Parkinson's Disease

Question 1

Define Parkinsons Disease

Answer 1

A bradykinesia disorder
Chronic, progressive and degenerative neurological condition

Question 2

What is the underlying pathophysiology in Parkinsons Disease?

Answer 2

Damage to the substantia nigra pc (site of dopamine production)
Decreased activity at dopaminergic synapses between the dorsal striatum and the SN
D1 - activity reduced - involved in the direct pathway - reduced direct pathway activity of basal ganglia - struggle to initiate movement
D2 - reduced activity - inovled in indirect pathway - loss of inhibition of indirect pathway - more inhibition of movement
Initiation of cell death in SNpc cause inc ROS - leads to accumulation of Lewy bodies, intracellular aggregates composed primarily of misfolded alpha-synuclein, disrupt cell function and impairs neuronal communication can spread from SN lewy bodyies to cortical lewy body.
Results in bradykinesia

Question 3

What are the four key features of Parkinsonism?

Answer 3

Must have = Bradykinesia
Also 1 of:
Rest Tremor - pill rolling
Postural instability
Rigidity (lead pipe) - hypertonicity - constant resistance when moving

Question 4

What is the key feature of bradykinesia that can be elicited during clinical exam of a patient with Parkinson disease?

Answer 4

Movements get smaller and slower over time
Ask to clench and release a fist repeatedly as fast as they can.

Question 5

What are some key features of Parkinson disease?

Answer 5

Hypomimic face
Forward tilit of trunk, stooped posture
Global flexion
Rigid back
reduced arm swing during gait
Shuffling, short and stepped gait
Hand an dleg tremor

Question 6

What are some potential causes of Parkinsons disease?

Answer 6

Idiopathic
Vascular parkinsonism
Medication that blocks dopamine
Rare - dementia with lewy bodies, Parkinsons puls syndromes (PSP and MSA)

Question 7

What are some non-modifiable risk factors for Parkinsons disease?

Answer 7

Parents of children with Gauchers disease
Genetic link is rare but can be AD (PARK1/4 genes) or AR (PARK2) - norm in early onset <50yrs
Previous head injury - particularly if multiple or later in life >55yrs

Question 8

What system should be used to diangose parkinsons disease?
What is the basic idea of this system?

Answer 8

UK Brain bank criteria
Clinical diagnosis
1 - diagnosis of parkinsonism (quadrant features)
2 - rule out exclusion criteria
3 - confirm supportive criteria for PD for definitive diagnosis
Should be reviewed every 6-12 months to check diagnosis

Question 9

What are the premotor features of parkinsons disease?

Answer 9

Anosmia - loss of smell
REM sleep behaviour disorder
Constipation
Mood changes

Question 10

What are the non-motor (movement) symptoms of Parkinson disease?

Answer 10

Swallowing difficulties, speech difficulties, drooling.
Cognitive impairement, ansomia, apathy, depression/anxiety, sleep disturbances and hallucination
Orthostatis HTN, falls, excessive sweating, pain
Constipation, urinary symptoms, gastroparesis, weight changes, sexual dysfunction.

Question 11

What other differential diagnosis need to be considered alongside parkinsons disease?

Answer 11

Essential tremor
Vascular Parkinsons
Parkinsons Plus Syndromes
Dementia with Lewy bodies.

Question 12

What imaging tool can be used to assist the diagnosis of parkins disease?
How?

Answer 12

A DAT scan - Dopamine Active Transporter scanner
Injects a radioactive tracer to identify dopamine transporters (areas of synpasis)
In parkinsons disease changes from a comma shape (healthy) to a dot shape (parkinsons disease)

Question 13

What non-pharmacological care might a patient with Parkinsons disease receive?

Answer 13

Dietician (struggle with swallow)
Occupational therapist
Speech and language therapist
Specialist in PD
Palliative care
Psychiatry
Parkinsons disease nurse specialist
Physiotherapist

Question 14

What are some examples of exclusion criteria from the UK brain bank for parkinsons disease?

Answer 14

Repeated stokes with stepwise progression
Cerebellar signs
Babinski sign
Early severe dementia with disturbances of memory or language
Supranuclear gaze palsy

Question 15

What are some examples of supportive criteria for PD from the UK brain bank criteria?

Answer 15

Unilateral onset
Rest tremor
Progressive disorder
Persistent asymmetry affecting mostly one side
Excellent response to levodopa
Clinical course of more than 10 yrs.

Question 16

What is important to remember regarding Parkinsons medication?

Answer 16

Should not be withdrawn abruptly or allowed to fail suddenly aka is vomiting
RIsk of acute akinesia or neuroleptic malignant syndrome

Question 17

How do the different drug classes used to treat Parkinson disease compare?

Answer 17

Levodopa - more improvement in motor symptoms and activities or motor living, fewer specified adverse events, more motor complication
Dopamine agonists - less improvement in motor and ADL, fewer motor complications, more specified adverse events
MAO-B inhibitors - less improvement in motor symptoms and ADL, fewer motor comp and fewer specified adverse events

Question 18

What is the first line treatment for Parkinson disease?

Answer 18

Offer levosopa - early stages with impact on QOL
Dopamine agaonist, levodopa or MAO-B inhibitors - early stages no impact on QOL

Patients/family should be informed about impulse control disorders and excessive sleepiness/sudden onset of sleep with dopamine agonists, and psychotic symptoms with all medications.

Question 19

What are some adjuvant treatments for parkinsons disease?
When should they be used?

Answer 19

If patient has dyskinesia and/or motor fluctuations
Dopamine agonist MAO-A inhibitors or COMT inhibitors as adjunct to levodopa.

Question 20

What is a key side effect of dopamine agonists /therapy in Parkinson disease?

Answer 20

Impulse control disorders

Question 21

What is the key epidemiology of Parkinsons disease?

Answer 21

1-2 per 1000 people
1% over 60yrs
Peak incidence 60-70yrs
More common in males 1.5-1
Note less common than essential tremor

Question 22

What are some protective factors against Parkinson disease?

Answer 22

Smoking - current smokes<prev smoker<no
Caffeine intake
Physical activity - aerobic exercise, moderate-vigorous activity

Question 23

What are the key features of the Parkinsons tremor?

Answer 23

Resting - exacerbated by rest improves with purposeful action
Pill-rolling - often index finger and the thumb
Begins unilateral - progress to be bilateral
Intermittent becomes continuous
75% patients at onset

Question 24

What is the typical progression of rigidity and gait disorders in parkinsons disease?

Answer 24

1 - unilateral involvement - blank faces, affected arim semiflexed, termor, leans to unaffected side
2 - bilateral, early posutral changes, slow shuffling gait with decreased excursion of legs
3 - pronounced gait disturbances and moderate generalised disability, postural instability with tendency to fall
4 - sig disability, limited ambulation with assistance,
5 - complete invalidism, confined to bed or chair, cannot stand or walk even with assistance