A genetic pre-disposition along with various neurophysiological reasons are attributed as the cause or onset of stuttering. The speech impediment in most cases presents itself early, usually between the ages of two and five years. A significant amount of research has been done to study and treat stuttering in infants and children. Speech therapists are trained to understand and guide children who stutter through both the technical and emotional aspects of disfluency.

However, not much is discussed about the sudden onset of speech impediments in adult or senior (over 55 years) individuals. There can a number of reasons for the disfluency besides a family history of it.

Changes in Brain Structure

Trauma in form of a stroke or aneurysm can alter brain structure and motor-neuron pathways. The part of the brain that controls how language is processed and speech formulated when damaged causes disfluency. A concussion caused by a fall or head injury can lead to structural changes in the human brain.

Degenerative Neurological Disorders

Neurological disorders that over time damage multiple brain functions like Dementia, Alzheimer’s Disease, Parkinson’s Disease and Epilepsy are cause the onset of stuttering and other speech impediments in adults. It makes it extremely difficult to form, arrange, and speak words. This form of the disfluency can range from not being able to verbalize words to an inability to construct a sentence.

Changes in Medicines

With age come a plethora of ailments and an equally high concentration of pharmaceuticals to combat them. A negative reaction of one or more of these medications can be changes in speech patterns, diction, and fluency.

Drug Abuse

The abuse of narcotics like heroin, cocaine, and LSD can cause trauma and deoxygenation in the brain leading to the onset of disfluency. Abusing and overdose of barbiturates (medicines that treat seizures, headaches, and seizures) can also traumatize the brain and lead to speech impediments.

Emotional Trauma

Anxiety, depression, and emotional distress brought on by increasing financial pressures, uncertainty and fear about one’s mortality, confusion, loss of memory and autonomy can trigger impairment in self-expression. The sudden onset of stuttering due to underlying psychological distress isn’t exactly sudden and occurs with a genetic history of the impediment.

Age has emerged as one of the strongest factors of risk for speech defects. The accumulated evidence suggests that stuttering when it develops later in life is both persistent, aggravated and difficult to recover from. More can be learnt about persistent stuttering by studying the adults afflicted by a sudden onset of stuttering that continues into advanced years. The differences between these cases and those of young children can help understand the impediment more extensively.