Parkinson's

Question 1

What is the definition of Parkinson’s disease

Answer 1

A progressive neurodegenerative disorder affecting dopaminergic neurones in the substantia nigra

Question 2

What is the main triad of symptoms in Parkinson’s

Answer 2

Pill rolling tremor, rigidity and bradykinesia

Question 3

What substance has been shown to cause severe Parkinsonism

Answer 3

MPTP

Question 4

What is a pathological hallmark of Parkinson’s

Answer 4

Lewy bodies in the substantia nigra - composed of alpha-synuclein

Question 5

What is the frequency of the resting tremor

Answer 5

4-6 Hz

Question 6

What are the central side effects of levodopa

Answer 6

Abnormal involuntary movements (dyskinesias)
Confusion
Visual hallucinations (patients are aware that these are hallucinations unlike psychosis)

Question 7

What are the systemic side effects of levodopa

Answer 7

Nausea and vomiting
Anorexia
Postural hypotension
Fluctuating response (on/off syndrome)

Question 8

What are the causes of Parkinsonism

Answer 8

Neurodegenerative disorders - idiopathic Parkinson’s disease, Parkinson’s plus syndromes
Drug induced: Antipsychotics, lithium, metoclopramide
Arteriosclerosis: atherosclerotic pseudoparkinsonism (legs only, less tremor)
Toxins: CO poisoning, MPTP
Congenital: Wilson’s disease
Trauma: Dementia pugilistica

Question 9

How do you treat drug-induced Parkinsonism

Answer 9

Add anti-muscarinic - procyclidine

Question 10

What pathways are affected by Parkinson’s

Answer 10

Extrapyramidal pathways

Question 11

What percentage of nigrostriatal dopaminergic neurones have to be lost for symptoms to appear

Answer 11

60-80%

Question 12

Would you expect to see the signs of Parkinson’s bilaterally

Answer 12

The physical signs are asymmetrical

Question 13

What is the sensation of a patient like in Parkinson’s

Answer 13

It is normal and unaffected

Question 14

What is the power of a patient in Parkinson’s

Answer 14

It is normal and unaffected

Question 15

What are the reflexes of a patient like in Parkinson’s

Answer 15

Normal

Question 16

Which direction are the plantar responses in Parkinson’s

Answer 16

Downgoing

Question 17

On examining the eyes of a Parkinson’s patient, what would you expect to find

Answer 17

Mild impairment of upgaze
Eyelids may be tremulous
Glabellar tap sign is elicited on repeated tapping (a primitive reflex)

Question 18

What features of multiple system atrophy differentiate it from Parkinson’s

Answer 18

Autonomic failure
Cerebellar dysfunction
Pyramidal features

In combination with extrapyramidal features

Question 19

On eye examination, how would you differentiate Parkinson’s from progressive supranuclear palsy

Answer 19

Failure of downgaze in progressive supranuclear palsy

Failure of voluntary gaze in progressive supranuclear palsy begins with loss of downgaze, then upgaze, then horizontal gaze

It is also associated with extrapyramidal dysfunction and dementia

Question 20

How can you partially alleviate side effects of levodopa (on/off syndrome and dyskinesias)

Answer 20

Frequent small doses of medications
Controlled release preparations
Combine levodopa use with - MAO-B inhibitor, COMT inhibitor or direct dopamine agonist to reduce central breakdown of dopamine

Question 21

Name a MAO-B inhibitor used in Parkinson’s

Answer 21

Selegiline

Question 22

Name a COMT inhibitor used in Parkinson’s

Answer 22

Entacapone

Question 23

Name some dopamine agonists used in Parkinson’s

Answer 23

Bromocriptine
Cabergoline

These drugs can also be used in early disease, potentially delaying the need for L-DOPA

Reduced use now due to side effects (valvular fibrosis defects)- non-ergolide versions preferred e.g. ropinerole

Question 24

What are the treatments used in PD?

Answer 24

Dopaminergic drugs: L-dopa: Motor symptoms
Dopamine agonists
MAO-B inhibitors

Anticholinergics: Reduce tremor
COMT inhibitors: Reduces GI breakdown of L-dopa
Glutamate antagonists: Amantadine
Apomorphine: reduce off periods

Question 25

What are the Parkinsons-plus syndromes?

Answer 25

Multi-system atrophy: Autonomic and cerebellar Progressive supranuclear palsy: Eye movements Corticobasilar degeneration: Unilateral parkinsonism with aphasia Lewy Body Dementia: Visual hallucinations, fluctuating cognition

Question 26

What disability scale is used to assess disability in PD?

Answer 26

UPDRS- Unified Parkinson's Disease Rating Scale

Question 27

How common are sleeping disorders in patients with Parkinson's?

Answer 27

Affects around 90%. Symptoms include: inability to turn, restless legs, insomnia, frequent waking. Violent enactment of dreams (muscle atonia in REM sleep)

Question 28

What symptoms of autonomic dysfunction might patients complain of?

Answer 28

``` Postural hypotension Constipation Hypersalivation and dribbling Urgency, frequency, nocturia ED Hyperhidrosis ```

Question 29

What mnemonic can be used to remember the side effects of L-DOPA?

Answer 29

``` DOPAMINE: Dyskinesia On-off phenomena Psychosis ABP decrease (autonomic postural hypotension?) Mouth dryness Insomnia N/V Excessive daytime sleepiness ```

Question 30

What is Parkinsonism?

Answer 30

A movement disorder characterised by bradykinesia and at least one of rest tremor, rigidity and postural instability

Question 31

How common is dementia in PD?

Answer 31

15-30% of patients, usually in late disease. Earlier cognitive symptoms are suggestive of LBD

Question 32

What signs are suggestive of a Parkinsons-Plus syndrome?

Answer 32

Additional clinical features: pyramidal, cerebellar or ocular signs. Cognitive signs, early falls or postural instability. Poor response to levodopa. Symmetrical signs early in disease (PD is asymmetrical)

Question 33

How do you diagnose PD?

Answer 33

Clinical diagnosis Imaging- exclude other pathologies.CT/MRI to exclude vascular cause. Dopamine transported SPECT scan (uses 18-fluorodopa): loss of nigrostriatal dopamine transporter binding, cant distinguish PD and PSPs.

Question 34

What are the surgical options for PD management?

Answer 34

Eligible patients require a firm PD diagnosis and have responded well to dopaminergic therapy, be cognitively intact and predominantly motor-related disability: Thalmotomy/subthalmotomy/pallidotomy: Destruction of parts of the brain overactive in PD. Deep brain stimulation: Reversible. Transplantation of dopamine producing cells: Currently in trials worldwide, ethical issues.