Parkinsons disease Patho-physiology

Question 1

What is PD

Answer 1

Parkinson’s disease is a progressive neurological disorder caused by the
degeneration of neurons in the substantia nigra, a part of the basal ganglia. This leads to a significant reduction (around 80%) in dopamine levels, a neurotransmitter essential for controlling movement. The lack of dopamine disrupts the balance between the direct and indirect pathways in the basal ganglia, which are critical for initiating and controlling voluntary movements.

Question 2

Substantia Nigra (in the midbrain)
- Main pathology in PD
- Relevant symptoms

Answer 2

*Main pathology in PD — loss of dopaminergic neurons.
*Relevant symptoms in Mr. Williams:
- Shuffling/festinating gait
- Bradykinesia (slow, hesitant movement)
- Resting tremor (right hand)
- Minimal arm swing
- Difficulty with fine motor tasks (cutlery)

Question 3

Striatum (In the basal ganglia)
- Main pathology in PD
- Relevant symptoms

Answer 3

*Main pathology in PD - Dopamine from substantia nigra is normally delivered here.
*Relevant symptoms:
- Freezing when turning or going through doorways
- Hesitant initiation of movement
- Difficulty navigating obstacles

Question 4

Subthalamic Nucleus (located at the junction of the midbrain and diencephalon)
- Main pathology in PD
- Relevant symptoms

Answer 4

*Main pathology in PD - Involved in motor circuit dysfunction due to dopamine loss.
*Relevant symptoms:
- Postural instability (balance issues)
- Rigidity (likely contributing to kyphotic posture)
- Falls

Question 5

Brainstem Nuclei (especially those involved in swallowing and autonomic control)
- Main pathology in PD
- Relevant symptoms

Answer 5

*Main pathology in PD - These are affected in later stages of PD.
*Relevant symptoms:
- Coughing/wheezing after eating (suggests dysphagia)
- Possible early signs of aspiration

Question 6

Frontal Lobe
- Main pathology in PD
- Relevant symptoms

Answer 6

*Main pathology in PD - Dopaminergic projections to this areas regulate mood and motivation.
*Relevant symptoms:
- Loss of motivation
- Feelings of loneliness and apathy
- Quiet, hesitant speech (also partly motor-related)

Question 7

Primary Motor Cortex

Answer 7

*Main pathology in PD - Poor input from basal ganglia affects cortical motor planning.
*Relevant symptoms:
- Impaired sit-to-stand transitions
- Slowness in movement execution

Question 8

Types of MS

Answer 8

> Relapsing & Remitting (RRMS):
* Relapse: Symptoms worsen (due to inflammation) over 1-2 years, causing fatigue,
functional decline, and a significant drop in ability.
* Remission: Recovery phase, where physical abilities improve, and symptoms may
partially or fully recover.
Secondary Progressive (SPMS):
* 70% of people with RRMS will develop SPMS after 5-7 years.
* Characterised by increasing severity and between them.
* Disease progression is more continuous over time.
frequency of relapses with less recovery
Primary Progressive (PPMS):
* Continuous, gradual decline without distinct relapses.
* Minimal to no remissions, leading to steady progression of symptoms.