Учебники / Voice Disorders and Their Management Freeman 2000

therapist is responsible for explaining the nature of the voice problem to the patient and working out a viable treatment programme.

The osteopath/physiotherapist

Most voice disorders involve some form of muscular compensation and/or musculoskeletal hyperfunction. While the laryngologist and speech therapist do address these issues, more specialized help is often needed. The osteopath/physiotherapist can be particularly helpful in assessing the postural contribution to vocal problems, particularly if the patient has suffered injury such as whiplash to the neck, or has long-term problems from injuries sustained in childhood. More specifically, they have an important role to play in assessing hyperfunction of the extrinsic laryngeal muscles and in some cases some of the intrinsic muscles as well. Research (Harris et al., 1992) has shown that laryngeal manipulation can be extremely effective in resolving hyperfunctional voice production. The physical examination of the larynx and related structures will be discussed later in this chapter in the ‘What to assess’ section.

The osteopath or physiotherapist can then treat the hyperfunctional muscle groups, with the appropriate soft tissue techniques that are central to manual therapy. Laryngeal manipulation, either on its own or in conjunction with voice therapy, appears to be extremely effective in relieving symptoms of laryngeal pain/discomfort and restoring normal vocal function (Harris and Lieberman, 1993). It is particularly effective for singers and actors whose vocal muscles remain habitually tense and who are suffering from vocal fatigue. This also applies to those suffering from the aftereffects of upper respiratory tract infections. Both groups require emergency treatment to get them back on stage to perform in the shortest possible time. Without this modality of treatment, all that is left for these patients is a short course of steroids, which inevitably carry side effects and should be avoided if at all possible (Harris, 1992). Laryngeal manipulation also appears to be particularly valuable in the treatment of patients suffering from symptoms of globus and those with arytenoid granulomata.

These patient groups may only need reassurance that they are healthy, and the restoration of a more relaxed laryngeal musculature, in order for the condition to resolve spontaneously. Others with more long-standing or serious hyperfunctional patterns will do better with vocal retraining in addition to manipulation. Clinical observation of these cases suggests that laryngeal manipulation increases the speed with which patients respond to vocal rehabilitation techniques.

At present, there are very few osteopaths/physiotherapists who are actively involved on a regular basis in voice clinics, or who are prepared to take a special interest in developing laryngeal manipulation. Speech and

language therapists and surgeons may need to take on this role, but will require special training. While surgeons have well-developed palpatory skills and the required knowledge of anatomy and physiology, speech and language therapists do not, as yet, have experience of palpation in their training and may also need a refresher course on their anatomy and physiology, especially if they have been qualified for some years! Speech and language therapists may also have reservations that manipulation requires them to touch their clients regularly, as part of their treatment. Many speech and language therapists are trained in counselling skills, or even doubly qualified as counsellors or psychotherapists. These professions do not usually include physical contact with clients because they are working with the client’s emotional system, with all the attendant projections, transferences and defence mechanisms. Physical contact provides a very direct path to the patient’s emotional mechanisms and may break down defences that are necessary to protect both the patient and therapist. Without careful handling and understanding, emotional problems may arise.

The singing coach/teacher/advisor

The singing coach may be a regular member of the assessment team, or brought in at intervals for clinics aimed specifically at performers. Some prefer to take voice clinic referral for assessments and courses of remedial work and report back, attending only with specific clients. As there is no formal professional training for singing teachers, many will feel they benefit considerably from regular attendance at the voice clinic, as it offers them a unique opportunity to learn about both normal and disordered voice.

Many multidisciplinary voice clinics report increasing numbers of professional or semi-professional actors and singers who have special needs from a voice assessment. They may have acute problems and need guidance as to whether it is safe for them to perform that night or long-standing vocal problems of a more nebulous nature. The singing coach has a valuable role to play here, both as a joint decision-maker and as a ‘vocal detective’.

Few speech and language therapists or surgeons have a great deal of knowledge of the world of performance, its demands on the voice or its environmental and physical stresses. Stereotypes abound, particularly with pop/rock singers, who are often assumed to know nothing about voice production or singing technique and to be likely to abuse their bodies with smoking, drugs and alcohol. In some cases this may be true, but there are many highly trained singers in this genre who have survived without vocal problems, do not smoke or take drugs and run well on herbal tea! These singers have much to teach us about voice use and survival.

