Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be

talking to you about facial nerve palsy. And you can find written notes on this topic at

zero tofinals.com slash facial nerve palsy or in the ear, nose and throat section of the zero definals

surgery book. So let's get straight into it. Facial nerve palsy refers to isolated dysfunction

of the facial nerve. This typically presents with a unilateral facial weakness, a weakness to the face on one side. It's important to

understand some basics about the pathway and the function of the facial nerve in order to understand

facial nerve palsy. So let's start with the facial nerve pathway. The facial nerve exits the brain

stem at the cerebellopontyne angle. On its journey to the

face, it passes through the temporal bone and the parotid gland. It then divides into five branches

that supply different areas of the face, and these branches are the temporal, zygomatic,

buckle, marginal mandibular, and the cervical branches.

Let's talk about the facial nerve function.

There are three functions of the facial nerve, motor, sensory, and parasympathetic.

Firstly, regarding the motor function, it supplies the muscles of facial expression.

It also supplies the steppeous muscle in the inner ear and the posterior digastric,

stylohyoid and the platisma muscles in the neck.

Regarding sensory, it carries taste from the anterior two-thirds of the tongue.

And finally, the parasympathetic function, it provides the parasympathetic nervous supply

to the submandibular and the sublingual salivavery glands, so it's

responsible for salivavery gland function, and also the lacrimal gland, so it stimulates tear

production. Let's talk about upper versus lower motor neurone lesions. A common task for exams is to distinguish between an

upper motor neuron and a lower motor neuron facial nerve palsy. It's essential to make this

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