Do We Know What Causes ALS?

ALS is a neurological disorder where a degradation of motor neurons occurs.  This progresses over the course of 3-5 years leading to complete muscle loss in vital organs.  In the early stages of the disease the patient experiences muscle weakness, stiffness, spastic and tightness, poor balance, slurred words, and can be limited to a single body region.  In middle stage of the disease symptoms become more wide spread, some muscles become paralyzed, joint pain, weakness in swallowing, and weakness in breathing.  The late stages of the disease present them self in the form of voluntary muscles are paralyzed, the ability to move air in and out of lungs, limited mobility, may no longer be able to speak, and eating/drinking no longer possible.  With such a progressive disease one would hope that we would know what causes it.

Sadly, in short the answer is we don’t know a direct cause.  5-10% of ALS patients develop due to genetic traits that have been passed down through family lines.  90-95% has a form of ALS called sporadic ALS.  This form of ALS still has no unknown direct cause or causes.  The research done on this disease has fallen short of finding any link to environmental factor which could be causing it.  Researchers have speculated a few ideas to what may be the cause of it though.  Some believe it could be caused by heavy metals like lead and mercury which have been linked to having neurological effects.  They also believe it could be organic solvents, many of which have been linked to cancers.  The findings, however, are mixed which leaves us with no conclusions.  They also think warfare may be the cause of it.  Reports say that people who went to war are 1.5-2.0 times more likely to get ALS then those who never went to war.  However, the numbers of people tested are too small which leaves most to believe that this might be just a statistical anomaly.  Some think ALS could be caused by some kind of unknown virus.  There is no evidence for this claim; however, they base their hypothesis off the Polo virus.  Finally, and my personal favorite speculation on the cause of the disease comes from a person’s diet.  They think that the combinations of foods a person specifically eats could cause it.  There is a little island called Guam where the ALS population is extremely high.  They think this is due to their diet of whole bats cooked in coconut milk.  All in all as of right now no research has come up with any specific cause or causes that are responsible for ALS.