral horn of Cervical and upper thoracic levels.

7- signals carried to musculature of the body except face and neck

Question 6

What is the clinical importance of the internal capsule of the pyramidal motor pathway

Answer 6

Internal capsule susceptible to compression from haemorrhage bleeds ( capsular strokes ) which could result in lesion of descending tracts

Question 7

Explain he Corticobulbar tract motor pathway

Answer 7

1- Arises from lateral aspect of primary motor cortex

2- receive same input as the corticospinal tract

3- pass through internal capsule to the brainstem

4- neurons terminate on motor nuclei of cranial nerves

5- synapse with lower motor neurones that carry signals to face and neck

Question 8

Where do the extrapyramidal tracts originate

Answer 8

Brainstem

Question 9

What are extrapyramidal tracts responsible for

Answer 9

involuntary and automatic control of musculature ex: muscle tone, balance, posture , locomotion

Question 10

What are pyramidal tracts responsible for

Answer 10

Voluntary control of the musculature of the body and face

Question 11

What are the 4 extrapyramidal tracts

Answer 11

1- Vestibulospinal
2- Reticulospinal
3- Rubrospinal
4- Tectospinal

Question 12

Explain the Vestibulospinal tract motor pathway

Answer 12

• 2 pathways : medial and lateral.
• arise from vestibular nuclei that receive input from organs of balance
• remains ipsilateral and tract conveys balance info to spinal cord

Control balance and posture by innervating anti-gravity muscles via lower motor neurons ( arm flexors/leg extensors )

Question 13

Explain the Reticulospinal tract motor pathway

Answer 13

2 tracts
Medial : arises from pons & facilitates voluntary movement and increase muscle tone

lateral: arises form medulla & inhibits voluntary movements and reduces muscle tone

Question 14

Explain the Rubrospinal tract motor pathway

Answer 14

• Originates from red nucleus ( midbrain )
• Fibres cross over when they emerge and descend spinal cord ( contralateral innervation )

Role in fine control of hand movements

Question 15

Explain the tectospinal tract motor pathway

Answer 15

• begins at colliculus of the midbrain , receives input form optic nerves
• neurons cross over and enter spinal cord , terminating at cervical levels
• function: coordinate head movements in relation to vision stimuli

Question 16

Where do the Motor pathway tracts receive inhibitory signals form

Answer 16

Cortex

Question 17

A movement to ensure stability is usually done before or after anticipated movement

Answer 17

Usually the Brain will ensue postural stability BEFORE anticipated movement ex: gastrocnemius contracting before biceps do when pulling on handle

Question 18

Define paraparesis

Answer 18

weakness of legs

Question 19

Define paraplegia

Answer 19

complete weakness of legs

Question 20

Define paraesthesia

Answer 20

abnormal sensation

Question 21

Define Quadra/tetraparesis

Answer 21

Weakness of arms and legs

Question 22

Define Hemiparesis

Answer 22

weakness of half of body

Question 23

Define prefix Mylo

Answer 23

something of the spinal cord

Question 24

Define prefix Radiculo

Answer 24

something of the nerve roots

Question 25

Define ataxia

Answer 25

lack of coordination of limb movements and or gait

Question 26

Damage above the medulla will result in what

Answer 26

- Contralateral hemiplegia | - pattern of flexed ULs & extended LLs

Question 27

Damage below the medulla will result in what

Answer 27

Spinal cord syndrome - Cervical sc = quadriplegia - thoracic or lumbar sc = paraplegia - hemisection of cord - Brown-sequard syndrome

Question 28

What is Brown-sequard syndrome

Answer 28

neurological condition due to a hemisection lesion of spinal cord. Results in hemiparaplegia of one side of body and hemianesthesia on the opposite side

Question 29

Define hemianestehesia

Answer 29

loss of sensation on side of body

Question 30

What will and UMN lesion result in terms of stretch reflex

Answer 30

Hyperexcitability of the stretch reflex due to loss of inhibitory control. Since stretch is applied quickly contraction is stronger ( increased tone ) = clasp knife

Question 31

List the signs of UMN lesions

Answer 31

``` 1- Hypertonia 2- Hyperreflexia 3- Clonus ( involuntary, rhythmic contractions ) 4- Babinski sign ( extensor plantar ) 5- muscle weakness ```

Question 32

How would hemiparesis look

Answer 32

1- Adducted + flexed UL 2- Extended LL 3- plantar flexed + inverted

Question 33

If there is spastic paraperesis of all 4 limbs the lesion must be above ...

Answer 33

C5

Question 34

Define spastic paraparesis

Answer 34

Weakness in limbs ( with muscle spasms )

Question 35

How would a lesion in the cervical spinal cord usually present as

Answer 35

1- Spastic paraperesis of 4 limbs if lesion above C5 If lesion complete 1- complete paralysis below lesion 2- loss of all sensory modalities below lesion 3- loss of bowel,bladder, sexual function

Question 36

How would a lesion in the thoracic or lumbar spinal cord usually present as

Answer 36

1- Spastic paraparesis in legs but normal arms 2- lesion will be below T1 Lesions often incomplete 3- bilateral leg weakness , not complete paralysis 4- impaired sensory function 5- defective bowel, bladder, sexual function

Question 37

If there's posterior column spinal cord lesion will there be UMN signs in the legs and why

Answer 37

No because the pyramidal tracts would be sparred since they are lateral

Question 38

Will the bladder be affected in a posterior column spinal cord lesion ? if not what type of lesion would affect it ?

Answer 38

Bladder will probably be intact , usually affected by anterolateral lesions

Question 39

Which conditions can cause UMN signs

Answer 39

