3D-Ultrasonography for evaluation of facial muscles in patients with chronic facial palsy or defective healing: a pilot study

Abstract

BackgroundWhile standardized methods are established to examine the pathway from motorcortex to the peripheral nerve in patients with facial palsy, a reliable method to evaluate the facial muscles in patients with long-term palsy for therapy planning is lacking.MethodsA 3D ultrasonographic (US) acquisition system driven by a motorized linear mover combined with conventional US probe was used to acquire 3D data sets of several facial muscles on both sides of the face in a healthy subject and seven patients with different types of unilateral degenerative facial nerve lesions.ResultsThe US results were correlated to the duration of palsy and the electromyography results. Consistent 3D US based volumetry through bilateral comparison was feasible for parts of the frontalis muscle, orbicularis oculi muscle, depressor anguli oris muscle, depressor labii inferioris muscle, and mentalis muscle. With the exception of the frontal muscle, the facial muscles volumes were much smaller on the palsy side (minimum: 3% for the depressor labii inferior muscle) than on the healthy side in patients with severe facial nerve lesion. In contrast, the frontal muscles did not show a side difference. In the two patients with defective healing after spontaneous regeneration a decrease in muscle volume was not seen. Synkinesis and hyperkinesis was even more correlated to muscle hypertrophy on the palsy compared with the healthy side.Conclusion3D ultrasonography seems to be a promising tool for regional and quantitative evaluation of facial muscles in patients with facial palsy receiving a facial reconstructive surgery or conservative treatment.

Correlation between electromyography and quantitative ultrasonography of facial muscles in patients with facial palsy

“…Our study confirms recent findings showing that quantitative ultrasonography can detect the decrease and re‐increase of facial muscle thickness after facial nerve lesion and reinnervation, respectively . Studies of other muscles affected by a neural disease combining ultrasound and EMG are quite rare.…”

“…[1][2][3] Our study confirms recent findings showing that quantitative ultrasonography can detect the decrease and re-increase of facial muscle thickness after facial nerve lesion and reinnervation, respectively. 7,12 Studies of other muscles affected by a neural disease combining ultrasound and EMG are quite rare. This diagnostic combination has been used mainly to study muscle volume changes and fascicle lengths during isometric contraction of limb muscles to obtain fundamental knowledge of muscle biomechanics.…”

Hering’s Law of the Frontal Facial Branch

“…Some authors have described the eyebrow elevation and increased horizontal forehead wrinkles of the contralateral peri-orbital region after permanent hemi-FPFB as being due to frontalis muscle hypertrophy 2,3 . The assumption of muscle hypertrophy, however, has never been confirmed by histopathologic biopsy nor diagnostic imaging techniques 4,5 . We think this phenomenon is just due to HL, that, as illustrated by our case just described, can already be observed directly after hemi-FPFB: hemi-FPFB results directly in eyebrow depression of the affected side with instantly over elevation of the contralateral eyebrow.…”

Chirurgie bei Läsionen des Nervus facialis

“…Vor kurzem wurde als neues Verfahren zur quantitativen Untersuchung der hochauflösende Ultraschall der mimischen Muskulatur etabliert [5]. Damit kann nach Fazialischirurgie auch das Muskelwachstum nach erfolgreicher Reinnervation quantifiziert werden.…”