Explaining the diagnosis

In explaining the diagnosis, it is important to (1) take the problem seriously and acknowledge that the symptoms are real, (2) explain that this is a positive diagnosis (as defined above) and that the diagnosis is not unknown or mysterious, (3) explain the reasons for the diagnosis by demonstrating or explaining its positive clinical signs (box 3), (4) provide written material and links to other resources. Suggestions to help with effective explanations are listed in box 4.

When the person referred for treatment has already had the diagnosis explained by the referring professional, it is still important for the speech and language professional to reinforce, consolidate, and, if necessary, expand the person’s understanding about the functional disorder diagnosis. When there is comorbid structural pathology, the therapist may need to discuss the extent to which it may or may not be an obstacle to improvement.33–38

Duration of treatment

Most patients referred with functional disorders of communication, swallowing and cough can benefit from speech and language therapy, often substantially/dramatically and sometimes rapidly. Many achieve some improvement or even elimination of one or more, and sometimes all of their symptoms during the initial consultation. While this does not necessarily mean that the functional disorder has fully resolved, such early symptomatic improvement is very encouraging. Others require several therapy sessions of symptomatic/behavioural work, integrated with counselling. Clinical experience suggests that intensive therapy, with sessions several times per week, may be most successful in helping patients to regain normal function and inhibit abnormal movements or struggle behaviours, and to maintain gains in the wider social context. We recognise, however, that limited resources may limit the frequency of therapy.

For some, several weeks or months of treatment may be required for a sustained improvement that generalises beyond the clinical setting. This has sometimes been attributed to the patient ‘being resistant’ or ‘failing to comply’ with recommendations, but generally speaking, patients do want to improve—that is why they are there—and are cooperative with treatment. Habituated patterns of movement and behaviour can take time and practice to overcome, and there may also be perpetuating influences (see table 1). Some therapists find it useful to develop a time-limited treatment contract which includes indications for ending therapy, a plan for self-management and strategies for coping with possible relapse of symptoms.

Suitability for treatment

Factors important for engagement with treatment include: (1) a reasonable degree of understanding and agreement with the diagnosis and (2) motivation and agreement to treatment.

Circumstances in which beginning or continuing symptomatic therapy is less likely to be successful or may be inadvisable, and which suggest a guarded or poor prognosis in some cases include:

• Transient, unpredictable or highly variable symptoms across settings.

• Resolution or improvement of symptoms will lead to a return to what may be an unsafe or ‘futile’ work environment or domestic situation.

• Unresolved litigation related to symptoms.

• Severe psychiatric comorbidity.

• Other severe FND symptoms are present, such as seizures, dissociative states, severe pain or fatigue. However, early treatment of communication symptoms may enable the person to engage better with treatment of the other symptoms.

• Patient doubts the diagnosis of FND, although some may accept/embrace it during successful symptomatic treatment.

• Poor confidence in therapist’s ability to help them resolve symptoms.

A trial of therapy is generally appropriate despite a degree of resistance or ambivalence. However, some positive response to treatment should be expected during the first 1–2 sessions; failure to respond at all during these initial sessions suggests it would be better to pause and revisit symptomatic treatment at a later date, or with another therapist.

General principles of symptomatic treatment

The principles of symptomatic management of functional communication, swallowing, and cough disorders can be helpfully informed by both perceptual-motor learning models as they have been applied to voice training and therapy39 40 and recommendations from physiotherapy and occupational therapy professionals with experience treating FND.6 7 Treatment involves learning or retraining of motor patterns, while highlighting the ways in which attention, expectations, illness beliefs and the vulnerability of our sense of agency (the experience of controlling one’s own movements) may inhibit normal movements and promote abnormal movements.

Assessment, diagnosis and treatment of specific symptoms

The following sections address specific symptoms. However, it should be noted that these specific symptoms are not mutually exclusive but often co-occur. An individual may experience a range of different symptoms at different times, including during treatment and recovery. The treatment strategies suggested here are based on available evidence and the combined clinical experience of the consensus group. They largely represent recommendations rather than high-level-evidence-based guidelines.

