Diagnosis and Treatment of Velopharyngeal Insufficiency

20 Pages·2009·0.67 MB·English

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Diagnosis and Treatment of
Velopharyngeal Insufficiency
Matthew T. Brigger
Jean E. Ashland
Christopher J. Hartnick
CLINICAL CASE vided additional history that suggested he
might have some degree of sleep apnea.She
gave support to the notion that,were he to
A 4-year-old boy presented for evaluation of
develop worse sleep apnea postoperatively,
his “abnormal voice.” His mother reports
there would be no access on the island to
that since he has been able to speak he has
anyone with expertise in diagnosing and
never made clear “s” and “p” sounds. She
managing such a condition. Given the his-
reports that to most people he is unintelli-
tory,a sphincter pharyngoplasty was offered
gible.She is seeking options for therapy,but
in place of a posterior pharyngeal flap.The
currently lives on a Caribbean island with
child underwent surgery uneventfully and
minimal access to speech services or surgi-
noticed immediate improvement.Six months
cal care. The child has no other medical
later his results were maintained.
problems, feeds well, and has no previous
surgical history. His examination shows a
healthy energetic boy with no evidence of
INTRODUCTION
craniofacial dysmorphisms. However, he
demonstrates markedly hypernasal speech.
Fiberoptic examination demonstrates a short The complex neuromuscular functions that
palate with decent lateral wall motion. regulate human speech are not limited to
Nasometry is consistent with marked nasal the larynx.The sphincteric interaction of the
air escape. Given his anatomic deficit, sur- palate (velum) within the pharynx is criti-
gical management was offered. In discuss- cal to the production of intelligible speech.
ing the potential risks and benefits of each Velopharyngeal insufficiency (VPI), or the
surgical option with his mother, she pro- inability to effectively seal the nasopharynx,
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226 CLINICAL MANAGEMENT OF CHILDREN’S VOICE DISORDERS
results in loss of resonant control of speech function (VPD).3 For the purposes of this
and in some cases,optimal intraoral pressure chapter,VPI is used to connote velopharyn-
to achieve orally directed speech sounds. geal inadequacy.
Given that the nasopharynx is effectively
closed during the vast majority of speech,
this can significantly impact speech intelli-
PERTINENT ANATOMY
gibility. A lack of speech intelligibility has
an obvious detrimental effect to affected
children, but even mild cases of VPI can A brief review of anatomy is requisite to
alter a child’s effective communication and understanding the problem of VPI and the
their well-being as speech provides a bridge potential implications regarding evaluation
to the people around us. The etiology of and treatment. In general terms, the velo-
VPI varies from residual speech patterns pharyngeal port is a sphincter that regulates
after cleft palate repair to congenital anom- airflow through the nasopharynx.The de-
alies of the soft palate (eg, shortness, sub- gree of regulation manifests in the produc-
mucous cleft) as well as weakness or motor tion (or lack thereof) of nasal resonance.
planning difficulties.1 Subsequently, the In simple terms,six muscles constitute the
approaches to assessment and intervention sphincter. These include the levator veli
are variable and often need to be tailored to palatini, tensor veli palatini, palatoglossus,
the individual child. palatopharyngeus,muscular uvula,and supe-
rior pharyngeal constrictor. All except for
the superior constrictor comprise the soft
palate, also known as the velum.Anatomi-
SEMANTICS
cally,the soft palate is located at the poste-
rior aspect of the maxilla protruding from
Terminology used within the VPI literature the hard palate.The Latin term velum refers
is limited by redundancy and inconsistencies. to a “ship’s sail”and connotes the flat sheet-
In addition to velopharyngeal insufficiency, like shape of the soft palate as it protrudes
commonly used terms include velopharyn- posteriorly. By separating the oropharynx
geal dysfunction, velopharyngeal inade- from the nasopharynx,the palate has both
quacy, and velopharyngeal incompetence. an oral and nasal surface.
