What Is Velopharyngeal Insufficiency (VPI)?
Velopharyngeal insufficiency (VPI) is a disorder resulting in the improper closing of the velopharyngeal sphincter (soft palate muscle in the mouth) during speech, allowing air to escape through the nose instead of the mouth. This is often observed during speech, when attempting to us consonants "p," "b," "g," "t" and "d." If this is not closed, snort sounds may be produced through the nose or you may hear air coming out of the nose during speech. Improper function of this structure also produces a nasal tone in the voice.
To close off the nose from the mouth during speech, several structures {velum (soft palate or roof of the mouth), the lateral pharyngeal walls (side walls of the throat) and the posterior pharyngeal wall (the back wall of the throat} come together to achieve velopharyngeal closure.
Velopharyngeal Insufficiency in Children
The most common cause of VPI is a history of cleft palate or submucous cleft (cleft covered by the lining or mucous membrane of the roof of the mouth). About 20% to 30% of children who have cleft palate with or without cleft lip will have persisting VPI after their palate repair. A small percentage of children with submucous cleft palate will also have VPI. Sometimes VPI develops after an adenoidectomy (a surgical procedure to remove adenoids or lymphoid tissue in the back of the nose). Children who are born with weak throat muscles or who suffer a traumatic brain injury that results in weak throat muscles may have VPI. Sometimes children have VPI from an unknown cause
The two main speech symptoms of velopharyngeal insufficiency (VPI) are hypernasality and nasal air emission.
- Hypernasality is sometimes called nasal speech. In English the sounds "m," "n" and "ng" are the only sounds that should resonate nasally. Hypernasality occurs when sounds other than these resonate through the nose, and it varies from mild to severe.
Some other consonants can be produced without velopharyngeal closure, including "h," "w," "y," "l" and "r."
The rest of the consonants are referred to as pressure consonants because they require buildup of air pressure in the mouth to produce normal sounds. - Nasal air emission occurs when air escapes through the nose on pressure consonants, and it can sound like puffs, squeaks or snorts, or it might make speech sound muffled.
Children sometimes develop unusual speech sounds to compensate for their VPI. A common one is a glottal stop, produced by stopping air with the vocal cords (as one would do when saying "uh oh").
Some other sounds are made by awkward stopping or restricting air with the tongue in the throat or mouth in unusual ways.
Velopharyngeal Insufficiency Diagnosis
To diagnose VPI, a speech language pathologist will assess your child’s speech.
Your child will also see an otolaryngologist (ear, nose and throat specialist) for an exam. This doctor will insert a flexible fiber optic tube into your child’s nose to see the back of their throat where their velopharyngeal muscles are attempting to close. This is called nasopharyngoscopy.
When figuring out whether your child has VPI, it is just as important to find out if your child has difficulties with articulation (the way they make sounds), speech coordination (putting the sounds together) and voice (producing a sound from the voice box or larynx).
VPI Treatment
1. Speech therapy
Some speech problems linked with VPI, such as mispronouncing words, can be treated by speech therapy.
Treatment focuses on teaching the child the correct manner and place of articulation. In most cases, VPI speech symptoms cannot be decreased solely by speech treatment.
2. Surgery:
The Furlow palatoplasty is designed to bring the abnormally positioned muscles of the palate into a more normal position so the palate can move better.
When doing a sphincter pharyngoplasty , the surgeon moves tissue from the back of the throat closer to the back of the palate.
A sphincter pharyngoplasty surgery is recommended when the surgeon decides that the palate is working as well as it can, but the back of the throat isn’t moving correctly so the sides of the complex are used to fill the gap.
Sometimes a child will have minimal movement of the palate or the throat and may require both of these surgeries to be done at the same time.
Some patients who have surgery will still have VPI and may require additional surgery.
