Researchers Find a Specific Biomarker for ALS that May Improve the Diagnostic Process
Diagnosing Amyotrophic Lateral Sclerosis (ALS) can take between 9 to 12 months. Finding a “biomarker” or a physical attribute that confirms ALS onset can reduce this diagnosis timeline dramatically. A recently published article shows evidence of a biomarker that could greatly reduce the time it takes to receive a diagnosis.
You may be wondering, “Why does getting a diagnosis take so long?” Because the average life expectancy for ALS patients is 2-5 years it can take up to 1/3rd of a patient's average remaining lifetime to get diagnosed. This may seem like some sort of cruel joke. Well, it's not a joke but it is a problem that needs to be fixed. The only way physicians can test for ALS is by eliminating all other possible options. There are about a dozen other diseases and disorders that can mimic ALS or show the same symptoms. There is no specific test a doctor can run that proves or disproves that someone has ALS… up till now.
Now researchers have found a biomarker that can differentiate ALS from mimicking diseases. A biomarker is something that doctors can measure that indicates the presence or absence of disease. Because the cause of sporadic ALS is unknown, finding a biomarker has proven to be difficult, but the biomarker identified in last week’s publishing seems to be promising.
Traditionally Biomarkers are found in the blood or body scans such as MRIs, EMG’s, etc... But none of these methods have rendered productive in finding an ALS biomarker. These researchers use a newly developed technique called Quantitative Susceptibility Mapping (QSM). Simply put, QSM is an adaptation of an MRI scan and appears to be the answer to our problems.
The QSM machine measures the section of the brain where our motor neurons start. This section of the brain is mapped out relative to the different muscles in our bodies. In other words, there is a section of the brain where all of our hand muscle neurons start, a face section, a foot section, and so on. Conceptually you can imagine that in this part of the brain there is a miniature person laying down along the top of the brain. Neurologists call this “person” a homunculus and will specify different parts of the brain by talking about the hand homunculus or the face homunculus.
By mapping this homunculus area of the brain in ALS patients using the QSM scan, the researchers can compare the data to people without ALS and people with diseases that mimic ALS. The results show a significant difference between ALS patients and people with mimicking diseases. This difference is especially evident when looking at the hand homunculus with the data showing 100% specificity in differentiating ALS from diseases that mimic ALS.
This study ran from 2015 to 2018 with the data being published just this last week. Further investigation of this data could prove that QSM scans can be a useful tool in speeding up the ALS diagnosis progress. This would in turn dramatically increase the number of people eligible for clinical trials and further speed up the race for a cure.