Multiple sclerosis presents a number of problems, not just in terms of causing degeneration in patients, but also in the study process. There are so many factors involved in the diagnosis of multiple sclerosis that it can be difficult to get a handle on the disease, especially since every case is as unique as the individual who has developed it.
However, one topic remains of significant interest, despite the difficulty in burden of proof, and that is clusters. What role, if any, do clusters play in the development of multiple sclerosis? To determine that, it’s important to understand how a cluster would be defined, especially in terms of MS and its prevalence.
What is a cluster?
In medicine, a cluster is defined as a community of people living close together in which a particular disease seems to develop at a higher rater or be more common among the population than the average. For example, a community that has a higher rate of radiation poisoning but isn’t close to a nuclear power facility would be of interest for study as a cluster.
A multiple sclerosis cluster would be a certain area where more people seem to develop the disease, and this interests doctors and scientists because it creates curiosity regarding the potential of environmental factors increasing risk of a disease that is otherwise somewhat mysterious.
What to look for in a cluster
When a cluster is determined to exist, researchers start to look at any environmental factor that could play a role in increasing the number of cases of the disease, including elements such as:
- Genetic factors, since clusters often provide large groups of relatives in the same area
- Infections that may be common in the area, including those that may be resolved with vaccines in an area where it’s common for people to choose not to vaccinate
- Diet that could be contaminated or could be vastly different from other areas, which could include a “trigger food” not otherwise recognized
- Environmental or industrial toxins that could have been released into the area that come in large quantities for that particular community but are trace in other areas
- Elements of the climate that are unique to the area which aren’t mimicked in other areas of the world
- Exposure to trace metals, since these have proven to be the cause of other epidemics in the past
Determining if one or more of these could factor into the development of multiple sclerosis could provide insight into the disease and ways to either prevent it or cure it, rather than just treat it. Therefore, even though no link to a cluster has yet been proven, studies continue, especially since the identification of an MS cluster is extremely difficult to identify in the first place.
Obstacles to identifying multiple sclerosis clusters
Unlike some other diseases, trying to study clusters of MS is extremely difficult due to a number of obstacles that stand in the way. One enormous hurdle is that multiple sclerosis cases are not required to be reported, and a nationwide registry for multiple sclerosis cases does not exist, as with some infectious diseases. Therefore, determining exact rates of development is tough.
Additionally, even a projected expected rate of MS cases for an individual area is different, since both environmental and population elements weigh into that expected rate. For example, family history can increase or decrease the expectation of MS in the area, as well as climate in that geographical location.
These, however, are not the only factors that make studying MS clusters so difficult.
- Availability of information – Aside from not having to report cases, some areas of the world simply don’t keep complete records, making it difficult to trace the diagnoses even locally.
- Criteria for diagnosis – While a very specific set of criteria have to be met in the United States, Canada, and other countries, not all nations require such diligence, so there could be questions as to whether all the diagnoses made are, in fact, accurate.
- Lag time – With infectious diseases like the flu, timing is relatively easy to determine, with incubation time known and a general consensus on the time frame during which a cluster of cases occur. However, with multiple sclerosis, the lag time is uncertain. How long does it take for the initial symptoms to trigger a visit to a physician? How long of a remission was there between episodes? How long did it take for the physician to test and identify the symptoms as related to MS? All of this makes it more difficult to determine if all the diagnoses occurred within a close enough time frame to call it a cluster.
- Chance – With the unpredictability of multiple sclerosis, and lack of sufficient theory as to what triggers the autoimmune response that leads to MS, the idea of random chance causing a cluster to appear is quite a valid concern among researchers.
Despite inconclusive evidence that true clusters of multiple sclerosis exist, or that any one common factor links a cluster of cases to date, researchers continue to search for and study MS clusters to determine if they play a role in the development of the disease. If a common thread can be found among patients in a single area, it could lead to research on that particular factor, which might determine that it is the trigger causing the autoimmune response.
Once a trigger is found, work can be done to create a resistance to that element, including vaccinations, cures, and even avoidance of that element. And while searching for that answer, the identification of an underlying cause could easily improve the medications used to treat the disease in the meantime. Because clusters have answered questions for a number of other common diseases, the hope is that, someday, finding an MS cluster for full evaluation will point toward a resolution for the degenerative disease and bring back the quality of life lost to so many from its rampant attack on the body.