``` 1- Brain tumour 2- ischaemic stroke 3- ICH 4- Post head injury 5- multiple sclerosis 6- spinal cord stenosis 7- prolapsed disc ```

Question 40

What does a LMN lesion mean ( damage where ? )

Answer 40

Damage to the peripheral nervous system : - motor neuron in anterior horn - nerve roots / plexus - peripheral nerve - muscle - neuromuscular junction

Question 41

What are the signs of LMN signs

Answer 41

1- Muscle wasting and flaccid tone 2- Waddling gait 3- Fasciculations 4- hyporeflexia

Question 42

What are patterns of LMN

Answer 42

1- Flaccid areflexic paraplegia 2- primal weakness ( difficulty rising ,stairs, hair washing ) 3- distal weakness : focal or widespread ( phone , writing ) 4- fatiguable weakness ( worse with repeated effort )

Question 43

what is Flaccid areflexic paraplegia

Answer 43

weakness or paralysis and reduced muscle tone due to trauma affecting nerves associated with muscle

Question 44

Define plexopathy

Answer 44

Disorder of brachial or lumbosacral plexus of nerves

Question 45

Define radiculopathy

Answer 45

symptoms due to pinching of nerve in spinal column

Question 46

What drops are seen with LMN lesions

Answer 46

``` 1- Foot drop - can't dorsiflex foot - floppy ankle 2- wrist drop - can't extend wrist - hand hangs flaccidly ```

Question 47

What could cause a wrist drop

Answer 47

radial nerve lesion due to penetrating trauma , extrinsic compression , humeral fracture or Motor neuron disease

Question 48

What could cause a foot drop

Answer 48

``` Lesion to - deep/common perineal nerve - sciatic nerve - lumbosacral plexus = L5 nerve root ```

Question 49

What are common LMN diseases in out-patients

Answer 49

``` 1- foot drop ( perineal ) 2- bells palsy ( facial ) 3- peripheral neuropathy ( diabetic? ) 4- ocular myasthenia gravis 5- muscular dystrophy 6- radiculopathy due to prolapsed disc ```

Question 50

What is ocular myasthenia gravis

Answer 50

muscles moving eyes and eyelids are fatigued and weakened. | Presenting with Dropping eyelids or double vision

Question 51

What are common LMN diseases in ward patients

Answer 51

``` 1- Motor neurone disease 2- cauda equina syndrome 3- Traumatic plexopathy 4- Guillain-barre syndrome 5- CIDP 6- Cristial illness neuropathy 7- Mysasthenia gravis 8- Inflammatory Myopathies ```

Question 52

What is Guillain-barre syndrome

Answer 52

Rare neurological condition affecting feet, hands and limbs causing weakness, numbness and pain

Question 53

What is CIDP

Answer 53

Chronic inflammatory demyyelinating polyradiculoneuropathy rare autoimmune disorder causing body to attack myelin sheaths

Question 54

What if patient presents with both UMN & LMN signs

Answer 54

Suspect damage to anterior horn in spinal cord. Could cause tract and segmental signs due to spinal cord lesion and still cause LMN signs due to lower motor neurons being affected . Could be MND

Question 55

Fasiculations and atrophy are lesion in ?

Answer 55

LMN

Question 56

Brisk reflexes and extensor plantar are lesion in ?

Answer 56

UMN

Question 57

What is the pathology of a basal ganglia problem

Answer 57

1- movements are fragmentary , incomplete and staccato 2- Hypokinesis 2- Hyperkinesis

Question 58

What is Hypokinesis

Answer 58

Too little movement - rigidity - resisting tremor - bradykinesia : deceased speed and amplitude of movement

Question 59

What is hyperkinesis

Answer 59

too much movement - essential tremor - chorea - ballism - myoclonus - dystonia

Question 60

What is the purpose of basal ganglia in extrapyramidal tracts

Answer 60

Sequencing and smooth control of movement. gives fluidity to movement

Question 61

Parkinson's disease is an example of problem in ?

Answer 61

Basal ganglia

Question 62

What is the purpose of the cerebellum

Answer 62

Coordinates muscle activity during learner movement and receives input from proprioceptors, inner ear and cortex

Question 63

Signs of cerebellar dysfunction

Answer 63

``` 1- Nystagmus 2- dysarthria 3- intention tremor / dysmetria 4- dysdiadochokinesia 5- wide based unsteady gait 6- truncal sway ```

Question 64

Left cerebellar hemisphere lesion will cause what

Answer 64

Left sided ataxia

Question 65

What are examples of extrapyramidal and cerebellar diseases in out patients

Answer 65

``` 1- Parkinson's disease 2- essential tremor 3- thyrotoxic tremor 4- Huntington's chorea 5- tics 6- wry neck ( torticollis ) ```

Question 66

What are examples of extrapyramidal and cerebellar diseases in ward patients

Answer 66

1- asterixis ( liver flap ) 2- anaesthesia induced myoclonus 3- alcohol related ataxia 4- viral cerebellitis ( in kids )