--- title: "Otosclerosis Part 2 - Symptoms, Signs, Investigations, Differential diagnosis" description: "ENT notes on Otosclerosis - Symptoms, Signs, Investigations, Differential diagnosis." source: "The ENT Resident" author: "Dr. Mausumi Das" canonical_url: "https://www.theentresident.com/ent-notes-lectures/otosclerosis-symptoms-signs-differential" categories: ["Otology"] video: "https://www.youtube.com/watch?v=j6Gu9z9HgRA" image: "https://media.theentresident.com/og-images/otosclerosis-symptoms-signs-investigation.png" --- # Otosclerosis Part 2 - Symptoms, Signs, Investigations, Differential diagnosis ENT notes on Otosclerosis - Symptoms, Signs, Investigations, Differential diagnosis. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=j6Gu9z9HgRA ## 👂 Otosclerosis - Clinical Features, Investigations & Differential Diagnosis Continued from **Part 1** - [Otosclerosis Causes, Pathogenesis, Types, Pathology](https://www.theentresident.com/ent-notes-lectures/otosclerosis-causes-types-pathogenesis.md). This is **Part 2** of the **Otosclerosis series**. In this section, we will cover: - How a patient with otosclerosis presents - Key **symptoms and signs** - **Audiological and radiological investigations** - Important **differential diagnoses** --- ### 📍 Common Sites of Otosclerotic Focus 🚨 **MCQ Alert** - The **most common site** of otosclerosis is: - **Fissula ante fenestram** - Located **anterior to the oval window** - ⭐ *Most common MCQ answer* > What are the other sites of Otosclerosis? --- ### 🧠 History taking in Otosclerosis #### ✅ Classical History - **Progressive bilateral hearing loss** - Onset in **early adulthood (20–30 years)** - **Female predominance** - Hearing loss **worsens during pregnancy** - Usually **painless** and **slowly progressive** 👉 **Typical MCQ question:** > *Middle aged woman with progressive bilateral conductive hearing loss worsened during pregnancy* #### ❌ History NOT Suggestive of Otosclerosis - Onset **before 10 years** or **after 40 years** - **Non progressive** hearing loss - Ear discharge - Ear trauma - Prominent vertigo as the main symptom --- ### 🔊 Symptoms of Otosclerosis - Hearing Loss (Most Common) - Usually Bilateral > What is the type of hearing loss seen in Otosclerosis? > What % of Otosclerosis patients have Unilateral hearing loss? > What are the Mechanisms of Conductive Hearing Loss in Otosclerosis? > When does Sensorineural Hearing loss occur in Otosclerosis? - 🩸 Circulatory Theories in Cochlear Otosclerosis - Otto Mayer’s Theory & Ruedi’s Theory > What is Otto Mayer’s Theory in Otosclerosis? > What is Ruedi’s Theory in Otosclerosis? - Paracusis Willisii - Seen in **20-78%** of patients - ⭐ **Classic symptom of otosclerosis** > What is Paracusis Willisii? - Tinnitus > What is the type of tinnitus seen in Otosclerosis? - Vestibular Symptoms - Vertigo is **uncommon** - Rarely the sole presenting symptom > What is the cause behind the vestibular symptoms in Otosclerosis? - Speech Pattern - **Soft, monotonous, well-modulated speech** - Patient hears own voice via **bone conduction** --- ### 👁️ Signs of Otosclerosis #### 🔍 Otoscopy - Tympanic membrane usually **normal** - May show **Schwartz sign** > What is Schwartz sign? What is its other name? #### 🔧 Tuning Fork Tests - **Rinne negative** - First at 256 & 512 Hz - Later at 1024 Hz - **Weber lateralized** to worse ear - **Absolute bone conduction**: Normal (↓ if cochlear involvement) > What is Bezold’s Triad? --- ### 🎧 Investigations of Otosclerosis 📊 **1. Pure Tone Audiometry** - Conductive hearing loss - Greater loss at **lower frequencies** - **Carhart’s notch** > What is Carhart's Notch? What are the causes of Carhart's Notch? - **Cookie Bite Audiogram** > What is Cookie Bite Audiogram? When is it seen? 📈 **2. Tympanometry** - **Type As** (stiffness) - **Acoustic reflex absent** 🧠 **3. HRCT Temporal Bone** Findings in **active otosclerosis**: - Hypodense lucent areas - Thickened stapes footplate - Narrowed oval & round windows Inactive lesions → hard to detect > What is Symons & Fanning CT Grading system of Otosclerosis? 🧲 **4. MRI** - Used mainly for **cochlear implant planning** --- ### 🔄 Differential Diagnosis of Otosclerosis - Ossicular Chain Discontinuity - Congenital Stapes Fixation - Tympanosclerosis - Secretory Otitis Media >📘 In my detailed notes, I’ve discussed an exhaustive list of Differential Diagnosis of Otosclerosis. > How would you rule out each of the Differential Diagnosis of Otosclerosis. --- ### 📌 Key Exam Pearls - Female + pregnancy + Conductive Hearing Loss = **Otosclerosis** - Most common site: **Fissula ante fenestram** - Carhart’s notch at **2000 Hz** - Schwartz sign = **active lesion** - Tympanometry: **Type As** - Paracusis Willisii = classic symptom --- 📘 **Next Part:** [Treatment of Otosclerosis — medical, surgical & indications.](https://www.theentresident.com/ent-notes-lectures/otosclerosis-treatment-surgery-stapedotomy.md) --- ## About This Note This free ENT note on Otosclerosis Part 2 - Symptoms, Signs, Investigations, Differential diagnosis was written by Dr. Mausumi Das and is paired with a corresponding video lecture. 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