Orofacial dystonia and asssociated bulbar symptoms in multiple system atrophy: A blinded video analysis

Abstract

BackgroundOrofacial dystonia (OFD) is considered a supporting feature for a diagnosis of Multiple System Atrophy (MSA). However, the association of OFD with other adjacent symptoms has not been explored. ObjectivesTo identify clinical characteristics of OFD and associated bulbar symptoms in MSA patients. MethodsIn this blinded trial, video clips of 24 MSA patients were reviewed by two movement disorder neurologists who rated the presence of OFD. Analysis was performed to determine correlations between the presence of OFD and clinical demographics as well as associated bulbar symptoms. ResultsThere were 14 patients with MSA-P and 10 patients with MSA-C. OFD was identified in seven patients (29.16%) and MSA-P as the majority (85.71%). Oromandibular dystonia (OMD) was hardly ever identified in isolation with the most frequent combination being OMD with upper facial dystonia, blepharospasm and platysma dystonia. All OMD patients had the jaw-closing subtype. Mean onset of OFD was 1.7 (SD = 0.5) years after the first symptom onset and 1.1 years (SD = 0.4) after the introduction of levodopa. Patients with OFD used significantly higher levodopa equivalent daily dosage (LEDD) than those without (p = 0.02). There were moderate correlations between the presence of OFD and LEDD (r = 0.458, p = 0.02), and dysarthria (r = 0.639, p = 0.001) while a strong correlation was demonstrated between the presence of OFD and dysphagia (r = 0.9, p < 0.001). ConclusionOFD is probably a manifestation of motor fluctuations in MSA and its presence is significantly associated with bulbar symptoms. Neurologists should inquire about dysphagia when encountering MSA patients with OFD for early recognition and appropriate management.