The singing advisor can bring to the clinic a unique understanding of the problems that are specific to performers, and ask the right case history

questions. Unless specialized in singers, most speech and language therapists or surgeons will not routinely ask about fold back, use of raked staging, marking in rehearsals or difficulties with company managers and agents, for example. Performance also brings with it another language. Suddenly, Spintos, Helden Tenors, Buffo basses and Lyric mezzos come out of the woodwork with problems of fach, register and specific and other incomprehensible symptoms, such as ‘a damper seems to come on the folds on F sharp above the stave’. It is easy for the more medically based team to dismiss singers as neurotic and voice-obsessed at best – and mad at worst. One wonderful thing about singing advisors is that they speak this language and can act as interpreters from ‘singer speak’ into ‘medical speak’, thus saving time and frustration on both sides and allowing an accurate diagnosis to be made with the minimum of misunderstanding.

Accurate diagnoses for singers can be difficult. Frequently, at first glance the larynx looks healthy and normal, and yet the singer is unable to perform at certain pitches or with certain dynamics. Stroboscopy is essential for these patients. So often, when examined with a strobed light, the intracordal cyst, fibrous plaque or sulcus vocalis appears on what seemed to be a pristine vocal fold. It is essential therefore, during the endoscopy, to ask the singer to vocalize at the pitch or dynamic where they experience the problem.

Sometimes technique that looks flawless in chest register may suddenly become hyperfunctional, higher in the range. Structural problems such as ventricular cysts, which are totally unrelated to phonation at one pitch of volume may suddenly interfere with, or affect, technique at another. The singing coach can often identify the components of the voice faster and most effectively.

Where the singer in clinic is really having difficulties with vocal technique, the singing teacher will have practical advice for the short term and a coterie of experienced colleagues to refer on to, at his or her finger tips. The role of interpreter is also necessary to relay the clinic findings and recommendations to the patient’s current or recommended teacher, or to their training establishment if they are students. Some singing coaches will provide an advice session or a few sessions of remedial work as part of the clinic services, but this is rare within the NHS, due to funding problems.

The psychologist/counsellor/psychotherapist

In ideal circumstances, every voice clinic needs access to a qualified and interested psychologist, counsellor or psychotherapist. The presence of emotional factors, as either a trigger or concomitant of voice problems, is almost universal and many patients would benefit from some form of counselling, either as the focus of their management or in conjunction with surgery or voice therapy. Where possible, the counsellor is most

valuable as a regular member of the clinic assessment team, seeing each patient. Where patients recognize and accept the psychological nature of their symptoms, the management is clear and the counsellor can take over immediately, reducing the possibility of resistance developing to the idea of a ‘psychological’ diagnosis. Where patients are unable to accept the psychological nature of their voice disorder, or if the disorder is multifaceted, the counsellor’s clinical observations can be pivotal to the team management plan and their role as a supervisor for others in the team, who may have to deal directly with the patient, is invaluable.

In reality, this ideal is hard to achieve. However, it is strongly advised that links are forged with the local psychiatry/psychology department in order that patients can be referred on for assessment and treatment. The importance of psychological supervision for clinicians treating voice patients, whether they are speech therapists, singing coaches or osteopaths/physiotherapists, cannot be overestimated. Voice patients often present with complex and confusing psychological symptoms and clinicians who work with them frequently experience strong emotions around these patients. They need support and counselling to protect themselves and the patients from collusion and/or dependencies that could affect their clinical judgement.

The phonetician/acoustics department

Where multidisciplinary voice clinic teams are involved in research or clinical audit, links with a university phonetics department may provide access to equipment and analysis that may not be available in an NHS setting. Each individual clinic will work out their own needs in this area, depending on the equipment they have available to them and their research/audit needs. Research projects may require patients to visit the university for some of their assessment, for example acoustic analysis, while audit may well be possible to achieve by sending tape-recorded clinical data for analysis. However, phonetics departments are likely to charge a fee for their services and will expect acceptable recording quality for any taped data.

Equipment

Equipment for the voice clinic is expensive and vital. The minimum requirement is stroboscopy, using either a rigid telescope or flexible fibreendoscope to visualize the larynx. As previously stated, it is not possible to view the movement of the mucosa over the body of the vocal folds during phonation with continuous light, and therefore stroboscopy is essential in order to eliminate microscopic or occult lesions that could be responsible the patient’s symptoms.

