--- title: "Signs in Facial Nerve Palsy | Bell's Phenomenon, Crocodile Tears & Tinel's Sign" description: "ENT notes on signs in Facial Nerve Palsy - Bell's Phenomenon, Crocodile Tears & Tinel's Sign." source: "The ENT Resident" author: "Dr. Mausumi Das" canonical_url: "https://www.theentresident.com/ent-notes-lectures/bell-phenomenon-crocodile-tears-tinel-sign-facial-palsy-signs" categories: ["Signs, Syndromes, Triads, and Compilation Lists in ENT", "Otology"] video: "https://www.youtube.com/watch?v=4jQaYVOY28M" image: "https://media.theentresident.com/og-images/bell-phenomenon-crocodile-tears-tinel-sign-facial-palsy-signs.png" --- # Signs in Facial Nerve Palsy | Bell's Phenomenon, Crocodile Tears & Tinel's Sign ENT notes on signs in Facial Nerve Palsy - Bell's Phenomenon, Crocodile Tears & Tinel's Sign. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=4jQaYVOY28M ## Signs in Facial Nerve Palsy Three classical signs are associated with facial nerve palsy. In this post, we will discuss: * Bell's Phenomenon * Crocodile Tears * Tinel's Sign --- ### Bell's Phenomenon #### 📌 Type of Sign 👉 Clinical Sign observed on **attempted forceful eye closure**. #### 🔍 What is the Sign? Bell's Phenomenon refers to the **upward and outward rolling of the eyeball when the patient forcibly tries to close the eyelids**. > Is Bell's Phenomenon a normal or abnormal response of the body? Why? #### 🩺 How is it Elicited? The patient is asked to **close the eyes tightly**. A **positive sign** is: ✅ The eyelids fail to close tightly, the eyeballs move **upwards and outwards**, and the cornea is hidden under the upper lid > What is the mechanism behind Bell's Phenomenon? #### 👨‍⚕️ Eponym Named after **Sir Charles Bell**, who first described this protective upward movement of the eye during eyelid closure. #### ⚠️ Important MCQ Trap **Bell's Phenomenon is NOT the same as Bell's Palsy.** | Term | Meaning | | --- | --- | | **Bell's Palsy** | Idiopathic lower motor neuron paralysis of the facial nerve | | **Bell's Phenomenon** | Upward rolling of the eyeball on attempted forceful eyelid closure | ⭐ Bell's phenomenon is seen in **lower motor neuron facial palsy** of any cause. Bell's palsy is only **one** of those causes. > Which is the muscle involved in Bell's Phenomenon? --- ### Crocodile Tears #### 📌 Type of Sign 👉 Clinical Sign seen during the **recovery phase of facial nerve palsy**. > What are the other names for Crocodile tears? #### 🔍 What is the Sign? Crocodile Tears refers to **lacrimation or tearing while eating or chewing**, occurring due to **misdirected regeneration of facial nerve fibres**. > What is the mechanism behind Crocodile Tears? #### 🐊 Why is it Called Crocodile Tears? The term refers to a **false, insincere display of emotion**, such as fake tears of grief. ⭐ Derived from the ancient myth that **crocodiles weep to lure their prey or show remorse while eating them**. #### ⚠️ Important MCQ Trap | Feature | Gustatory Lacrimation | Gustatory Sweating | | --- | --- | --- | | **Condition** | Crocodile Tears | Frey's Syndrome | | **Nerve involved** | Facial nerve | Auriculotemporal nerve (branch of Trigeminal nerve) | | **Finding** | Tearing while eating | Sweating over the parotid area while eating | ⭐ Both occur **during eating**. --- ### Tinel's Sign #### 📌 Type of Sign 👉 Clinical Sign elicited by **nerve tapping**. #### 🔍 What is the Sign? Tinel's Sign is a clinical test to detect **irritated or regenerating nerves**. #### 🩺 How is it Elicited? The examiner **lightly percusses or taps over the injured nerve**. A **positive sign** is: ✅ An intense **tingling or pins and needles sensation** along the distribution of the nerve, felt distally 👉 A positive Tinel's sign indicates **ongoing nerve recovery**. #### Seen In * Facial nerve regeneration after injury or surgery * Facial nerve reanimation procedures * Peripheral nerve injuries * Carpal tunnel syndrome ⭐ In ENT, it is used mainly in **facial nerve regeneration and reanimation surgery**. ⭐ The **classical non-ENT association** is **carpal tunnel syndrome**. #### 👨‍⚕️ Eponym Named after **Jules Tinel**, a French neurologist, who described this tingling phenomenon in regenerating nerves. > What is the difference between Tinel's sign & Chvostek's Sign? > [What are the signs seen in Hypocalcemia?](https://www.theentresident.com/ent-notes-lectures/chvostek-trousseau-sign-hypocalcemia.md) --- ### ⭐ High Yield Rapid Revision Table | Sign | Elicited By | Finding | Significance | | --- | --- | --- | --- | | Bell's Phenomenon | Attempted forceful eye closure | Upward and outward rolling of the eyeball with failure of eyelid closure | Lower motor neuron facial palsy | | Crocodile Tears | Observed during eating or chewing | Lacrimation instead of salivation | Aberrant regeneration in the recovery phase of facial nerve palsy | | Tinel's Sign | Tapping over the nerve | Tingling or pins and needles sensation distally | Irritated or regenerating nerve | --- ### 🧠 Viva Pearls * Bell's phenomenon is upward and outward rolling of the eyeball on attempted forceful eyelid closure. * Bell's phenomenon is not the same as Bell's palsy. * Bell's palsy is idiopathic lower motor neuron paralysis of the facial nerve. * Crocodile tears occurs in the recovery phase of facial nerve palsy, due to misdirected regeneration of parasympathetic fibres. * Gustatory sweating is seen in Frey's syndrome and involves the auriculotemporal nerve. * Tinel's sign is elicited by tapping over an injured nerve, producing distal tingling. * A positive Tinel's sign indicates ongoing nerve recovery. * Tinel's sign is named after Jules Tinel, a French neurologist. * The classical association of Tinel's sign is carpal tunnel syndrome. --- ## About This Note This free ENT note on Signs in Facial Nerve Palsy | Bell's Phenomenon, Crocodile Tears & Tinel's Sign was written by Dr. Mausumi Das and is paired with a corresponding video lecture. 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