PSY2003 W4/8 Motor Disorders (L)

Question 1

What are the two descending motor pathways?

Answer 1

Dorsolateral tracts and ventromedial tracts

Question 2

What are the similarities between both descending motor pathways?

Answer 2

Both contain a direct corticospinal route and indirect route via brainstem nclia.

Question 3

What is the difference between dorsolateral and ventromedial tracts?

Answer 3

The indirect route are vie red nucleus for dorsolateral tracts but via tectm, vestibular nuclia, reticular formaiton and cranial nerve nuclei for ventromedial tracts.

Question 4

Where does Ventromedial tracts project to?

Answer 4

Diffuse innervation projecting to both slies and multiple segments of spinal cord, to proximal muscles of trunk and limbs.

Question 5

Where does Dorsolateral tracts project to?

Answer 5

Sometiems project directly to alpha motor enuron, to distal muscles (fingers)

Question 6

What is Motor cortex Damage?

Answer 6

Issues descending motor commands for muscle activation, regulates activity levels in spinal cord circuits, is where the upper motor neuron begins.

Question 7

What would you predict to be the symptoms of motor cortex damage?

Answer 7

Voluntary movement: Impaired movement, poor high level coordination, weakness of movement, upper motor neuron syndrome.

Question 8

What is cerebral palsy?

Answer 8

A result of damage to motor control strucutres of the brain, usually the motor cortex. Affects the upper motor neurons, most common movement disorder inchildren

Question 9

When does the injury of Cerebral palsy often occur?

Answer 9

Pre or peri- natally (about 50% cases associated with premature birth)

Question 10

What symptoms does cerebral palsy show?

Answer 10

Stiffness, weakness of muscles, poor coordinaiton

Question 11

What is a Stroke?

Answer 11

Interrption of the blood supply to the cortex (motor often), upper motor neurons affected, FAST (face, arms, speech, time)

Question 12

Symptoms of a stroke?

Answer 12

Symptoms depend on extent and location by usually typical of motor cortex damage

Question 13

What are the two main causes of a stroke?

Answer 13

Cerebral haemorrhae and cerebral ischemia

Question 14

Why is time so important with aneurisms?

Answer 14

If an aneurism is spotted before rupture, can sometimes be treated, e.g. by and clipping the feeding blood vessel< Prevention of bursting: maintain low blood pressure, avoid strenuous activity

Question 15

What causes cerebral haemorrhage?

Answer 15

Uselly cuased by an aneurism, blood is toxic to neural tissue.

Question 16

What causes cerebral ischemia?

Answer 16

Cause by an interruption of the blood supply to part of the brain due to blockage of a blood vessel.Blockages can be caused by specific ‘plugs’ (thrombus or emboli), or cardiovascular disease (atherosclerosis)

Question 17

Why is fine motor control important in motor disorders?

Answer 17

Most prominent symptoms and most widespread across causes of motor cortex damage are often those relating to fine motor control

Question 18

Why is fine motor control relating to symptoms of motor disorders?

Answer 18

The homunculus – large representations for these activities – unlikely to be missed by damage, and require co-ordination across sub-regions

Question 19

What is the upper motor neuron syndrome?

Answer 19

Collection of symptoms that results from damage to UMNs (e.g. in cortex, where they originate) or their pathways (e.g. spinal cord). • Leads to not only lack of voluntary control of muscles via lower motor neurons, but also a lack of regulation of LMNs and spinal reflex circuits

Question 20

What is the babinski reflex?

Answer 20

Detects upper motor neuron damage. When toas curl down: normal response, toes curl up: positive response (suggest problem with upper motor neuron)

Question 21

Why can it be difficult separating the impact of brain damage on cognitive and motor function?

Answer 21

motor impairments, slurred speech but are not cognitive impairment just motor damage

Question 22

What is the basal ganglia?

Answer 22

The basal ganglia are a group of nuclei lying deep within cerebral hemispheres

Question 23

Short definition of PD

Answer 23

Involuntary tremor, slowness of movement, rigidity. Difficulty initiating voluntary movements.

Question 24

Short definition of Huntingdon’s disease

Answer 24

Sudden, jerky, involuntary movements with no purpose. No weakness, ataxia or sensory deficit.

Question 25

Short definition of Tardive dyskineasia

Answer 25

Repetitive, involuntary, purposeless movements. Difficulty in stopping movements.

Question 26

Short definition of Hemiballismus?

