Parkinson’s: towards early detection of the disease using quantitative MRI

When symptoms appear, the disease is already installed in the brain. Currently, there is no way to detect it before it is too late. But researchers think they have found: it would be a question of identifying tiny structures that form deep in the brain as the disease progresses.

The Parkinson disease is a neurodegenerative disease progressive that develops in the brain well before the appearance of the first symptoms. On average, ” patients remain asymptomatic until 50-70% of neurons at dopamine are destroyed and the brain is no longer able to compensate for this loss “, explains theInserm. This phase can last several years, but when the symptoms appear, it is often too late to treat the disease. They can be motor, such as akinesia (slowness of movements), of the rigidity or tremors, but also cognitive, or concern the sleepbalance, or even thesmell. The treatments, although they cannot stop the evolution of the disease, provide dopamine, making it possible to limit the motor symptoms.

Currently, the diagnostic mainly relies on the elimination of other pathologies possible that the Parkinson diseasethanks in particular to MRIs or scans. It can also go through the improvement of motor symptoms following dopaminergic treatment, or through a neurological assessment and the symptoms experienced by the patient. But a study published in the journal Science Advances reveals a technique that would make it possible to diagnose the disease more reliably. It is based on quantitative MRI, more simply called qMRI. Like conventional MRI, it relies on theapplication of magnetic fields not dangerous for humans which cause vibes atomics which are then detected. Quantitative MRI makes it possible to obtain more precise biophysical properties of tissues, and to target “hidden” places in the brain, buried deeply and detail them more precisely than conventional MRI.

Tiny structures indicative of disease

Researchers at the Hebrew University of Jerusalem further studied the striatum, a nerve structure located below the cerebral cortex, believed to be the ” center of motivation and severely affected by Parkinson’s disease. By observing the brains of 99 diseased but early-stage patients (less than four months after diagnosis) and 46 healthy people, they spotted tiny structural differences located in the putamen, the lateral part of the striatum. Differences that are due to the drop in dopamine caused by the disease. “In patients with Parkinson’s disease, we have found gradients abnormalities in the putamen, revealing changes in the posterior putamen that explain patients’ dopaminergic loss and motor dysfunction,” describes the study.

They also compared these anomalies in the brains of sick patients to those in the brains of people with normal aging. This enabled them to confirm that the observed microstructures were indeed specific to Parkinson’s disease. But their method, if it promises an early diagnosis of the disease in the years to come, is far from being ready for real clinical application. The team thus foresees between three and five years before being able to actually translate their technology into a clinical tool.