--- title: "Intracranial Complications of CSOM" description: "ENT notes on Intracranial Complications of CSOM." source: "The ENT Resident" author: "Dr. Mausumi Das" canonical_url: "https://www.theentresident.com/ent-notes-lectures/intracranial-complications-csom" categories: ["Otology"] video: "https://www.youtube.com/watch?v=-mbVdf7mwro" image: "https://media.theentresident.com/og-images/intracranial-complications-csom.png" --- # Intracranial Complications of CSOM ENT notes on Intracranial Complications of CSOM. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=-mbVdf7mwro ## 🧠 Intracranial Complications of CSOM Chronic suppurative otitis media (CSOM), especially when associated with **cholesteatoma**, can lead to **life-threatening intracranial complications** due to proximity of the middle ear and mastoid to the cranial cavity. These complications often **coexist**, may be **silent initially**, and require **early diagnosis and aggressive management**. **Intracranial Complications** of CSOM are :- 1. Extradural Abscess 2. Subdural Abscess 3. Meningitis 4. Otogenic Brain Abscess 5. Sigmoid Sinus Thrombosis 6. Otitic Hydrocephalus --- ### 🟡 Extradural Abscess #### 📖 Definition of Extradural Abscess **Extradural abscess** is a **collection of pus between the bone and the dura mater**. - Occurs as a complication of: - **Acute otitis media** - **CSOM with cholesteatoma** - Often **coexists with other intracranial complications** - May act as a **precursor to brain abscess** > What is the other name for Extradural abscess? --- #### 🧬 Pathology of Extradural Abscess **Two mechanisms of spread:** 1. Direct bone erosion 2. Thrombophlebitic spread > Describe the two pathways of spread of Extradural abscess. >What are the sites of Extradural Abscess? --- #### 🩺 Clinical Features of Extradural Abscess - **Often asymptomatic** - Frequently discovered **incidentally during mastoidectomy** - Most important symptom: - **Persistent localized headache** - Headache relieved by **free flow of pus from ear** - *Spontaneous abscess drainage* - Others: - Severe otalgia - Malaise - Low-grade fever - Pulsatile purulent ear discharge --- #### 🔍 Investigations of Extradural Abscess - **Contrast-enhanced CT / MRI** - Shows **dural elevation** --- #### 🩻 Treatment of Extradural Abscess - **IV antibiotics** (pre- and post-operative) - **Mastoidectomy** - Remove bone till **healthy dura** is seen - If suspicion persists → remove intact **tegmen tympani / sinus plate** - **Close post-operative monitoring** - To prevent meningitis, brain abscess, sinus thrombosis --- ### 🔴 Subdural Abscess #### 📖 Definition of Subdural Abscess **Subdural abscess** is a **collection of pus between the dura mater and arachnoid mater**. --- #### 🧬 Pathology of Subdural Abscess - Spread via: - Bone + dura erosion - Thrombophlebitic spread (bone intact) --- #### 🩺 Clinical Features of Subdural Abscess **Hallmark presentation:** - Sudden, unusually severe headache - Fever and vomiting - **Rapid deterioration** **Symptoms due to:** 1. Meningeal irritation 2. Cortical venous thrombophlebitis 3. Raised intracranial tension >What are the symptoms of meningeal irritation seen in Subdural abscess? >What is Kernig's sign? >What are the symptoms of Cortical venous thrombophlebitis seen in Subdural abscess? >What are the signs and symptoms of Raised intracranial tension seen in Subdural abscess? --- #### 🔍 Investigations of Subdural Abscess - **MRI with contrast** (investigation of choice) - Differentiates extradural vs subdural abscess - Shows **multiple lobulated subdural collections** - Lumbar puncture is contraindicated >Why is Lumbar Puncture contraindicated in Subdural Abscess? --- #### 🩻 Treatment of Subdural Abscess 🚨 **Neurosurgical emergency** - High-dose **IV antibiotics** - **Burr hole drainage** - **Radical mastoidectomy** → Performed **after intracranial abscess is controlled** --- ### 🟠 Meningitis #### 📖 Definition of Meningitis **Meningitis** is inflammation of the **leptomeninges (pia + arachnoid)** with **bacterial invasion of CSF**. --- #### 🧬 Etiology in Otogenic Meningitis - Infants & children → **Acute otitis media** - Adults → **Cholesteatoma** - Others: - Temporal bone fracture - CSF leak - Ear & mastoid surgeries > What are the different Routes of Spread in Meningitis? --- #### 🩺 Clinical Features of Meningitis **Early symptoms:** - Fever with chills and rigors - Headache - Projectile vomiting - Photophobia - Irritability, restlessness **Classical signs:** - Neck rigidity - **Kernig sign** - **Brudzinski sign** **Others:** - Seizures (infants) - Cranial nerve