Parkinson's Disease
Parkinson's disease is a condition in which parts of the brain become progressively damaged over many years (NHS, 2022). It i s part of a group of
conditions known as Parkinsonism. These are a groups of disorders that affect the Basal Ganglia of the brain. The most common type of
Parkinsonism diseases is known as Parkinson's Disease/ Idiopathic Parkinson's Disease (no apparent cause).
It's thought around 1 in 500 people are affected by Parkinson's disease. Most people with Parkinson's start to develop sympto ms when they're over
50, although around 1 in 20 people with the condition first experience symptoms when they're under 40. Men are slightly more likely to get
Parkinson's disease than women (NHS, 2022).
Parkinson's Disease is a chronic progressive disease that affects the nerves in the
substantia nigra which is located in the basal ganglia and affects the
neurotransmitter Dopamine. Dopamine is important for regulating motor control.
Idiopathic Parkinson's Disease accounts for approximately 70% of all cases with the
underlying cause remaining unknown with some experts believing that it may be a
combination of environmental and genetic factors.
There has been some research to identify some genetic factors that lead to
Parkinson's. This is due to protein misfolding, aggregation and inflammatory and
immunological responses leading to cell death.
Genetic Causes of Parkinson's Disease:
• Alpha synuclein, LRRK2
• Parkin, Pink1, DJ1, FBox7
• GBA
• Numerous additional loci (SNCA, tau, COMT)
Pathophysiology of Parkinson's:
• Dopamine is a excitatory and inhibitory neurotransmitter and is
largely responsible for movement.
• The Basal Ganglia area of the brain also plays a key role in
movement initiation and in releasing movement sequences.
• With Parkinson's Disease, there is a loss of dopaminergic neurons
(the neurons that transmit dopamine).
• There is a build-up of lewy body production (leading to abnormal
a-synuclein deposits).
• Genetic misfolding and aggregation lead to a mitochondrial and
lysosomal dysfunctions which result in this a-synuclein build up.
• This build up then leads to a cytoskeletal dysfunction within the
cell further leading to an over/under production of dopamine.
Key Points:
1. The Basal Ganglia is altered
2. As dopamine is depleted→ some pathways are insufficiently
activated → slows movement and affects timing.
3. As dopamine is depleted→ some pathways are
overactivated → more acetylcholine is available→ causes an
increase in muscle activity
Clinical Presentations of Parkinson's Disease:
1. Preclinical phase: imaging biomarkers
2. Prodromal Parkinson’s: No biomarkers,
however symptom onset
3. Symptomatic Phase:
• Bradykinesia/Akinesia
• Rigidity
• Tremor
• Postural Abnormality
• Cognitive changes
Neurological Conditions Page 1
Parkinson's disease is a condition in which parts of the brain become progressively damaged over many years (NHS, 2022). It i s part of a group of
conditions known as Parkinsonism. These are a groups of disorders that affect the Basal Ganglia of the brain. The most common type of
Parkinsonism diseases is known as Parkinson's Disease/ Idiopathic Parkinson's Disease (no apparent cause).
It's thought around 1 in 500 people are affected by Parkinson's disease. Most people with Parkinson's start to develop sympto ms when they're over
50, although around 1 in 20 people with the condition first experience symptoms when they're under 40. Men are slightly more likely to get
Parkinson's disease than women (NHS, 2022).
Parkinson's Disease is a chronic progressive disease that affects the nerves in the
substantia nigra which is located in the basal ganglia and affects the
neurotransmitter Dopamine. Dopamine is important for regulating motor control.
Idiopathic Parkinson's Disease accounts for approximately 70% of all cases with the
underlying cause remaining unknown with some experts believing that it may be a
combination of environmental and genetic factors.
There has been some research to identify some genetic factors that lead to
Parkinson's. This is due to protein misfolding, aggregation and inflammatory and
immunological responses leading to cell death.
Genetic Causes of Parkinson's Disease:
• Alpha synuclein, LRRK2
• Parkin, Pink1, DJ1, FBox7
• GBA
• Numerous additional loci (SNCA, tau, COMT)
Pathophysiology of Parkinson's:
• Dopamine is a excitatory and inhibitory neurotransmitter and is
largely responsible for movement.
• The Basal Ganglia area of the brain also plays a key role in
movement initiation and in releasing movement sequences.
• With Parkinson's Disease, there is a loss of dopaminergic neurons
(the neurons that transmit dopamine).
• There is a build-up of lewy body production (leading to abnormal
a-synuclein deposits).
• Genetic misfolding and aggregation lead to a mitochondrial and
lysosomal dysfunctions which result in this a-synuclein build up.
• This build up then leads to a cytoskeletal dysfunction within the
cell further leading to an over/under production of dopamine.
Key Points:
1. The Basal Ganglia is altered
2. As dopamine is depleted→ some pathways are insufficiently
activated → slows movement and affects timing.
3. As dopamine is depleted→ some pathways are
overactivated → more acetylcholine is available→ causes an
increase in muscle activity
Clinical Presentations of Parkinson's Disease:
1. Preclinical phase: imaging biomarkers
2. Prodromal Parkinson’s: No biomarkers,
however symptom onset
3. Symptomatic Phase:
• Bradykinesia/Akinesia
• Rigidity
• Tremor
• Postural Abnormality
• Cognitive changes
Neurological Conditions Page 1
