Mediator Variable vs Moderator Variable. There is often confusion among students concerning the difference between a mediator variable and a moderator variable. The explanation involves some concepts that haven't been introduced at this point but it can still be worthwhile to discuss these types of variables.n analysis of variance (ANOVA) terms, a moderator effect can be represented as an interaction between a major independent variable and a factor that specifies the appropriate conditions for its operation, that is, the effect of the major independent variable depends upon the value of the moderator variable.
The most common form of myelopathy in human, cervical spondylotic myelopathy (CSM), is caused by arthritic changes (spondylosis) of the cervical spine, which result in narrowing of the spinal canal (spinal stenosis) ultimately causing compression of the spinal cord.
However, one of the more worrisome reasons that these symptoms are occurring is that bone spurs and other degenerative changes in the thoracic spine are squeezing the spinal cord. Myelopathy affects the entire spinal cord, and is very different from isolated points of pressure on the individual nerve roots.