Upon the Commissioner's own motion or upon the application of any party in interest upon the ground of a change in the conditions, or whenever doubts have arisen as to the jurisdiction of the Commissioner at the time the petition was presented, the Commissioner may at any time within six years of the date of award review any award by giving at least six days' notice thereof to the parties personally, or to the attorneys appearing in the cause. On such review, the Commissioner may make an order ending, diminishing, or increasing the compensation previously awarded, subject to the maximum or minimum provided in this chapter. If it appears that the petition for hearing was presented without previous authority or that for other reason the Commissioner did not have jurisdiction in the cause, the Commissioner may make an order striking off the award, and shall state conclusions of fact and rulings of law and immediately send to the parties a copy of the award. Such a review shall not affect any money already paid. (Amended 1993, No. 225 (Adj. Sess.), § 13.)