Jaw-opening dystonia in Parkinson’s disease improved by FOslevodopa-foscarbidopa Continuous Subcutaneous (FOCS) infusion

Abstract

Abstract Background: Jaw-opening dystonia (JOD) is an unusual manifestation of Parkinson’s disease (PD) appearing in on-periods or off-periods. We present the case of a PD patient who presented with episodic JOD considered as off- and on-dystonia based on L-dopa concentration and improved by FOslevodopa-foscarbidopa Continuous Subcutaneous (FOCS) infusion. Case presentation: A 55-year-old man with a 14-year history of PD was hospitalized for induction of FOCS infusion therapy to control motor complications and wearing-off phenomena. The symptoms of JOD began with mild tightness in the lower jaw, followed by sudden involuntary JOD lasting for a few seconds at off-periods. After initiating the treatment by FOCS infusion, mild JOD appeared, coinciding with a relatively lower level of L-dopa concentration in the afternoon, despite the patient’s relatively good movement symptoms. Optimizing the administration rates of FOCS infusion during the day and night by adding an additional dose resulted in near-complete relief of JOD. Conclusions: JOD can occur in both off-dystonia and on-dystonia in PD based on L-dopa concentration and is treatable with FOCS infusion, a new and minimally invasive device-aided therapy.