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.
Cervical stenosis only causes symptoms if it causes compression of the nerve roots or spinal cord. If so, the patient is said to have radiculopathy (compression of a nerve) or myelopathy (compression of the spinal cord). The symptoms of radiculopathy are limited to pain, weakness or numbness in one arm. The symptoms of myelopathy are much more diffuse and can be quite confusing.