Why don't scientists look into neurogenic Stuttering to see what is wrong in the brain?

Why don't scientists look into neurogenic Stuttering to see what is wrong in the brain? Developmental or acquired after a stroke the end result is the same: Stuttering. Why don't scientists look into Stuttering caused let's say after a stroke to see what is wrong on the people's brain afterwards? And if neurogenic Stuttering is curable why isn't developmental? I don't get it.