JCPSLP Vol 20 No 2 July 2018

(Pereira et al., 2011) drew two main conclusions. While differences in outcome measurement and risks from bias were problematic across studies, combined therapy was effective in producing a successful outcome of functional change for FNP and, importantly, treatment should involve both specific facial exercises and biofeedback. All four of the studies within the review were able to demonstrate functional improvement and reduced synkinesis, although no study reported an advantage of one method of biofeedback (e.g., mirror vs EMG) over another. Pereira and colleagues, however, recommended the availability and low cost of a mirror as a suitable form of biofeedback to enable the client to actively participate in the generation of movement and synkinesis prevention. A home program was also recommended to reinforce the strategies. A further set of studies compared the treatment advantage of EMG with no biofeedback and then compared EMG directly with mirror biofeedback. These studies found the biofeedback group had statistically fewer cases of synkinesis and a higher number of cases with complete recovery and mild dysfunction than the non- biofeedback group, concluding that biofeedback produced a better quality recovery than when it was not used. There were no significant differences found between outcomes using the mirror and EMG methods, but the mirror biofeedback enabled participants to reduce the number of treatment sessions, using their mirror at home once trained in careful muscle exercise, with less frequent checking required with their clinicians. The EMG biofeedback approach, however, was reported to be preferable for those participants who had difficulty observing their palsy in the mirror. In summary, the literature on rehabilitation of FNP supports the use of client specific, neuromuscular re- education of graded movements of the affected muscles innervated by the facial nerve combined with biofeedback involving the use of a mirror and EMG. The Dalla Toffola et al. studies (2005, 2012) suggest that the EMG is a particularly valuable tool in developing the individualised, precise, fine grading of exercise development for FNP clients especially in early stages when it is difficult to see movement via the mirror. Biofeedback in speech-language pathology There is limited evidence of SLPs using and/or evaluating specific rehabilitation techniques with FNP in the literature, despite the high co-occurrence of dysarthria and dysphagia, both core areas of SLP practice. Interest in biofeedback, however, is not new to speech-language pathology. Huckabee and Cannito (1999) and Crary, Carnaby Mann, Groher, and Helseth (2004) found positive effects and increased clinical efficiency using sEMG biofeedback in the learning of functional swallowing movements post stroke which are inherently difficult to self-monitor. Parallels may be drawn between swallowing post stroke and the needs of the person with FNP where there is the need to relearn difficult small muscle movements of the face for facial expression, speech and swallowing. Stepp (2012), in reporting on sEMG with speech and swallowing intervention, recommended that SLPs improve their understanding of sEMG and gain consensus as to the appropriate methodology for both research and the future applications in the clinic. She proposed that the non-invasive nature of sEMG indicated that it should be a method of choice for clinical use and, while more reliability of repeated sEMG measurements is

beyond the immediate nerve damage, with such visible changes in facial expression and appearance frequently reducing self-esteem and increasing social avoidance (Devriese et al., 1990; Van Gelder et al., 1990). This can have a direct impact on quality of life, “greatly influencing the patient’s social life and employment” (Dalla Toffola et al., 2005, p. 809). Physical interventions in FNP Traditionally, given the reduced movement of the facial musculature and likelihood of synkinesis developing, FNP has been an area of treatment and research for physiotherapists (Manikandan, 2007). Two intervention approaches have prevailed in the literature. Mime therapy is a physical rehabilitation technique involving mime tasks for a range of facial expressions and aims to increase symmetry and muscle control while reducing synkinesis (e.g., Pereira et al., 2011). Careful activation of single muscles is involved, with controlled contraction actively promoting targeted localised movement. This is in contrast to gross and spontaneously attempted movement (Beurskens & Heymans, 2006; Manikandan, 2007), which is more likely to cause a mass action of facial muscles involving the stronger side of the face in a less controlled movement. A second approach, neuromuscular education is not dissimilar, involving the relearning of facial movements but with specific feedback for both appropriate and abnormal movement patterns (Van Swearingen, 2008). Two systematic reviews evaluating physical therapies for Bell’s palsy have generated conflicting results; one suggesting there is insufficient evidence for specific physical interventions (Teixeira, Soares, Vieira, & Prado, 2008) and the other (La Touche, Escalante, Linares and Mesa, 2008) concluding that facial exercises did result in improvement of facial symmetry and mobility, and a reduction in synkinesis. The use of biofeedback in treatment of FNP Biofeedback has also been frequently used with FNP, particularly using electromyography (EMG), where a needle is placed into the muscle to record electrical activity, and surface EMG (sEMG), a non-invasive method where no needle is required for placement of the electrode. These methods enable the client to regain control of muscle contraction/relaxation by providing the client and clinician with an immediate external display of myo-electrical potentials and information about very small episodes of muscle contraction which are normally subliminal. Through education around facial anatomy, clients acquire motor skills which can then become automated and used spontaneously, with the client able to take an active role in their own recovery (Van Gelder et al., 1990). Dalla Toffola et al. (2005) and Baricich et al. (2012) suggest that the neuroplasticity of the nervous system underlies this process, and that this specific biofeedback can increase client self-monitoring for appropriate grading of movement of their facial muscles, while avoiding inappropriate effort on contraction. The use of a mirror, seen more commonly in clinical practice, is another way of providing visual biofeedback to the client. While a mirror is useful when the participant can see sufficient movement, the low levels of activation that are apparent using EMG in the early stages of recovery cannot be detected, even in the presence of good visual acuity. A systematic review that specifically focused on studies where biofeedback, irrespective of type, was incorporated into “facial exercise therapy” for LMN FNP

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JCPSLP Volume 20, Number 2 2018

Journal of Clinical Practice in Speech-Language Pathology