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# Abducens (sixth) nerve palsy

The eye cannot turn outward, causing horizontal double vision. In older adults it is often vascular; with headache or papilloedema, raised pressure.

Updated Nov 5, 2026

On this page

- The basics What it is
- Who gets it
- Causes
- Risk factors
- Pathophysiology
- In ophthalmology

- Clinical Symptoms and signs
- Red flags
- Diagnosis
- Differential diagnosis
- Complications
- Prognosis

- Treatment Goal of treatment
- Treatment

- Study Test yourself

- Connections Connections

## What it is

Weakness of the [lateral rectus muscle](https://durgical.com/en/anatomy/lateral-rectus-muscle/) from damage to the sixth cranial nerve. The affected eye cannot abduct, producing horizontal double vision that worsens looking towards the affected side and at distance. Because the nerve has a long course inside the skull, it is often affected by raised intracranial pressure, where it is a false localising sign.

See it in 3D

- [Abducens nerve (VI)](https://durgical.com/en/anatomy/abducens-nerve/)
- [Lateral rectus](https://durgical.com/en/anatomy/lateral-rectus-muscle/)

## Who gets it

The most common isolated ocular motor nerve palsy; in adults over 50 often microvascular, in children often after viral illness or from tumours.

## Causes

- Microvascular ischaemia (diabetes, hypertension)
- Raised intracranial pressure
- Tumours of the brainstem, skull base or [cavernous sinus](https://durgical.com/en/anatomy/cavernous-sinus/)
- Trauma
- Multiple sclerosis
- Petrous apex infection after otitis media in children

## Risk factors

- Diabetes and hypertension
- Head trauma
- Conditions raising intracranial pressure

## Pathophysiology

The nerve runs a long path from the [pons](https://durgical.com/en/anatomy/pons/) over the petrous apex and through the cavernous sinus; stretching from raised pressure, ischaemia of its blood supply, compression or inflammation stop it conducting, so the lateral rectus is weak.

## Symptoms and signs

- Horizontal double vision, worse at distance and looking towards the affected side
- Eye turned inward (esotropia)
- Head turned towards the affected side to keep single vision

## Red flags

- Headache, vomiting or papilloedema
- Other cranial nerve palsies or neurological signs
- Age under 50 or no vascular risk factors
- No recovery after about three months
- Ear pain and discharge in a child

## Diagnosis

**Clinical**
Limited abduction of one eye with an esotropia greater at distance; fundus exam for papilloedema and a full neurological exam.

**Tests**
Glucose and blood pressure; ESR and CRP over 50; lumbar puncture after imaging if raised pressure is suspected.

**Imaging**
MRI of the brain when the patient is young, there are other signs, papilloedema or no recovery.

## Differential diagnosis

- Myasthenia gravis
- Thyroid eye disease (restriction of the [medial rectus](https://durgical.com/en/anatomy/medial-rectus-muscle/))
- Orbital medial wall fracture
- Decompensated esophoria
- Duane syndrome (congenital)

## Goal of treatment

Find and treat the cause and relieve double vision.

## Treatment

**Medical**
Control of vascular risk factors in microvascular palsy, which usually recovers within months.

**Conservative**
Patching one eye or prisms to relieve double vision.

**Surgical**
Strabismus surgery or botulinum toxin for persistent deviation.

## Complications

- Persistent double vision
- Amblyopia in young children

## Prognosis

Microvascular palsies usually recover within about three months; the outlook of other causes depends on the cause.

## Test yourself

Think of the answer, then tap the question to see it.

## Which muscle is weak in sixth nerve palsy?

The lateral rectus, so the eye cannot turn outward.

## Why is sixth nerve palsy a false localising sign?

Because raised intracranial pressure stretches the nerve along its long course, regardless of the lesion's site.

## When is MRI needed?

In young patients, with other neurological signs, papilloedema, or no recovery after about three months.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/conditions/abducens-nerve-palsy/)

## In ophthalmology

- [Strabismus surgery: what it does and what follows](https://durgical.com/en/ophthalmology/strabismus-surgery-what-it-does-and-what-follows/)

## Connections

## In physiology 1

- [Control of eye movements: fixation, saccades, pursuit and gaze centres](https://durgical.com/en/physiology/control-of-eye-movements-fixation-saccades-pursuit-and-gaze-centres/)

## Related conditions 5

- [Raised intracranial pressure and brain herniation](https://durgical.com/en/conditions/raised-intracranial-pressure-and-brain-herniation/)
- [Idiopathic intracranial hypertension](https://durgical.com/en/conditions/idiopathic-intracranial-hypertension/)
- [Type 2 diabetes mellitus](https://durgical.com/en/conditions/type-2-diabetes-mellitus/)
- [Multiple sclerosis](https://durgical.com/en/conditions/multiple-sclerosis/)
- [Oculomotor (third) nerve palsy](https://durgical.com/en/conditions/oculomotor-nerve-palsy/)

Educational information, not medical advice. For any symptom, see a health professional.

Sources: [Abducens Nerve Palsy](https://www.ncbi.nlm.nih.gov/books/NBK482177/) (StatPearls Publishing (NCBI Bookshelf), 2023).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/conditions/abducens-nerve-palsy/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/conditions/abducens-nerve-palsy/