"Facial Nerve Examination Simplified | Step-by-Step Guide for Clinical Practice"

The facial nerve (Cranial Nerve VII) examination involves assessing its motor, sensory, and parasympathetic functions. Here’s a step-by-step guide: 1. Inspection Look for facial asymmetry at rest. Note drooping of the mouth, flattening of the nasolabial fold, or inability to close the eye. 2. Motor Function Ask the patient to perform the following movements: 1. Raise eyebrows: Tests the frontalis muscle. Normal: Symmetrical wrinkling of the forehead. 2. Close eyes tightly: Tests orbicularis oculi. Normal: Symmetrical tight closure. Try to gently open their eyelids to check resistance. 3. Show teeth or smile: Tests lower face muscles. Normal: Symmetrical showing of teeth. 4. Puff out cheeks: Tests orbicularis oris and buccinator muscles. Check for air leakage from the lips. 3. Sensory Function (Rarely tested clinically) Test taste on the anterior 2/3 of the tongue using sweet, sour, salty, or bitter substances. Note: This is mediated via the chorda tympani branch of the facial nerve. 4. Reflexes Corneal reflex: Use a wisp of cotton to lightly touch the cornea (not the sclera). Afferent limb: Trigeminal nerve (CN V). Efferent limb: Facial nerve (CN VII). 5. Parasympathetic Function Ask about dry eyes or mouth (lacrimal and salivary gland function). This is less commonly assessed clinically. 6. Special Notes Distinguish upper motor neuron (UMN) from lower motor neuron (LMN) lesions: UMN lesion: Forehead sparing (due to bilateral cortical innervation). LMN lesion: Affects the entire side of the face (e.g., Bell's palsy). Would you like a mnemonic or table to remember the steps?