Parkinson's disease is a progressive neurodegenerative disorder that impacts the central nervous system.
Its characteristic motor symptoms arise from the depletion of dopamine, a vital neurotransmitter.
This depletion is linked to the death of a specific group of cells located deep within the brain, in an area known as the substantia nigra.
While the precise reason for this cell death remains unknown, its impact on dopamine levels is central to the disease.
The hallmark motor deficits of Parkinson's include slowed physical movement (bradykinesia), muscle rigidity, involuntary resting tremors, postural instability, and gait disturbances.
These symptoms stem from abnormal functioning of the basal ganglia, a collection of deep brain structures responsible for controlling the automatic and precise aspects of movement without conscious effort.
Normally, neurons in the basal ganglia release dopamine, which is crucial for motor control.
In Parkinson's disease, either the release of dopamine or the function of its receptors is compromised.