Week Seven - Movement Disorders Flashcards

1
Q

What are the characteristic features of all movement disorders?

A

An abnormality of the form and velocity of movements of the body and are often associated with neuropsychological deficits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The term “movement disorder” has become synonymous with what?

A

The term “movement disorder” has become synonymous with basal ganglia disease and extrapyramidal features.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is it unsurprising that movement disorders are also frequently associated with cognitive and neuropsychiatric problems?

A

because of the extensive cerebral cortical connectivity of basal ganglia structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Normal motor control requires maturation of what 2 systems?

A

musculoskeletal and NS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

All the voluntary muscles of the body are directly innervated by what?

A

The motor neurons in the spinal cord and hindbrain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is not innervated by the motor neurons in the SC and hindbrain?

A

The muscles that activate the eye, which are innervated from midbrain nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The control of voluntary movements has three stages, what are they?

A

Planning, initiation and execution, which are performed by different brain regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are alpha-motor neurons responsible for?

A

The execution of movements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What brain areas are involved in planning movement?

A

cortical association areas and BG and cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What brain areas are involved in actual initiation of movement?

A

Motor cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What area of the brain is responsible for fine tuning movements?

A

Cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Movement is involved in a circuit -

The highest level of the hierarchy comprises many regions of the brain, including those associated with?

A

Memory, emotions and motivation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The intent to ‘move’ is formed where?

A

In the highest level of the hierarchy, in the command neurons (typically, pyramidal neurons in the motor cortex).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Movement is involved in a circuit -

What occurs in the middle level?

A

Information is relayed to the middle level, which is located in the sensorimotor cortex of cerebral cortex, the basal ganglia of the subcortical nuclei, the cerebellum, and the brainstem.

Postures and movements required to perform the task are determined.

Receive input from receptors in the muscles, the joints, the skin, eyes

Creates a motor program, that defines the information required to perform the desired task.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What modulates activity in the middle level?

A

Feedback loops involving these independent subcortical systems (the cerebellum and the basal ganglia) modulate activity at the brainstem and cortical levels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What can movement disorders be categorised into?

A

Akinetic-Rigid: move too little and Hyperkinetic: move too much

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do bradykinesia and hypokinesia refer to? (used interchangeably with akinetic)

A

Bradykinesia means ‘slow movement’

Hypokinesia refers to poverty of movement, or movements that are smaller in amplitude than that intended.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What term best captures the essence of PD?

A

Hypokinesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which type of movement disorders are harder to diagnose?

A

Hyperkinetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What further subtypes have hyperkinetic movements disorders been broken down into?

A

jerky and non-jerky syndromes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do jerky syndromes comprise?

A

myoclonus, chorea, and tics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do non-jerky syndromes comprise?

A

tremor and dystonia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is Myoclonus? (j)

A

Sudden, brief, shock-like involuntary movements which we may all experience on occasion when falling off to sleep.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is Chorea? (j)

A

Quick, irregular, semi-purposive, and predominantly distal involuntary movements which can impart a “fidgety” look to the patient.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are Tics? (j)

A

Abrupt, jerky, non-rhythmic movements (motor tics) or sounds (vocal tics) that are temporarily suppressible by will power. These movements are preceded by a feeling of discomfort or an urge that is temporarily relieved by the tic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are Tremors? (nj)

A

An involuntary, somewhat rhythmic, muscle contraction and relaxation involving oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is Dystonia? (nj)

A

An abnormal movement in which a person’s muscles contract uncontrollably. The contraction causes the affected body part to twist involuntarily, resulting in repetitive movements or abnormal postures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is PD defined as?

A

A progressive degenerative disorder of the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the major symptoms of PD?

A

bradykinesia, temor and rigidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the anchor feature of PD?

A

Bradykinesia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Walking characteristics of those with PD?

A

Slowed gait and the feet tend to shuffle along the floor as if weighted down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What happens to handwriting in those with PD?

A

Becomes small and imprecise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is a resting tremor (symptom of PD)?

A

Shaking that occurs in relaxed muscles typically in hands.

Results from activation of opposing muscle groups

34
Q

What is rigidity (symptom of PD)?

A

Increased muscle tension that feels ratchet-like when resistance is applied.

Repeated movements of arm and leg joints resulting in stiffness and jerkiness

35
Q

What is Dysarthia?

A

Weakness in muscles used for speech causing slow speech (normally a late feature)

36
Q

What is Dysphagia?

A

Difficulty swallowing

37
Q

What is the posture like in those with PD?

A

stooped with flexion of the trunk and is a hallmark feature of PD

38
Q

What % of those with PD experience dementia?

A

70-80% (is a late feature)

39
Q

If dementia occurs early in ‘PD’ patients what do we do?

A

We usually change diagnosis to ‘dementia with Lewy bodies’

40
Q

Dementia produces a greater impact on what in people with PD than people with AD and why?

A

Social and occupational functioning due to the combination of motor and cog impairments

41
Q

What increases the risk of developing dementia with PD?

A

increasing age
longer duration of disease
being male
hallucinations

42
Q

Approx what % of patients have significant depressive symptoms and anxiety with PD?

A

30-40% depressive

40% anxiety

43
Q

What are movement disorders primary linked to?

A

Dopamine deficits

44
Q

Psychotic symptoms are frequent in what % of people with PD?

A

up to 50%

45
Q

What are the 2 principle categories of PD?

A

Degenerative PD

Symptomatic/Secondary PD

46
Q

Define Degenerative PD?

