American researchers have recently used a technique to identify the presence of certain proteins in the brain which are characteristic signs of Parkinson’s disease.
- Parkinson’s disease is a chronic pathology, which can go undetected for many years.
- The symptoms of Parkinson’s disease are mainly characterized by motor disorders.
- In a new study, a technique was used to detect Parkinson’s disease early.
Symptoms of Parkinson’s disease usually occur when 50-70% of dopamine neurons are destroyed and the brain can no longer compensate. The absence of manifestations can therefore last several years before the diagnosis of this degenerative pathology is made.
A technique for early detection of Parkinson’s disease
According to a new study published in the journal The Lancet Neurology, researchers used the α-synuclein seed amplification assay (αSyn-SAA) technique to detect the presence of misfolded α-synuclein protein aggregates in the brain. This accumulation of proteins is a characteristic sign of Parkinson’s disease. This process would therefore make it possible to improve the early detection of the pathology.
For the purposes of this research, the scientists examined data from the Parkinson’s Progression Markers Initiative (PPMI), to assess the usefulness of the αSyn-SAA technique in the early diagnosis of neurodegenerative pathology.
Among the 1,123 participants in the cohort, some people had already been diagnosed with Parkinson’s disease and others had genetic variants (GBA and LRRK2) linked to the disease. So-called “prodromal” participants were also included. The latter had no motor problems, but suffered from sleep disorders and/or a loss of smell, which may be early signs of Parkinson’s disease. The inclusion of prodromal volunteers helped determine whether αSyn-SAA could predict the onset of Parkinson’s disease and help diagnose people with established symptoms.
Loss of smell, a warning sign of Parkinson’s disease?
According to the study authors, the αSyn-SAA technique accurately identified patients affected by Parkinson’s disease, particularly in people who had already been diagnosed with the disease (88% positive results).
Regarding sporadic cases, that is to say without known genetic cause, 93% of people had a positive αSyn-SAA result. The results, however, varied for patients with genetic forms of Parkinson’s disease. Nearly 96% of people with the GBA variant had a positive αSyn-SAA result, compared to 68% of people with the LRRK2 variant.
Among prodromal participants with loss of smell, 98% had results αSyn-SAA positive. Loss of smell was the clinical feature that most strongly predicted an αSyn-SAA result. Among all participants with Parkinson’s disease who had a loss of smell, 97% had a positive αSyn-SAA result, compared to 63% of patients whose sense of smell had not changed.
“While loss of smell appears to be an important predictor of Parkinson’s disease, it is important to note that this study identified people whose αSyn-SAA results were positive, but who had not yet lost their sense of smell. , indicating that α-synuclein pathology may be present even before there is a measurable loss of smell.Our study only involved patients at one time, and further research is needed to discover how patients’ sense of smell may change over time, and how this is related to the accumulation of a-synuclein aggregates in the brain”noted Dr. Tanya Simuni, of Northwestern University (USA), and lead author of the study.