velopharyngeal_insuff

15

Click here to load reader

description

This e book discusses the topic velopharyngeal insufficiency, its features and management

Transcript of velopharyngeal_insuff

Page 1: velopharyngeal_insuff

Velopharyngeal Insufficiency and its

management

Dr T Balasubramanian

Drtbalu's otolaryngology online

Page 2: velopharyngeal_insuff

Velopharyngeal insufficiency

Introduction:

Velopharyngeal insufficiency includes any dysfunction that causes insufficiency / incopetence at the junction of nasopharynx with that of oropharynx. Classically in English language only three phonemes i.e. (n/m/ng) are produced by nasal air escape. All the other sounds are produced by oral air flow. Velopharynx is considered as an articulator along with jaw, lips, tongue, pharynx and larynx. These articulators infact work cohesively to produce meaningful speech.Velopharyngeal closure occurs as the velum moves in the postero superior direction. The lateral pharyngeal walls move medially sealing the nasopharynx from oropharynx.

Factors affecting velopharyngeal valve during speech:

1. Height of the vowel2. Type of consonant3. Proximity of nasal sounds to oral sounds4. Length of utterance5. Speech rate6. Tongue height

Any abnormality in the velopharyneal closure mechanims leads to abnormal speech.

Velopharyngeal incompetance:This leads to:

a. Hypernasalityb. Nasal turbulencec. Speech disturbances due to abnormal articulation

Muscles acting on velopharynx:

Tensor veli palatini:This muscle tenses the soft palate and opens the auditory tube during swallowing. This muscle is supplied by the mandibular division of trigeminal nerve.

Levator veli palatini:It pulls the velum in a postero superior direction thus acting as a major elevator of velum. It also serves to hold velum in its superior position. It derives its motor nerve supply from pharyngeal plexus which are formed from branches of glossopharyngeal, vagus and facial nerves. This muscle occupies the intermediate 40% of the length of the soft palate.

Musculus uvulae:

It arises from palatal aponeurosis posterior to the hard palate. It inserts into the uvula. This muscle adds the much needed bulk to the upper surface of palate. It derives its motor supply from pharyngeal plexus.

Drtbalu's otolaryngology online

Page 3: velopharyngeal_insuff

Palatoglossus:

This muscle constitutes the anterior pillar of tonsil. It terminates on the side of base of tongue. It serves to elevate the tongue upwards and backwards. It has the potential to lower the velum and hold it in position. Its nerve supply is via the pharyngeal plexus.

Palatopharyngeus:

This muscle forms the posterior pillar of tonsil. It arises from soft palate and inserts into the posterior border of thyroid cartilage. By adducting posterior pillars it is able to narrow the pharyngeal isthumus. It also raises the larynx, lowers pharynx and maintains the position of velum. It derives its nerve supply via the pharyngeal plexus.

Superior constrictor:

This muscle isone of the most important constrictor of pharynx. When it contracts it draws the velum posteriorly managing to shut it of during the process of swallowing. This muscle is supplied by pharyngeal plexus.

The major muscle mass of velum is levator veli palatini. The elevation and posterior motion of velum is attributed to this muscle. Variations in the angle of insertion to the skull base involving this muscle may change elevation angle of soft palate. The action of this muscle is opposed by palatoglossus and palatopharyngeus muscles.

Lateral wall movements of velum show individual variations. It also depends on speech context. Lateral movement of velum is attributed to selective contraction of uppermost fibers of superior constrictor muscle. Since the lateral fibres of superior constrictor is closely related to palatopharyngeus it goes without saying that palatopharyngeus muscle is also involved in this type of movement.

Passavant's ridge:

This is actually a thickening present in the posterior wall of nasopharynx. This feature is seen in some individuals while speaking / swallowing. It is more common in patients with cleft palate. This thickening is caused by uppermost fibres of superior constrictor and palatopharyngeus muscle. This projection may involved in velopharyngeal closure.

Causes of velopharyngeal incompetence:

According to DAntonio and Crockett velopharyngeal incompetence can be divided into three categories:

1. Insufficiency: This encompasses sturctural defects involving soft palate resulting in insufficient tissue to accomplish perfect closure of velopharynx. A well known example of this condition is cleft palate.

