Functional Movement Disorder; Importance of Proper Diagnosis and Treatment: A Case Report

Abstract

Purpose: Dystonia is a common movement disorder, causing chronic pain, with a wide range of aetiologies. Delays in identification and initiation of effective treatment should be minimized to improve patient's pain and optimize the outcomes. This case report aims to underscore the successful treatment of chronic dystonia with the use of mood-modifying serotonin and norepinephrine reuptake inhibitors, and encourage clinicians to consider a diagnosis of functional (psychogenic) movement disorder in patients with dystonia that is refractory to usual treatment. Patients and methods: This case report describes a 40-year-old female who presented to a chronic pain clinic for pain related to primary dystonia with associated head tremor. Her symptoms were refractory to nearly a decade of quarterly Botulinum toxin injections. Based on careful evaluation of the patient’s history, a normal neurological examination, elevated GAD-7, PHQ-9 and IEQ scores, and unsuccessful symptom management with Botulinum toxin to-date, a diagnosis of functional movement disorder (FMD) was made. Low-dose Cymbalta was initiated. Results: The patient achieved near complete symptom remission and resolution of her chronic pain within 2 months, and achieved complete resolution by 2 years. Conclusion: A diagnosis of FMD should be considered in all patients with dystonia, but especially in patients who respond inadequately to Botulinum toxin injections or other rehabilitation therapies. The treatment of comorbid psychiatric conditions can result in substantial benefit, and remission, of dystonia due to FMD.

Keywords

• Dystonia
• torticollis
• functional movement disorder
• psychogenic movement disorder
• Chronic pain