Speech-Language Pathology/Stuttering/Other Fluency Disorders
Head injuries and strokes
Head injuries and strokes can cause repetitions, prolongations, and blocks - some cases being the result of Broca's aphasia, and others being an acquired disorder of neurogenically-based stuttering. Neurogenic stutterers lack the same types of struggle behavior, and the fears and anxieties of developmental stuttering.
Developmental stutterers can fluently speak certain memorized phrases, such as the "Pledge of Allegiance." Neurogenic stutterers are disfluent on everything. Developmental stutterers can speak fluently in certain (typically low-stress) situations. Neurogenic stutterers are disfluent everywhere.
Stuttering therapy techniques and devices help some individuals with neurogenic speech disorders, but don't help others. Because different people have different areas of their brains injured, a treatment that's effective for one person may not be effective for another person.
Rarely, traumatic experiences caused an adult to stutter. Psychogenic stuttering typically involves rapid, effortless repetitions of initial sounds, without struggle behavior.