2. Incompetence: This is due to motor defects caused by neurologic dysfunction like paresis /

Drtbalu's otolaryngology online

Page 4: velopharyngeal_insuff

paralysis involving motor nerve supply to muscles of velopharynx. This can be caused by skull base surgery / tumors involving jugular foramen / CNS impairment due to stroke.

3. Mislearning: All conditions causing velopharyngeal incompetence without loss of soft palate or motor defects are included here.

Congential causes that can lead to velopharyngeal incompetence:

1. Cleft palate2. Congenitally short palate3. Palatopharyngeal disproportion4. Submucous cleft palate (due to absence of musculus uvulae)5. Longitudinally oriented levator veli palatini6. Hypertrophic tonsil (by impeding palatal closure ) rare7. Muscular dystrophy8. Myasthenia gravis

Assessment of patients with velopharyngeal incompetence:

Nasal occlusion / mirror fogging tests can be performed while the patient is producing phenomes which require normal nasal airflow.Hyponasal resonance is commonly noted when the patient articulates “M” “N” and “NG”.Normally a mirror when held close to the nose of the patient fogs equally when the patient articulates the following consonents (M,N and NG).

If the quality of voice is the same with / without occlusion of nose then nasal / nasopharyngeal obstruction should be considered. The examiner also will fail to feel nasal vibrations while the patient speaks.

Phoneme specific velopharyngeal incompetence due to mislearning can be corrected by speech therapy.

When velopharyngeal incompetence is suspected after clinical examination then the following testing protocol can be used to clinch the diagnosis.

1. Nasometry2. Imaging studies like lateral cephalometry3. Speech videofluroscopy4. Speech endoscopy

Nasometry:This is an objective assessment of nasal and nasopharyngeal patency. This assessment is performed by assessing the ratio of sound intensity between nose and mouth. This test is performed by asking the patient to voice certain standard pharses and sentences. Nasometry is used in the initial evaluation and documentation of speech dysfunction.

Pressure flow measurement:This is another method of assessing velopharyngeal function during speech. Nose is covered with a small mask in order to accurately measure the amount of nasal airflow. In addition to this a probe is also introduced into the mouth to measure oral pressure. If velopharyngeal function is normal no

Drtbalu's otolaryngology online

Page 5: velopharyngeal_insuff

airflow will be detected during production of non nasal phonemes. Oral pressure can be identified if nasal air escape is present during production of non nasal sounds.

Methods of imaging velopharyngeal function:

Imaging is indicated in patients with:

1. Significant hypernasality2. Speech therapy is not progressing according to expectations3. If diagnostic dilemma is present4. If surgery is contemplated

Lateral cephalometric X-rays dont provide information on dynamic movement of velopharyngeal mechanism. Other useful methods of imaging this area include:

Speech fluroscopy:This is a standard imaging technique used to assess dynamic function of velopharyngeal area. During this test a speech pathologist is also present along with the radiologist who performs it. This is actually a modification of the commonly performed Barium swallow. A small amount of barium is introduced through the nose to coat the velopharynx inorder to improve visualisation of this area. The whole procedure is performed under fluroscopic guidance. The patient is instructed to articulate specific phonemes and sentences. The movement of velopharyngeal sphincter area is studied fluroscopically. For the sake of accuracy this study may need to be performed in 2-3 views. Study of lateral view demonstrates the length, thickness, antero-posterior and superior motion of soft palate as well as anterior movement of posterior pharyngeal wall (Passavant's ridge). The antero posterior view assess the lateral wall motion. An enface view (submento vertical view) will look down into the velopharynx and assesses lateral wall, velar and posterior wall motion.

Limitations of this procedure:

1. Because of the danger of radiation exposure the study time will have to be short2. Patient should be co operative3. Image interpretation needs lots of experience4. This imaging modality may miss small fistulas and intermittent closure patterns

Speech endoscopy:

This is a very useful test to study the dynamic velopharyngeal area. It is only minimally invasive. A speech language pathologist should also be present along with the surgeon who performs the test. A flexible nasopharyngoscope is introduced through the nose after topical anesthesia. It is inserted upto the level of velopharynx. The best image could be obtained when the scope is positioned high inthe nasopharynx because if it slides below it would cause fish eye distortions. If the scope is passed through the middle meatal region instead of inferior meatus it ensures optimal positioning. The patient is instructed to utter certain phrases, words and sentences while the image is being recorded. It is also ideal to use a microphone to record the voice generated.

