Very interesting question! And I am glad I am not the only one who has pondered on this. You'd be surprised to know the amount of quality research there has been into stuttering. A while ago I got obsessed with the neurological sources of stuttering. And as someone has pointed out earlier, there is a reduced level of blood flow into the Broca's region that is responsible for speech. For a long time I was a staunch denier of neurological connections of stuttering. Because to me it signified a sense of permanency. That we're bound neurologically to be this way. This belief led me to research more, since after years of therapy, I have improved a lot. I started to research on the impact of speech therapy on neurological patterns of stuttering. Voila! It's been done. People whose speech improved over a period of time displayed greater blood flow to the broca's region than previous results. Thus bursting the myth of permanency. This further led me to research on neuroplasticity, the theory that our brain is constantly reshaping itself. Wonderful stuff out there. At the end of the day, neurological patterns of stuttering are not permanent (far from it) and can be changed by concerted practice and internalisation. What makes the research on stuttering so difficult? Funding of course is one of the prime reasons. But, I believe what afflicts research more is the personalised nature of stuttering. Stuttering affects every person differently. It's never the same for two people. My therapist tells me that therapy is never the same for two people, we have to tweak it to suit the person's stutter. Different situations affect us differently, bring forth varied emotions, etc. Even if we could pin point the exact region or area or understand what stuttering is, it is very unlikely that we will see a drug come out that alleviates it permanently. One cannot side step the deep psychological aspect of stuttering. And you voiced my biggest irritant with stuttering too. The sudden fluency that we gain. Days when we are absolutely fluent and yet dreadfully know in our minds that it's short lived. But you know, after years and years of therapy and practice (both speech and psychological reinforcement), the time span for those bad spells is drastically shorter than before. I think it's a lost battle waiting for science to come up with a solution. We all would love a cure, but it's not coming any time soon. And even if it does, it won't be enough just by itself. Take matters in your hands. Challenge yourself. Fall, burn and crumble and rise again like a phoenix.