A study supported by the Alzheimer’s Drug Discovery Foundation (ADDF) and published today in Molecular Psychiatry reports that a combination of functional assessments and biomarkers —specifically blood tests and brain scans — may pave the way for early diagnosis of a form of dementia called chronic traumatic encephalopathy (CTE).
CTE is a progressive degenerative brain disease caused by repetitive brain trauma. It is most often found in military veterans, who were the subject of this study, and in athletes involved in contact sports. In addition to dementia, CTE symptoms can include aggression, depression, impaired judgment, impulse control problems, memory loss and suicidal thoughts.
The biomarkers used in this study were PET scans looking at excess retention of tau protein in the brain and blood tests measuring leakage of the protein Nf-L (neurofilament protein-light chain) from the brain into the bloodstream. Both changes signal neurodegeneration in the brain. “Finding non-invasive biomarkers for early diagnosis of Alzheimer’s and other neurodegenerative brain diseases is crucial to helping us understand how they develop and how they can be stopped,” said Howard Fillit, MD, ADDF Founding Executive Director and Chief Science Officer.
The study was conducted at the Icahn School of Medicine at Mt. Sinai in New York. Researchers examined findings in both humans and rats to make side-by-side comparisons of changes in biomarkers and behaviors following exposure to repeated brain trauma. The veterans were exposed to repeated blasts while serving in the Middle East, often from improvised explosive devices (IEDS). Their brain trauma was replicated in the animals by exposing the rats to repeated air blasts in a shock tube.
Currently, CTE can only be diagnosed post-mortem through analysis of brain tissue, but researchers say the results of their study are “highly promising for developing a clinical biomarker signature that may one day support the diagnosis of CTE during life.” Larger studies will be needed to replicate their findings and establish whether and how PET scans and Nf-L blood tests can be combined with functional assessments to make a definitive diagnosis.
But CTE research is advancing rapidly, according to Dr. Fillit. “Studies such as this will advance our understanding of CTE, Alzheimer’s, and other neurodegenerative diseases, improve the rigor and efficiency of clinical trials, and may ultimately provide screening tools to identify patients for clinical trials and measure the success of treatments.”