Answer 26

Violent, involuntary movements (ballistic movements).

Question 27

Short definition of Tourette’s syndorme?

Answer 27

Sudden, repetitive, [involuntary] movements or utterances

Question 28

Stats on Parkinson’s disease?

Answer 28

2nd Most common neurodegenerative disease. Affects 3/1000 people, 1/100 in >60s, 1/25 in >80s. Affects ~50% more males than females (3:2 ratio)

Question 29

Why does PD occur?

Answer 29

Around 10% of cases occur due to mutation of one of several gene ==> monogenic PD

Question 30

why is it useful to study genetic causes of primarily ‘non-genetic’ diseases, as these often occur in a small minority of affected people…?

Answer 30

Most (90% or more) cases of these disease are sporadic. Soe are caused by mutation in a sinle gene (1-10%)

Question 31

Parkinson’s disease symptoms?

Answer 31

Initation of movement is impaired, but certain cues/contexts can help: plaucity of spontanous moement, bradykinesia, akinesia, increased muscle tone- rigidity, resting tremor, suffling gait, flexed posture, imapired balance, mask-like expression

Question 32

What are the limits of L-dopa and other drugs treating PD?

Answer 32

PD arises following degeneration of nigrostrital neurons, which ultimetely the increasing dopamine availability usin drugs stops beting effective.

Question 33

What drug is revolutionised PD treatment and is a huge milestone in neurologiy?

Answer 33

L-Dopa

Question 34

What is a big limitation of L-dopa?

Answer 34

It does not really address the non-motor symptoms of PD!!

Question 35

Why are we only treating half of the disease?

Answer 35

Dominance of the “nigrostriatal dopamine” account for PD è Turns out, this probably is not the cause of PD

Question 36

What is Deep Brain sitmulation ?

Answer 36

Surgery treatmet, rapidly becoming more and more effective. Electrical stimulation of specific BG structures to counteract excessive inhibitory output.

Question 37

What are the Limitation of Deep Brain stimulation?

Answer 37

But not without some side effects. Not similarly effective for all. And, crucially, DBS also fails to deal with non-motor symptoms. Confounded by DBS typically being used in later stage disease. It may actually make some non-motor symptoms worse

Question 38

Alpha-sunuclein and Lewy bodies

Answer 38

Happens throughout the brain, dopamine neurons in substantia nigra may be aprticularly vulnerable, crucially, this explanation may also account for non-motor symptoms.

Question 39

What is cerebellar dysfunction?

Answer 39

Like basal ganglia, no direct projection to the lower motor neurons – instead modulate activity of upper motor neurons

Question 40

What the cerebellum ?

Answer 40

Contains approx. half total number of CNS neurons, just 10% of total brain weight, projects to almost all upper motor neurons, when damages the resulting impaiments in movemnt is ataxia, voluntary movement loses fluidity and appears mechanical, slow and roboti like, intention tremor, dysarthria

Question 41

What are the two types of ataxia?

Answer 41

Disturbances of posture and gait and decomposition of movement

Question 42

What is dysathria?

Answer 42

disruption of fine control of speech, slurring

Question 43

What s Ataxia?

Answer 43

A collection of disorders, unified by their symptoms, rather than their causes. • Can be defined most simply as a loss of voluntary co-ordination of muscles – it is thus a neurological finding in a patient, and not a disease (though it may be caused by various diseases)

Question 44

What are the types of ataxia?

Answer 44

divided up in slighlty different ways depending on what source your read, focus on symotoms, cause or more detailed diagnosis

Question 45

What is motor neuron disease?

Answer 45

Motor neuron degeneration and muscel wasting

Question 46

Why muscle wasting ?

Answer 46

Degenerative, progessive incurable

Question 47

What causes Motor neuron disease?

Answer 47

~10% of cases have genetic component – environmental, toxic, viral and other factors implicated in the other 90% - i.e. we don’t know!

Question 48

Who gets it (incidence) ? (motor neuron disease)

Answer 48

Anyone, but more common in men. But risk strongly modulated by age. About 5,000 people in the UK have it right now. Symptoms, rate of progression and life expectancy highly variable.

Question 49

What are the types of Motor neuron disease?

Answer 49

MND and Als are used interchangable but ALS is a subtype (most common) Generally distinction of subtypes related to effects on either upper or lower motor neurons. Often they are altered cogntive function, ability to communication, affecive cane.