Brain scan Shows Potential to Predict Parkinson’s, Dementia Years Before Symptoms
Paris, France – A new international study reveals a potential breakthrough in predicting the onset of Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) - sometimes years before clinical symptoms appear. Researchers have found that a specialized MRI technique measuring brain waste clearance, called diffusion tensor imaging along the perivascular space (DTI-ALPS), can identify individuals with isolated REM sleep behavior disorder (iRBD) who are at higher risk of developing these neurodegenerative diseases. The findings, published in Neurology, offer a promising new avenue for early diagnosis and potential intervention.
iRBD, characterized by acting out dreams, is recognized as the strongest known predictor of synucleinopathies – disorders linked to the buildup of the protein alpha-synuclein, including PD and DLB. However, not everyone with iRBD will develop these conditions, making it crucial to identify biomarkers that can predict individual trajectories.
The study, conducted across five international centers, involved 250 patients with iRBD and 178 healthy controls. Researchers discovered that iRBD patients exhibited a lower DTI-ALPS index in the left side of the brain compared to the control group (mean difference = −0.034, 95% CI −0.067 to −0.001; p* = 0.043).
Over an average follow-up period of 6.1 years, 65 of the 224 iRBD patients followed in the study converted to a synucleinopathy. Notably, those who *did convert had considerably lower left DTI-ALPS indices than those who did not (mean difference = −0.050, 95% CI −0.098 to −0.003; p* = 0.038).
The research team found that a lower left DTI-ALPS index was associated with a 2.43-fold increased risk of converting to Parkinson’s disease (hazard ratio = 2.43, 95% CI 1.13-5.25; *p = 0.012). Importantly, other standard MRI measurements within the periventricular regions of the brain did not show similar differences between groups.
“Patients with iRBD exhibit a reduced DTI-ALPS index, suggesting altered glymphatic function,” the study concludes. The glymphatic system is the brain’s waste clearance pathway, and its dysfunction is thought to contribute to the accumulation of harmful proteins associated with neurodegeneration.
These findings suggest that the DTI-ALPS index could serve as a valuable prognostic biomarker for identifying individuals with iRBD who are most likely to progress to PD or DLB, potentially allowing for earlier interventions and clinical trials focused on slowing disease progression. the study underscores the growing understanding of sleep disorders as potential early warning signs for devastating neurological conditions.
