6.1.2 Movement Disorders

Question 1

What happens in Parkinson’s disease?

Answer 1

Degeneration of dopaminergic neurones in the substantia nigra

Results in reduced levels of dopamine

Causes a loss of dopamine-driven movement pathways

Question 2

What are the symptoms and signs of parkinson’s?

Answer 2

Tremor- unclear (may be due to dysfunction of indirect pathway supressing unwated movements)

Rigidity- unclear (may be due to lack of co-ordiation between agonists and antagonists)

Akinesia/ Bradykinesia- loss of cortical excitation

Postural instability

Pill-rolling tremor

Hypophonia- bradykinesia of larynx and tongue

Expressive aphasia

Decreased facial movement- bradykinesia of facial muscles

Micrographia- (small handwriting) bradykinesia in hands

Dementia- protein aggregates

Depression- basal ganglia has roles in cognition and mood

Somtimes TRAPPED D*ck Means Femoral Hernia

Shuffling gait

Tremor
Rigidity
Akinesia/bradykinesia
Postural instability
Pill-rolling tremor
Expressive Aphasia
Dementia

Depression

Micrographia
Facial weakness
Hypokinesia

Question 3

What is Huntington’s disease?

Answer 3

Autosomal dominant disease, increased number of CAG repeats, number of repeats correlates to age of onset, more repeats lower age of onset

Loss of inhibitory projections from the corpus striatum to GPe

Question 4

What is the usual onset of Huntington’s?

Answer 4

30-50 years old

Question 5

What are the features of Huntington’s?

Answer 5

Chorea-increased motor cortex activation

Dystonia- uncomfortable contractions of agonists and antagonists leading to odd postures (ratio between antagonists and agonists is lost)

Loss of co-ordination

Cognitive decline and behaviour disturbances (basal ganglia role in higher mental function)

CDCD

Question 6

What is Hemiballismus?

Answer 6

Rare hyperkinetic disorder

Affects only half of the body

Unilateral explosive movements