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Velopharyngeal Insufficiency
Velopharyngeal insufficiency (VPI), often called velopharyngeal incompetence, refers to a disorder resulting in incomplete soft palate closure against the posterior and lateral pharyngeal walls during production of non-nasal phonemes (such as p, f, s, sh, and t sounds). Another less common manifestation of VPI is incomplete closure of the velum (soft palate) during swallowing resulting in oral contents spilling into the nasopharynx and nasal cavity.
Perceptually, VPI may result in one of several abnormalities during speech production. Hypernasality refers to an increase in nasal resonance during vowel production. Nasal emission refers to the sound of air escape from the nose during production of pressure consonants. Nasal rustle, also known as nasal turbulence, is a type of nasal emission, which occurs when air passes through secretions or a narrow opening in the nasopharynx resulting in a prominent nasal gurgling or hissing sound during speech.
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Submucous cleft palate
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VPI is most commonly seen in children with a history of cleft palate, and it occurs in approximately 20-30% of patients after cleft palate repair. Submucous cleft palate occurs in roughly one in 1,200 children and may result in VPI. Submucous cleft palate may present with the classic triad of bifid uvula, zona pellucidum (an amuscular central portion of the velum), and hard palate notch. Alternatively, occult submucous cleft palate may present only with VPI and no obvious physical abnormality. VPI also may be seen in children with mental retardation, underlying hypotonia due to underlying diagnoses such as Down syndrome or cerebral palsy, and in individuals with substantial hearing loss.
Velocardiofacial and Digeorge syndrome are frequently associated with VPI. These two syndromes are both caused by microdeletions in the long arm of chromosome 22, thus much of the current literature refers to these syndromes as 22q11.2 microdeletion syndrome since they both fall under the umbrella of this genetic abnormality. Absence of the thymus gland with associated immunodeficiency, cardiac defects, low intelligence, learning disabilities, auricular deformity, and late development of psychiatric disease are other features of 22q11.2 microdeletion syndrome.
Persistent postsurgical VPI is seen in a small percentage of patients after adenoidectomy (estimates range from 1 in 1,450 to 1 in 10,000 patients undergoing adenoidectomy). Transient postsurgical VPI may occur in as many as 15% of patients undergoing adenoidectomy but generally resolves within a few weeks without any treatment. When postadenoidectomy VPI is noted, speech therapy is generally instituted for a brief period before proceeding to more aggressive treatment.
Formal diagnosis of VPI should be made by a speech pathologist experienced in the diagnosis and treatment of VPI. Nasometry and PERCI-SARS testing are adjuvant tests that aid in the diagnosis of VPI. These tests use different measures to compare nasal and oral aspects of speech to established normative values. Even though these tests supply objective information, formal perceptual testing by an experienced speech pathologist remains the gold standard for diagnosis of VPI. Longstanding VPI often results in compensatory speech abnormalities that add to the complexity of the treatment plan.
The otolaryngologist may aid in the diagnosis of VPI by examining the velopharyngeal mechanism during production of non-nasal phonemes. Absence of closure of the palate against the pharyngeal walls and bubbling through the velopharyngeal opening during speech are seen in VPI. Identifying the closure pattern (coronal, sagittal, circular) of the velopharyngeal mechanism can aid in surgical planning as well.
Sphincter pharyngoplasty and pharyngeal flap procedures are the mainstay of VPI treatment. The pharyngeal flap may be inset into the posterior soft palate to occlude the central portion of the velopharyngeal opening and to provide suspension of the velum. This procedure results in good speech results but a high rate of nasal obstruction and obstructive sleep apnea. The sphincter pharyngoplasty procedure rotates two superiorly based flaps from behind the tonsillar pillars to narrow the velopharyngeal opening resulting in a narrower central velopharyngeal opening which is more natural in appearance on nasal endoscopy. Reported rates of nasal obstruction and obstructive sleep apnea are lower after sphincter pharyngoplasty when compared to pharyngeal flaps.
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