Specific symptoms: functional voice disorders

Functional voice symptoms include dysphonia, aphonia, odynophonia (pain using the voice), vocal fatigue and mutational falsetto or puberphonia (high pitched voice after puberty). Globus is common, and excessive physical effort is a hallmark feature of these disorders. There is a (usually) sudden or intermittent loss of volitional control over the initiation and maintenance of phonation despite normal structure and function as observed during laryngoscopy and clinical examination. Since the voice is often closely associated with the expression of emotion, sudden total or partial loss of voice is often presumed to be linked to psychological factors and negative emotions associated with stress. Furthermore, patterns of vocal hyperfunction related to dysregulated or imbalanced laryngeal muscle activity are often observed, both of which are consistent with current FND models that emphasise the interplay between ‘top down’ and ‘bottom up’ influences on peripheral sensorimotor processing.52–54 As a consequence, in the past these disorders have often been referred to as ‘psychogenic’, or ‘conversion dysphonia’, with others more recently preferring the more aetiologically neutral term of ‘functional’ or ‘primary muscle tension dysphonia’.8 55

Onset may follow acute stress or longer-term difficulties, sometimes characterised by conflict over speaking out, expressing negative emotions, a sense of powerlessness; sometimes related to personality vulnerabilities.18 56 57 Importantly, many patients do not recall any emotionally stressful incidents, but will associate their loss of voice with a recent upper respiratory tract infection, a medical procedure involving the head and neck, or some form of blunt injury which cannot account for the nature and severity of the vocal symptoms. Therapists often comment that while some patients do not report or recall significant stresses prior to onset, once they have their voice back, they might reopen conversations about possible psychosocial triggers. Helpful assessment methods and diagnostic features are listed in the full version (see online supplemental file 1).

Treatment includes strategies to bypass problematic movement patterns by facilitating short, instinctual responses and overlearned or reflexive utterances (table 3). It is advisable to inform patients that you are going to ask them to do some things differently which may entail making unusual sounds or carrying out gestures or bodily movements not associated with their usual way of talking. These activities can elicit normal phonation easily, without conscious preparation, since they are neither generally associated with use of the voice, nor are they experienced as being directly related to a conscious intent to communicate. If they were, they may trigger patterns of inhibitory muscular tension and exaggeration of the symptoms.

Specific treatment strategies may be necessary to reduce excessive musculoskeletal tension when present. They may include focal palpation of the laryngeal region, circumlaryngeal massage and manual repositioning with gentle but firm lowering or compression of the larynx (when within professional scope and competence).58 59 The speech and language professional should reassure the patient that their pattern of excessive tension does not represent an irreversible muscular abnormality, but rather reflects a well-intentioned, but misdirected effort to achieve normal voice. Just prior to touching the neck, throat and larynx, it is important to explain what the clinician will do and why, and to ask permission to palpate, massage or reposition the larynx.

Use of traditional evidence-based techniques for dysphonia such as Vocal Function Exercises, Semi-Occluded Vocal Tract Exercises, and Resonant Voice Exercises may be useful for modifying voice, consolidation and generalisation.

Once normal phonation has been achieved, generalisation beyond the clinical setting is relatively straightforward, but it can be particularly challenging for some individuals in specific psychosocial contexts (ie, a schoolteacher returning to the classroom after developing functional aphonia following significant difficulties in managing rebellious student behaviours and lack of support from school leaders). Under these circumstances, sustained improvement may be difficult to achieve, especially if there is evidence of long-standing anxiety, comorbid depression or ongoing medicolegal or workers’ compensation issues.43 Outcomes are more likely to be positive if the patient understands the relationship between the voice problem and any ongoing psychosocial issues and has strategies in place to deal with them. Basic supportive counselling (and use of additional psychological approaches within individual scope) by the speech and language professional is often sufficient, but referral for additional support from a mental health professional is sometimes essential.48 49 60–62

Systematic reviews of randomised controlled trials exploring the efficacy of symptomatic voice therapy for ‘functional dysphonia’ report moderate-to-good evidence for the direct symptomatic and behavioural voice therapies, either alone or in combination with indirect therapies that may involve education and vocal hygiene.63 64 More recently an extensive evaluation of the evidence for the efficacy of therapy for functional and structural neurological voice disorders has shown similar findings.65 These studies did not appear to distinguish between patients within their broadly defined functional dysphonia groups (ie, no structural abnormality) and those traditionally termed 'psychogenic/conversion aphonia dysphonia’ as being discussed in this paper.

Another subtype of functional communication disorders is functional mutism, in which the patient does not produce sound, even with a whisper, or may mouth words with accurate but inaudible articulatory movements. This is in contrast to selective mutism which reflects voluntary refusal to speak, sometimes only in specific circumstances (often in the context of anxiety). In functional mutism the inability to speak is experienced as involuntary. Selective mutism and functional mutism sometimes overlap. In some cases the history reveals a breakdown in communication with significant others, and/or there is a conflict over speaking out or expressing negative emotions. The person may ask for access to an electronic device to assist with communication, which raises interesting issues about offering aids that may serve to perpetuate the ongoing pattern of mutism. When possible, communication without aids should be encouraged.