These terms are often used interchangeably. Regarding the musculature,motor con-
When specific terminology is used, varia- trol is primarily mediated through branches
tions of the classification introduced by Trost of cranial nerve X except for the tensor veli
in 1981 seem to be the most common.2 In palatini which is innervated by a motor
the classification,an all encompassing term branch of cranial nerve V.The paired leva-
velopharyngeal inadequacy is used to de- tor palatini serve as the primary muscle
scribe velopharyngeal mislearning (faulty mass of the soft palate and form a sling sus-
learning of articulation patterns), velopha- pended from the skull base.4 The muscle
ryngeal incompetence (neurologic dysfunc- serves to elevate the palate in a posterior
tion leading to impaired motor control of direction. This motion is counteracted by
the palate),and velopharyngeal insufficiency the action of the palatoglossus (anterior
(an anatomic deficiency of insufficient tis- tonsillar pillar) and the palatopharyngeus
sue for closure). A similar, widely used all (posterior tonsillar pillar).Although the lev-
encompassing term is velopharyngeal dys- ator veli palatini provides the muscular
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DIAGNOSIS AND TREATMENT OF VELOPHARYNGEAL INSUFFICIENCY 227
mass of the velum, the tensor veli palatini and respiration.10 Ultimately the complex
contributes the majority of the fibrous com- neuromuscular interaction and subspecial-
ponent referred to as the palatal aponeuro- ization of muscle fibers highlights the
sis.4 The primary action of the tensor veli importance of approaching VPI as more
palatini is to facilitate middle ear aeration than a simple anatomic deficit and realizing
and overall has a minimal effect on velopha- that the manifestations of VPI can result
ryngeal closure.5The muscular uvula tenses from a variety of insults.
the palate as well as providing a bulge on
the posterior nasal surface of the palate
which has been postulated to be instrumen- Closure Patterns
tal in tight velopharyngeal closure.6 The
superior pharyngeal constrictor serves to The relatively simplistic discussion of the
provide lateral wall motion of the nasophar- musculature involved in velopharyngeal
ynx to close the velopharyngeal port.7Addi- closure described above fails to reveal the
tionally, it may contribute to the presence high degree of coordination, complexity,
of Passavant’s ridge, a transverse mucosal and variation involved.The sum motion is
bulge along the posterior pharyngeal wall one in which the palate elevates posteriorly
noted in 20% of the population.8 and contacts the pharyngeal wall circumfer-
From a functional standpoint,an inter- entially.On a lateral view,the palate appears
esting distinction is made between the phys- to flex like a knee due to the bulge of the
iology involved in closing the nasopharynx uvula maximizing contact with the poste-
during swallowing versus speech exercises. rior pharyngeal wall (Fig 16–1).11Perhaps a
A common situation is seen when children
have evidence of severe VPI with speech,
but exhibit no nasal regurgitation during
swallowing.Shprintzen and colleagues clas-
sified differences in pneumatic (speech,
blowing,and whistling) and nonpneumatic
(gagging and swallowing) closure mecha-
nisms based on videofluoroscopic findings.7
Furthermore,an electromyographic (EMG)
study of levator function during speech,
blowing, and swallowing suggests that dif-
ferent muscle types are activated during swal-
lowing exercises as compared to speech
and blowing exercises.9By determining the
mean power frequencies of EMG signals,
Nohara et al. concluded that pneumatic
activities tend to activate slow-twitch motor
units while swallowing tends to trigger fast
twitch motor units.9This work is corrobo-
rated by the hypothesis that the human
pharyngeal constrictors possess a subspe- Fig 16–1. Lateral fluoroscopic view demon-
cialized slow twitch inner layer of muscle strating “kneelike” contact between palate
fibers that appears to be related to speech and posterior pharyngeal wall.
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228 CLINICAL MANAGEMENT OF CHILDREN’S VOICE DISORDERS
better way to look at velopharyngeal anat- assessment of closure patterns is instrumen-
omy is through closure patterns. In 1973, tal in characterizing the nature and location
Skolnick and associates used videofluoros- of the velopharyngeal air escape. Such
copy to delineate four patterns of velopha- knowledge is critical in selecting operative
ryngeal closure.12 The most commonly procedures to effectively seal the gap.
