Parkinson’s disease, like Alzheimer’s disease, is caused at least in part by tangled proteins that steadily build up on neurons.
In Parkinson’s disease these clumps are called Lewy bodies. They primarily target dopaminergic neurons in a part of the midbrain called the substantial nigra, the area that controls movement.
The illness is characterized by tremors, instability/loss of balance, poor coordination and stiffness, and generally affects people in their 50s, 60s and beyond, although early-onset cases have been recorded.
These are the well-known symptoms we’re all familiar with. But cognitive decline and Parkinson’s disease dementia may also accompany these symptoms. Researchers have recently discovered biomarkers of cognitive decline in Parkinson’s disease, which can help people receive treatment earlier. Here’s how to know if someone is coming down with this type of dementia.
As there’s still no cure for Parkinson’s disease, early intervention and prevention are key. According to the Alzheimer’s Association, as many as 50-80% of Parkinson’s disease patients will develop dementia. Symptoms of Parkinson’s disease dementia include:
- Difficulty sleeping
- Memory changes
- Visual hallucinations and trouble interpreting visual information
Cognitive impairment in Parkinson’s disease increases anywhere from 50 to 200% in the first several years of the disease.
Until recently, researchers didn’t know which Parkinson’s patients would also have cognitive decline. And without signals of early detection, families and doctors had no choice but to wait until the symptoms appeared, by which time heavy damage to the neurons had already been inflicted.
Biomarkers of Parkinson’s Disease Dementia
A three-year study published in May, 2017 followed 423 newly diagnosed Parkinson’s disease patients.1 The researchers used methods ranging from MRI scans to testing cerebrospinal fluid to discover four distinct biomarkers of cognitive decline in Parkinson’s.
- A decrease in brain volume across all four brain lobes
The brain has four lobes, or areas.
- The frontal lobe controls cognitive skills like memory, language and judgment
- The temporal lobe controls hearing and speech
- The parietal lobe regulates spatial sense and navigation
- The occipital lobe governs vision
Parkinson’s disease dementia causes tissue loss or shrinkage in all these areas, while patients without Parkinson’s dementia show reduced brain volume primarily in the frontal lobe only.2
- Pathological levels of beta-amyloid plaques, like those found in Alzheimer’s disease
Lewy bodies are made of a protein called alpha synuclein that folds back on itself and gets sticky. This is different than the beta-amyloid plaques that characterize Alzheimer’s disease. However, there does seem to be a similar mechanism that drives both these proteins to clump together and tangle.
Research suggests that beta-amyloid plaques may drive the development of alpha synuclein by impairing protein clearance, increasing inflammation or in other, unknown ways.3
- Dopamine deficiency
If proteins are attacking dopamine receptors in the brain, it stands to reason there will be a deficiency. Dopamine levels affect your focus, mood, sleep, cognition and more. Symptoms of low dopamine include:
- Brain fog and inability to concentrate or finish tasks
- Mood swings
- Sensitivity to stress
If you or someone you know is experiencing these symptoms, it’s best to get your dopamine levels tested.
- Some genetic variations
Some patients with Parkinson’s disease dementia have particular gene mutations that make them more susceptible to PD-related cognitive decline.
Protect Yourself from Parkinson’s Disease
Because Parkinson’s begins with low and falling dopamine, keeping levels of this important neurotransmitter high is essential. The amino acid L-tyrosine is a building block of dopamine. You can find it in a quality supplement. Foods that help boost dopamine in the brain include:
- Raw cacao or dark chocolate
- Wheat germ
- Mustard greens
- Nuts and seeds
- Meat, including game like quail, buffalo and moose
While Parkinson’s disease remains idiopathic, meaning we don’t know exactly what causes it or why, scientists are making advances in understanding it. The sooner we can recognize it, before the phy sical symptoms start, the better chance we have of delaying its progress.
- Multiple modality biomarker prediction of cognitive impairment in prospectively followed de novo Parkinson disease.
- Cerebral atrophy in Parkinson’s disease with and without dementia: A comparison with Alzheimer’s disease, dementia with Lewy bodies and controls.
- Examining the mechanisms that link β-amyloid and α-synuclein pathologies.