Bell's palsy - Emerging treatments

Botulinum toxin (e.g., onabotulinumtoxinA, abobotulinumtoxinA, rimabotulinumtoxinB)

Chemodenervation has become a mainstay of treatment of long-term sequelae of Bell's palsy such as synkinesis and facial contracture. One placebo-controlled, double-blinded trial comparing botulinum toxin (BTX) with saline injection into facial zones demonstrating synkinesis following Bell's palsy and other conditions demonstrated statistically significant improvements in symptoms for those receiving BTX compared with those receiving saline placebo.[69] Chemodenervation of the lacrimal gland is also effective in the management of gustatory hyperlacrimation (Bogorad's syndrome or crocodile tears). One systematic review found that there was an overall trend toward improvement in quality of life after BTX therapy, with the majority of studies demonstrating a statistically significant benefit. However, aspects of life in which patients saw benefit varied between studies and some showed minor adverse effects.[70] Individualised BTX therapy after thorough patient evaluation and choosing proper injection technique has been recommended to reduce adverse effects, maximise efficacy, and improve patient satisfaction.[71]

Physiotherapy

A comprehensive physiotherapy programme for long-term sequelae of Bell's palsy includes patient education, soft-tissue mobilisation, mirror and electromyography (EMG) biofeedback, and neuromuscular re-training. Conclusions of one meta-analysis stated there is no high quality evidence to support significant benefit or harm from any physiotherapy for idiopathic facial paralysis.[72] However, good evidence exists to support the use of physiotherapy in the management of chronic Bell's palsy (also known as non-flaccid, post-paralytic facial paralysis).[73] One study of patients with long-standing synkinesis following Bell's palsy and other conditions receiving 3 months of comprehensive facial physiotherapy, as opposed to being wait-listed, demonstrated statistical improvements in patient-reported facial stiffness and facial disability index scores, and in quantitative assessment of lip length.[74] One trial in patients with acute flaccid facial paralysis (onset within 3 weeks) resulting from Bell's palsy or other conditions who received physiotherapy that included EMG biofeedback demonstrated significantly improved facial grading system scores at 1 year compared with those receiving physiotherapy without EMG biofeedback.[75] In another randomised controlled trial (RCT), it was demonstrated that 74% of patients with Bell's palsy presenting with severe to complete flaccid facial palsy (i.e., House-Brackmann grade V/VI) who received combination pharmacological therapy plus comprehensive physiotherapy within 10 days of symptom onset demonstrated improved expert-assessed outcomes at 6 months over those receiving pharmacological therapy alone.[76]

Acupuncture

Reports on the use of acupuncture for the management of facial paralysis are emerging.[77][78][79][80][81] One Cochrane systematic review identified six published RCTs, but found severe limitations in trial design, which prevented the establishment of reliable conclusions on the efficacy of acupuncture.[77] One study reported improved outcomes and shortened recovery times with early acupuncture intervention in patients with Bell’s palsy.[81] Similar findings of improved cure rates and shortened time to cure, along with reduced occurrence of sequelae, have been reported in one meta-analysis, which suggested that acupuncture is a safe and effective technique for the management of patients in the acute phase of Bell’s palsy; however the analysis noted that the evidence was limited and of low quality and that large, high quality multicentre RCTs are needed.[80]

Hyperbaric oxygen

One Cochrane systematic review on the use of hyperbaric oxygen therapy in the management of moderate-to-severe Bell's palsy found no good-quality studies evaluating this treatment.[82] One study demonstrated the benefit of hyperbaric oxygen therapy in severe Bell's palsy, but the study was of low quality as the outcome assessor was not blinded to treatment allocation.[83]