observed pattern is the situation in which
the posterior surface of the velum comes
into broad apposition with the posterior Normal Versus Abnormal Speech
pharyngeal wall in the absence of lateral pha-
ryngeal wall motion.Two circular patterns
Etiology and Pathophysiology
of closure are described.The first pattern in-
volves a combination of lateral wall motion VPI is most commonly seen in children
and posterior velar movement to achieve with associated craniofacial developmental
velopharyngeal closure.A secondary circular anomalies of which cleft palate is the most
pattern with posterior pharyngeal motion common. Despite successful palatoplasty,
(Passavant’s ridge) is described. However, post repair prevalence of VPI has been
this motion pattern must be interpreted with reported to be 20 to 50%.11,13A special case
caution as Passavant’s ridge does not always is the submucosal (occult) cleft palate. In
correspond to the level of closure.The least this situation, no overt cleft is seen, but a
common closure pattern is referred to as failure of the midline fusion of the velar
sagittal and demonstrates minimal velar muscles is present often manifesting as a
movement combined with medial apposi- bifid uvula, hard palate notch, or a bluish
tion of the lateral pharyngeal walls. An line of a visible diastasis (Fig 16–2). The
A B
Fig 16–2. Submucous cleft with bifid uvula.A.Intraoral view.B.Intranasal view, note midline
groove.
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DIAGNOSIS AND TREATMENT OF VELOPHARYNGEAL INSUFFICIENCY 229
majority of these children will have no cardiac anomalies, VPI, and characteristic
speech deficits during their lifetime.14How- facial dysmorphisms.18The prevalence in the
ever, a subset will present with VPI often United States is estimated to be 1:2000.18
after adenotonsillar surgery.In a review of The difficulty lies in the wide variability of
126 children with VPI after adenoidectomy, presentations and propensity to be under-
26% were noted to have a previously uniden- diagnosed. Proper diagnosis is essential in
tified submucosal cleft palate or bifid uvula.15 that patients with VCFS must be screened
In a different study, 55% of children with for potentially lethal cardiac anomalies.
VPI in the absence of an overt bony cleft From a surgical standpoint,there have been
were noted to have a submucous cleft on a number of reports of carotid artery medi-
endoscopic examination.16 alization which may possibly represent
hazardous surgical anatomy (Fig 16–3).19,20
Additionally,surgical outcomes for VPI have
Associated Syndromes been reported to be inferior to the results
achieved in children without VCFS.21
Over 200 syndromes have been described
where cleft palate is a reported manifesta-
tion.Any such syndrome can be associated Postadenoidectomy
with VPI.Of special note is velocardiofacial
syndrome which typically does not manifest VPI manifesting after adenoidectomy is rel-
an overt palatal cleft. The syndrome was atively rare and generally of short duration,
first described in 1977 by Shprintzen and with most cases resolving within 6 weeks.
colleagues.17The syndrome has a wide spec- Given the bulk of adenoid tissue,many chil-
trum of phenotypes including congenital dren produce velopharyngeal closure by
Fig 16–3. Computed tomography demonstrating carotid artery
medialization.
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230 CLINICAL MANAGEMENT OF CHILDREN’S VOICE DISORDERS
approximating the velum to their adenoid VPI.Hypertrophied tonsils have been asso-
pad. In most children, removal of the ade- ciated with clinical VPI and resolution has
noid pad is of no consequence because their been documented after tonsillectomy.25Addi-
velum has adequate length to reach the pos- tionally, neuromuscular disorders resulting
terior pharyngeal wall. However, in select in poor control of pharyngeal musculature
children,the new dynamics of velopharyn- can result in hypernasality and dysarthria.
geal closure do not allow adequate apposi-
tion. Permanent VPI after adenoidectomy
requiring intervention is reported to occur in
DIAGNOSTIC EVALUATION
approximately 1:1500 adenoidectomies.22,23
In retrospect,many children have suggestions
of marginal velopharyngeal competence As delineated above,VPI represents a com-
including physical stigmata of a submucosal plex problem with a variety of manifesta-
cleft,preoperative hypernasality or regurgita- tions.The degree of complexity mandates a
tion (Table 16–1).In a review of 23 children multidisciplinary approach to the diagnosis
with VPI after adenoidectomy, 14 children and treatment of affected children. Often
were found to carry the VCFS genotype.24In these children are best served in the setting
situations where an adenoidectomy appears of a tertiary care referral center with coor-
to be indicated in a child with features con- dinated access to speech pathologists,sur-
cerning for marginal velopharyngeal com- geons, dentists, audiologists, and social
petence,a superior pole adenoidectomy can workers.
be performed in which the inferior aspect
of the adenoid pad is maintained to prevent
the development of VPI. History
Evaluation of a child with suspected VPI
Other Causes starts by simply listening with a keen ear.
