Parkinson's Disease Flashcards
Overview with specific relevance to SLT
What is Parkinson’s?
A progressive neurodegenerative disorder affecting the brain
What are the main characteristics of Parkinson’s
Tremor, Rigidity, Slowness of Movement
What causes Parkinson’s?
Most cases are sporadic but there may be a genetic component. A small % is genetic - this cases have earlier onset and progress more rapidly
What the pathology of Parkinson’s? (i.e. what is damaged)
Damage to extrapyramidal system.
Involved pathological changes affecting dopaminingic neurons in the substantia nigra in the midbrain
What happens in the earlier stages of Parkinson’s? (i.e. what is damaged in the earlier stages)
Dopaminingic neurons are damaged - therefore they have less ability to manufacture and store dopamine.
The neurons accumulate Lewy bodies
What happens in the later stages of Parkinson’s? (i.e. what is damaged in the later stages)
Brain shows depigmentation, loss of neurons and gliosis (scarring) in the substantia nigra
Besides motor control, what else is the nigrastatal system involved in?
Cognitive and executive function, and reward (addictive behaviours can emerge)
What might be happening at a cellular level in Parkinson’s?
abnormal protein processing, oxidative stress, mitrochondrial dysfunction, excitotoxicity, inflammation, immune responses (don’t know what is primary event)
List two secondary causes of Parkinson’s
Drug-Induced Parkinson’s
Traumatic Parkinson’s
Describe the tremor in PD
slow pill rolling tremor, present only at rest
usually begins unilaterally in one hand
often noticed first by family/spouse
can involve the leg, lips, jaw or tongue
worse with anxiety, stress or emotional excitement
Describe Bradykinesia
generalised slowness of movement and major factor of disability associated with PD
Patients find it hard to describe
in arms it starts with reduced manual dexterity of fingers
Reduced arm swinging when walking
Legs dragging (shorter shuffling steps)
Describe Rigidity
increased tone -> resistance to passive movement
‘Cog wheel’ rigidity = increased tone with superimposed tremor
Features of More Advanced PD?
Postural Instability
Freezing
What are the communication difficulties in PD?
Hypokinetic Dysarthria (difficulty fractioning complex movements, articulation is unclear) Hypophonia Hypomimia Pallilalia Micrographia
Are there swallowing difficulties in PD?
Yes in the advanced stages of PD. Difficulty initiation voluntary movements is a contributed factor
What are the non-motor features of advanced PD
Anosmia - reduced smell
Autonomic dysfunction (e.g. constipation, bladder and sexual dysfunction)
Cognitive Impairments (decision making, abulia)
Fatigue
Disordered sleep
Neuropsychiatric (depression, anxiety, psychosis and hallucinations)
How do you diagnose PD
Neurological exam and history taking
Essential criteria: bradykinesia and either rigidity or tremor
PLUS: 2 supportive criteria - rest tremor, response to dopaminergic meds, presence of leva-dopa induced dyskinesia, no red flags for other diagnoses
What does L-dopa do?
Chemical building block that is converted to dopamine in the brain. Effective for many motor symptoms, but less effective as the disease progresses and there are significant side effects
What does a dopamine agonist do?
Mimics the action of dopamine by binding to dopamine receptions and acting like dopamine.
Less effective but less side effects
What does MAO-BI do?
It blocks dopamine breakdown - preserving existing dopamine.
Less effective than L-dopa but less side effects
used as an adjunct to boost/prolong L-dopa
What does COMT inhibitors?
Blocks L-dopa breakdown.
Less effective
How would you treat someone with Minimal PD?
might not treat, or might use MAO-BI (to boost dopamine)
How would you treat someone with Mild PD?
First - dopamine agonist
Hoe would you treat someone with Mod/severe PD?
Generally, will treat with L-dopa
