What is Velopharyngeal Insufficiency?
When velum, commonly known as the soft palate, fails to close tightly against the posterior wall or pharyngeal wall of throat, during speech, allowing the air to come out of the nose and making the speech difficult to understand due to hypernasality and/or nasal air emission is called as Velopharyngeal Insufficiency. Speech requires sound (from vocal cords) and airflow from lungs which are directed into the oral cavity (mouth) for the production of all speech sounds. Swallowing and speaking activities mainly depends on the ability to achieve adequate closure of velopharyngeal area. Important part of speech production is the velopharyngeal valve which is mainly built up of the following structures.
- Lateral Pharyngeal Walls and,
- Posterior Pharyngeal Walls.
Velopharyngeal insufficiency mainly leads to dysfunction of parts of throat and roof of the mouth at the time of speech. Hyper nasality (a resonance disorder) or audible nasal emission (a speech sound disorder) occurs if complete closure does not occur at the time of speech. Inadequate airflow makes some consonants sound to be weak or omitted.
Symptoms of Velopharyngeal Insufficiency
There are mainly 2 symptoms of Velopharyngeal Insufficiency which happens when the palate does not touch the back of the throat during speech. They are as follows.
Hyper Nasality (Nasal Speech). The sounds which are produced through the consonants m, n and ng are basically the only sounds which sound nasal. Hyper nasality is the cause when nasal speech happens to resonate other sounds through the nose. This condition can be mild or can become severe at sometimes. Nasal speech can be heard at the time of saying vowels or sounds like w, y, l, or r.
Nasal Air Escape (Sounds). Nasal Escape or also known as Nasal Air Emission happens when air escapes from the nose when someone makes pressure consonants. The pressure consonants can be p, t, d, b, k, g, z, f, v, s, sh, zh, ch, th and dj mainly. They are so called as pressure consonants because when the palate closes it builds up pressure in the mouth and seals off the mouth from the nose.
Causes of Velopharyngeal Insufficiency
The main causes of Velopharyngeal Insufficiency (VPI) include.
- Structural causes which you can find in some examples like cleft palate
- Neuromuscular causes which are observed in velocardiofacial (VCF) syndrome
- Functional causes like splinting of palate after tonsillectomy surgery, imitation of familial or cultural role models, as well as phoneme-specific problems
- Abnormal Anatomy
- Abnormal Neurophysiology (velopharyngeal incompetence)
- Particular articulation errors (velopharyngeal mislearning).
Diagnosis of Velopharyngeal Insufficiency
Before moving on to the treatment part, it is very important to find out what type of velopharyngeal insufficiency is a patient suffering from. Here are some of the following steps through which it can be diagnosed.
Velopharyngeal Insufficiency can be diagnosed by perceptual speech assessment through a speech pathologist. Many patients may develop new pronunciations as compensation for the consonants, where much of the sounds are produced inside the pharynx, where adequate airflow is present.
Nasometry to Diagnose Velopharyngeal Insufficiency.
It is a method which is mainly used to measure the acoustic correlates of resonance and velopharyngeal function through a computer-based instrument. This gives a speech pathologist a complete nasalance score which is the total percentage of nasal sound during speech production. Evaluation of hypernasality can be done through nasometry; hence, it is also use for pre and post-surgical comparisons.
This is an endoscopic technique in which a small endoscope is passed through the patient’s nose to the nasopharynx which is mainly done by the physician or the speech pathologist. This passage views the velum (soft palate) and the pharyngeal wall (throat walls) during nasal breathing and at the time of speech. Detailed view of size, location and causes of velopharyngeal insufficiency can be visualized without harming a patient.
Videofluoroscopy for Diagnosing Velopharyngeal Insufficiency.
Videofluoroscopy is a radiographic technique which usually measures the length and movement of the velum and also the lateral and posterior pharyngeal walls during speech. The entire posterior pharyngeal wall can be visualized through this technique.
Magnetic Resonance Imaging (MRI) to Diagnose Velopharyngeal Insufficiency.
This is basically a new approach for diagnosis of velopharyngeal insufficiency which is noninvasive. Atoms in the body can be imaged as this is a property of nuclear magnetic resonance. This can be repeated more often at short period of time because this is a non-radiographic technique. However, this process is not widely used for clinical diagnostic purpose as this requires radiation and it is much more expensive than the videofluoroscopy or nasopharyngoscopy.
Treatment of Velopharyngeal Insufficiency
Treatment mainly depends on the types and the causes of velopharyngeal insufficiency. The treatment of velopharyngeal incompetence or the velopharyngeal insufficiency usually requires surgery; however, it does not affect the way of talking. Some of the treatments are described below.
- Speech Therapy. This therapy is usually needed after a surgery to help make the sounds correctly. It is more appropriate to consult a speech therapist who has previously dealt with velopharyngeal insufficiency and successfully corrected it. Treatment can be done with a surgery or even with a prosthetic device in the case when no surgery can be performed.
- Nasal Continuous Positive Airway Pressure Therapy. Continuous positive airway pressure therapy (CPAP) is beneficial for patients suffering from velopharyngeal insufficiency. This therapy is a palate-strengthening program done through a nasal mask for about 8 weeks which causes velum to open and close against air pressure.
- Operative Techniques. Here are some of the operative techniques which are used to treat velopharyngeal insufficiency.
- Pharyngeal flap
- Sphincter palatoplasty
- Posterior wall augmentation.
- Non-operative Techniques for Velopharyngeal Insufficiency. Prosthesis is mainly used as a non-surgical procedure in a situation where surgery for velopharyngeal dysfunction is contraindicated.
Prevention of Velopharyngeal Insufficiency
Velopharyngeal insufficiency mainly doesn’t have any preventions and it can’t be prevented. However, if you are pregnant women then you should have to take care a lot. During pregnancy, women should reduce the risk of infections as sometimes it puts the unborn baby at risk for developing a cleft palate/cleft lip.
Pharyngeal flap and sphincter pharyngoplasty found to be the safe procedures for treatment of velopharyngeal insufficiency. Even after going through a surgery many patients may not achieve complete closure and show a decreased size in velopharyngeal openings.