The stroboscope

Stroboscopes are available from a number of companies; those made by Storz, Kay Elemetrics and Richard Wolf appear to be reliable and the producers offer reasonable aftercare/maintenance service, which is essential. Stroboscopes cost in the region of £8000. This price includes a microphone but excludes the endoscope and necessary cables.

The endoscope/telescope

The larynx may be viewed using a rigid telescope introduced into the oral cavity and rested on the back of the tongue. A prism at the distal end allows visualization of the larynx. There are choices in the degree of angle used, the most common being 90 or 70 degrees. The view using a rigid telescope is excellent as it allows a good magnification of the vocal folds and is ideal combined with stroboscopy for identifying microscopic/occult lesions. It also has the advantage that it can be conveniently sterilized in the clinic with isopropyl alcohol, after which it is washed in water. The drawback of using rigid telescopes is that in order to view the larynx the tongue needs to be pulled forward, interfering with the supraglottic resonators. There is some evidence that this posture may also alter vocal fold closure patterns during the examination (Sodersten and Lindestadt, 1992). Good models are available from companies such as Storz, Wolf and Olympus and cost between £1800 and £2500. It may be difficult to acquire the excellent but rather more expensive Japanese models from Machida or Nagashima.

Fibreoptic nasendoscopy provides a good alternative method of viewing the larynx with stroboscopy. Most modern nasendoscopes have a diameter between 3.5 and 4.2 mm and the tip is vertically manoeuvrable. Recent improvements and the new generation of fused silicon fibreoptic bundles allow better picture definition and smaller bundle diameter. These advantages are somewhat offset by the increase in rigidity their construction requires. In the future nasendoscopy will be able to provide similar quality video images to rigid telescopes. Rhinolaryngeal video endoscopes are a recent innovation (Olympus and Pentax). A small monochrome camera chip is placed at the distal tip of the endoscope so that the picture is no longer dependent on the fibre bundles. The field under review is then rapidly illuminated by sequences of red, green and blue light flashes from a special stroboscopic light generator. The camera input is reconstructed into high definition full colour pictures in a dedicated video processor. At present, these systems are very expensive; the endoscopes are large in diameter and they are not yet capable of producing stroboscopically slowed down images of vocal fold vibration, but hopefully this will come in time.

The advantages of nasendoscopy are that the view of the larynx is minimally invasive, allowing the patient to use their habitual phonation

pattern and giving a good view of the supraglottic resonators. It is also excellent for viewing patients who have a brisk gag reflex and are unable to tolerate a rigid telescope in the mouth. The disadvantage is that it requires either at least 20 minutes to sterilize the endoscope (by soaking in Cidex) between patients or disposable sheaths and fitting apparatus, inevitably adding to clinic running costs. Patients tolerate nasendoscopy well on the whole, particularly if topical anaesthesia is used. Application of Co-phenylcaine forte spray (Paedpharma) seems to be less irritating to the patient’s nose than the more commonly used Xylocaine, which produces a marked stinging sensation when first introduced. Good fibreoptic nasopharyngoscopes are available from such companies as Olympus, Pentax and Storz and cost around £5000–£8000.

Video equipment

The most useful equipment to add to stroboscopy is a camera and video recorder to allow the laryngeal images to be studied in slow motion by the clinic team. Single and three chip cameras are available for this purpose and have their strengths and weaknesses. Single chip cameras are small, extremely light sensitive and relatively cheap, starting at approximately £2200. The three chip cameras give better colour and more lines, but tend to be less light sensitive and far more expensive at approximately £5000. Additionally, the reduction in light sensitivity may make it necessary to buy a more expensive laryngoscope in order to achieve adequate light values for good video recording. This is becoming less important, as some systems now incorporate image enhancement. Whether the camera is digital or analogue is not critically important.

Video recorders vary in price between approximately £1000 and £3500 depending on the format and number of special features such as high quality freeze-frame, frame by frame, slow motion, etc. The standard format for video recorders in the UK and Europe is VHS but this system is now ageing and many clinics have switched to S-VHS. S-VHS records light values (luminance) and colour (chrominance) separately, improving the picture definition, particularly for re-recordings made from edited video material. As most clinicians need to edit videos these days for various purposes, it is worth buying a recorder that is at the upper end of the price bracket, as the freeze-frame capability and time-coding are superior on the more expensive models.