Drtbalu's otolaryngology online

Page 6: velopharyngeal_insuff

Endoscopic assessment not only ensures assessment of dynamic functions of velopharynx it can also assess static anatomy of the whole area which include nasal septum, adenoid pad, musculus uvulae. The absence of musculus uvulae indicates submucosal cleft palate. While the patient is articulating the velar and lateral wall motion are observed. The presence or absence of Passavant's ridge is documented. Incomplete closure can be documented by viewing the bubbling of mucous in the velopharynx. This test enables a clear assessment of dynamic and static functions of this vital area in production of speech.

Normal velopharynx as seen in videoendoscopy

Drtbalu's otolaryngology online

Page 7: velopharyngeal_insuff

Four primary velopharyngeal closure patterns are observed both during endoscopy and videofluroscopy. They include:'

1. Coronal2. Sagittal3. Circular4. Circular with Passavant's ridge

Drtbalu's otolaryngology online

Page 8: velopharyngeal_insuff

Coronal type:This is a coronally oriented gap seen in roughly 55% of normal population. The soft palate (velum) moves posteriorly without any significant contribution from the lateral / posterior walls.

Sagittal type:This closure pattern is seen in 10 – 15% of population. The gap is oriented inthe sagittal plane because of the major contribution of closure is from the lateral walls.

Circular type:This closure type is seen in 10% of population. There is significant amount of motion of velum and lateral walls in order to obtain this type of closure.

Circular type with Passavant's ridge:

Drtbalu's otolaryngology online

Page 9: velopharyngeal_insuff

This closure is seen in 10% of population. It is more or less similar to the circular type of closure, but there is contribution from Passavant's ridge.

Study of the closure pattern will help the clinician in deciding how best to close the defect (surgery/obturator). The gap must be filled somehow.

Managment:

Management of velopharyngeal incompetence include:

1. Speech therapy2. Obturator to fill the defect3. Surgery

Treatment modality is decided by a team comprising of:

SurgeonSpeech pathologistDental Surgeon

The decision to manage velopharyngeal incompetence with speech therapy is a difficult one as there is a closure defect which should be managed. Speech therapy cannot change the abnormal structure but can change abnormal function by teaching the patient corrective maneuvers.

Speech therapy is indicated in a child with mild VPincompetence / inconsistent VPincompetence. Inconsistent VPincompetence occurs when the child is fatigued. Speech therapy will ensure compensation from the various articulators.

Before taking the decision of sumitting the patient to speech therapy the following factors should be taken into account:

1. Age of the patient2. Severity of the disorder3. Cognition4. Phonetary inventroy of the patient5. Expressive vocabulary6. Ability of the parent of the child in participating / co operating with the programme

Speech therapy will not be useful in the following scenario:

Drtbalu's otolaryngology online

Page 10: velopharyngeal_insuff

Hypernasality with unobstructed nasal emission. This is actually caused by a large velopharyngeal opening which needs to be corrected surgically.Obligatory errors where the defect is structural. It could be a large incompetence involving velopharyngeal area / dental malocclusion.

Auditory feed back therapy:

In this therapy the child's awareness to the nasality in speech should be increased by presenting normal sounds & hypernasal sounds and encouraging the child to listen to it. The child should also be encouraged to match the articulated sound with that of the normal ones. In order to increase the awareness the child is made to listen to his / her own speech recordings.

Listening tube:This is a rubber tubing one end of which is attached to one nare while the other is attached to the patient's ear. When the child articulates with this tube if there is a nasal leak it would be heard loud in the ear. The child is encouraged to produce speech without / minimizing the nasal leak which could be heard via the listening tube.To increase oral air flow the same device can be connected both to the ear and oral cavity. Child is encouraged to speak in such a way audible airflow from the oral cavity occurs.

