Parkinson's, a neurodegenerative disease that affects more than 160,000 people in Spain, lacks a specific test for its diagnosis. Its detection is difficult until the first characteristic symptoms appear, which makes it difficult to research treatments and apply medical strategies to slow down its progression. However, a new laboratory test shows that it can detect the disease before symptoms appear. A possible paradigm shift in diagnosis, research and treatment trials that has been one of the star themes of the sixth edition of the World Parkinson's Congress held in Barcelona.
Last May, The Lancet Neurology published the first large-scale trial of a technique to detect alpha-synuclein, a protein that abnormally accumulates in neurons of people with Parkinson's and that may be related to impaired brain function. nervous system. Developed by 33 centers in twelve countries and with the participation of more than a thousand patients, the study concludes that the test identifies Parkinson's in 87.7% of cases. Accuracy increases to 98.6% of those who present the typical olfactory deficit of the disease.
The test is performed by extracting cerebrospinal fluid, an invasive technique that requires a lumbar puncture, similar, for example, to when epidural anesthesia is applied during childbirth. Although a Japanese research group has just described in Nature Medicine "the possibility of performing this test in blood, which would facilitate its application", explains Miquel Vila, director of the research group on neurodegenerative diseases at the Vall d'Hebron Research Institute.
At the moment, says Vila, this test is not yet applied systematically. "It is done at an experimental/research level, but the idea is that it can be generalized." One of the centers where it is practiced, and can be requested for care, is the Hospital Clínic de Barcelona, explains the neurologist Eduard Tolosa, a world authority on Parkinson's and one of the presidents of the congress held in Barcelona. In his opinion, the synuclein test "is a before and after." It will avoid visits to different doctors due to the disparity of symptoms and, "perhaps most importantly, it will allow the disease to be detected before the classic symptoms of tremor, or slowness, or speech difficulties appear."
This is the first time that scientists have identified an objective biomarker that can be found not only in people with symptoms (the majority appear over 60 years of age) but also in younger individuals (those diagnosed around 40 years of age represent 10%) who do not They have symptoms but have some risk factors.
Early detection is essential, according to Dr. Tolosa: "The clinical trials that have been carried out in the last fifteen years to curb the disease have failed and the reason, we believe, is that they have been carried out at too late stages, when the Motor disease has already declared itself and irreversible damage to the brain has occurred. Hospital Clínic is immersed in the Healthy Brain Aging project with the aim of determining the percentage of the population with risk factors for Parkinson's (genetic in 10% of cases, loss of smell, sleep disorders with aggressive nightmares) which will facilitate diagnose it before neuronal deterioration occurs. “It is an online questionnaire that anyone over 50 who has not been diagnosed can answer in no less than twenty minutes. It is a great help for us”, says Tolosa.
Nearly 3,000 people have participated in the Barcelona World Congress, a forum that brings together doctors and researchers as well as Parkinson's patients and caregivers.
