A case of primary focal lingual dystonia induced by speaking

Clinical and Phenomenological Characteristics of Patients with Task-Specific Lingual Dystonia: Possible Association with Occupation

BACKGROUND

Lingual dystonia is a subtype of oromandibular dystonia, which is a movement disorder characterized by involuntary sustained or intermittent contraction of the masticatory and/or tongue muscles. Lingual dystonia interferes with important daily activities, such as speaking, chewing, and swallowing, resulting in vocational and social disability.

OBJECTIVE

The aim of this study was to investigate a possible relationship between occupation and the development of lingual dystonia.

METHODS

Phenomenological and clinical characteristics of 95 patients [53 females (55.8%) and 42 males (44.2%), mean age 48.0 years] with task-specific, speech-induced lingual dystonia were analyzed. Structured interviews were carried out to obtain information regarding primary occupation, including overtime work and stress during work. The factors that might have influenced the development of lingual dystonia were estimated using multivariate logistic regression analysis of the 95 patients with lingual dystonia and 95 controls [68 females (71.6%) and 27 males (28.4%), mean age 47.2 years] with temporomandibular disorders.

RESULTS

Overall, 84.2% of the patients had regular occupations; 73.8% of the patients with regular occupations reported working overtime more than twice a week, and 63.8% of them experienced stress at the workplace. Furthermore, 82.1% of the patients had engaged in occupations that required them to talk to customers or other people under stressful situations over prolonged periods of time for many years (mean: 15.6 years). The most common occupation was sales representative (17.9%), followed by telephone operator (13.7%), customer service representative (10.5%), health care worker (9.5%), waiter or waitress (5.3%), receptionist (5.3%), and cashier (5.3%). Twenty-nine patients (30.5%) had tardive lingual dystonia. Logistic regression analyses revealed that frequent requirements for professional speaking (p = 0.011, odds ratio: 5.66), high stress during work (p = 0.043, odds ratio: 5.4), and neuroleptic use (p = 0.032, odds ratio: 2.52) were significant contributors to the manifestation of lingual dystonia.

CONCLUSION

Professions in which conversations in stressful situations are unavoidable may trigger lingual dystonia. Therefore, speech-induced lingual dystonia can be regarded as occupational dystonia in certain cases.

The focal dystonias: current views and challenges for future research

The most common forms of dystonia are those that develop in adults and affect a relatively isolated region of the body. Although these adult-onset focal dystonias are most prevalent, knowledge of their etiologies and pathogenesis has lagged behind some of the rarer generalized dystonias, in which the identification of genetic defects has facilitated both basic and clinical research. This summary provides a brief review of the clinical manifestations of the adult-onset focal dystonias, focusing attention on less well understood clinical manifestations that need further study. It also provides a simple conceptual model for the similarities and differences among the different adult-onset focal dystonias as a rationale for lumping them together as a class of disorders while at the same time splitting them into subtypes. The concluding section outlines some of the most important research questions for the future. Answers to these questions are critical for advancing our understanding of this group of disorders and for developing novel therapeutics.

Botulinum toxin in the treatment of lingual dystonia induced by speaking

Primary lingual dystonia is a rare condition, especially when it is only induced by speaking. Trihexyphenidyl failed to improve the symptoms. Several case series have demonstrated the effectiveness of botulinum toxin injection for the management of focal lingual movement disorders. Only 1 case of botulinum toxin injection for primary lingual dystonia induced by speaking has been reported, but this treatment has limited effectiveness. Our patient was treated with botulinum toxin using a superficial approach for injection into the tongue with continuing excellent results. Lingual botulinum toxin injection is a fairly simple, safe and viable treatment option for lingual dystonia induced by speaking.

Unusual focal dyskinesias

This chapter reviews focal dyskinesias that affect a restricted region of the body in isolation. Focal dyskinesias often affect body parts not commonly involved in isolation by movement disorders and are not readily classified into one of the major categories of movement disorders or peripheral nerve excitability syndromes. The clinical features and phenomenology of these "unusual focal dyskinesias" are discussed according to the region affected (ear, lip, chin, jaw, tongue, abdomen, and diaphragm (belly dancer's dyskinesias), back, scapula, and limbs). The phenomenology and origin of the unusual focal dyskinesias remain the subject of debate. Most are characterized by slow semirhythmic jerky movements at variable (usually slow) frequencies superimposed on sustained postures, consistent with dystonic movements. However, the body parts affected and pattern of occurrence (in repose rather than during action) are different to those usually seen in primary dystonia. Many of the unusual focal dyskinesias are associated with trauma and pain to the affected region, prompting the suggestion that the movements follow central sensorimotor reorganization occurring spontaneously or secondary to changes in the peripheral nervous system. In other cases, inconsistent signs and spontaneous recovery suggest a psychogenic origin.