Visual feed back therapy:

A thin air paddle is placed in front of the child's nasal cavity. If there is hypernasality the air paddle will flutter while the child speaks. The child is encouraged to speak without causing the flutter movement of air paddle.

Tactile Kinesthetic feedback:

This procedure is performed while the patient is articulating a vowel, preferably (ah). The soft palate is raised with a tongue blade. If the voice produced on elevation of velum (soft palate) is better then it can be safely assumed that these patients will benefit from palatal lift procedure. The child is also trained to raise and lower the velum while articulating. This training really helps in overcoming minimal velopharyngeal incompetence due to muscle fatigue.

Tactile feed back:

The child is made to touch the sides of the nose while speaking with specific instructions to feel for the vibrations. Then the child is instructed to speak with minimal or no vibrations in that area. This calls for active participation on the part of the child.

Lowering the back of the tongue as in yawning:

The child is asked to simulate Yawning maneuver while articulating. The child is made to practice this movement while articulation. This indirectly increases velopharyngeal space.

Attempts to increase the volume of spoken word:The child can be encouraged to increase vocal effort and spoken volume. This indirectly leads to increased respiratory support, velopharyngeal effort, oral air pressure and force of articulation. After the child learns this process the volume of speech can always be reduced to normal.

Drtbalu's otolaryngology online

Page 11: velopharyngeal_insuff

Increase in oral activity:

Increased anterior oral activity causes a corresponding increase in the posterior and velopharyngeal activity. By increasing mouth opening the oral resistance can be effectively reduced followed by a corresponding increase in the oral resonance.

Cul-de-sac / Nose:In this technique the patient is asked to pinch the nose while articulating. This eliminates nasal air emission while the patient trains. A nose clip can be used for this purpose. The patient trains with it to produce sounds without causing excessive air emission through the nasal cavity.

Light quick contacts:If the patient learns how to make use of light quick contacts while voicing plosives it will prevent excessive build up air pressure within nasopharynx causing air leak via the nose. This ofcourse needs lot of training on the part of the patient and patience on the part of therapist.

Compensatory articular Productions:This method was conceived in an effort to tide over inadequate oral pressure problems for normal sound generation. Encouraging compensatory aritcular voice production increases the intelligibility of the spoken word. If surgical correction is contemplated for velopharyngeal incompetence then it is better to wait till the surgical procedure is over before starting this process.

Glottal stop:

Accurately speaking this is a voiceless glottal plosive used in spoken languages. This is usually produced by obstructing airflow in the vocal tract. This is known as glottal stop because the gap between the vocal folds suddenly narrow till no air is allowed to escape during production of a sound. Glottal stop phonetically speaking is voiceless because vocal cord does not vibrate during this process. It is actually a oral consonent as the air is allowed to escape through the mouth.This procedure can be used to treat patients with velopharyngeal incompetence. The child is asked to place the hand over the neck during production of glottal stop. The jerk caused during the process is felt. The child is then trained to produce voiceless plosives slowly, followed by an “h” before the vowel to eliminate glottal stop (p-hhhha for pa). The child is taught to whisper a syllable. During whisper the vocal folds will not adduct. Then gradually the child is taught to add smoothness to the voice.

Treatment by using appropriately designed prosthesis:

Prosthetic therapy for mangement of velopharyngeal incompetence has been there for a long time.When an appropriately designed and positioned prosthesis is used it causes a palatal lift. This pushes the palate up and back into contact with the posterior pharyngeal wall there by improving competence of the velopharyngeal area. This will be really helpful in patients with a short soft palate which is unable to seal of the velopharynx during the process of phonation.

Drtbalu's otolaryngology online

Page 12: velopharyngeal_insuff

Image showing palatal prosthesis used in palatal lift procedure

Limitations of Palatal prosthesis:

1. Experienced prosthodontist service should be available2. Adequte maxillary dentition is mandatory because the prosthesis is actually anchored to the

maxillary dentition3. During loss of deciduous teeth keeping the prosthesis in position is rather difficult4. The child should be really co operative with the dentist5. The prosthesis should be removed every day and cleaned which could sometimes be

cumbersome.

