Restless tongue: Lingual Tardive Dyskinesia – A rare case report

Abstract

Tardive Dyskinesia is a movement disorder characterized by involuntary repetitive body movements, like chewing motions, cheek puffing, tongue protrusion and lip pursing. These symptoms appear during sleep and/or wakefulness. Report of involuntary movements of tongue is very rare, with a prevalence of only 15%–20%. Risk factors include old age, female gender, and patients receiving drugs with anti-dopaminergic activity, for long term. We report a case of 62 years old male patient with a long history of antidepressants and mood stabilizers, who presented with involuntary tongue movements. The patient was treated by altering the dose and discontinuation of a few medicines, which resulted in a slight decrease in the frequency of the movement. The case is discussed here to spread awareness and vigilance about this condition, in order to aid in early diagnosis and management, to avoid negative impacts on psychologic health and quality of life of the patient.

Graphical abstract

1. Introduction

Faurbye coined the term “Tardive” in 1964. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) classifies Tardive Dyskinesia (TD) as “involuntary athetoid or choreiform movements lasting at least a few weeks generally of tongue, lower face and jaw, and extremities, developing in association with use of neuroleptic medication for at least few months and persisting beyond 4–8 weeks”.¹ As described, drugs are the major etiology followed by older age, female predilection, presence of mood disorder, alcohol, cigarette smoking, substance abuse etc. for causing TD. Occurrence of TD is estimated to be 2%–5% annually.² It affects 1 out of 4 patients who have been on treatment with dopamine receptor blocking agents (DRBAs).³ Here by we report a case of 62 years old male patient with involuntary tongue movements having history of antidepressants and mood stabilizers since 10 years.

2. Case presentation

A 62 years old male patient reported to Department of Oral Medicine and Radiology, with a complaint of pain and burning sensation in lower sided left back cheek region since 1 month. On further questioning, he added continuous involuntary movements of tongue since 6 months. Movements were involuntary and were increasing at the time of rest. Medical history revealed patient was on antidepressant drugs since 10 years for disturbed sleep. Also added that, he was diagnosed with depression. Patient was taking antidepressant drugs like Imipramine 25 mg (TCA), Venlafaxine 75 mg (Atypical antidepressant), Lithium 300 mg (Mood Stabilizer), Mirtazapine 30 mg (Atypical antidepressant), Ropinirole 0.5 mg (Dopamine Agonist), Nitrazepam 10 mg (Anti-anxiety), and Lorazepam 2 mg (Anti-anxiety) since 10 years. He also reported habit of tobacco chewing with lime 3 packets per day since 20 years. No other relevant family history was present. General physical examination was unremarkable. On intraoral examination, the tongue showed involuntary repetitive, purposeless movements when he opened his mouth. The movements were less apparent when he was speaking. Other functions like swallowing, taste and speech were unaffected. Patient was assessed using Abnormal Involuntary Movement Scale (AIMS).⁴ There were no movements noted in other body parts. The AIMS score was matching with Category 1 (Face) in which it matched Item 4 (Tongue) with Code 3 (Moderate Spontaneous Movements). AIMS contains additional section of Global Judgement including Patient's awareness of abnormal movements scores aware, here in present case our patient was Scored 2 (Mild Distress) as he was aware of the movements and asked for treatment regarding it (Table 1).

Table 1.

AIMS score correlation.

Timeline	Category	Item	Code	Score
Before treatment	1 (face)	4 (tongue)	3 (moderate spontaneous movements)	3
	2 (extremity movements)	5 (upper body) 6 (lower body)	0 (none)
	3 (trunk movements)	7 (neck, shoulder, hips)	0 (none)
	4 (global judgment)	8 (severity) 9 (incapacitation) 10 (awareness)	0 (no awareness)
	5 (dental status)<	11 (current problem) 12 (denture worn) 13 (edentia)	No
	Movements disappear in sleep	Yes	Yes
After treatment	1 (face)	4 (tongue)	2 (mild movements)	2
	2 (extremity movements)	5 (upper body) 6 (lower body)	0 (none)
	3 (trunk movements)	7 (neck, shoulder, hips)	0 (none)
	4 (global judgment)	8 (severity) 9 (incapacitation) 10 (awareness)	0 (no awareness)
	5 (dental status)	11 (current problem) 12 (denture worn) 13 (edentia)	No
	Movements disappear in sleep	Yes	Yes

The provisional diagnosis of tardive dyskinesia was given after eliminating other differential diagnoses of dyskinesia and dystonia like Parkinson's disease, Tourette syndrome, Huntington's disease, Rabbit syndrome, Chorea acanthocytosis, Cerebral palsy etc. (Table 2).⁵

Table 2.

Differential diagnosis.