Although children are often referred for
VPI has been noted in a variety of other set- grossly abnormal speech, a great deal can
tings.Any surgery that involves orthognathic be learned by listening to the child speak.
maxillary advancement (often performed in Using standard phrases weighted with sibi-
children with craniofacial abnormalities) by lants and plosives will help to uncover the
definition puts a child at risk for developing extent of VPI. A comprehensive history is
imperative for all children.Particular empha-
sis on any developmental anomalies, past
Table 16–1. Physical Examination Findings for medical history and past surgical history
a Submucosal Cleft Palate
may yield clues to syndromic associations
or other problems that can be seen in the
Prevention of Postadenoidectomy VPI:
setting of VPI.Eliciting any history of hear-
Recognize the Signs of a Submucosal
ing loss or other anomalies that potentially
Cleft
increase the child’s communication difficul-
bifid uvula ties is essential.A developmental and psy-
chological history is useful in determining
hard palate notch
the extent of disability imparted by the
bluish line of a visible diastasis
communication difficulties.
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DIAGNOSIS AND TREATMENT OF VELOPHARYNGEAL INSUFFICIENCY 231
Physical Examination A headset with two directional microphones
(nasal and oral) is connected through a
A comprehensive physical examination is converter to a computer. The child being
requisite in all children with VPI.All children evaluated wears the headset and voices stan-
must be assessed for the presence of syn- dardized passages.A nasalence score relating
dromic stigmata,craniofacial dysmorphisms the nasal acoustic energy as related to the
and the presence of cardiac abnormalities. total acoustic energy is displayed graphically
A thorough head and neck examination on the computer screen and a nasalence
includes an assessment of the middle ear score is generated.The score is then com-
status.An oral exam is performed to identify pared to normative data, such as with the
the presence of a cleft and status of repair. MacKay-Kummer Simplified Nasometric
As described below,flexible nasopharyngos- Assessment Procedures (SNAP) test.28Addi-
copy has proven to be a well tolerated and tionally,nasometry can be useful in therapy
invaluable tool in examining and formulat- in the form of biofeedback as discussed
ing a treatment plan for these children. below.
A further note on orofacial examina-
tion is necessary at this point.The complete
evaluation consists of close intraoral exam- Assessment of
ination with attention to oromotor skills,the Velopharyngeal Closure
occlusal and dental status as well as direct
visualization and palpation of the velum. Flexible Nasapharyngoscopy
Facial examination during speech in rela-
tion to characteristic grimaces and gestures Flexible nasopharyngoscopy has become
are often noted. indispensable in the evaluation of children
with VPI.The development of high-quality
small-caliber flexible endoscopes permits
Perceptual Evaluation excellent visualization in most children.The
flexible endoscope is passed transnasally
Several perceptual evaluation scales have to a position in the posterior nasal cavity
been developed and validated. One of the allowing a complete view of the velum and
most commonly used is that of McWilliams nasopharynx.Children of all ages can be eval-
and Phillips which is sometimes referred to uated anatomically;however,it is generally
as the Pittsburgh Weighted Speech Scale.26 around age six that children can cooperate
This weighted scale rates five components and perform comprehensive volitional vocal-
of speech including nasal emission, facial izing tasks for a complete evaluation.Flexible
grimace, nasality, phonation, and articula- nasopharyngoscopy provides an excellent
tion (Fig 16–4).Points are assigned for each view of the nasal surface of the palate and
subgroup and summed to give an overall may provide the only sign of a submucous
score that can be used to track outcomes. cleft palate as described above.Additionally,
flexible nasopharyngoscopy allows an exam-
ination of the larynx, which may uncover
Nasometry additional pathologies associated with com-
pensatory measures,such as vocal nodules,
Nasometry is based on the measurement that may have developed in response to
of nasal acoustic energy within speech.27 the VPI.
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Fig 16–4. Perceptual weighted speech score used at Massachusetts General Hospital.
