Role of α-synuclein in Parkinsonism
The protein α synuclein occurs in healthy brains. However, in
, abnormal forms of α-synuclein form sticky clumps (Lewy bodies) within the brain nerve cells,
leading to the characteristic clinical features.
This protein also forms clumps in other conditions such as multiple system atrophy
(MSA) and in dementia with Lewy bodies (DLB).
‘Early diagnosis of Parkinsonism may offer new hope for patients’
It is a degenerative brain disorder affecting the elderly. It is characterised by severe tremors at rest, stiffness of limbs, slowness of movement and impaired balance.
The disease may also affect emotions and cognition.
A few patients may develop depression and visual hallucinations
They also may have an increased risk of developing dementia
, with decline in intellectual functions, such as reasoning and memory.
How is Parkinson's Disease Diagnosed?
There is no†diagnostic test†to clearly identify the disease,
but brain scan may be done to rule out other disorders that may have similar symptoms.
Improvement of symptoms with Levodopa,
a drug used in its treatment may confirm its diagnosis.
Presence of aggregates of α synuclein
protein called Lewy bodies
in the brain by pathological post-mortem
examination is the only definitive evidence of the disease.
In a few cases, the course of the disease may indicate that it is after all NOT Parkinson's disease and some authorities recommend periodic review of the diagnosis.
Why Earlier Attempts to Detect Alpha Synuclein Failed?
As mentioned earlier, the Lewy bodies can only be detected in brain cells only after death.
Earlier efforts to develop a test for presence of alpha-synuclein protein in the spinal fluid of patients did not yield results
because the protein is also found in healthy brains.
Thus its presence per say is not indicative of disease. It is only when the abnormal protein aggregates together that it causes symptoms.
Latest Research Measures Stickiness of Protein
Dr. Alison Green and her team at the University of Edinburgh used a highly sensitive technique that measures the stickiness of proteins.
This technique referred to as 'real-time quaking induced conversion',
can detect minute variations in the properties of brain proteins such as alpha synuclein that helps delineate between presence and absence of disease.
Degree of Accuracy of the Technique
In early trials, the technique correctly diagnosed 19 out of 20 samples from patients with Parkinson's disease,
and in addition, three samples from persons considered to be at risk
for the condition.
No false positive results occurred
in any of the 15 control samples from healthy volunteers.
The technique also accurately identified patients suffering from a type of dementia caused by Lewy bodies, but not other types of dementia.
Possible Applications of the Test
Dr. Alison Green, of the National CJD Research and Surveillance Unit at the University of Edinburgh, said: ."We have already used this technique to develop an accurate test for Creutzfeldt Jacob Disease, another neurodegenerative condition. We hope that with further refinement, our approach will help to improve diagnosis for Parkinson's patients."
She further added, "We are also interested in whether it could be used to identify people with Parkinson's and Lewy body dementia in the early stages of their illness.
These people could then be given the opportunity to take part in trials of new medicines that may slow, or stop,
the progression of disease."
If the test results are further validated in a larger sample group, it could mean a major breakthrough in early diagnosis of Parkinson's disease and improving the outlook and quality of their life.References :
- Unraveling the mystery of alpha synucelin - (http://www.pdf.org/winter16_asynuclein)