8 Movement Disorders Flashcards Preview

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Flashcards in 8 Movement Disorders Deck (17)
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1
Q

Muscle wasting can be caused by a lower motor neuron lesion. What else can cause it?

A

Disuse- can cause muscle wasting

2
Q

Basal ganglia anatomy: fill in the missing labels

A
  • Globus pallidus: external and internal segment
  • Caudate + putamen = striatum (functionally related)
  • Putamen + globus pallidus = lentiform nucleus
3
Q

What is the role of the substantia nigra? (SNc)

A

Source of dopamine in midbrain

4
Q

How does the cerebellum connect with the rest of the CNS? (route)

A
  • Superior cerebellar peduncle- connects to midbrain
  • Middle cerebellar peduncle- connects to pons
  • Inferior cerebellar peduncle- connects to medulla
5
Q

Explain why cerebellar lesions (eg tumours) can cause hydrocephalus.

A

Cerebellum sits above 4th ventricle

6
Q

What is the normal function of the basal ganglia thought to be?

A

Reinforcing appropriate movements and removing inappropriate ones

7
Q

Explain the role of dopamine in movement with relation to the motor cortex.

A

Dopamine- kickstarts movement

  • Excites direct pathway: Stimulates D1 receptors on striatal neurones
  • Inhibits indirect pathway: activates inhibitory D2 receptors on striatal neurones
8
Q

Explain why if the substantia nigra is affected unilaterally (rare) then there will be contralateral signs.

A

Basal ganglia regulate ipsilateral motor cortex BUT decussation of corticospinal tract.

9
Q

Explain how parkinson’s disease is caused with reference to the substatia nigra and dopamine.

A

Degeneration of dopaminergic neurones in SNc

Loss of dopamine driven facilitation of movement via both pathways

10
Q

What are the signs and symptoms of Parkinson’s disease?

A
  1. Tremor
  2. Rigidity
  3. Bradykinesia
    1. Hypophonia (quiet speech- slow movement of larynx and tongue)
    2. Decreased facial movement/mask like faces
    3. Micographia (small handwriting)
    4. Festinating gait
  4. Dementia
  5. Depression
11
Q

Using the following diagram- explain why a loss of dopamine causes reduced movement in Parkinson’s disease.

A

Dopamine inhibits indirect pathway which is inhibitory so there excitatory overall

Dompanine stimulates direct pathway

So loss of dopamine means reduced excitation of the cortex causing symptoms such as bradykinesia.

12
Q

Outline the function of the cerebellum.

A
  1. Sequencing and coordination of movements
    1. Work with basal ganglia to coordinate movement from sensory inputs
13
Q

What are the signs of cerebellar disease? (6)

A

DANISH

Dysdiodokinesia

Ataxia

Nystagmus

Intention tremor

Slurred/Staccato speech

Hypotonia

14
Q

How is Huntington’s chorea caused?

A
  • Autsomal dominant
  • Progressive
  • Early onset (30-50 years)
  • Associated- loss of inhibitory projections from striatum to globus pallidus externus
  • HYPERKINETIC FEATURES
    • Increased movement- breaks taken off thalamus
15
Q

What are the features of Huntington’s chorea?

A
  • Chorea- dance like movements- increase motor cortex activation
  • Dystonia- uncomfortable contracts- agonist and antagonist contract at same time due to loss of coordination
  • Loss of co-ordination
  • Cognitive decline and behavioural disturbances
16
Q

What is Hemiballismus?

A

Rare disorder

Damage to subthalamic nucleus which normally inhibits thalamus via Globus Pallidus internus

(May be due to sub-cortical stroke (lacunar infarct))

Causes:

UNILATERAL EXPLOSIVE BALLISTIC MOVEMENTS

17
Q

Damage to cerebellum- are they ipsilateral or contralateral signs?

A

Ipsilateral input from spinal cord

(Contralateral input from sensory cortices)

Contralateral output to sensory cortices

Ipsilateral signs as decussation of corticospinal pathway