Adapted from McWilliams and Phillips.26
232
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DIAGNOSIS AND TREATMENT OF VELOPHARYNGEAL INSUFFICIENCY 233
Multiview Fluoroscopy addition to potential difficulties in standard
positioning with resultant child compliance
Multiview fluoroscopy was for many years issues are potential limitations of the study.
the primary means of assessing velopharyn- An important concept is that often video-
geal closure. Three views are traditionally fluoroscopy and nasopharyngoscopy pro-
used after instilling a small amount of high- vide complementary information.
density barium into the child’s nose to coat
the nasopharynx. The anteriorposterior
Grading and Standardization of
view allows assessment of lateral pharyn-
Velopharyngeal Closure
geal wall motion (Fig 16–5).The lateral view
Measurements
allows visualization of palatal motion and the
posterior pharyngeal wall (see Fig 16–1). In 1990,an international working group of
The closure pattern of the sphincter is clinicians and researchers headed by Karen
viewed directly in the base view (Fig 16–6). Golding-Kushner reported a standardized
Videofluoroscopy allows excellent visuali- grading scale for reporting findings on naso-
zation of the shape of the velum and angle pharyngoscopy and multiview fluoroscopy.29
of elevation in lateral view and may serve as The scale serves to outline both quantitative
a better tolerated alternative for children and qualitative scoring to accurately describe
who are noncompliant with nasendoscopy and grade the anatomic defects associated
The requirement of ionizing radiation in with VPI.
Fig 16–5. Anteroposterior videofluoroscopy Fig 16–6. Base view videofluoroscopy dem-
demonstrating visualization of lateral wall onstrating closure pattern.
motion.
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234 CLINICAL MANAGEMENT OF CHILDREN’S VOICE DISORDERS
Nasopharyngoscopy,Multiview expand consonant repertoires,and to min-
Fluoroscopy,or Both? imize patterns of glottal stops.
As language and speech emerge for the
Over time, much has been written about
toddler and preschool age child,it is impor-
the merits and disadvantages of both naso-
tant to discern if speech errors are develop-
pharyngoscopy and multiview fluoroscopy.
mental,obligatory,or compensatory.When
Both are used to accurately assess velopha-
children with cleft or noncleft velopharyn-
ryngeal anatomy to assist in developing a
geal problems display articulation errors
treatment plan, particularly surgical meth-
and resonance abnormalities, the develop-
ods.Nasopharyngoscopy allows an excellent
mentally appropriate articulation issues are
view of velopharyngeal closure patterns,but
addressed first.It is important to remediate
can be limited by optical distortion and tol-
these developmental speech errors as well
erance by the child undergoing the exam.
as establish accurate placement of the artic-
Multiview fluoroscopy allows an excellent
ulators and manner of production (eg,frica-
view of lateral wall motion as well as clo-
tive versus stop consonants), even when
sure patterns.As stated above, the closure
the anatomy prohibits the ability to achieve
patterns of the velopharynx were initially
an orally produced sound.This is especially
described based on fluoroscopic studies.
true for children under four years of age
Difficulties arise in interpreting anatomic
with a cleft palate who are often too young
findings in the presence of multiple shad-
for consideration of a secondary surgery.
ows.Additionally,postsurgical examination
Behavioral therapy with a speech-
particularly in the setting of a pharyngeal
language pathologist can be helpful in mild
flap is quite difficult with fluoroscopy,but
VPI and phoneme specific VPI. Speech/
is easily visualized directly with nasopharyn-
resonance therapy is not indicated when:
goscopy.A recent review suggests that both
(a) nasal emissions are present in all non-nasal
modalities provide complementary data,
consonants with subsequent hypernasality
but that nasopharyngoscopy may provide a
related to a short or poor moving palate or
higher correlation with VPI severity.30 Cur-
excessively deep pharynx,(b) nasal air loss
rently, our practice is to perform flexible
related to a palatal fistula,or (c) articulation
nasopharyngoscopy on all children to visu-
errors related to severe dental malocclu-
alize anatomy and assist in surgical planning sions that require physical management.31,32
and proceed to multiview fluoroscopy in
Speech/resonance therapy cannot work
children where additional information may
against atypical anatomy and if attempted
prove useful,particularly in children under
may cause undue frustration to the child.
six years of age who have limited coopera-
Perhaps the primary concern for every
tion for a functional endoscopic assessment.
child, parent, and VPI surgeon is to avoid
operating when a child has a functional
speech abnormality that can be masking as
what appears to be VPI secondary to ana-
TREATMENT: BASIC TENETS
tomic deficit. A thorough evaluation by a
speech and language pathologist is often nec-
Prior to surgical repair of a cleft palate or essary to accurately diagnose such disorders
primary VPI,a speech-language pathologist preoperatively.As described below,compre-
with specialized training can help guide par- hensive therapy often involves much more
ents to elicit sound play with their infant, than simply filling the anatomic defect.