---
title: "Otogenic Brain Abscess"
description: "Comprehensive ENT notes on Otogenic Brain Abscess - causes, pathology, clinical features, investigations, and treatment - ideal for MBBS and ENT students."
source: "The ENT Resident"
canonical_url: "https://www.theentresident.com/ent-notes-lectures/otogenic-brain-abscess"
categories: ["Otology"]
video: "https://www.youtube.com/watch?v=gFHNT0qxoEc"
image: "https://media.theentresident.com/og-images/otogenic-brain-abscess.png"
---

# Otogenic Brain Abscess

Comprehensive ENT notes on Otogenic Brain Abscess - causes, pathology, clinical features, investigations, and treatment - ideal for MBBS and ENT students. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=gFHNT0qxoEc

## 🧠 Otogenic Brain Abscess

### 📌 Definition of Otogenic Brain Abscess

**Otogenic Brain Abscess**  is a localized collection of pus in the brain parenchyma, usually occurring as a complication of **chronic suppurative otitis media (CSOM)** or **acute otitis media**.  

**Incidence:**  
  - Accounts for **50% of brain abscesses in adults**  
  - **25% of brain abscesses in children** are otogenic  

**Common Sites:**  
  - Temporal lobe 
  - Cerebellum 

>What is the most common site of otogenic brain abscess?

**Age Distribution:**  
  - **Bimodal peaks:** Pediatric age group and 4th decade  

**Sex Distribution:**  
  - Male : Female = **3 : 1**  

---

### 🧠 Causes of Otogenic Brain Abscess

- **Children:** Most commonly due to **acute otitis media**  
- **Adults:** Most commonly due to **cholesteatoma**  

---

### 🧬 Routes of Infection of Otogenic Brain Abscess

- **Cerebral abscess:**  
  - Direct spread via **tegmen**  
  - **Retrograde thrombophlebitis** 

- **Cerebellar abscess:**  
  - Spread through **Trautmann’s triangle**  
  - Sometimes retrograde thrombophlebitis  

>What are the boundaries of Trautmann's Triangle?

---

### 🦠 Microbiology of Otogenic Brain Abscess

- **Aerobes:** Staphylococcus, Streptococcus pneumoniae, Streptococcus haemolyticus, Proteus, E. coli, Klebsiella, Pseudomonas  

- **Anaerobes:** Peptostreptococcus, Bacteroides fragilis  

>Which is the most common microorganism seen in Otogenic Brain Abscess?

---

### 🔬 Pathological Stages of Otogenic Brain Abscess

1. **Early Cerebritis (Day 1–3):**  
   - Perivascular inflammation  
   - Mild symptoms (headache, fever, malaise)  

2. **Late Cerebritis (Day 4–9):**  
   - Pus formation  
   - Enlarged necrotic center  
   - Cerebral edema  

3. **Early Capsule Formation (Day 10–13):**  
   - Capsule forms on cortical side  
   - **Ring enhancement on CT/MRI**  
   - Symptoms: Raised intracranial pressure, focal neurological signs  

4. **Late Capsule Formation (Day 14+):**  
   - Dense collagenous capsule, necrotic core  
   - Reduced edema, gliosis outside capsule  
   - Risk of rupture → ventricles/subarachnoid space → fatal meningitis  

---

### 🩺 Clinical Features of Otogenic Brain Abscess

**Due to Raised Intracranial Pressure**

- Severe generalized headache 
- Nausea & projectile vomiting  
- Lethargy → drowsiness → coma  
- Papilledema   
- Bradycardia, subnormal temperature  

**Localizing Features**

- **Temporal Lobe Abscess:**  
  - Nominal aphasia  
  - Contralateral homonymous hemianopia   
  - Contralateral motor paralysis   
  - Epileptic fits  
  - Oculomotor palsy, pupillary changes 

- **Cerebellar Abscess:**  
  - Suboccipital headache, neck rigidity  
  - Spontaneous nystagmus  
  - Ipsilateral hypotonia, ataxia  
  - Past pointing, intention tremor  
  - Dysdiadochokinesia  

---

### 🧪 Investigations of Otogenic Brain Abscess

- **Imaging:**  

  - **CT Brain:** Ring-enhancing lesion (temporal lobe/cerebellum)  

  - **MRI Brain:** More sensitive, detects early spread/ventricular rupture 

  - **CT Temporal Bone:** To evaluate ear disease  

- **Lumbar puncture:**  

  - Usually avoided (risk of coning)  

>What is the Investigation of choice (IOC) of Otogenic Brain Abscess?

>What are the findings on performing lumbar puncture in Otogenic Brain Abscess?

---

### 💊 Treatment of Otogenic Brain Abscess

**1- Medical**

- **Antibiotics:**  
  - 3rd gen cephalosporins, chloramphenicol, metronidazole  
  - Aminoglycosides if pseudomonas suspected  
  - Guided by culture sensitivity of ear discharge  

- **Intracranial pressure control:**  
  - Dexamethasone   
  - Mannitol 20%   

>What is the dose of Dexamethasone and Mannitol for reducing intracranial pressure in Otogenic brain abscess?

- **Ear discharge management:** Suction clearance, topical ear drops  

**2- Surgical**

**Neurosurgery:**  
  - Repeated aspiration via burr hole 
  - Excision  
  - Open drainage & evacuation 

**Otologic Surgery:**  
  - Performed after neurological stabilization  
  - **Acute OM cases:** Often resolve with antibiotics  
  - **CSOM cases:** Require **radical mastoidectomy**  

---

### ⚠️ Complications of Otogenic Brain Abscess

- Ventriculitis  
- Status epilepticus  
- Respiratory failure  
- Motor/speech/visual deficits  
- Encephalitis  
- Septicemia  

---

###  🩻 Differential Diagnosis of Otogenic Brain Abscess

- Subdural empyema  
- Bacterial meningitis  
- Viral meningoencephalitis  
- Superior sagittal sinus thrombosis  
- Acute disseminated encephalomyelitis

---

## About This Note

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