Parkinson's Disease

Question 1

What is the aetiology of PD?

Answer 1

Unknown

Question 2

Outline the pathophysiology of PD

Answer 2

Chronic, progressive movement disorder

Triad of bradykinesia, tremor and rigidity

Degeneration of substantia nigra = deficiency of dopamine

Question 3

What are the symptoms and signs of PD?

Answer 3

Tremor = resting

Bradykinesia - shuffling gait, falls

Hypertonia = rigidity (lead-pipe, sometimes cog-wheel)

Hypophonia

Reduced facial expression

Micrographia

Dementia (can see lewy-body before PD)

Depression

Question 4

How should PD be investigated?

Answer 4

Hx of symptoms - timeline, lifestyle, previous head injury

Neurological exam - gait, handwriting

Bloods = Hb, TFT (hypo), U+Es, LFTs, B12/folate

MSU = rule out infection

Imaging = CT, MRI, PET

DAT scan

Carbidopa-levodopa test - do symptoms improve

Question 5

How is PD managed?

Answer 5

Lifestyle = aerobic exercise

Carbidopa-levodopa
- SE = nausea, orthostatic hypotension

MAO B inhibitors = help prevent breakdown of dopamine by inhibiting monoamine oxidase B

COMT inhibitors (have to use with levodopa) = entacapone, tolcapone

DBS - deep brain stimulation = electrodes in the brain, generator in the chest

Question 6

What are the possible complications of PD?

Answer 6

Dementia

Depression

Swallowing difficulties

Question 7

How is PD clinically diagnosed?

Answer 7

Clinical diagnosis

Bradykinesia + at least ONE of the following

• Muscular rigidity = typically lead pipe (can be cog wheel - when tremor present)
• 4 – 6 Hz rest tremor = pill rolling
• Postural instability not caused by primary visual, vestibular, cerebellar, or proprioceptive ◦ dysfunction

Question 8

What are the features of supportive criteria for a PD Dx?

Answer 8

Unilateral

Rest tremor present

Progressive

Persistent asymmetry

Excellent response (70 – 100%) to LD

Severe LD-induced chorea

LD response for ≥5 years

Clinical course of ≥10 years

Question 9

What are the non-motor symptoms of PD?

Answer 9

Neuropsychiatric dysfunction
◦ Mood Disorders
◦ Apathy + anhedonia
◦ Frontal executive dysfunction
◦ Dementia + Psychosis

Sleep Disorders
◦ Sleep fragmentation + insomnia 
◦ RBD 
◦ PLMS / RLS
◦ Excessive daytime somnolence

Autonomic dysfunction
◦ Orthostatic hypotension
◦ Urogenital dysfunction
◦ Constipation

Sensory symptoms + pain
◦ Olfactory dysfunction
◦ Abnormal sensations
◦ Pain

Question 10

What is a DAT scan?

Answer 10

Focus on the activity of the dopamine transporter

Loflupane I123 injection

Used with single-photon emission computed tomography (SPECT)

Detecting dopamine transporters (DaT) in suspected parkinsonian syndromes

Question 11

What is deep brain stimulation?

Answer 11

Deep brain stimulation involves the implantation of a wire, with 4 electrodes at its tip, into one of 3 target sites in the brain:

• the thalamus (this procedure is known as thalamic stimulation)
• the globus pallidus (this procedure is pallidal stimulation)
• the subthalamic nucleus (this procedure is subthalamic stimulation)

Question 12

Outline Hoehn and Yahr scale

Answer 12

• STAGE 1 = Unilateral disease
• STAGE 2 = Bilateral disease, without impairment of balance
• STAGE 3 = Mild to moderate bilateral disease; some postural instability; physically independent
• STAGE 4 = Severe disability; still able to walk or stand unassisted
• STAGE 5 = Wheelchair bound or bedridden unless aided

Question 13

Outline UPDRS

Answer 13

Unified Parkinsons Disease Rating Scale

42 question assessment
• 1 = mentation, behaviour, mood
• 2 = ADL
• 3 = motor sections
• 4 = modified Hoehn and Yahr scale
• 5 = Schwab and england ADL scale