Velopharyngeal insufficiency
Velopharyngeal insufficiency refers to the inability of the velopharyngeal sphincter to close completely during production of the oral (nonnasal) sounds of speech.
The primary effects of velopharyngeal insufficiency are nasal air escape and hypernasality.
Incidence
Satisfactory speech results occur in about 80% of pts after primary palatoplasty
Further 15 % achieve normal speech with speech therapy
5% require further management with due to insufficient secondary palate closure
In this 5% air escapes through the nasopharynx when attempting to produce certain sounds precludes normal speech
Important to realize that the presence of abnormal speech is not an indication for surgery and thorough assessment of the defect is need
Normal speech production
Sphinter remains open
Nasal sounds – M N
Useful to test for overcorrection post surgery – Mamma made some mittens
Complete closure required
Plosive consonants – K T P – Pick up the book
Fricative consonants – F S - Suzy sees the scissors
Voice requires quality, richness and carrying power
Also clear, precise consonants
Classification based on aetiology
velopharyngeal insufficiency(VPI) - structural origin and includes structural problems associated with the velum or the side walls at the level of the nasopharynx with insufficient tissue to accomplish adequate closure
velopharyngeal incompetence(VP incompetence) – neurogenic origin
velopharyngeal mislearning -mislearning or functional origin
Velopharyngeal dysfunction – all encompassing term for the above and does not imply a specific etiology
Pathophysiology
Previously thought that VP closure resulted from a short velum. And thus the push back procedures were used with little success. Now known that the closure of the VP is a complex mechanism and thus need accurate Ix
Four closure patterns (Skolnick)
Coronal - mostly palate (most common)
Sagittal - mostly lateral wall (least common)
Circular - both palatal and lateral wall
Circular with Pasavants ridge – posterior, palatal and lateral walls
Aetiology
Cleft
unrepaired
repaired
submucous cleft
fistula
NonCleft
anatomic
neuromuscular
behavioral/functional
Cleft palate
poor muscle sling
poor elevation
short palate
immobile scarred palate
subclinical disease may manifest later due to:
adenoidal involution at the time of puberty
adenoidectomy
Orthognatic (LeFort) advancement – controversial.
Mr Baker says this does not occur
Noncleft
Anatomic
> congenitally short palate
> reduced palatal bulk
> deep/enlarged pharynx
>adenoidectomy
> maxillary advancement
> tumour resection
Neuromuscular
> cerebral palsy
> head injury
> cva
> neuromuscular disorder – amyotrophic lateral sclerosis
combined
velocardiofacial syndrome (shprintzen syndrome)
square nose, narrow ala base
long face, retruded chin
hypotonia
cardiac defects
intellectual impairment or learning disabilities(50%)
CLINICAL
hypernasality
nasal emission
nasal turbulence
nasal substitution
compensatory articular patterns (distortions, substitutions, and omissions).
weak omitted consonants
nasal/facial grimace
hoarseness
low volume voice
monotonous voice
breathiness
unusual pitch variations
nasal fluid regurgitation
utterances or sentences are short and their speech tends to take on a choppy pattern because of the leak
DIAGNOSIS
Oral examination
size
movement
symmetry
elevation on phonation
dentition
occlusion
fistula
nasal air escape using mirror
Perceptual evaluation – the most important
attempts to define characteristic speech of vpi and quantify severity
consult speech therapist
Investigations
information on :
type of closure
size of vp gap
evidence of fatigue
consistency of performance
Videofluroscopy
video recorded radiograph
barium paste nasally
lateral and frontal views
Townes view (30 head down, mouth wide open)
info on size of gap, pattern of closure and degree of palate elevation
Method
barium paste instilled intranasally which coats the surface of the oropharynx and then the pt is asked to duplicate certain sounds while the fluoroscopic images are taken with the lateral , frontal and submental views being the most important
when the adenoids are enlarged the Townes view demonstrates the VP orifice better than the basal views
Nasendoscopy
direct visualization of the velopharyngeal mechanism
recommended in conjunction with video fluoroscopy giving mainly quantitative information and the nasendoscopy giving mainly qualitative information
fine flexible scope
rigid scope
type and degree of closure
not successful in young children
useful adjunct to vf in difficult cases
some use routinely
Nasometer
Nasalance is a ratio of the nasal acoustic output relative to oral plus nasal acoustic output and is expressed as a percentage.
sensitivity and specificity of nasometry in correctly identifying subjects with more than mild hypernasality in their speech - 89% and 95%, respectively.
other
accelermeter
aeromechanics
CT and MRI angiography
useful in picking up abnormal medial displacement of the carotid artery
abnormality of the internal carotid is common in VCF syndrome
10% found to be located just under the pharyngeal mucous membrane and thus can be endangered in raising pharyngeal flap
Sommerlad (Cleft Palate Craniofac J. 2004 Jul) - Examination and palpation of the pharyngeal walls after the patient is positioned for surgery appear to be reliable in detecting abnormal pulsations and allow accurate surgical planning. Routine vascular imaging, even in patients with pulsations on preoperative nasendoscopy is not essential and may not always be reliable, as shown by the variation in endoscopic, MRA, and intraoperative findings.
Management
Nonoperative treatment
Speech therapy
generally not enough in itself for structural problems related to VPI.
It is, however, valuable for small gaps or inconsistent closure
very valuable either before or after surgery, or both, in order to eliminate compensatory strategies that patients develop over time.
Prosthesis
Poorly tolerated in children. Mainly indicated where surgical risks are prohibitive.
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