FEATURES	Tardive dyskinesia	Rabbit syndrome	Parkinson's disease	Chorea acanthocytosis	Tourette syndrome
Onset	Old age	Old age	Old age	Young adults	Childhood
Gender predilection	Female	Female	Male	No gender predilection	Male
Type of movement	Involuntary, purposeless, irregular movements	Rapid twitching in perioral area, resembling chewing movements of a rabbit (Without tongue involvement)	Rigid, slow and diminished spontaneous movements, with pill-rolling tremors	Involuntary jerking movements, unintended tongue protrusion and habitual tongue and lip biting	Waxing and waning hyperkinetic movements, which are sudden and brief, like eye blinking, nose twitching etc.
Pattern of movement	Repetitive movements	Rhythmic tremors	Rhythmic tremors	Repetitive movements	Repetitive movements
Other features	Rarely involves movements of limbs or trunk	Movements of masticatory muscles along the vertical axis of mouth	Muscle stiffness, stooped posture, speech and writing changes	Cognitive and behavioral changes, myopathy, seizures	Unwanted sounds (tics) like coughing, grunting etc.

The patient was clinically evaluated for any sharp cusp tips and coronoplasty was performed in order to avoid chronic irritation to the moving tongue. Patient was referred to a psychiatrist to alter the current medications. He was gradually weaned off from Nitrazepam, Venlafaxine and Ropinirole, and the patient was switched from Lorazepam to Clonazepam (2 mg) and Clozapine (200 mg) was added to it. Patient was kept on follow up after 3 months for further evaluation using AIMS Scale showing Code 2 (Mild Movements) in Item 4 (Tongue). Also, counselling was done to help uplift patient's emotional and social spirit, which helped patient to regain his confidence. These measures altogether decreased movements of tongue, which was now scored 2 (mild movements) instead of 3 (moderate spontaneous movements) for tongue movements and scored 1 (Aware, No distress) instead of 2 (mild distress) in Global Judgement Section (Table 1).

3. Discussion

Pathophysiology of antipsychotic drugs (e.g. dopamine antagonist) induced tardive dyskinesia include prolonged blockade of post-synaptic dopamine (D₂) receptors leading to dopamine receptor super-sensitivity as well as damage to GABA and cholinergic neurons in striatum. Oxidative stress and consequent damage in striatum might also result in TD.² (Fig. 1).⁶

Fig. 1.

Pathogenesis of Tardive Dyskinesia.

Similarly in our case, history of patient revealed that he was on antidepressants and mood stabilizers since 10 years, suggesting a strong link between drugs and tardive dyskinesia. Long term use of antidepressants medication induced Tardive Dyskinesia in two patients was reported by Anelyssa et al.^7,8

Other risk factors associated with TD like older age, mood disorder, substance abuse, mentioned in various literature that co-relates with our case presenting with 65 years male with altered mood disturbances, and adverse habit of tobacco with lime. Females are considered as one of the other risk factors while males are rarely one of them considering our case of male to be rare representation of TD.¹

Cases of oral dyskinesia involving chewing motions and lip pursuing have been reported till date by Pekkan et al. and S. Lumetti et al. Our case typically represents continuous purposeless movements of tongue which is very rare, suggestive of lingual tardive dyskinesia. Although available literature related to lingual tardive dyskinesia is scarce.⁹

Preventing tardive dyskinesia is important, and it can be achieved by altering anti-psychotic drugs, by dose reduction, by switching to another drug and minimizing the duration of therapy. The first-line management of tardive dyskinesia is the withdrawal of antipsychotic medication if clinically feasible. Yet, for many patients with serious mental illness, the discontinuation of antipsychotics is not possible due to disease relapse. Switching from a first-generation to a second-generation antipsychotic with a lower D2 affinity, such as clozapine or quetiapine, or else, by using vesicular monoamine transporter 2 (VMAT2) inhibitors.¹⁰

To reduce the risk of trauma to the tongue due to constant movements, we performed coronoplasty and kept him on follow up. We observed that, when we built up confidence of patient and made him assured above harmless nature of condition, the movements were reduced on follow up without patient yet has not changed drugs. We referred the patient to his psychiatrist to alter the regimen and counselled the patient, which resulted in significant decrease in dyskinetic tongue movements.

4. Conclusion

Tardive dyskinesia is a movement disorder, mainly affecting oro-facial areas. Hence, an oral physician plays a major role to identify. It may be a subconscious activity and patients are not aware about it, however it may lead to muscle fatigue and affects function of organ involved. When it involves external part of face, it becomes a psychosocial matter for a person. But in the present case, it was an intraoral part, which was not considered psychosocial treatment for the patient and he was aware about it and showed mild distress regarding it. As it mainly affects old age individuals, its early identification and correction can help to avoid future morbidity and provide relief to the geriatric patients.

Presentation at a meeting

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Source of funding

*No source of funding

CRediT authorship contribution statement

Pritesh Ruparelia: Conceptualization, Formal analysis, Supervision, Validation, Visualization, Writing – review & editing. Udita Pandya: Conceptualization, Data curation, Investigation, Writing – original draft, Writing – review & editing. Navneet Gill: Investigation, Visualization, Writing – review & editing. Oshin Verma: Data curation, Investigation, Project administration, Writing – original draft, Writing – review & editing.

Declaration of competing interest

None.

Appendix A. Supplementary data

The following is the Supplementary data to this article: