Mo. Rev. Stat. § 287.470

Upon its own motion or upon the application of any party in interest on the ground of a change in condition, the commission may at any time upon a rehearing after due notice to the parties interested review any award and on such review may make an award ending, diminishing or increasing the compensation previously awarded, subject to the maximum or minimum provided in this chapter, and shall immediately send to the parties and the employer's insurer a copy of the award. No such review shall affect such award as regards any moneys paid.