In addition to the camera and video recorder, a medical grade high resolution TV monitor is required. They cost up to £1500 depending on the quality and number of lines required. A small tie-clip microphone costing approximately £200 is also necessary to record the patient’s voice during the assessment. Cables and a C mount adaptor to connect the Laryngoscope or nasendoscope to the camera may further increase the

cost. A character generator to add the patient’s name and clinic date to the film will cost between £200 and £1000, depending on the facilities, but is not essential in an everyday clinic setting. VAT, as always, is extra on all these items of equipment.

Looking to the future, clinics that invest in a fairly powerful computer will be able to install a frame grabber card. Using this card, the video input is digitized and stored to disc or to a read-write CD or DVD ROM, allowing vast amounts of data to be economically and compactly stored and indexed. It also allows for colour ‘stills’ to be easily printed from the video and stored for reference in the patient’s notes. With less sophisticated systems, a single memory grade video printer such as the Sony Mavigraph TM can be attached to the video recorder, which can download a selected freeze-frame image and print it out on PVC paper for the clinic notes. Recent models now include a red-green-blue facility. Polaroid offer a similar system, which while versatile, requires the top of the range version to provide adequate definition.

Audio-recording

The equipment described above is a priority for visualizing the larynx, but in order to analyse the patient’s phonation pattern more broadly, other techniques can be used. Perceptual analysis, still the cheapest, easiest and yet valid measure of dysphonia, requires a good audio tape recorder (Laver et al., 1981; McAllister et al., 1994). Where possible, a digital audiotape recording system (DAT) is ideal, as it is excellent for both perceptual and computer analysis of dysphonic voices. It is also the best system for recording the patient’s progress through therapy. However, a good analogue system is still necessary, as most clients do not have DAT recorders at home and their therapy practice tapes need to be made to a good standard. A good DAT audiotape recorder costs in the region of £1000.

Electroglottograph/electrolaryngograph

The electroglottograph or electrolaryngograph is another valuable method of analysing the vocal output and measuring vocal change in treatment, accurately but non-invasively. This system measures the length of time the vocal folds are in contact with each other during phonation. It is linked to a computer and monitor which displays a waveform that can be printed out for the patient notes. The system can also analyse and represent longer samples of connected speech in the form of a histogram. A recent development (Laryngograph Ltd.) links the EGG equipment with stroboscopy so that the EGG data on vocal fold contact is synchronized with the videostroboscopy.

Two systems are readily available, the Electrolaryngograph (Fourcin and Abberton, 1971) and the Electroglottograph (Rothenberg, 1992). The

Laryngograph workstation, which is most commonly used in the UK, costs approximately £5000. This includes a suitable personal computer (PC), the laryngograph processor, the interface card, and software programmes for spectrography and phonetograms. The computer may also be used to run the Aerophone software (see airflow equipment) if airflow measures are required. Where the clinic already possesses a suitable computer, the Laryngograph system alone costs £3000.

Spectrography

Speech spectrographic analysis provides another non-invasive method of analysing the vocal output. Spoken material, collected either in real time or on audiotape, can be analysed using the appropriate computer software and displayed as a spectrograph on the computer screen. The display allows the clinician to measure the fundamental frequency and the associated formants created by the vocal tract. When the data is collected and analysed in real time, it can be used as visual biofeedback to show patients when they successfully achieve the pattern of formants required for different vowels and for spoken phrases. The most commonly used spectrographic analyses are available either from Laryngograph (see above) or Kay Elemetrics Ltd. as part of their CSL Speech Laboratory. Laryngograph will supply the necessary software separately for both their spectrograph and phonetogram, together with the digital signal processing (DSP) card, which can be installed on most types of computer. The DSP card costs £1000 and the spectrograph and phonetogram software packages cost £1000 respectively. Other packages are commercially available and liaison with the nearest university phonetics department may prove valuable.

Airflow studies

Airflow measures may be possible to access via the physiotherapy or respiratory physiology department, or may come as separate software that can be installed on the clinic computer. Measurements such as vital capacity, resting respiration and forced respiration are available, but the most useful for the voice clinic team will be the airflow patterns that occur in continuous phonation and speech. The Aerophone, produced by F-J Electronics appears to be most commonly used and costs approximately £5000. Like the laryngograph, it requires a suitable PC for operation. It is also available as an add-on unit for the Kay system.

