Oromandibular Dystonia Related to Sertraline Treatment in a Child

To the Editor:

Oromandibular dystonia (OMD) presents with repetitive/uncontrollable contractions in jaw, lower face, and mouth. It can lead to difficulty in opening (jaw-opening OMD) and closing (jaw-closing OMD, C-OMD) of the mandibular joint and affect oral functions (Gonzalez-Alegre et al. 2014). Although etiology is not completely known, encephalitis, encephalopathies, metabolic diseases (e.g., Wilson's disease), psychogenic factors, and drugs (e.g., phenytoin, cyclizine, metoclopramide, antispychotics, and SSRIs) were implicated among children (Balasubramaniam et al. 2008). Among adults, family history of essential tremor/dystonia, occupations depending on speaking, cerebellar and dental disorders, and tardive syndromes may cause OMD (Gonzalez-Alegre et al. 2014). It is more frequent among females (Gonzalez-Alegre et al. 2014; Uvais et al. 2016).

OMD in youth associated with sertraline treatment has been previously reported among adolescent and adult females (Uvais et al. 2016). In this study, we report a case of OMD related to sertraline in a prepubertal male child.

A 10-year-old boy was referred to child psychiatry clinic due to “fear of death, difficulty sleeping, and poor appetite.” The symptoms started a month after witnessing the aftermath of a suicide bomb and included hypervigilance, sadness, social isolation, and avoidance of reminders. Medical history and family history were normal. Mental status examination revealed anxiety, hypervigilance, and depression. Psychomotor retardation and depression prevented completion of self-report scales at intake.

He was diagnosed with posttraumatic stress disorder according to the DSM 5 criteria, with severe symptoms, Clinical Global Impressions Scale (CGI-S = 6). Trauma-focused cognitive behavioral therapy (TF-CBT) was planned, and 25 mg/day sertraline was initiated with a titration to 50 mg/day a week later. On the 10th day, the patient was brought to the outpatient clinic by his mother complaining of a sudden onset of difficulty in swallowing and jaw pain. It was learned that his mother had continued drug administration at 25 mg/day. Neurological consultation demonstrated limited and painful mastication, trismus, teeth clenching, lateralization of the tongue, and increased salivation consistent with C-OMD. Otherwise, neurological and physical examinations, laboratory investigations, electroencephalogram, and cranial MRI were normal. Sertraline was suspected in the etiology and stopped. Intramuscular 2.5 mg biperiden resolved the symptoms in 1 hour. TF-CBT was continued. Evaluation with the Naranjo algorithm (Naranjo et al. 1981) revealed a score of 7 (probable). Informed consent was obtained from the legal guardian of the patient for publication.

In contrast to previous reports (Balasubramaniam et al. 2015; Uvais et al. 2016), sertraline-related OMD appeared in a male child at the start of the treatment in our case. Family history was negative and no stressors and/or neurological/medical conditions could be found. No concomitant treatment was present and relationships with sertraline were judged as “probable.” Sertraline may cause OMD due to enhanced serotonergic neurotransmission in mesocortical circuits from the ventral tegmental area leading to a dopaminergic deficit, affect other basal ganglia, or cerebellar circuits (Uvais et al. 2016). Despite reversibility and favorable response to anticholinergic treatment, OMD, as a rare side effect among prepubertal children, should be kept in mind by the clinicians.