Parkinson's Disease Flashcards
Briefly: what is the pathophysiology of Parkinson’s disease?
The basal ganglia are a group of structures situated in the middle of the brain. They is responsible for coordinating habitual movements such as walking or looking around, controlling voluntary movements and learning specific movement patterns. Part of the basal ganglia called the substantia nigra produces a neurotransmitter called dopamine. Dopamine is essential for the correct functioning of the basal ganglia. In Parkinson’s disease, there is a gradual but progressive fall in the production of dopamine.
Parkinson’s disease:
M>F
or
F>M
M>F
Explain the TRAP mnemonic of Parkinson’s features.
- Tremor (resting): unilateral/asymmetrical + worse on walking or distracted
- Rigidity: asymmetrical tonicity/stiffness, limbs heavy and feel weak/fatigued
- Akinesia (but really bradykinesia): slowed movement, loss of kinetic versatility
- Postural instability: falls/balance difficulties
Which feature of Parkinson’s is the most important?
BRADYKINESIA!
- you CANNOT diagnose it without this.
- lack of initiation of movement
- difficulty with repetitive movements
- can demonstrate with finger tapping
Outline the typical presentation of Parkinson’s disease
- The typical patient is an older aged man around the age of 70.
- Stooped posture
- Forward tilt
- Facial masking
- Reduced arm-swing
- Shuffled gait
- Unilateral tremor “pill-rolling” 4-6 Hz
- Cogwheel rigidity
- Others: depression/sleep disturbance/anosmia/postural instability/cognitive impairment or memory problems
Compare and contrast a Parkinson’s tremor with an essential tremor
Outline some other clinical features of PD.
- Motor abnormalities
- Non-motor abnormalities
- Cognitive impairments
- Autonomic dysfunction
- Neuropsychiatric problems
Outline non-motor symptoms of PD.
- Hyposmia (specific to alpha-synuclein)
- Psychochosis (visual hallucinations) - alpha-syn
- REM sleep behaviour disorder - alpha-syn
- Mood disorder (frontal lobe involvement) - act out dreams
- Apathy
- Constipation
- Autonomic - orthostatic hypertension/bladder/bowels/erectile dysfunction
Outline the autonomic features of PD.
Orthostatic hypertension/bladder/bowels/erectile dysfunction = bad prognosis
Non-motor symptoms + motor abnormalities =
Parkinson’s disease
Non-motor symptoms + motor abnormalities + autonomic dysfunction =
Multi-system atrophy
What modality is used to DIAGNOSE Parkinson’s disease?
DAT scan
What finding on DAT scan indicates Parkinson’s?
- Full stop
- Comma is normal
Give some differential diagnoses of Parkinson’s disease.
• Essential Tremor
• Cerebro-vascular Disease – lower body
parkinsonism
• Parkinson Plus Syndrome – PSP, MSA, CBD
• Drug Induced Parkinsonism
• Dementia – AD, VD, FTD, LBD
• Gait Disorder – NPH / CJD
What are the treatment options for Parkinson’s disease?
- Increase Dopamine Concentration
- Dopamine Agonists
- Manipulate other Transmitters
- Manage Specific Symptoms