Newswise — Lewy body disease, ranking as the second most prevalent neurodegenerative condition after Alzheimer's disease, has recently been the focus of research conducted by a team from Lund University. Their groundbreaking study reveals the possibility of early detection of the disease, even before the onset of noticeable symptoms, through a spinal fluid test. This significant development was published in Nature Medicine. Additionally, the researchers demonstrated a strong correlation between Lewy body disease and a reduced sense of smell, which could serve as an early indicator before other evident symptoms emerge.
It is worth noting that Lewy body disease encompasses both Parkinson's disease and Lewy body dementia. When the disease primarily manifests with movement difficulties, it is referred to as Parkinson's disease. On the other hand, when cognitive impairments are more prominent, it is termed Lewy body dementia. These critical findings were also presented at the Alzheimer’s Association International Conference, signifying their potential impact on the field of neurodegenerative research.
"Lewy body disease arises from the misfolding of the alpha-synuclein protein within the brain, resulting in the formation of harmful clusters known as Lewy bodies," explains Oskar Hansson, Professor of Neurology at Lund University and senior consultant at Skåne University Hospital.
Until recently, it was challenging to definitively determine whether individuals experiencing movement difficulties or cognitive impairments had Lewy bodies in their brains, as this confirmation could only be made postmortem. However, a significant breakthrough has occurred with the development of a spinal fluid test. Now, it is possible to identify the presence of the misfolded protein in living individuals. Oskar Hansson's research group conducted a large-scale study involving more than 1,100 individuals, all of whom initially exhibited no cognitive impairments or motor difficulties. Surprisingly, nearly ten percent of them were found to have Lewy bodies in their brains, as indicated by the spinal fluid test. This groundbreaking discovery indicates that Lewy body disease can be detected even before the first symptoms become apparent.
"As we began the study, none of the participants showed any cognitive or neurological issues. However, intriguingly, we observed that those individuals who had Lewy bodies in their brains experienced a decline in their cognitive functions over time. Moreover, these same individuals were the ones who later developed either Parkinson's disease or Lewy body dementia," reveals Oskar Hansson.
In addition to this significant finding, the research also uncovered a compelling association between Lewy bodies and a diminished sense of smell, even before the appearance of other symptoms. As the disease progresses, the sense of smell continues to deteriorate. This correlation is so distinct that Oskar Hansson suggests it might be reasonable to conduct smell tests on individuals over 60 years of age. Subsequently, if any concerns arise, further investigation through spinal fluid testing could aid in the early detection of Lewy body disease.
Nevertheless, Oskar Hansson stresses the importance of recognizing that there are numerous causes of loss of smell that are unrelated to Lewy body dementia. This underscores the significance of conducting the spinal fluid test, as it serves as a crucial diagnostic tool to distinguish Lewy body disease from other potential causes of olfactory impairment.
Brain changes that interact
In another research publication, the same group investigated a cohort of over 800 individuals facing cognitive difficulties and made a significant discovery. Among this group, approximately one-fourth showed test results indicative of Lewy body disease. Strikingly, about 50 percent of those with Lewy body disease also exhibited an accumulation of amyloid and tau proteins, known to be associated with Alzheimer's disease. Notably, for individuals with both amyloid, tau, and Lewy bodies, the disease progressed at a faster rate, indicating an interaction between these brain changes. This finding holds immense clinical importance, as it can aid in predicting the prognosis for patients.
Oskar Hansson is optimistic about the potential impact of this test for Lewy body disease and foresees its application in diagnostic and prognostic assessments at clinics dealing with individuals experiencing movement disorders and cognitive symptoms. Its implementation is likely to commence in the near future, enhancing the medical approach and care for such patients.
Oskar Hansson expresses his hope that, similar to the progress made for Alzheimer's disease, a blood test for Lewy body disease could also be developed in the future. However, there is a significant challenge to overcome in this endeavor. The concentration of brain-originating proteins in the blood is often 100-1000 times lower than in the spinal fluid, posing difficulties in detecting Lewy body changes through blood tests.
Nonetheless, Oskar Hansson remains positive and draws parallels to the advancements achieved for Alzheimer's disease. He highlights that just five years ago, such a blood test for Alzheimer's seemed improbable, yet it has now become a reality. Emphasizing their commitment to enhancing the methodology, he concludes with optimism for the future of Lewy body disease diagnostics, indicating that with continued research efforts, a breakthrough in blood testing could be achieved.
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