Adult-onset dystonia

Dystonia is defined as involuntary sustained muscle contractions producing twisting or squeezing movements and abnormal postures. The movements can be stereotyped and repetitive and they may vary in speed from rapid to slow; sustained contractions can result in fixed postures. Dystonic disorders are classified into primary and secondary forms. Several types of adult-onset primary dystonia have been identified but all share the characteristic that dystonia (including tremor) is the sole neurologic feature. The forms most commonly seen in neurological practice include cranial dystonia (blepharospasm, oromandibular and lingual dystonia and spasmodic dysphonia), cervical dystonia (also known as spasmodic torticollis) and writer's cramp. These are the disorders that benefit most from botulinum toxin injections. A general characteristic of dystonia is that the movements or postures may occur in relation to specific voluntary actions by the involved muscle groups (such as in writer's cramp). Dystonic contractions may occur in one body segment with movement of another (overflow dystonia). With progression, dystonia often becomes present at rest. Dystonic movements typically worsen with anxiety, heightened emotions, and fatigue, decrease with relaxation, and disappear during sleep. There may be diurnal fluctuations in the dystonia, which manifest as little or no involuntary movement in the morning followed by severe disabling dystonia in the afternoon and evening. Morning improvement (or honeymoon) is seen with several types of dystonia. Patients often discover maneuvers that reduce the dystonia and which involve sensory stimuli such as touching the chin lightly in cervical dystonia. These maneuvers are known as sensory tricks, or gestes antagonistes. This chapter focuses on adult-onset focal dystonias including cranial dystonia, cervical dystonia, and writer's cramp. The chapter begins with a review of the epidemiology of focal dystonias, followed by discussions of each major type of focal dystonia, covering clinical phenomenology, differential genetics, and diagnosis. The chapter concludes with discussions of the pathophysiology, the few pathological cases published of adult-onset focal dystonia and management options, and a a brief look at the future.

Lingual protrusion dystonia: frequency, etiology and botulinum toxin therapy

The purpose of this study was to examine lingual protrusion dystonia (LPD); its frequency, etiology and response to botulinum toxin therapy. Previous literature suggests that LPD is more frequently the result of heredodegenerative disease and that the use of botulinum toxin therapy in LPD is associated with significant adverse effects. This is a retrospective database and record review from a movement disorder clinic. Of 421 dystonia patients, we identified 17 with LPD (4%). Of these cases, the diagnoses were: primary cranial dystonia (5), primary generalized dystonia (2), tardive dystonia (7), heredodegenerative disease (1), multifactorial (1) and post-infectious (1). All primary cases had concomitant oromandibular dystonia. In some secondary cases the LPD was the only cranial feature. Nine received botulinum toxin injections and 55.6% sustained moderate or marked improvement. Of 89 total botulinum toxin sessions, 66.3% had an excellent response, and 92.1% had some response. 97.8% of the sessions resulted in no significant adverse effects. On one occasion one patient developed severe dysphagia requiring placement of a percutaneous gastrostomy (PEG) tube. We conclude that LPD is rare, most commonly the result of tardive and primary dystonia. Botulinum toxin therapy may be very effective but needs to be utilized with care because of the possibility for the development of dysphagia.

Primary lingual dystonia induced by speaking

We describe a 46-year-old woman who presented with lingual dystonia induced only by speaking, which responded well to anticholinergic treatment.

Episodic focal lingual dystonic spasms

We present the clinical history of a woman with idiopathic episodic focal lingual dystonic spasms. Although dystonic spasms of the tongue have been reported as a primary persistent phenomenon and as a feature of secondary dystonias, primary episodic lingual dystonias are rare, tend to be unilateral, and in contrast to most other paroxysmal movement disorders, do not appear responsive to anti-epileptic drugs.