Huntington’s and Parkinson’s Disease Flashcards
What causes Huntington’s disease?
A mutation in the huntingtin gene that produces a sticky, toxic protein.
What is the first brain region to degenerate in Huntington’s disease?
The striatum.
What are early motor symptoms of Huntington’s disease?
Jerky, involuntary movements (chorea) in arms, fingers, neck, and tongue.
What is a surgical approach used to treat Huntington’s?
Gene therapy using viral vectors to target and suppress the mutant gene in the striatum.
What risk is associated with bilateral brain injections for Huntington’s?
Microglial activation and inflammation visible on MRI.
What often causes death in Huntington’s patients?
Continuous muscle contraction leading to choking or respiratory failure.
What is Parkinson’s disease caused by?
Death of dopamine-producing neurons in the substantia nigra.
What early symptom is often overlooked in Parkinson’s?
Loss of smell (anosmia).
What brainstem disorder during sleep is often seen early in Parkinson’s?
REM sleep disorder — acting out violent dreams.
What are the classic motor symptoms of Parkinson’s?
Bradykinesia (slowness), akinesia (lack of movement), resting tremor, shuffling gait.
What frequency is the typical resting tremor in Parkinson’s?
~5 Hz.
What structural brain change is seen in Parkinson’s disease?
Accumulation of alpha-synuclein proteins into Lewy bodies.
What is alpha-synuclein normally responsible for?
Helping release dopamine at terminal boutons.
What happens when alpha-synuclein misfolds?
It clumps into Lewy bodies, eventually killing dopamine neurons.
At what percentage of substantia nigra neuron loss do Parkinson’s symptoms appear?
Around 70% loss (30% remaining function).
What role do microglia play in Parkinson’s progression?
Chronic inflammation and cytokine release, often triggered by environmental damage.
What are known risk factors for Parkinson’s?
Age, genetics (e.g., parkin gene), exposure to pesticides/herbicides, heavy metals, head trauma.
What synthetic compound induces Parkinson’s symptoms in animal models?
Rotenone.
What substances are linked to reduced Parkinson’s risk?
Caffeine (2 cups/day = 15% ↓ risk), and nicotine (up to 50% ↓ risk).
What surgery did Michael J. Fox undergo to manage symptoms?
Thalamotomy to reduce hand tremor.
