Do you have other symptoms,such as prolongations,strange facial and body expressions,or extra sound?I've only caught blocks and other presentations are always normal like the writer of <Redefining Stutter>. Have you tried Joseph Sheehan's conflict theory?He pointed out that blocks are induced from your mental contradictions between fears of being ridiculed about your stutter and urges to spit your words out,although I can't find relevant researches about it but it's making some senses for me.