Facial palsy

Abstract

The facial nerve is arguably one of the most important cranial nerves as its injury may result in not only the inability to produce voluntary facial expressions but also the loss of protective eyelid closure and glandular secretions. Facial nerve injuries present a multitude of serious problems for patients that may hugely impact their quality of life and general health including: difficulties with eating or drinking, loss of articulate speech, ocular injury and significant psychosocial morbidity. The clinical presentation of patients with a facial palsy may vary, both in the timing of onset and the extent of the resultant palsy. Understanding the history behind any given case of facial palsy will help determine its aetiology. In Bell’s palsy (idiopathic lower motor neuron facial palsy) for example, the onset is typically rapid (24 - 72 hours) and accompanied by ipsilateral periauricular pain and hyperacusis [1]. A palsy resulting from neoplastic nerve compression, however, is typically insidious in onset and accompanied by systemic features such as malaise and weight loss. It is imperative therefore to take meticulous histories and undertake careful clinical examination of all patients with facial palsy in order to make accurately diagnose them. Whilst a multitude of aetiologies exist (HSV, Lyme disease, tumour, autoimmune etc.) [2], the principal management of all cases of facial palsy follows a common pathway. All patients should be offered symptomatic relief if required and effective prevention of secondary pathologies, such as exposure keratitis must be actively provided whilst the underlying cause is sought and definitive treatment commenced. In this chapter, we will be discussing the anatomy of the facial nerve, the possible causes of facial nerve palsy, how to assess and diagnose facial palsy. We will also provide a framework to guide initial patient management, treatment strategies to prevent consequent impairment and importantly describe numerous surgical options available to patients with established facial palsy.