**Dr. R. Rajeshwari, DNB (Neurology)**

Consultant Neurologist, MediPulse Hospital, Jodhpur, India

**1**

**Chapter 1**

*Pratap Sanchetee*

**2. Historical perspective**

facial palsy in 1821 [2].

**3. Emotional vs. volitional facial paresis**

**1. Introduction**

Introductory Chapter: Bell's Palsy

The seventh cranial nerve, commonly known as the facial nerve, is a compound nerve having motor, parasympathetic, and sensory components. Its motor portion innervates muscles for facial movement and expression. In addition, it is involved in taste over the anterior two-third of the tongue. Its parasympathetic component supplies secretomotor fibers to submandibular and sublingual salivary glands and the lacrimal gland. A small twig of this nerve carries sensations from the pinna and the external auditory meatus. Facial paralysis is a common clinical condition that significantly impacts a patient's quality of life [1]. Seventh cranial nerve paralysis has been categorized as supranuclear if the lesion is above its nucleus in the pons and as intranuclear if the lesion is below the nucleus. This categorization is important from diagnostic, therapeutic, and prognostic points of view and must be made clinically at the initial presentation itself. The peripheral facial nerve palsy, popularly known as Bell's palsy, is an acute disorder of the facial nerve, which produces full or partial loss of voluntary movement on one side of the face. Less common features are loss of taste sensation over the ipsilateral half of the tongue, hyperacusis, tingling or numbness of the cheek/mouth, and ocular pain.

James Douglas (1675–1742) in the eighteenth century gave the description of unilateral facial paralysis. However, Cornelis Stalpart van der Wiel in 1683 first clearly observed and recorded a case that was later described as Bell's palsy. Sir Charles Bell (1774–1842), Scottish surgeon anatomist, and First Professor of Anatomy and Surgery at the Royal College of Surgeons, London, is credited with the first authentic description of the anatomy of the facial nerve and its association with the idiopathic peripheral

Perhaps the most difficult and poorly understood component of facial palsy is the distinction between voluntary and emotionally driven facial expressions. It must be appreciated that human facial emotional expression is a complex phenomenon resulting from the summation of activity of a large-scale neural network in the cerebral cortex [2]. Gower's description provides an early description of a clinical dissociation between voluntary and emotionally driven facial expressions [3, 4]. Emotional facial paresis results in impaired activation of face muscles with emotion but normal
