Parkinson’s News Today recently published an article containing new information about biomarkers in Alzheimer’s disease that can be linked to the early stages of Parkinson’s disease.
Many people with Alzheimer’s (about 80%) are also diagnosed with dementia affecting memory and language. Parkinson’s on the other hand affects various motor skills, with mental degeneration appearing only in the later stages.
Alzheimer’s, dementia, and Parkinson’s have been known to share various underlying connections. These include the protein alpha-synuclein and the tangles and plaques found in both Parkinson’s and Alzheimer’s diseases.
The number of neurodegenerative cases is increasing due to the aging population. This creates an urgent need for rapid and reliable diagnoses.
What are Lewy Bodies?
Misfolding of the protein alpha-synuclein in Parkinson’s patients affects chemicals in the brain causing lesions. These deposits are called Lewy bodies, a form of dementia second only to Alzheimer’s dementia. Lewy body dementia shares symptoms with Parkinson’s and Alzheimer’s dementia.
The researchers had a theory that Lewy bodies can lead them to different diseases associated with Parkinson’s and Alzheimer’s or other brain disorders.
Testing the Theory
Researchers at the University of Pennsylvania decided to test this theory and measure levels of three Alzheimer’s biomarkers in the cerebrospinal fluid surrounding the spinal cord and brain.
- Amyloid plaque: The accumulation of beta-amyloid proteins in the brains of Alzheimer’s patients.
- Phosphorylated tau: Causes the formation of neurofibrillary tangles, also due to an abnormal protein. However, this occurs inside the neuron rather than outside. Their exact role is unknown.
- Total tau: Elevated T-tau has been found in dementia with Lewy bodies and Alzheimer’s disease. As a biomarker, Tau has been used for analyses of the brain or peripheral fluids.
About the Study
Samples of cerebrospinal biomarkers were collected from 416 Parkinson’s patients over a three-year period. The same type of cerebrospinal biomarker samples was taken from 192 healthy people as controls.
The samples included amyloid plaques and tau tangles composed of tau protein or beta-amyloid that are characteristic of Alzheimer’s disease.
Researchers found that p-tau and t-tau levels remained fairly stable in patients at first. However, in the second and third year, they found a somewhat mild increase. But in healthy people, both biomarker levels rose over time.
These changes indicated that it might be possible to use the biomarkers of Alzheimer’s to predict the clinical decline that has been observed in Parkinson’s patients.
The researchers hope to conduct additional studies to further identify predictive values for relevant changes.