Specific symptoms: functional stuttering

Functional stuttering is distinguished from developmental or neurogenic stuttering by new onset in adulthood (without prior developmental speech output difficulties), extremes of variability or consistency on sound, syllable, word or phrase repetitions, unusual patterns of rate and pausing, increased dysfluency with more simple speech tasks, and lack of improvement with activities that usually promote fluency. Of note, functional dysfluency may be internally inconsistent but may also be unusually consistent in presentation compared with developmental stuttering, such as stuttering on every syllable or word, or on the first word of every sentence.34 66–68 Helpful assessment methods and positive diagnostic features are shown in the full version (see online supplemental file 1).

Case reports suggest functional dysfluency may follow stressful life events associated with conflict and difficulties with communication of negative emotions in close relationships or with an important person; dealing with high burden of responsibility or criticism in the work place where it is difficult to speak out and defend oneself; recent accident or illness sometimes in association with mild head injury leading to transient concussion; in situations where personal injury lawsuit or workers compensation may be an issue; or in association with posttraumatic stress disorder following combat. Clinicians emphasise that close attention needs to be given to these psychosocial issues, while also recognising that the absence of a clear psychological trigger should not discount a functional diagnosis. Functional dysfluency can co-occur with other functional neurological symptoms, and in patients with comorbid neurological disease including stroke, epilepsy or traumatic brain injury.38 67 69 70

Although positive outcomes have been reported in case studies of treatment of functional stuttering in adults, it remains unclear what elements of these treatments explain their effectiveness.38 67 Some potential approaches to symptomatic treatment are summarised in table 4.

When functional dysfluency does not resolve quickly with treatment, psychological impacts can be severe. Generalised anxiety and social anxiety in anticipation of speaking activity have significant implications for self-identity, close relationships, social participation and quality of life. While diagnosis of a psychological disorder is outside the scope of practice for speech language professionals, recognition of psychosocial factors in functional stuttering (as in developmental stuttering) allows therapists to appreciate the lived experience of stuttering and to guide appropriate therapy. Alongside symptomatic treatment, the therapist might helpfully include psychological approaches targeting features of avoidance, rumination and self-doubt.71 72 As with developmental and neurogenic presentations of stuttering, collaboration with mental health professionals may be helpful in the management of secondary anxiety disorders and psychological distress.73

Specific symptoms: functional articulation symptoms

Functional articulation disorders are characterised by substitutions or distortions of specific sounds, some of which may be associated with developmental errors (eg, ‘wead’/‘read’, ‘wittle’/’little’, ‘thome thoap’/’some soap’). Some sounds are produced with marked variability and unusual and exaggerated tongue, lip or jaw movements. These distortions may be accompanied by other unusual prosodic features, such as inappropriate patterns of loudness, with telegraphic speech and hesitations or exaggerated facial movements. Errors may be consistent and limited to particular sounds, or unusual and associated with unusual tongue posturing (eg, speaking with consistent tongue retraction). The patient may complain of weakness while exhibiting paradoxical strained voice quality. Functional articulation symptoms sometimes develop after dental, surgical or traumatic injury to the mouth, tongue or facial structures, or in combination with other functional symptoms affecting voice or fluency.5 74 75 Examination features are detailed in the full version (see online supplemental file 1).

In addition to the general treatment approaches outlined above, traditional treatment approaches used for developmental and neurological articulatory disorders may be effective. Some treatment strategies are suggested in table 5.

Specific symptoms: other functional communication disorder symptoms (eg, language, prosody and accent)

Language impairments impacting on understanding, word finding, syntax, reading and writing may occur in FNDs, often along with other functional cognitive symptoms.76 Diagnosis is generally made on the basis of significant internal inconsistency in performance compared with well-described lesion-based patterns of aphasia, dysgraphia and alexia. An example of such inconsistency would be disproportionate difficulty with reading during formal assessment in comparison to day-to-day reading. In some cases, however, these problems may be abnormally consistent in comparison with lesion-based aphasia, dysgraphia, etc.

Subjective word finding or memory and concentration difficulties are not uncommon in patients with FND, and often appear to reflect inefficient allocation of attentional resources. Once other speech or communication symptoms, or other functional symptoms, are effectively treated, such cognitive symptoms may resolve. If the symptoms persist, some patients may benefit from being taught simple compensatory strategies for word retrieval deficits and similar difficulties.

