Bilateral muscle activation in postparalytic facial synkinesis: a cross-sectional high-resolution surface electromyography study
Year: 2026
Type: article
Study design: Observational Study
Abstract: Facial synkinesis (FS) is a facial muscle coordination disorder following facial paralysis. We hypothesized that FS involves the entire network of facial muscles on both sides of the face. Bilateral facial high-resolution surface electromyography (HR-sEMG), using a total of 58 electrodes, was performed during 11 standardized facial movements in 36 healthy adult participants (53% female, 18-67 years) and 36 patients with FS (81% female, 24-70 years). Differences between the synkinetic and contralateral sides of patients and healthy controls were evaluated using linear mixed-effects models. Each movement task elicited a complex activation pattern involving nearly all measured facial muscles. In healthy controls, HR-sEMG activity was highest in the muscles primarily responsible for generating the intended voluntary movement. Notably, in patients with FS, muscles not normally expected to be strongly involved in a given movement showed markedly higher activity on the synkinetic side, and often also on the contralateral side, compared with healthy controls. Thus, facial movements in FS evoke a complex pattern of activity that only partially serves the intended movement and is further characterized by involuntary activation in muscles outside the primary movement region and on the contralateral side.
Source: Scientific Reports
Institutions: Jena University Hospital, Friedrich Schiller University Jena
Language: English
Subfield: Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,690
Award: G4026711181
OpenAlex ID: W7123710017