Stuttering is also believed to be caused by neurophysiology. Neurogenic stuttering is a type of fluency disorder in which a person has difficulty in producing speech in a normal, smooth fashion. Individuals with fluency disorders may have speech that sounds fragmented or halting, with frequent interruptions and difficulty producing words without effort or struggle. Neurogenic stuttering typically appears following some sort of injury or disease to the central nervous system. Injuries to the brain and spinal cord, including cortex, subcortex, cerebellar, and even the neural pathway regions.