Nothing in the Industrial Insurance Act precludes a worker who is receiving a permanent total disability pension from engaging in employment which is not "gainful." Part-time employment paying less than full-time employment at minimum wage may not be gainful. Therefore, unless medical evidence of diminution of disability is presented or evidence establishes the worker has returned to "gainful" employment, pension benefits cannot be terminated. ....Norman Pixler, 88 1201 (1989) [dissent] [Editor's Note: The Board's decision was appealed to superior court under Spokane County Cause No. 89-2-04666-5.]