Laryngopedia

To educate about voice, swallowing, airway, coughing, and other head and neck disorders

Laryngopedia By Bastian Medical Media

Multimedia Encyclopedia

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Macrophenomenology of voice

Macrophenomenology of voice:

As the sun’s trajectory, the North Star, and the magnetic compass are to navigation, so macrophenomenologies are to the diagnostic process that we use at our practice (see: integrative diagnostic model). Particular vocal macrophenomenologies might include things like: audible air-wasting, a three-second maximum phonation time, positive swelling checks, and latency of response. Elicited macrophenomenologies of the voice such as these, taken together, orient the examiner to a specific diagnosis. By contrast, see microphenomenology. Also, see elicitation.


Marfan syndrome

A genetic connective tissue disorder caused by a defect in gene FBN1, which codes for abnormal structure of fibrillin-1, a protein crucial for formation of normal connective tissue. Most critical is Marfan syndrome’s effect on heart and blood vessels, which tend to dilate and be at risk of rupture. Connective tissue in bones, ligaments, and other parts of the body is also affected.

Laryngologists may encounter Marfan syndrome because parts or all of the aorta may need to be replaced over time, due to abnormal dilation of the weakened arterial wall, with risk of rupture. When such surgery is done, the left recurrent nerve is at risk of injury, and this would lead to left vocal cord paralysis. With Marfan syndrome, it is rare to live to age 70.

Photos:


Maximum phonation time (MPT)

The maximum time an individual can sustain a sung tone, after having filled the lungs maximally. In the literature, maximum phonation time (MPT) is often reported as having been measured on the vowel / i / (eee) at spontaneous, comfortable pitch and loudness.

However, MPT may vary markedly with pitch, vowel, effort, register, and so forth. Furthermore, MPT may differ dramatically among individuals all of whose larynges are otherwise considered normal. Hence, MPT is a useful measure primarily when it is very abnormal (less than seven seconds), and also when production constraints are more specific than “comfortable pitch and loudness.” At our practice, we routinely measure MPT at average/anchor frequency, during spontaneous speech.


Medial

Toward the midline of a person’s body, along the left-right axis. For example: the medial end of each eyebrow is the end that approaches the bridge of the nose. The opposite of lateral.


Medialization laryngoplasty

A surgical procedure performed to push a paralyzed, atrophied, or scarred vocal cord toward the other vocal cord and reduce flaccidity. A medialization laryngoplasty is typically performed under sedation and local (not general) anesthesia, on an outpatient basis.

Audio:

Patient with vocal cord paralysis, BEFORE medialization laryngoplasty:

Same patient, one week AFTER medialization laryngoplasty:

Photos:

Videos:

Injection Medialization for Vocal Cord Paresis
See an example of one variant of vocal cord paresis and how it limits the voice. Then watch a medialization procedure in which voice gel is injected into the vocal cord affected by paresis, and hear how the voice thereafter improves.

Membranous glottis

The anterior two-thirds of the vocal cord’s visible length and also, during breathing, the space between this segment of both cords. Also called the musculomembranous glottis. The layers of the membranous glottis, in order from deepest to most superficial, are: the thyroarytenoid muscle; the vocal ligament, made of elastin and collagen fibers; the mucosa, which comprises both a loose attachment zone called the lamina propria or Reinke’s space and, on the very surface of the cord, a layer of squamous epithelium. The other one-third of each vocal cord’s visible length is called the cartilaginous glottis.


Microlaryngoscopy

Microlaryngoscopy is an endoscopic procedure focused upon the larynx, performed under general anesthesia. A hollow lighted tube rests on the upper teeth and the base of the tongue and allows the physician to see the vocal cords. An operating microscope is used to brightly illuminate and highly magnify the vocal cords. Then, tiny instruments and/or a laser are used to remove the abnormality from the vocal cord or cords.


Microphenomenology of voice

As plankton counts in the water, measurement of ocean temperature, and trace magnesium level of the water are to navigation, so microphenomenologies are to the diagnostic process that we use at our practice (the integrative diagnostic model). Particular vocal microphenomenologies may include such things as jitter, shimmer, electroglottography measurements, transglottal airflow rate, and so forth. Microphenomenologies such as these, even when taken together, tend to be non-specific and do little to narrow the list of possible diagnoses. By contrast, see macrophenomenology.