Surgical interventions available include:

1. Intravelar veloplasty2. Furlow double opposing Z plasty3. Spincter pharyngoplasty – Surplus tissue from lateral wall is used to close the defect4. Superiorly based pharyngeal flap operations – Redundant posterior wall tissue is used to

close mid portion of velopharynx.

Among these procedures the intravelar veloplasty and Furlow double opposing Z plasty attempts to improve velopharyngeal function by re orienting the levator sling.

If levator veli palatinie is oriented longitudinally as in submucosal cleft palate or palatoplasty velar motion can be improved by reorienting the muscle. The traditional way of reorienting levator veli palatini is intravelar veloplasty. This surgery involves dissection of levator muscles from their posterior attachment to the hard palate, nasal and oral mucosa in order to achieve a more anatomic transverse orientation. Results are not very satisfactory. It may however be used with reasonable success in re-repair of soft palate in patients who have undergone palatoplasty without levator re orientation procedure.

Intravelar veloplasty:

Drtbalu's otolaryngology online

Page 13: velopharyngeal_insuff

This surgical procedure is performed under general anesthesia introduced via endotracheal intubation. The patient is placed in Trendelenberg position. A Dingmann mouth gag is used to open the mouth.

Dingmann mouth gag

The mucoperiosteal flaps are based on the descending palatine artery. The flap is designed in such a way that its anterior tip is adjacent to the lateral incisor. Greater palatine neurovascular bundle is infiltrated with a small amount of local anesthetic. The palate is also infiltrated with local anesthetic. The hard palatal flaps are elevated to the neurovascular bundle without injuring its vascular supply. The hamulus is exposed in order to free enough oral mucosa for good closure. The levator muscle in these patients could be seen to be inserted into the posterior border of the hard palate. This alignment makes the muscle non functional. This muscle is dissected from the posterior border of hard palate taking care not to injure the thin nasal mucosa. The muscle is then freed from the oral mucosa and nasal mucosa. The dissection is carried up to the back of the hamulus and the levator is followed up to the skull base. The palate is then closed in three layers.

Double opposing Z plasty Palatoplasty:

This technique was originally described by Furlow. This procedure reorients the levator while thickening and thickening the palate. This procedure can be used as a primary closure, repair of submucosal cleft palate or as a secondary procedure if the levators are longitudinally oriented. The surgical procedure is more or less similar to intravelar veloplasty except for the fact that 4 flaps are designed. Two myomucosal posterior based flaps and two mucosal anterior based flaps.

Drtbalu's otolaryngology online

Page 14: velopharyngeal_insuff

Diagram showing the 4 flaps elevated

Drtbalu's otolaryngology online

Page 15: velopharyngeal_insuff

Diagram showing end result of Furlow Z plasty

The four flaps i.e. Two posterior based myomucosal and two anterior are elevated. These four flaps are repositioned to allow for tension free closure. Nasal suture line repair is performed first followed by oral suture line closure. The left nasal mucosal flap is rotated across midline to the margin of right hard palate and sutured. The right myomucosal flap is rotated to left to be inserted into the left hemipalate. This maneuver brings the levator muscle across the midline. Ofcourse the tension line is not in the midline but is present laterally there by minimizing the risk of palatal perforation.

Sphincter pharyngoplasty:

This is the commonly used surgical treatment for velopharyngeal incompetence. Main advantage of this procedure is that there is negligible risk of post operative airway oedema / obstruction. This procedure is very useful in managing coronal and circular closure patterns which are rather common in patients with velopharyngeal deficiency. In this procedure myomucosal flaps are elevated from lateral pharyngeal wall and is inserted into an incision at the posterior nasopharyneal wall at the level of greatest closure of velopharynx. Movement of the palate to the flap accomplishes complete closure of velopharynx. Studies reveal an improved palatal motion following this procedure.

Posterior wall augmentation:

This is performed in those patients with very small posterior midline gap. Materials like hyaluroninc acid, fat, teflon, proplast and cartialge have been tried out in this procedure with varying degrees of success. Gray introduced a technique called rolled posterior pharyngeal flap for aumenting the posterior pharyngeal wall. In this procedure a superiorly based flap is raised and folded upon itself and sutured to make a ridge like structure in the posterior pharyngeal wall.

Drtbalu's otolaryngology online