---
title: "Halo Sign Explained in ENT"
description: "ENT notes on Halo Sign seen in ENT."
source: "The ENT Resident"
author: "Dr. Mausumi Das"
canonical_url: "https://www.theentresident.com/ent-notes-lectures/halo-sign-csf-leak-otosclerosis"
categories: ["Signs, Syndromes, Triads, and Compilation Lists in ENT", "Otology", "Rhinology"]
video: "https://www.youtube.com/watch?v=E5KSeN4MEx8"
image: "https://media.theentresident.com/og-images/halo-sign-csf-leak-otosclerosis.png"
---

# Halo Sign Explained in ENT

ENT notes on Halo Sign seen in ENT. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=E5KSeN4MEx8

## Halo Sign in ENT

There are two Halo Signs in ENT:

* Halo Sign of the Nose
* Halo Sign of the Ear

---

### Halo Sign (Nose)

#### 📌 Type of Sign

👉 **Clinical bedside sign**

Performed using **filter paper**.

#### 🔍 What is the Sign?

Halo Sign refers to a **Double ring appearance on filter paper** seen when a mixture of Blood & Cerebrospinal Fluid (CSF) is dropped onto absorbent paper.


#### 🩺 Where is it Seen?

Seen in cases of **Suspected CSF Leak**.

Especially:

* CSF Rhinorrhea
* CSF Otorrhea

> What are the other names of Halo sign seen in CSF Leaks?

#### 🧪 How is the Test Performed?

A drop of suspected nasal discharge is placed onto Filter paper.

If CSF is mixed with blood:

* Blood remains concentrated centrally
* CSF spreads outward

creating a characteristic **Double Ring Appearance**.

> Why does the double ring appareance occur in CSF Leaks?

#### 🎯 Why is it Called Halo Sign?

The clear outer ring surrounds the central blood spot like a **Halo** around an object.

Hence the name **Halo Sign**.

#### Does Halo Sign Confirm CSF Leak?

❌ No, it is only suggestive.

> What is the most common cause of CSF Leak?

> What is the Gold Standard Test for Confirming CSF Leak?

> What is the most Important Complication of Untreated CSF Leak?

---

### Halo Sign (Ear)

#### 📌 Type of Sign

👉 **Radiological sign**

Seen on **CT Temporal Bone**.

#### 🔍 What is the Sign?

Halo Sign refers to a **Radiolucent ring surrounding the cochlea** giving a **Double Ring Appearance** on CT scan.

#### 🩻 Where is it Seen?

Seen in **Cochlear Otosclerosis**.

#### 🧠 Why Does it Occur?

In cochlear otosclerosis there is **Demineralization of the otic capsule** around the cochlea.

This produces a **Hypodense zone** surrounding the cochlea.

The resulting radiolucent ring creates the characteristic **Halo Appearance**.

#### 🎯 Clinical Significance

Presence of Halo Sign indicates **Inner ear involvement** and suggests a **Sensorineural component** to the hearing loss.

#### 🎯 Why is it Called Halo Sign?

The radiolucent ring surrounds the cochlea like a **Halo** creating a characteristic double-ring appearance.

> What section of the CT scan of Temporal bone is the halo sign best seen in?

> What is the most Common Bone Involved in Otosclerosis?

> What is the most Common Site of Otosclerosis?

> What are the audiological Findings seen in Otosclerosis in Pure Tone Audiogram & Impedance Audiometry?

> What is the most Common Hearing Loss seen in Otosclerosis?

---

### ⭐ High Yield Rapid Revision Table

| Feature | Halo Sign (Nose) | Halo Sign (Ear) |
| --- | --- | --- |
| Type | Clinical sign | Radiological sign |
| Test | Filter paper test | CT Temporal Bone |
| Appearance | Double ring pattern | Radiolucent cochlear ring |
| Seen In | CSF Rhinorrhea / CSF Leak | Cochlear Otosclerosis |
| Mechanism | Different diffusion of CSF and blood | Demineralization of otic capsule |
| Significance | Suggests CSF leak | Indicates cochlear involvement |

---

## About This Note

This free ENT note on Halo Sign Explained in ENT was written by Dr. Mausumi Das and is paired with a corresponding video lecture.

Canonical page of this note: https://www.theentresident.com/ent-notes-lectures/halo-sign-csf-leak-otosclerosis

When citing or referencing this content, please credit The ENT Resident and link to the canonical page above.

## Related Notes by Category

- Signs, Syndromes, Triads, and Compilation Lists in ENT: https://www.theentresident.com/ent-notes-lectures/category/signs-syndromes-triads-lists-in-ent.md
- Otology: https://www.theentresident.com/ent-notes-lectures/category/otology.md
- Rhinology: https://www.theentresident.com/ent-notes-lectures/category/rhinology.md

## About The ENT Resident

The ENT Resident is an educational website and resource library created by Dr. Mausumi Das (MS ENT) for ENT residents, ENT postgraduates preparing for exams, and MBBS students.

Dr. Mausumi Das writes the notes, draws the diagrams, and records the lectures herself.

Browse all ENT notes and lectures on The ENT Resident: https://www.theentresident.com/ent-notes-lectures.md

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