What is the diagnosis and management approach for a 55-year-old female presenting with abnormal tongue movements, suspected to be related to a movement disorder (DD)?

Differential Diagnosis and Management of Abnormal Tongue Movements in a 55-Year-Old Female

The most critical first step is determining whether these tongue movements represent tardive dyskinesia (TD), a functional movement disorder, or another hyperkinetic disorder, as this fundamentally changes both prognosis and treatment approach.

Initial Diagnostic Approach

Key Clinical Features to Assess

Examine for positive signs that distinguish between etiologies:

• Tardive dyskinesia characteristics: Repetitive, stereotyped movements of the tongue (protrusion, lateral movements, rolling), often accompanied by other orofacial dyskinesias; typically associated with antipsychotic or dopamine-blocking medication exposure 1

• Functional movement disorder features: Inconsistent movements that vary with attention, distraction, or during spontaneous conversation; presence of excessive effort, struggle behaviors, or unusual tongue postures; symptoms that are internally inconsistent or disproportionate to any structural findings 2

• Other hyperkinetic patterns: Fasciculations/myokymia (fine, rippling movements), choreic movements (rapid, irregular, non-repetitive), dystonic postures (sustained abnormal positioning), or tremor 3, 4

Essential History Elements

Obtain specific medication history:

• Current and past use of antipsychotics (typical or atypical), metoclopramide, prochlorperazine, or other dopamine antagonists 1
• Duration of exposure and temporal relationship to symptom onset 1

Assess for functional disorder indicators:

• Sudden onset or onset following specific stressor 2
• Symptom variability with attention, distraction, or during automatic activities 2
• Presence of other functional neurological symptoms 2
• Psychological stressors, trauma history, or comorbid anxiety/depression 2

Management Based on Diagnosis

If Tardive Dyskinesia is Confirmed

Initiate valbenazine (INGREZZA) as first-line pharmacologic treatment:

• Starting dose: 40 mg once daily; after one week, increase to 80 mg once daily 1
• Mechanism: VMAT2 inhibitor that reduces dopamine release and improves involuntary movements 1
• Efficacy: In controlled trials, 80 mg dose showed mean improvement of -3.2 points on AIMS dyskinesia score versus -0.1 for placebo (p<0.001) 1

Critical monitoring requirements:

• Screen for depression and suicidal ideation before initiating and throughout treatment, as valbenazine carries warnings for these risks 1
• Monitor for parkinsonism (difficulty moving, tremor, gait disturbances) and QT prolongation 1
• Dose reduction to 40 mg daily required in CYP2D6 poor metabolizers and moderate/severe hepatic impairment 1

Concurrent medication management:

• Review and minimize or discontinue causative dopamine-blocking agents if clinically feasible 1
• Avoid MAOIs (contraindicated within 14 days) 1

If Functional Movement Disorder is Diagnosed

Implement speech and language therapy with motor retraining as primary treatment:

Education and explanation (therapeutic in itself):

• Provide clear, positive diagnosis explanation: movements reflect reversible patterns of abnormal motor control, not structural damage 2
• Emphasize that symptoms are real but result from excessive muscle tension that can be brought under voluntary control 2
• Demonstrate clinical signs showing symptom variability to help patient understand the diagnosis 2

Symptomatic treatment strategies:

• Natural reflexive behaviors: Cough, yawn-sigh, gargling with firm sound, tongue trills with voiced consonants (e.g., "drr") 2
• Attention redirection: Bubble blowing with vocalization, large body movements while making sounds, speaking while walking 2
• Physical maneuvers: Circumlaryngeal massage with concurrent vocalization, postural manipulations 2

Treatment structure:

• Intensive therapy (multiple sessions per week) shows superior outcomes 2
• 86.7% of functional movement disorder patients show improvement with multidisciplinary rehabilitation programs 5
• Outcomes are not negatively affected by longer symptom duration or psychiatric comorbidities 5

Psychological intervention:

• Address predisposing, precipitating, and perpetuating factors 2
• Challenge catastrophic thinking and hypervigilance to symptoms 2
• Refer for formal CBT if comorbid anxiety, depression, or trauma history present 2

Critical Pitfalls to Avoid

Do not dismiss functional disorders as "psychogenic" or "not real" - these are genuine neurological conditions with specific positive diagnostic features requiring active treatment 2

Do not delay valbenazine initiation in confirmed TD - earlier treatment correlates with better outcomes, and symptoms may worsen without intervention 1

Do not overlook medication-induced causes - even brief exposure to dopamine antagonists can trigger TD, and 70% of TD patients in trials were on atypical antipsychotics 1

Do not assume psychiatric comorbidity precludes functional disorder diagnosis - anxiety and depression are common perpetuating factors, not exclusion criteria 2, 5

Additional Diagnostic Considerations

If neither TD nor functional disorder fits the presentation:

• Consider oromandibular dystonia (sustained jaw/tongue postures, may worsen with stress or hormonal factors) 6
• Evaluate for fasciculations suggesting lower motor neuron pathology 3, 4
• Assess for choreic movements in context of Huntington's disease or other basal ganglia disorders 2, 4

Neuroimaging and laboratory studies should be guided by specific clinical features suggesting structural pathology, but are not routinely required for TD or functional disorder diagnosis 2