Week 9 : PD

Question 1

What is parkinsonism

Answer 1

clinical syndrome characterised by a disorder of movement consisting of tremor, rigidity, elements of bradykinesia, hypokinesia, akinesia and postural abnormalities

Question 2

What is Parkinson’s disease

Answer 2

clinical syndrome of Parkinsonism associated with a distinctive pathology

Question 3

Aetiology of parkinson’s

Answer 3

typically a slowly progressive degenerative disease
primarily related to a lack of dopamine
most common disease affecting the basal ganglia

Question 4

epidemiology of parkinson’s disease

Answer 4

2nd most common neurological disease in Australia (following dementia)
M 1.5: 1 F

Question 5

pathophysiology of parkinson’s disease

Answer 5

reduction in dopamine
- disturbance of the central dopaminergic pathway from the substantia nigra to the striatum

deep pigmentaton and neuronal loss in the substantia nigra

presence of lewy bodies with consequent changes to neural conduction in the nigrostriatal pathway
- BG, brainstem, spinal cord and cortex

Question 6

pathophysiology of parkinson’s disease #2

Answer 6

idiopathic
a family hx is the strongest risk factor for the development of the disease

genetic mutations

rural residence is a significant risk factor for PD
positive association between PD and pesticides
negative association with cigarette smoking

genetic and environmental factors are now thought to interact and increase the risk of developing PD

Question 7

diagnosis of PD

Answer 7

35% Misdiagnosed /mismanaged
primarily clinical diagnosis
- presence of bradykinesia and progressive reduction of speed amplitude of repetitive movements
- rigidity, resting tremor and/or postural instability
- absence of red flags

Question 8

what are the four clinical subtypes of PD

Answer 8

earlier disease onset (<55 years)
tremor dominant
postural imbalances and gait disorder (PIGD)

Question 9

disease progression, prognostic factors and mortality

Answer 9

high variability in impairments of functions, activity limitations and participation restriction
postural and axial symptoms evolve more rapidly than other motor features are appear to be the index of disease progression.

Question 10

Hoehn and Yahr staging scale is used clinically to stage PD progression

Answer 10

it’s not linear
doesn’t include non-motor functioning

slide 11

Question 11

MDT involved with PD

Answer 11

as many as 19 health professionals and institutions may be involved in one patient’s care

Question 12

medication for PD

Answer 12

first choice in care
aims to correct the neurotransmitter imbalance within the basal ganglia circuity
PD frequently necessities multiple doses of multiple medications
current pharmacological management largely based on dopamine precursor levodopa and dopamine agonists

Question 13

levodopa

Answer 13

gold standard : offers best symptomatic relief of rigidity, bradykinesia and tremor

Question 14

dopamine agonists

Answer 14

often prescribed to alleviate other diabling complications such as restless legs, sleep fragmentation, early morning akinesia

Question 15

Neurosurgery

Answer 15

thalamotomy

deep brain stimulator

Question 16

thalamotomy

Answer 16

lesioning procedure, not widely used now

Question 17

deep brain stimulator

Answer 17

high frequency electro-stimulation through permanent implanted electrodes in the brain
-battery implanted in chest wall below clavicle and connects to DBS by subcutaneous wire
Mimics lesioning procedure without destroying brain tissue; can be performed bilaterally; stimualation can be adjusted postoperatively; reversible

subthalamic nucleus (bradykinesia and rigidity) 
Globus pallidus (dyskinesia)

Question 18

Transplant surgery

Answer 18

foetal nigral cells (dopamine- producing) are introduced into appropriate areas of the brain to replace degenerating substantia nigra
they may restore dopamine production by results inconclusive at this stage
experimental only

Question 19

clinical manifestations of PD: Resting tremor

Answer 19

Temor: approximately rhythmic, involuntary and roughly sinusoidal movement of a body part
• Resting tremor is a cardinal sign of PD
– Often the first sign of PD
– Typically unilaterally
– More prominent distally
– Commonly observed in: hands, feet, lips, chin, jaw
– Usually supressed by voluntary activity, sleep and complete relaxation
– Results from oscillations in a hyperactive long loop reflex pathway triggered at the thalamic level and influenced by peripheral afferents

Question 20

Clinical manifestations of PD : bradykinesia

Answer 20

Bradykinesia: umbrella term to describe slowness of or absence of movement
– Hypokinesia: reduced amplitude of movement
– Akinesia: reduced spontaneous movement (e.g. facial expression, arm swing during gait), slowness to initiate movement and freezing while moving
• Most disabling manifestation of PD
• Affects performance of all motor actions and associated postural adjustments and articulation and phonationMechanisms poorly understood
– Failure of basal ganglia to reinforce the cortical mechanisms that prepare and execute motor commands
– Cueing or directing attention towards the size and/or speed of the movement can normalise many movements
– Compensation not limitless

Question 21

clinical manifestations : freezing

Answer 21

-Freezing: difficulty starting or continuing rhythmic repetitive movements (e.g. gait, handwriting, speech)
• Distinct clinical sign of PD
• Freezing of gait (FOG): episodic gait disturbance, typically experienced when walking through an enclosed space or turning
– Festination (progressive shortening of stride length and increasing cadence) often occurs prior to freezing
– Feet appear to stick to the floor while momentum carries the centre of body mass forward
– Occurs more frequently in cluttered environments, stressful circumstances or when patient is distracted

Question 22

clinical manifestations : Postural instability

Answer 22

postural instability: inability to make appropriate postur