New Biomarker in Spinal Fluid Improves Parkinson’s & Lewy Body Dementia Diagnosis
A new biomarker in cerebrospinal fluid (CSF) is offering the potential for more accurate diagnoses of Parkinson’s disease and Lewy body dementia (LBD), according to research published today in Nature Medicine.
The international research consortium, led by Dr. Katharina Bolsewig and Professor Charlotte Teunissen of the Laboratory of Neurochemistry at Amsterdam UMC, identified DOPA decarboxylase – a protein essential for dopamine production – as a key indicator of these neurodegenerative diseases. The study demonstrates significantly elevated levels of the protein in the CSF of patients with Parkinson’s and LBD compared to healthy individuals, and crucially, allows for differentiation from Alzheimer’s disease.
“The importance of this discovery for clinical practice is considerable, as dementia with Lewy bodies is often demanding to diagnose correctly at present,” said Professor Sebastiaan Engelborghs of VUB and UZ Brussel, a key contributor to the research. “Because of the strong overlap of symptoms with other forms of dementia, patients are regularly misdiagnosed. Misdiagnosis can lead to less effective or, in some cases, harmful treatment. The new measurement method provides doctors with an objective tool for determining the right course of action at an early stage.”
Researchers developed two highly sensitive laboratory tests to measure DOPA decarboxylase levels in CSF. Results showed protein concentrations in affected patients were up to 2.5 times higher than in healthy controls. Higher biomarker concentrations correlated directly with the severity of pathological changes in the brain, reinforcing the test’s biological relevance.
The discovery addresses a critical need for improved diagnostic tools in Lewy body disorders, which, alongside Parkinson’s disease, represent the second most common neurodegenerative diseases after Alzheimer’s. Current diagnostic methods often rely on clinical observation and can be hampered by overlapping symptoms.
While the findings represent a significant advancement, the consortium emphasized the need for further standardization of the testing methods before widespread clinical implementation. “We can speak of a fruitful international collaboration,” Engelborghs stated. “This publication brings a crucial biomarker closer to the patient, precisely in cases where diagnosis is still too often associated with uncertainty.”
Recent progress in Parkinson’s disease research also includes a phase 1 clinical trial evaluating an antisense oligonucleotide targeting the LRRK2 protein, demonstrating the treatment’s tolerability and its ability to reduce LRRK2 levels in cerebrospinal fluid, according to a separate article published in Nature Medicine on March 24, 2026.