Speech Defects (Aphasia, Dysphonia, and Stuttering)
Because speech is essential to human communication, anything that interferes with it can be isolating and emotionally distressing. Primary mutism, in which a person cannot speak due to absent vocal cords or another structural defect, is rare. More commonly, difficulty speaking is secondary to other conditions, including paralysis, deafness, retardation or other mental disorders, and larynx cancer. In certain cases, a person knows how to speak but has difficulty forming words.
Three often encountered disorders are: Aphasia (from the Greek, meaning "without speech"), in which brain damage impairs a person's ability to speak and/or understand spoken or written words. Sudden aphasia usually is due to a stroke or a head injury, whereas the likely cause of slowly developing aphasia is a brain tumor or progressive dementia.
Stuttering, in which speech is disrupted by the involuntary repetition or prolongation of certain sounds. About 2.5 million Americans stutter. The problem usually begins between ages two and five, with male stutterers outnumbering females threefold. Many youngsters outgrow stuttering by the time they reach adolescence, but for others it remains a lifelong problem. Until recently, stuttering was attributed mostly to anxiety or other emotional problems. Although these may be contributing factors, research implicates subtle brain abnormalities as the major cause.
Spastic dysphonia (from the Greek, meaning "faulty sound"), a neuromuscular disorder in which unpredictable spasms compress the vocal cords, causing irregular speech that may sound choked or whispered. The problem, which originates in the nerve cells at the base of the brain that control the laryngeal muscles, usually begins between ages 40 and 50 and affects more women than men. In some cases, the condition seems to be hereditary; in others, it is triggered by an injury, stroke, or exposure to certain chemicals. Stress intensifies the symptoms but does not cause them.
Diagnostic Studies and Procedures
The nature of the speech problem is usually obvious; hence, diagnostic studies are directed to finding a possible underlying cause. In the case of aphasia, tests generally include X-rays and CT scans or MRI to assess a stroke or look for a tumor. An evaluation by a psychologist or psychiatrist may be recommended if the aphasia is associated with Alzheimer's disease or other forms of dementia.
An ear-nose-throat specialist (ENT physician or otolaryngologist) is able to diagnose dysphonia by inserting a flexible viewing tube into the larynx and observing the structure and functioning of the vocal cords.
The underlying causes of aphasia and dysphonia may be treated with drugs, surgery, or a combination of the two.
A promising experimental treatment for dysphonia involves injecting very small amounts of botulinum toxin, the substance that causes botulism, into the muscles that control the vocal cords. Preliminary studies show that this can restore normal or near-normal speech for up to four months, after which the injection is repeated. The injections are administered through the neck under local anesthesia.
Stuttering is best treated with a combination of the speech therapy and self-help techniques described below.
Biofeedback. This technique may help some persons overcome stuttering and mild dysphonia.
Music Therapy. Stutterers and people with aphasia can often sing without difficulty. A form of music therapy called melodic intonation can improve the ability to communicate.
Speech Therapy. Trained therapists use a combination of physical therapy, speech techniques, computer aids, tape recordings, and other devices to help patients overcome aphasia or stuttering. Patients are taught special techniques for talking on the telephone and public speaking. An experimental method of communication called computerized visual communication employs pictures on a computer screen to represent the various parts of speech.
Visualization and Meditation. These and other relaxation techniques can help a person overcome some speech problems, especially those that are worsened by stress.
Speech therapists usually prescribe fluency exercises, which should be done daily. A tape recorder can be helpful in measuring progress.
The National Aphasia Association a suggests the following to help those with speech problems:
- Reduce background noise and give the speaker your full attention. Be patient; refrain from finishing sentences or speaking for the person unless it is absolutely necessary.
- Try not to ask questions that require complicated answers. Give the person time to answer or to backtrack and correct a mistake.
- Speak simply, slowly, and use a normal tone of voice. If the person has suffered brain damage and reacts with incomprehension, repeat what you said, perhaps using simpler key words.
Other Causes of Speech Problems
In addition to the disorders listed earlier, speech problems may be caused by cerebral palsy and other birth defects, Parkinson's disease, multiple sclerosis, and autism. Laryngitis causes temporary loss of voice. Rarely, a type of hysterical neurosis can produce mutism.