A

Where a variety of sporadic and genetic degenerative diseases cause nigrostriatal neurodegeneration

47
Q

Define Symptomatic/Secondary D?

A

Caused by non-degenerative lesions of the same system or other sites of the straitopallidothalamic-cortical motor circuitry

48
Q

The etiology of both Degenerative PD

Symptomatic/Secondary PD is definable how?

A

By disorders affecting the nigrostriatal dopamine transmission and/or downstream signalling pathways

49
Q

What are the 2 types of Degenerative PD? MUST KNOW

A

Sporadic and genetic

50
Q

What are the types of

Symptomatic/Secondary PD? MUST KNOW

A
Infectious
toxic
drug-induced
brain tumours
metabolic
51
Q

What is the BG?

A

A brain area comprising a distributed set of brain structures in the telencephalon, diencephalon and mesencephalon

52
Q

What are the forebrain components of the BG?

A

caudate nucleus, putamen, nucleus accumbens and global pallidus

53
Q

The globus pallidus is divided into what 2 segments?

A

internal (medi) and external (lateral)

54
Q

What are the 2 pathways in the BG that control the fine tuning of voluntary motor activities?

A

Direct (activation of D1 receptor which stimulates) - motor cortex to striatum to Gpi to thalamus - activation of motor cortex

Indirect (activation of D2 receptor which inhibit) - inhibition of motor cortex - is the breaks

55
Q

The two BG pathways have what effects?

A

agonistic net effects

56
Q

What do the two dopamine receptors bind to?

A

the striatum and either stimulates or inhibits each pathway, aiming to stimulate the motor cortex

57
Q

What is the key feature of PD in relation to dopamine receptors, the pathways and Bg etc?

A

In people with PD the internal segment of the BG is hyper-activity - inhibiting the thalamus and cortex

58
Q

What is Levodopa?

A

Most effective symptomatic treatment of PD

59
Q

Problems with L-DOPA?

A
  1. dopa resistant motor symptoms (freezing episodes, speech impairment)
  2. dopa resistant non-motor signs (autonomic dysfunction, mood/cognitive impairment)
  3. drug related side effects (psychosis, motor fluctuations)
60
Q

What are other pharmacological treatments to help with PD?

A
Dopamine agonists
COMT inhibitors
MAO-B inhibitors
Anticholinergics
Amantadine
61
Q

What is the general idea of dopamine agonists?

A

To stimulate dopamine receptors directly

62
Q

Why are COMT inhibitors used and what do they do?

A

Are used in combination of L-DOPA and work by blocking the action of enzymes that break down l-dopa

63
Q

What do MAO-B inhibitors do?

A

They stop the breakdown of dopamine in the break

64
Q

Why are anticholinergics useful?

A

They are helpful for tremors and may ease dystonia associated with wearing-off or peak-dose effect of l-dopa

65
Q

What is Amantadine?

A

An antiviral drug used for people who may have developed dyskinesias following long-term use of l-dopa

66
Q

What technique has been developed to treat severe cases of PD?

A

Deep brain stimulation

67
Q

How does deep brain stimulation work?

A

Very thin wire electrodes are inserted through the skull and brain into the subthalamic nucleus or Gpi.

A cable connected to electrode is then threaded to the chest with a pacemaker which is planted under the skin

68
Q

What can patients do with the pacemaker used in DBS?

A

During times of extreme tremore, the patient can activate it and it stimulates the subthalamic nucleus immediately stopping tremors

69
Q

Limitation of DBS?

A

Bradykinesia and rigidity still often persist

70
Q

Dangers of DBS?

A

Invasive and serious risk of infection/haemorrhaging

71
Q

What is Huntington’s Disease (HD)

A

A progressive disorder combining chorea with behavioural disturbances and dementia

72
Q

How is HD transmitted?

A

Transmitted via an autosomal dominant inheritance pattern.

73
Q

What is HD caused by?

A

An abnormally large number of repeats of the nucleotide sequence CAG on chromosome 4.

74
Q

The effect of the mutated version of the gene in HD is what?

A

To disrupt the indirect pathway neurons in the striatum, particularly those of the caudate nucleus. Effectively, GABAergic cells in the striatum expressing D2 receptors (indirect pathway) degenerate over time.

75
Q

Is there a cure/effective treatment for HD?

A

No

76
Q

Why does the loss of indirect pathway neurons in the striatum cause the dyskinesias of Huntington’s disease?

A

With the loss of these neurons, the excitatory effect of the direct pathway is no longer kept in check by the inhibition of the indirect pathway.

Thus, the motor cortex gets too much excitatory input from the thalamus, disrupting its normal functioning and sending involuntary movement commands to the brainstem and spinal cord.

77
Q

What is the first manifestation of HD?

A

Chorea - may be the only one for several years

78
Q

The majority of HD patients exhibit neuropsychiatric AND cognitive disturbances symptoms such as?

A

dysphoria, agitation, irritability, apathy, and anxiety.

deficit in attention and concentration, memory retrieval, “executive” functions, and psychomotor speed.

79
Q

What can be used to treat chorea symptoms?

A

Drugs that suppress dopaminergic activity, such as antipsychotics (eg, risperidone, olanzapine), and dopamine-depleting drugs (e.g., reserpine)

80
Q

What is Hemiballismus? What does it result from?

A

Hemiballismus is usually characterised by involuntary flinging motions of the extremities. The movements are often violent and have wide amplitudes of motion.

Hemiballismus results from a unilateral lesion to the subthalamic nucleus.

Involuntary, ballistic movements result from the loss of the excitatory STN projection to the GPi