Parkinson’s disease causes changes in the brain’s structure and function, most notably the progressive loss of brain cells that produce dopamine, leading to movement issues. These changes can also affect cognitive and emotional functions, causing issues with memory, attention, and executive functions like planning and decision-making. Over time, the disease can progress to more severe cognitive decline or dementia, with symptoms including memory loss, difficulty with communication, and problems with problem-solving.
Neuropathological changes
Dopamine cell loss: The core pathology is the death of neurons in the brain that produce dopamine, a key chemical messenger for movement control.
Lewy body formation: Abnormal clumps of a protein called alpha-synuclein (Lewy bodies) are a hallmark of Parkinson’s and contribute to nerve cell dysfunction and death.
White matter degradation: Studies show changes in the white matter, the brain’s communication pathways, which can be linked to specific symptoms like gait disturbances.
Pathology spread: The disease process is thought to spread in a predictable pattern through the brain over time, affecting different areas as it progresses.
Cognitive changes
Early-stage symptoms: Mild cognitive changes, such as difficulty with multitasking, slowed thinking, and problems with attention, can occur even at the time of diagnosis.
Executive function: Impairment of executive function is common, leading to problems with planning, organizing, and switching between tasks.
Memory problems: Short-term memory and working memory can be affected.
Language difficulties: Some people may experience word-finding problems or trouble with language, particularly under stress.
Parkinson’s disease dementia: In later stages, some people develop Parkinson’s disease dementia, which involves more severe memory and thinking problems that can affect daily living.
Other brain-related changes
Emotional and behavioral changes: Depression, anxiety, and apathy (a lack of interest or emotion) can occur and are related to the brain changes associated with the disease.
Sleep disruption: Sleep issues are common and can negatively impact cognitive function.