FAS is a disorder of speech in which listeners perceive the affected individual as speaking with a foreign or regional accent. Onset of FAS may occur in neurological disease or damage, for example after stroke or brain injury. Recent review of cases of self-reported FAS suggest that in some cases symptoms are the result of an FND. Functional FAS can be identified by the presence of internally inconsistent changes in the person’s articulation and prosody, alterations to vowel and consonant production, stress, rhythm and intonation37 77–80 (see online supplemental file 1).

Similarly, while immature features (eg, developmental articulation errors) may persist in the speech of some adults, the sudden emergence of such features, and incongruity with the person’s former manner of speaking, age, level of maturity and occupation, suggests an FND.58 Such immature speech is often characterised by a combination of prosodic, voice and articulatory alterations such as elevated pitch, exaggerated inflectional patterns and common developmental errors (eg, th/s, w/r); immature speech may be accompanied by infantile gestures and expressions. Functional immature speech may co-occur with functional voice disorders or stuttering and may disappear when the voice or fluency symptoms have resolved with intervention. Treatment by the speech and language professional may be directed towards modification of these obvious speech, voice and infantile pragmatic behaviours. However, in view of the possible symbolic implications of these regressive symptoms, in cases where there is clear evidence of relational difficulties or emotional problems, referral for referral for family therapy with an emphasis on close interpersonal relationships or psychodynamic psychotherapy may be appropriatenecessary.

Functional FAS may resolve spontaneously or during treatment; but there is relatively little information about the best treatment approaches to use when symptoms persist. Of note, FAS may or may not impact on communicative effectiveness. Others have suggested attention to detailed phonetic analysis with traditional speech therapy while recognising comorbid psychological factors,81 or strategies routinely used for accent reduction in non-native speakers of English.82 In a case described by Lee et al,79, functional FAS resolved with speech and language therapy approaches combined with CBT. Some treatment suggestions for functional FAS and other disorders of language, prosody and accent are offered in the full version (see online supplemental file 1).

Specific symptoms: globus pharyngeus

Globus pharyngeus is a functional disorder which presents as a recurrent, non-painful but uncomfortable sensation of a lump in the throat, in the absence of dysphagia, odynophagia, gastro-oesophageal reflux disease (GORD/GERD) or a histopathology-based oesophageal motility disorder. Globus commonly co-occurs with functional voice disorders.

Symptoms may be persistent or intermittent and are experienced as a sensation of a foreign body in the throat (eg, hair, crumb); a tightening or choking feeling; a lump in the throat; or sensations of throat strain or itch. Globus is more obvious between meals and improves with eating, but there is often a sense of food and/or liquid sticking or passing with difficulty through the oesophagus. Globus is often associated with throat clearing, a sense of mucus build up or dry throat, repeated swallowing, chronic cough or hoarseness and, over time, dysphonia with pharyngolaryngeal tension.33 83

Studies have shown links between globus and psychological stress,84 85 with many patients reporting exacerbation of their symptoms during periods of high emotional intensity. Although common, psychological and psychiatric disorders may be an outcome rather than a predisposing factor.

Globus must be distinguished from dysphagia, but while the two symptoms do not necessarily co-occur, empirical data suggests that 20% of patients with functional dysphagia experience globus sensation with swallowing.86 Within gastroenterology, globus is defined often using the Rome IV criteria as a diagnosis of exclusion.33 35 This is in contrast to the inclusive methods preferred here for diagnosis of functional voice and speech disorders.

There are few adequately controlled treatment trials for globus. Although spontaneous remission may occur with reduction in psychological stress, 75% are still symptomatic after 3 years. One study suggested that globus symptoms resolved after reassuring diagnostic investigation by an ear, nose, throat physician83 87 88 ; others have cautioned against over investigation.83 88

While therapeutic trials of proton-pump inhibitors are sometimes recommended in order to exclude GERD as a cause of globus, it should be noted that in a randomised controlled trial, globus resolved as frequently in patients administered esomeprazole as in those given placebo.89 Antidepressants may be helpful, even in the absence of mood symptoms, in reducing oesophageal pain and discomfort.90 In one small trial, the SSRI antidepressant paroxetine was found both effective and superior to low dose amitriptyline (a tricyclic antidepressant), which was superior to the proton-pump inhibitor lansoprazole in treatment of refractory globus.91

There is good preliminary evidence for the effectiveness of speech and language therapy in treating globus.36 88 92 93 These approaches to management are summarised in the full version (see online supplemental file 1).

Specific symptoms: functional dysphagia

Functional dysphagia is more often oropharyngeal rather than oesophageal since oropharyngeal musculature is under voluntary rather than autonomic control. For both types of dysphagia exclusion of disease is vital, but for oropharyngeal dysphagia identifying positive features is an important part of the diagnosis and explanation when due to a functional disorder. Positive signs include inability to swallow in the absence of drooling or excessive oral secretions, or inability to control anything in the mouth but ability to spit saliva into a cup.

