Assessment and rehabilitation interventions for central facial palsy in patients with acquired brain injury: a systematic review

Objectives: A systematic review covering assessments and interventions for central facial palsy (CFP) in patients with acquired brain injury. Methods: PubMed, Embase, Cinahl, PsycInfo, and Web of Science were screened until April 2019. Assessments were defined as clinical- and instrumental tools and rating scales. Interventions were defined as rehabilitation interventions alleviating CFP. Results: 690 articles were screened based on the title and abstract. Interrater agreement was 98.12% . Sixteen articles were included: six clinical trials and 10 observational studies. Assessment: Commonest scale for assessing CFP was the House-Brackmann facial nerve Grading System. Strain gauges for measuring lip and cheek strength were applied in five studies and neurophysiological methods of assessing motor neuron pathways were applied in three studies. Interventions: An oral screen for improving lip strength was reported in three studies. Other interventions reported were neuromuscular electrical stimulation, Castillo Morales therapy, mirror therapy, exercises with electromyography feedback, and acupuncture. Conclusions: Scales for assessing peripheral facial palsy were applied for assessing CFP. Based on neurophysiological differences in the manifestation of peripheral facial palsy and CFP, these scales should be validated in patients with CFP. More studies on interventions for CFP are required before conclusions may be drawn about their effectiveness.