Mitomycin C topical application

Mitomycin C topical application is the use of the medication Mitomycin C to prevent post-procedural scarring in the larynx or trachea. Outside the field of laryngology, Mitomycin C is used more commonly as a cancer chemotherapy agent, but within laryngology, Mitomycin C is often applied by a clinician to prevent scarring after procedures like laryngeal or tracheal dilation or division of a glottic web.

A common way to apply Mitomycin C would be to take the drug in dilute form (e.g., 0.3mg per ml), saturate a cottonoid sponge with it, and then “paint” it on the area where one wants to inhibit a scarring response, holding the sponge in position for about three minutes. Mitomycin C’s mechanism of action is reported to be absorption of the drug by fibroblasts, which are then “decommissioned” from producing collagen, the major component of scar tissue.


Mixed AB-AD spasmodic dysphonia

The combination of both abductor (AB) and adductor (AD) vocal cord spasms in a person who has spasmodic dysphonia (SD). Most individuals with SD have a predominance of one spasm type or the other—AB or AD—such that we classify the person as having either “AB-SD” or “AD-SD.” Some individuals, however, have a significant amount of both types of spasms. That is, a person experiences phonatory arrests or squeezedowns caused by AD spasms, followed suddenly by dropouts to a whisper caused by AB spasms. This kind of person is described as having “mixed AB-AD spasmodic dysphonia.”

Treatment for SD usually involves two-muscle Botox injections: for AD-SD, injecting into both of the thyroarytenoid muscles; for AB-SD, into both of the posterior cricoarytenoid muscles. Treatment for mixed AB-AD SD usually begins with the two muscles causing spasms of which the patient is most aware; if the results are not satisfactory (often because the untreated kind of spasms come to the fore without competition from the other kind of spasms), some of these patients are then eventually treated with four-muscle injections.


Modeling (during vocal capability battery)

This term is used to indicate the process of clinician production of a sound that the patient is then asked to imitate or attempt to imitate. Not unlike “call and response” in some kinds of vocal music. The response is then judged to answer the examiner’s inner questions: “What does this voice do that it shouldn’t and what can’t it do that it should be able to do?” Modeling is performed by the clinician to elicit the voice’s phenomenology.


Motivated laryngeal examination

A “Motivated” laryngeal examination is an examination in which the clinician “pushes” the larynx to reveal its secrets. If topical anesthesia is used, this can be done without undue discomfort to the patient, and laryngeal images can be close and clear rather than far and fuzzy.

Photos:


Mucosa

The mucous membranes (or mucosa) are to our interior as skin is to our exterior. Mucosa covers or lines various body cavities and internal organs. In laryngology, the mucosa of the vocal cords is the point of main susceptibility to vibration-induced traumatic abnormalities such as nodules, polyps, capillary ectasia, and so forth. Mucosa also lines the nose, mouth, pharynx, esophagus, and tracheobronchial tree.


Mucosal bridge

A mucosal bridge lies in the family of disorders such as epidermoid cyst and glottic sulcus. Imagine a cyst that opens in two places, spilling its contents completely. The result is a narrow bridge of mucosa, attached anteriorly and posteriorly.

Photos:

 


Mucosal Chatter

Mucosal chatter is an audible phenomenon of injured vocal cord vibration. It is commonly heard in the softly-sung upper voice of persons with nodules, polyps, etc.

Hoarseness or roughness are broad and nonspecific descriptors useful only for severe injuries. Small injuries that are nevertheless impairing the singing range may leave the speaking voice sounding normal. I suppose “hoarseness of singing range” could be used, but again, that would be an unsophisticated and basic description of vocal phenomenology. To hear more useful phenomena of injury, we elicit and thereby investigate the upper range of singing (even in nonsingers) because high, soft singing makes the phenomenology apparent.  This is why we have described “vocal cord swelling checks” and created a video to teach how to elicit them, and also how to evaluate and communicate the phenomenology that results. In particular, delays of phonatory onset (“onset delays”) above approximately C5 (523 Hz) may indicate mucosal injury even when speaking voice sounds normal. Also heard is air-wasting, where there is a “scratchiness” to the excess airflow. Segmental vibration is also a common audible phenomenon of a mucosal disorder can also be easily taught and recognized.

