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While uncommon, vocal cord dysfunction related to tardive dyskinesia can occur and may be life-threatening.
In findings presented at CHEST 2024, the researchers describe tardive dyskinesia (TD) as a rare cause of tachypnea and present criteria for monitoring patients for TD-related vocal cord dysfunction.
The case report at the center of the researchers’ findings involved a woman aged 65 with a history of COPD, a major depressive disorder with psychotic features while on treatment, TD secondary to medication, and dysphagia. She rushed to the ED for worsening shortness of breath.
The shortness of breath was present for approximately 10 months and required multiple ED visits and hospitalizations, with worsening in the previous 2 months and the development of dysphagia and noisy breathing. The presence of stridor led to an evaluation by otolaryngology, which indicated paradoxical movement of her vocal cords. The rest of the workup resulted in TD of the vocal cords being identified as the most likely etiology of her vocal cord dysfunction.
Assessing Vocal Cord Dysfunction in TD
The findings “bring awareness to a rare manifestation of TD and a rare cause of tachypnea and stridor,” the researchers wrote.
“While TD is a well-described complication of anti-psychotics, and oro-buccal-lingual and facial dyskinesias are the most common manifestations, TD of the vocal cords as a medication side effect is rare,” the authors noted.
Further, even with medications associated with the highest risk for TD, laryngeal dysfunction as a side effect remains uncommon.
However, investigators noted the importance of assessing patients with progressive symptoms to identify worsening TD. During such screening, if TD presents with stridor, dyspnea on exertion, interrupted speech, or other respiratory symptoms of concern, “vocal cord dysfunction from TD should be considered, although it is a diagnosis of exclusion.”
According to the findings presented at CHEST 2024, botulinum toxin injections every 3-6 months are recommended for patients with vocal cord dysfunction related to TD.
Laryngeal TD in the Literature
Additional research shows that the occurrence of laryngeal TD varies with the age of the patients (ranging from 20 to 81), sex, psychiatric diagnoses, and medications used.
The researchers of one case study on the topic note that laryngeal TD is a “rare but life-threatening complication of antipsychotic medications,” That study also described potential misdiagnoses, including an anxiety attack, and emphasized the importance of otolaryngology in establishing an accurate diagnosis.
Another case study on laryngeal TD suggests that the condition is infrequently described in the literature but is also under-reported “given [that] the disorder is not well defined and patients may not be aware of the problem.” Study investigators in that case report also emphasized the life-threatening nature of this rare TD manifestation and called for greater recognition of the condition.