Symptoms of ‘globus’, a feeling of it being ‘hard’ to swallow, pain on swallowing, choking sensations and coughing94 are often described by patients with functional dysphagia. Patients often adopt avoidance behaviours as an attempt to reduce the perceived risk of choking. Examples include subtly reducing food intake and textures, changing head postures, eating slowly and with raised bodily tension and social avoidance. Fear of choking is common and functional dysphagia may ultimately lead to unintended weight loss, social withdrawal, anxiety, panic and depression.86 95 96 The impacts on quality of life are not dissimilar to those experienced by patients suffering dysphagia in association with head and neck cancer.97 98

Functional oesophageal dysphagia can be diagnosed using Rome IV criteria, which unlike other disorders in this paper, are based on exclusion of disease rather than positive clinical features of functional disorder, with diagnostic criteria requiring that the following symptoms are present for at least 3 months, with onset 6 months before diagnosis: (1) a sense of solid or liquid food sticking, lodging, or passing abnormally through the oesophagus: (2) an absence of mechanical obstruction, GERD or oesophageal motility disorder causing these symptoms.99 Such patients require varying levels of investigation, the details of which are outside the scope of this article.

In some cases functional dysphagia is an isolated symptom, with muscle tension or laryngeal hypersensitivity100; in other cases dysphagia may be present as one of a range of functional motor symptoms, for example, in stroke-like presentations; or may be associated with significant phagophobia or psychiatric symptoms. Functional symptoms elsewhere in the gastrointestinal tract, such as cyclical vomiting, may impact on food intake goals.

There have been no randomised controlled trials for treatments specifically targeted at functional dysphagia as opposed to globus. Antidepressants are sometimes used on the basis of evidence of benefit in overlapping disorders causing oesophageal discomfort.90

An overview of educational, behavioural and psychological strategies that may be used by speech and language professionals in the management of functional dysphagia are summarised in the full version (see online supplemental file 1). Of note, a recent trial of Cognitive Behaviour-Enhanced Swallowing Therapy in patients recovering from head and neck cancer had promising outcomes; a similar approach may be beneficial in treatment of functional dysphagia.98

Specific symptoms:cough and vocal cord dysfunction (laryngeal hypersensitivity syndrome)

The group suggests that conceptualising laryngeal hypersensitivity syndrome as a functional disorder is appropriate. Chronic cough and vocal cord dysfunction (also known as paradoxical vocal fold motion and inducible laryngeal obstruction) can be considered manifestations of laryngeal hypersensitivity syndrome. Symptoms can occur in the absence of a known cause or persists despite thorough medical management. Cough and vocal cord dysfunction persist as a result of reversible changes in function or aberrant involuntary learnt behaviours, rather than primarily due to ongoing disease or damage, but not necessarily in the presence or as a result of significant psychological distress. Importantly, it is possible to have laryngeal hypersensitivity syndrome without meeting criteria for DSM-5 somatic symptom disorder (in which disproportionate time, energy, thoughts, anxious feelings and behaviours persist in relation to the seriousness of the symptoms), which is the way the American College of Chest Physicians have framed conditions previously described as psychogenic cough.101 102

It seems likely that the term psychogenic cough has been used inappropriately for a range of types of refractory cough. Idiopathic cough,103 medically unexplained cough,10 104 chronic refractory cough,105 neurogenic cough or laryngeal/cough hypersensitivity syndrome,106 all refer to cough of unknown aetiology that persists despite medical treatment. Psychiatric comorbidity is far from universal and often secondary rather than causal.103 107

Referral should follow respiratory assessment by a physician, which should usually include investigations including spirometry. This group recognises two patterns of dysfunctional cough: (1) persistent habitual cough, and (2) cough which occurs intermittently in a ‘hypersensitive’ pattern but without objective evidence of airway hypersensitivity, in response to salient stimuli as part of a conditioned response, and with or without perceived panic or autonomic arousal. Respiratory exposure chamber testing may be indicated in some persistent cases. In most cases the diagnosis should be clearly established prior to referral for speech therapy. However, in those cases where patients may self-refer, they should be encouraged to seek formal assessment by a respiratory physician.

The assessment process can help the patient to understand the nature of their disorder, to recognise the key triggers that stimulate their urge to cough and then, how they respond behaviourally to those triggers. Strategies and behavioural guidelines for treatment, as recommended by a speech and language professionals, physiotherapists and respiratory physicians specialising in this area are summarised in the full version (see online supplemental file 1).108–110