Velopharyngeal Insufficiency Workup

Updated: Apr 17, 2019
  • Author: Michael J Biavati, MD, FACS, FAAP; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Workup

Diagnostic Procedures

Voice and resonance evaluation: A voice and resonance evaluation completed by a speech/language pathologist (SLP) can provide informative data in determining the appropriate course of treatment of velopharyngeal dysfunction (VPD). A thorough voice and resonance evaluation for VPD includes articulation assessment, oral motor assessment, and measurement of nasal airflow.

  • Articulation assessment: Measures of articulation ability, such as the Articulation Proficiency Scale, are administered at the single-word level to determine articulation errors. The patient's speech intelligibility is rated based on this scale and characterized as mild, moderate, or severe. Types of articulation errors also are described, including distortions such as nasal emissions, glottal stops, or nasal fricatives. The patient's response to correction of articulation errors, distortions, nasal emissions, and hypernasality also is assessed in order to determine prognosis for improvement with speech therapy.

  • Oral motor assessment: A subjective oral motor assessment is completed by observing range of motion and speed of the lips and tongue and observing the soft palate and velar elevation when pronouncing the phoneme /ah/. Overall facial symmetry and muscle tone also are noted.

  • Measurement of nasal airflow: The MacKay-Kummer Simplified Nasometric Assessment Procedures (SNAP) test is administered to children aged 3-9 years with Pentax Medical's Nasometer to assess the ratio of oral airflow to nasal airflow. For children aged 9 years and older and for adults, the Zoo Passage, Rainbow Passage, and Nasal Sentences are substituted as standard reading passages. Nasometer results are compared to normative data. A score 3 standard deviations above the mean indicates hypernasal resonance, i.e., speaking with too much airflow and resonance in the nasal cavity. A score 3 standard deviations below the mean indicates hyponasality, which is defined as insufficient nasal resonance for the nasal phonemes (ie, /m/, /n/, /ng/).

Cephalometry can be used to delineate factors such as C1 vertebral abnormalities, excessive pharyngeal depth, and short velum that contribute to VPD in VCF syndrome. [2]

Fiberoptic nasoendoscopy: Following voice evaluation, a determination of the need for fiberoptic nasoendoscopy (FN) is made based on the test results. Indications for FN include hypernasality (either consistent or inconsistent), poor oral airflow with nasal escape, and structural abnormalities of the soft palate. If none of these conditions exist and the patient presents with sufficient oral airflow for most phonemes, speech therapy typically is recommended with periodic reevaluation prior to completion of nasoendoscopy.

  • Sedation: Sedation is typically not used for this procedure. In certain instances, children under 5 and older children who are uncooperative sedation may be helpful. Typically oral midazolam (Versed) is administered at a dose of 0.5 mg/kg (up to 10 mg) and given 15-20 minutes prior to FN. This dosage provides adequate amnesia and sedation while allowing the child to perform the necessary tasks for the examination. Higher doses of midazolam may make the examination difficult because the child is sedated too heavily.

  • Topical anesthesia: Prior to placement of the fiberscope, the nasal cavity is examined for any obstructions that may inhibit passage of the scope into the nasopharynx. The nose then is decongested and anesthetized with a mixture of 4% lidocaine and 0.05% oxymetazoline hydrochloride, which is sprayed into the nose with an atomizing device.

  • Procedure: The fiberscope is passed through the nostril, superior to the inferior turbinate, to the posterior nasal choana. Passage of the scope along the floor of the nose does not position the fiberscope high enough to allow for visualization of the entire velopharyngeal sphincter. With the fiberscope in place, the patient is asked to repeat a series of words and sentences loaded with phonemes that require increased oral airflow (eg, plosives, fricatives) in order to observe the velar closure pattern. The examination is videotaped for later review. Patients who are unable to vocalize these phonemes may be grossly assessed by this technique by looking at overall VPC and identifying any deficiency in each of the specific planes of closure.

  • Advantages and disadvantages: Nasoendoscopy is superior to other methods of assessing VPD (ie, videofluoroscopy) in that it allows for direct visualization of the velopharyngeal sphincter. This is especially important in the postsurgical patient when the velopharyngeal anatomy is altered, such as following placement of a pharyngeal flap. As compared with videofluoroscopy, FN is slightly more invasive and requires a moderate degree of cooperation from the child to obtain an adequate examination.

Videofluoroscopy: Videofluoroscopy (VF) is performed by the SLP in conjunction with a radiologist. Unlike nasopharyngoscopy, VF enables the examiner to see through tissues, so that movement can be discerned at all vertical and horizontal planes within the pharynx. A 3-dimensional perspective can be gained using frontal and lateral projections, along with base or Towne projections.

  • Procedure: VF usually is performed without sedation. Barium is instilled through the nose using a nose dropper in order to contrast soft tissues against the surrounding skeletal structures. Fluoroscopic views then are obtained in the lateral, anteroposterior (frontal), and base projections while the patient articulates phonemes that require increased oral airflow. The lateral view helps the examiner visualize the velum, posterior pharyngeal wall, and tongue. The frontal view enables assessment of the lateral pharyngeal walls along the entire vertical extent of the pharynx.

  • Advantages and disadvantages: VF allows more precise localization of the level of VPC by measuring the level against the spine. Observation of the tongue is also important, as the tongue may contribute to closure in a compensatory fashion by lifting the palate, as is seen in swallowing. This information may be missed with nasopharyngoscopy alone. VF has the obvious disadvantage of radiation exposure. In addition, when normal anatomy is altered (eg, postsurgery), interpretation of the images may be difficult.