What is Parkinson’s Disease?
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What is Parkinson’s Disease?
Parkinson’s disease is a neurodegenerative disorder that primarily affects movement. It develops gradually, sometimes beginning with a tremor in a single hand that is barely noticeable. However, while tremors are common, the disorder can cause stiffness, walking difficulties, etc.
The Role of Dopamine
Parkinson’s disease occurs when certain neurons in the brain, particularly those responsible for producing dopamine, gradually degenerate or die. Dopamine is a chemical messenger that enables smooth, coordinated muscle movements. As dopamine levels fall, brain signaling is disrupted, leading to motor symptoms such as tremors, stiffness, and slowed movement, along with a range of non-motor symptoms.
What is Neurodegeneration?
Neurodegeneration refers to the progressive loss of structure or function in neurons, including cell death. In Parkinson’s disease, this neurodegeneration primarily occurs in the dopamine-producing neurons in the substantia nigra. One of the main causes of this degeneration is the buildup of Lewy bodies, which are clumps of misfolded α-synuclein protein that interfere with normal cellular functions and lead to neuron death. With continued neurodegeneration, symptoms gradually worsen.
How Parkinson’s Affects the Brain
In Parkinson’s disease, the loss of dopamine-producing neurons primarily occurs in the substantia nigra, which is a key region within the basal ganglia, the brain network responsible for regulating movement. As dopamine levels progressively decline, communication between brain regions becomes disrupted, especially those involved in planning and executing voluntary actions.
However, Parkinson’s is not limited to movement-related symptoms. As the disease advances, other parts of the brain, including the cortex, brainstem, and limbic system, can also be affected. This wider neurodegeneration helps explain the non-motor symptoms of Parkinson’s, such as mood changes, cognitive impairment, sleep disturbances, and autonomic dysfunction.
While the exact mechanisms behind these changes are still being studied, increasing evidence implicates the toxic accumulation of alpha-synuclein and chronic cellular stress as key contributors. These underlying changes drive the diverse and evolving symptoms experienced by people living with Parkinson’s disease.