Vocal cord mucosal chatter adds an extremely rapid “shudder” on top of the pitch of the voice. I have used “chatter” rather than “shudder” because the latter suggests a lower frequency than the former. It could be called a very fine-grained diplophonia…but typical diplophonia, caused by independent vibrating segments, is a much grosser vocal phenomenon. While chatter is more subtle, once it is pointed out and taught briefly, most people can easily distinguish between onset delays, diplophonia, segmental vibration, the transient “squeaking” of a micro-segmental vibration,  the crackling sound of mucus dancing on the vocal cords, and “chatter.”  Those who master recognition of these phenomena can easily communicate them to colleagues. For our purposes, let me stress again that the above phenomena—and chatter in particular—do not happen in the normal larynx, where vocal cord margins match perfectly and the mucosa oscillates normally.  When heard—even in the person with a normal speaking voice—the examiner can strongly suspect a mucosal abnormality even before examining the vocal cords.  In fact, where these phenomena are heard and initial examination looks normal, it would be a good idea to “look harder.”

Patient examples:

Videos:


Mucosal edema or swelling

Mucosal edema or swelling is the build-up of edema (tissue fluid) within the mucosa, the layer of tissue that lines the body’s interior. In the larynx, this build-up of edema usually occurs at the mid-point of the vocal cords, as the body’s response to vocal overuse, and it resembles a small, low-profile blister.

Vocal overuse triggers this build-up of edema because, with vocal overuse, the vocal cords undergo more vibratory stress and trauma than they are designed to handle. The body responds by gathering edema to form a protective cushion. However, this swelling distorts the vocal cord’s shape and can limit its flexibility, which can thereby impair the voice, making it sound acutely husky or hoarse.

From mucosal edema to nodules:

If the voice is rested even moderately, this edema fluid will disperse rapidly—within 12 to 24 hours if not severe—so that the swelling vanishes and the voice returns to normal. However, if the voice continues to be overused, then the body may build up more chronic swelling materials (no longer just edema), so that the vocal cords develop nodules.

Photos:


Mucus retention cyst

A cyst that forms when one of the mucus glands just below the vocal cord’s free margin becomes plugged. Mucus glands in this location secrete mucus in order to bathe and lubricate the vocal cords, but if a gland becomes obstructed, then the mucus it produces gets trapped and accumulates, leading to a mucus retention cyst. A mucus retention cyst typically occurs without any correlation to vocal overuse, in contrast to epidermoid cysts as well as nodules and polyps.

Signs:

A mucus retention cyst can cause hoarseness, because it interferes with the normal vibrations of the vocal cords and the accuracy of their match with each other (see the videos below). The cyst is most often unilateral—that is, occurring on one cord but not the other. It appears as a bulge or deformation of the vocal cord’s free margin, and sometimes undersurface, and it may be yellowish in color.

Treatment:

The cyst may be surgically removed, by creating a small incision on the vocal cord and then dissecting the cyst from the cord. Photos of the surgical process can be found below. Also, the two videos below show how removing this kind of cyst can improve the voice.

Photos:

Videos:

Mucus Retention Cyst: Before and After
Watch this video to see images and hear audio of a mucus retention cyst’s effect on the vocal cords, followed by the surgical removal and the post-surgical results.
Mucus Retention Cyst II: Before and After
Another example of a mucus retention cyst, with images and audio before, during, and after the cyst’s surgical removal. This video highlights a bit more of the vocal capability battery.

Multi-modality treatment

Multi-modality treatment is therapy that combines more than one method of treatment. See also: single modality treatment, combined modality treatment.


Muscular Tension Dysphonia (MTD)

The term muscular tension dysphonia (MTD) was coined by Morrison and Rammage at the University of British Columbia. This is a syndrome consisting of some or all of the following:

1) Excess tension, sometimes to the point of discomfort/ pain in the paralaryngeal and suprahyoid muscles;

2) An open posterior glottic chink during phonation;

3) High larynx position in the neck;

4) Inappropriate contraction of pharyngeal constrictors with phonation;

5) Often but not always, vibratory mucosal injury.

The vocal cord mucosal changes associated with MTD are usually fleshy vocal nodules. This syndrome is seen most often in young women.

Photos of muscular tension dysphonia:

 


Mycobacterium abscessus: an infection of the larynx


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