palsies - Hemiplegia - Initially exaggerated reflexes → later absent - Papilledema (late) - Altered consciousness → coma > What is Kernig's sign? > What is Brudzinski sign? --- #### 🔍 Investigations of Meningitis - HRCT temporal bone - MRI brain - Fundoscopy → papilledema - Lumbar puncture (after imaging) > What findings are seen in Lumbar puncture in Meningitis? --- #### 🩻 Treatment of Meningitis ⚠️ **Medical treatment takes precedence** - **IV third-generation cephalosporins** (7–10 days) - Modify antibiotics as per culture - **Corticosteroids** → reduce neuro-audiological sequelae - Surgery: - Only after stabilization - AOM → myringotomy ± cortical mastoidectomy - CSOM → radical / modified radical mastoidectomy --- ### 🔵 Otogenic Brain Abscess #### 📖 Definition of Otogenic Brain Abscess A **localized collection of pus in brain parenchyma** secondary to otitis media. > What is the most common site of Otogenic Brain Abscess? - Bimodal age distribution: - Pediatric age group - Fourth decade - Male predominance - Children → AOM - Adults → Cholesteatoma --- #### 🧠 Stages of Brain Abscess of Otogenic Brain Abscess 1. Early cerebritis (Day 1–3) 2. Late cerebritis (Day 4–9) 3. Early capsule formation (Day 10–14) 4. Late capsule formation (> Day 14) > Describe the progression of Otogenic brain abscess through it's different stages. --- #### 🩺 Clinical Features of Otogenic Brain Abscess 1. **Raised ICT:** - Headache - Vomiting - Lethargy - Papilledema - Bradycardia - Subnormal temperature 2. **Localizing signs** involving either **Temporal lobe** or **Cerebellum** > What are the Localizing signs seen when Temporal lobe is involved and when Cerebeluum is involved? --- #### 🔍 Investigations of Otogenic Brain Abscess - **CT / MRI brain** - Ring-enhancing lesion - **CT temporal bone** - **Lumbar puncture contraindicated** --- #### 🩻 Treatment of Otogenic Brain Abscess 1. **Medical** - IV antibiotics - Mannitol / dexamethasone 2. **Neurosurgical** - Burr hole aspiration - Excision - Open drainage 3. **Otologic** - AOM → antibiotics - CSOM → radical mastoidectomy --- ### 🟣 Sigmoid Sinus Thrombosis #### 📖 Definition of Sigmoid Sinus Thrombosis Inflammation of the **lateral venous sinus wall** with formation of an **intraluminal thrombus** > What are the other synonyms of Sigmoid Sinus Thrombosis? --- #### 🧬 Pathology of Sigmoid Sinus Thrombosis 1. Perisinus abscess 2. Endophlebitis 3. Mural thrombus 4. Intrasinus abscess 5. Proximal & distal extension > Describe the different stages of Sigmoid Sinus Thrombosis. --- #### 🩺 Clinical Features of Sigmoid Sinus Thrombosis - **Picket-fence fever** with chills & rigors - Headache - Progressive anemia - Emaciation - **Griesinger sign** - Papilledema - Jugular vein tenderness - Positive **Tobey Ayer** & **Crowe Beck** tests > What is Picket fence fever? What is the mechanism behind it? > What is Griesinger sign? > How would you perform and interpret **Tobey Ayer** test? > How would you perform and interpret **Crowe Beck** test? --- #### 🔍 Investigations of Sigmoid Sinus Thrombosis - Peripheral smear (rule out malaria) - Blood culture - Lumbar puncture → ↑ pressure - **CECT brain** → **Delta sign** - MRI --- #### 🩻 Treatment of Sigmoid Sinus Thrombosis - IV antibiotics - Mastoidectomy + sinus exposure - Rare: - Internal jugular vein ligation - Anticoagulation --- ### 🟤 Otitic Hydrocephalus #### 📖 Definition of Otitic Hydrocephalus → Raised intracranial pressure with **normal CSF findings** > What is the other name of Otitic Hydrocephalus? --- #### 🩺 Clinical Features of Otitic Hydrocephalus - Severe headache - Diplopia - Blurred vision - Nystagmus --- #### 🔍 Investigations of Otitic Hydrocephalus - Lumbar puncture: - CSF pressure > **300 mm H₂O** - Normal CSF contents - MRI brain --- #### 🩻 Treatment of Otitic Hydrocephalus - Reduce intracranial pressure: - Mannitol - Acetazolamide - Corticosteroids - Diuretics - IV antibiotics - Surgical: - Repeated lumbar puncture - Lumbar drain - Lumboperitoneal shunt - Mastoidectomy --- ## 📌 Exam Pearls - Extradural abscess is often **silent** - Subdural abscess = **neurosurgical emergency** - LP contraindicated in **subdural abscess & brain abscess** - Meningitis → **medical treatment first** - Temporal lobe abscess = most common otogenic abscess - Picket-fence fever = **sigmoid sinus thrombosis** - Normal CSF + raised ICP = **otitic hydrocephalus** --- ## About This Note This free ENT note on Intracranial Complications of CSOM was written by Dr. Mausumi Das and is paired with a corresponding video lecture. 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