Phonetograms

A phonetometer maps a visual record of the patient’s range of pitch and intensity. It is non-invasive and easily carried out, provided that the

patients are able to match the frequency of a computer generated tone with a sustained vowel. The patient matches the tone as loudly, then as softly, as they can throughout their range. The intensity values are plotted on to a graph in decibels, showing the highest and lowest scores at each frequency. When the plotted values are connected they form an outline that represents the patient’s vocal and dynamic range (see Carding, Chapter 5). Software for this analysis can be installed on the clinic computer, increasing the scope of assessments available to suit individual patient needs. Phonetograms are particularly useful for assessing the dynamic range of singers and performers.

What to assess

Stroboscopy

Stroboscopic visualization of the larynx is used to determine laryngeal health and function. First, a description of the vocal folds is necessary, reporting the presence of any obvious lesions, their relative size, shape and position on the folds or elsewhere in the larynx. Where no obvious lesions are present, the colour of the vocal folds, the presence of enlarged blood vessels and the quality and texture of the mucosa are noted. If videostroboscopy is available, a printout of an appropriate freeze-frame is recommended for inclusion in the notes.

Otherwise the surgeon may make a sketch of the vocal findings or fill in the relevant details on a schematic picture.

A description of the vocal fold movement during phonation is necessary. The symmetry of vocal fold movement is recorded, together with the degree of closure and closure pattern. The presence of any other muscular activity within the larynx is noted; for example, the partial adduction of one or both false folds, the position of the base of the epiglottis and the position of the arytenoid cartilages. It can be very useful to observe these features at different vocal pitches, particularly when the patient is a singer or actor. It is important to note whether the vocal folds lengthen and shorten appropriately when the patient is asked to glide up and down their pitch range.

Finally, observation of the mucosal waves is reported. Are the mucosal waves present over the entire surface of the free borders of both vocal folds or is there any sign of deep tethering where the wave disappears? Are there areas where the mucosa appears to rock, rather than allowing smooth passage of the waves? Do the vocal folds vibrate symmetrically, so that both waves emerge from the subglottis and roll over the folds at the same time and at the same rate?

Do the mucosal waves respond to changes in vocal pitch, being of greater amplitude in modal voice and smaller at higher frequencies? (Hirano and Bless, 1993).

Stroboscopy smooths out irregular vibration, and therefore in clinics where there is adequate funding for instrumentation, an excellent technique known as Videokymography may be used graphically to document vibratory irregularity, subharmonic beating of the folds and antero-posterior and left-right asymmetry of vibration patterns (Svec and Schutte, 1996). Inevitably, it requires the acquisition of another specially adapted video camera and related hardware.

These observations all help to build up a picture of the type of vibratory pattern used by each patient. Any lesions or areas of concern are noted along with the habitual vocal fold posture. These can then be compared with the findings at follow up.

Palpation of the extrinsic laryngeal muscles is essential, along with a description of the patient’s general and head and neck posture. Where possible a manual therapist, such as an osteopath, needs to work with the voice clinic team in order to help develop palpatory skills for those not trained in palpation (e.g. speech therapists and singing teachers) and also to help with the development of a suitable protocol. The most relevant areas to examine are:

•the patient’s general symmetry, weight bearing, spinal curvature;

•the state of the cervical spine and any hyperlordotic segments;

•the quality and tone of the cervical musculature;

•the position in which the head is carried;

•symmetry of jaw opening and excessive activity in the jaw muscles;

•the quality and tone of the suprahyoid musculature;

•the quality and tone of the thyrohyoid muscles/membranes;

•the quality and tone of the cricothyroid muscles and appropriate opening and closing of the cricothyroid visor;

•the quality and tone of the strap muscles;

•the ease of lateral shift of the larynx;

•the areas that the patient reports as painful or tender, which should be noted.

Where the clinic has access to a manual therapist who is experienced in laryngeal manipulation, the state of the posterior cricoarytenoid muscles and the crico-arytenoid joint may also be assessed.

Each member of the assessing team can rate the degree of tension palpated in the extrinsic laryngeal muscles and place it on a 3–5 point scale; the majority consensus rating can then be recorded in the patient’s notes, to ensure practitioner agreement. More detailed protocols can be developed such as the Lieberman protocol (Harris et al., 1998).