Highlights:
- Cognitive decline
associated with Parkinson's disease can be a debilitating condition but it
is often identified only after there has been considerable damage to the
neurons.
- Interventional
strategies post the onset of cognitive decline are aimed at protecting the
few healthy neurons that still persist.
- New biomarkers
can be used to identify the risk of cognitive decline early, that can help
devise early interventional strategies to protect the neurons.
A research team
from University of Pennsylvania's Perelman School of Medicine has identified
novel biomarkers to predict cognitive
impairment in Parkinson's disease. These biomarkers can be used to determine
which Parkinson's disease patients will suffer from significant cognitive
decline during the initial three years of the disease progression. The study,
with potential benefits in improving care for Parkinson's disease patients, was
published in the Journal PLoS ONE.
Professor
of Psychiatry, Dr. Daniel Weintraub, who is the lead author of the study, said
that the findings could be used to improve the understanding of the changes
that occur in the brain, that are associated with cognitive decline. The
clinical care of Parkinson's disease patients could be improved by detecting
the signs of cognitive decline early.
‘Early identification of risk for cognitive decline will help in providing personalized interventional strategies that could delay decline.’
A
Landmark Study
The
research team led by Dr. Weintraub analyzed 423 newly undiagnosed but untreated
Parkinson's disease patients who did not show symptoms of dementia when they
were enrolled in the study. This study was sponsored by
The Michael J. Fox Foundation for Parkinson's Research and is
considered the landmark study which could be used to improve interventional
strategies for people with Parkinson's disease.
What
were the findings from the study?
The
study found that
- 15 to 38 % of the
study participants developed cognitive
decline three years after they enrolled in the study.
The
research team conducted genetic tests, brain scans and analyses of
cerebrospinal fluid (CSF) and found that cognitive decline correlated with
several biomarkers like
- Lowered brain
volume and thickness, indicative of atrophy of the brain
- Genetic mutations
- single nucleotide polymorphisms in the COMT and the BDNF genes
- Deficiency in
Dopamine
- Lower levels of
beta-amyloid protein, a marker of Alzheimer's disease
Clinicians can use the information in the
study to identify patients who are at high risk and provide them with
interventional strategies which could delay the onset or utilize efforts to
enhance their cognitive skills.
This
study involved only white males who were newly diagnosed with
Parkinson's disease; further studies that include
people from other ethnic backgrounds will help validate the effectiveness of
these biomarkers in determining cognitive decline across ethnicities. The
studies will also help in identifying if the novel biomarkers are risk factors
for late onset Parkinson's disease or whether they are indicators of cognitive
decline.
Parkinson's Disease
This is one of the most significant
neurodegenerative diseases that affect millions of people across the world.
- Nearly 1 million
Americans live with Parkinson's disease
- More than 5
million people worldwide live with Parkinson's disease
- 60,000 Americans
are diagnosed every year while there are many who go undetected
This
common and incapacitating neurodegenerative disease affects many people but is
generally detected among people over the age of 60 years. The major symptoms of
the disease include
- Akinesia
- Bradykinesia
- Tremor
- Postural
instability
The diagnosis of this condition is
largely dependent on an assessment of symptoms. It is routinely misdiagnosed
with other neurodegenerative diseases in the clinical setting; misdiagnosis
occurs
- 50% of the time
in primary care
- 10% of the time
by movement specialists
The
current methods of ascertaining the condition are based on the presence of
Lewy bodies and Lewy neurites in the
residual neurons or axons during postmortem analysis. The diagnosis of this
condition occurs very late, when
50-60%
of dopaminergic neurons in the substatia nigra are lost. This limits the
effectiveness of the treatment strategies as the number of remaining neurons is
very low.
Therefore,
there is an urgent need to identify biomarkers associated with the condition so
that treatment strategies help the patient before there has been considerable
damage to the neurons. The current study identified potential biomarkers which
can be used to identify patients who are at high risk for cognitive decline
even before the symptoms set in. Nearly
10
to 15% of the Parkinson's disease incidences are believed to be due to
genetic factors. An individual is at high risk of developing the condition when
the mother, father or the sibling has the condition. Three genes have been
previously found to be associated with Parkinson's disease, namely
PARK2, LRRK2 and Glucocerebrosidase.
The
current study identified polymorphisms in two genes,
COMT and BDNF, which are found to be indicators of cognitive
decline. Genetic testing could be used to identify high risk patients so that
better treatment modalities may be used to delay cognitive decline.
References :- A Landmark Study of Parkinson's Disease - (http://www.ppmi-info.org/)
Source: Medindia
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