There has been no published research in this area. However, the anecdotal feedback has been excellent. Research is currently underway by Carol York in Austin, Texas. Based upon clinical feedback, she has an excellent protocol for working with this disorder.
Your clinician should be preparing you with a number of self-control techniques as part of the EMDR treatment. You should feel confident that you can stop the treatment and any disturbance at any time before you ever begin processing.
I urge you to discuss your concerns thoroughly with your therapist.