Parkinson's and Movement Disorders

Question 1

What is the most common movement disorder?

Answer 1

Parkinson’s disease

Question 2

What is the age distribution of Parkinson’s disease?

Answer 2

Incidence rapidly increases over 60

Mean age of diagnosis = 70

Question 3

What are the cardinal features of Parkinson’s disease?

Answer 3

Tremor
Bradykinesia
Rigidity
Postural instability

Question 4

What is dyskinesia?

Answer 4

Reversible levodopa-induced motor complication
Abnormal involuntary movements
- Choreic
- Dystonic
- Ballistic
- Myotonic

Question 5

How is dyskinesia treated?

Answer 5

Adjusting levodopa dose

Question 6

What is dystonia?

Answer 6

Involuntary muscle contraction involving abnormal movements and postures
More sustained abnormal posture than dyskinesia
Can be
- Under-treated Parkinson’s disease motor symptom
- Complication of levodopa treatment

Question 7

What is the mechanism of action of levodopa?

Answer 7

Replacement of dopamine via prodrug

Question 8

On which symptoms of Parkinson’s disease is levodopa most effective?

Answer 8

Hypokinetic motor symptoms
Also works on
- Tremor
- Rigidity

Question 9

With which other drug is levodopa always combined, and why?

Answer 9

Combined with peripheral decarboxylase inhibitor to minimise peripheral conversion to dopamine

Question 10

What are the gastrointestinal adverse effects of levodopa?

Answer 10

Nausea

Abdominal cramping diarrhoea

Question 11

What are the neurological adverse effects of levodopa?

Answer 11

Somnolence
Dizziness
Headache

Question 12

What are the psychiatric adverse effects of levodopa?

Answer 12

Confusion
Hallucinations
Delusions
Agitation
Psychosis

Question 13

What are the cardiovascular adverse effects of levodopa?

Answer 13

Orthostatic hypotension

Question 14

What are motor fluctuation, in terms of levodopa-related complications?

Answer 14

Wearing-off = end-of-dose effect
On-off syndrome = episodes of unpredictable “off” alternating with “on” +/- dyskinesia
Failure to turn “on” = due to excessively prolonged/severe “off” period
Acute akinesia = akinetic state last for days and not responding to antiparkinson medications = sudden exacerbation

Question 15

What are other medications used in Parkinson’s disease?

Answer 15

COMT inhibitors
MAO inhibitors
Dopamine agonists
Anticholinergics
Amantadine

Question 16

What are non-motor features of Parkinson’s disease?

Answer 16

Orthostatic hypotension
Urine frequency
Constipation

Question 17

What are the psychological aspects of Parkinson’s disease?

Answer 17

Depression
Anxiety
Apathy and abulia
Sleep disturbance

Question 18

What are the differential diagnoses of a tremor?

Answer 18

Parkinsonian
Essential
Enhanced physiological
Drug induced
Cerebellar
Dystonia

Question 19

What are the characteristics of an essential tremor?

Answer 19

Gradual onset
Bilateral
Resting tremor worse than kinetic
Ethanol improves tremor
FHx

Question 20

What are the characteristics of a Parkinsonian tremor?

Answer 20

Asymmetrical
Onset latency = tremor starts later than posture
Pronation-supination tremor
Coarse tremor

Question 21

What sort of balance is affected in Parkinson’s disease?

Answer 21

Medio-lateral balance more than antero-posterior

Question 22

Why is an MRI done in Parkinson’s disease if it is a clinical diagnosis?

Answer 22

To look for structural problems

• Normal pressure hydrocephalus
• Subdural haematoma
• Stroke in basal ganglia

Question 23

What things does bradykinesia cause in Parkinson’s disease?

Answer 23

Hypo-expressions
Slower blinking >  dry eyes
Eating slower
Drooling
Gastroparesis > full early on
Constipation

Question 24

What is akinetic rigid syndrome in Parkinson’s disease?

Answer 24

Don’t have tremor, but

• Stiff
• Rigid
• More falls

Question 25

What proportion of Parkinson's patients have akinetic rigid syndrome, and what proportion are tremor dominant?

Answer 25

Akinetic rigid syndrome = 30% | Tremor dominant = 70%

Question 26

What is the prognosis for patients with akinetic rigid syndrome, compared with those who are tremor dominant?

Answer 26

Faster progression Worse response to medication Poorer outcome

Question 27

What is the abnormal protein in Parkinson's disease?

Answer 27

Alpha synuclein

Question 28

Which part of the brain is disproportionately affected in Parkinson's disease?

Answer 28

Substantia nigra

Question 29

What are the pre-motor features of Parkinson's disease?

Answer 29

``` Anosmia Mood disturbance - apathy Impulsive behaviours Sleep disturbance - Insomnia - Nightmares - Myoclonic jerks - Cramps - Rigidity - Vivid dreams - REM behaviour disorder ```

Question 30

What happens when Parkinson's disease progresses to the cortex?

Answer 30

Parkinson's disease dementia

Question 31

How can bradykinesia be tested on examination?

Answer 31

``` Tapping fingers Opening and closing hands Toe tapping Heel tapping Have to make movements big and quick to demonstrate frequency and amplitude ```

Question 32

Compare rigidity and spasticity

Answer 32

``` Rigidity = extrapyramidal Spasticity = pyramidal ```

Question 33

Compare lead pipe rigidity to clasped knife rigidity

Answer 33

Lead pipe = resistance stays the same | Clasped knife = resistance decreases

Question 34

What produces cogwheeling in Parkinson's disease?

Answer 34

Tremor superimposed over rigidity

Question 35

How is postural instability tested for on examination?

Answer 35

Retropulsion test > will fall like leaf/take >6 steps

Question 36

What are the features of gait in Parkinson's disease?

Answer 36

``` Difficulty standing up Slight flexion of knee, anterior flexion of trunk, anterior flexion of neck Gait initiation problem = difficulty taking 1st step Shortened stride length Reduced step height Reduced arm swing Narrow-based gait Festination Reappearance of tremor ```

Question 37

How is mediolateral balance tested on examination?

Answer 37

Heel-to-toe walking | Stand on 1 leg while other leg's knee held above waist height

Question 38

What drugs can cause a drug-induced tremor?

Answer 38

``` Thyroxine Caffeine Anti-psychotics, especially typical Dopamine blocking agents; eg: metoclopramide Beta agonists; eg: salbutamol ```