Neuro-Ophthalmic
CN IV Palsy
Also known as: CN IV palsy, trochlear palsy, fourth nerve palsy, superior oblique palsy, vertical diplopia head tilt
Filed as: Urgent
Source-cited from the record's own evidence list. Clinical content programme led by Dr Ankit Mathur, PhD, Grad Cert Ocu Thera, B.S. Optom. How the clinical content is governed
Clinical decision support only
Overview
Weakness of the superior oblique, producing vertical or oblique double vision that the patient often eases with a head tilt away from the affected side. The hypertropia increases on contralateral gaze and on ipsilateral head tilt. A longstanding childhood tilt points toward a congenital palsy, while new diplopia or a recently adopted head posture warrants urgent assessment for an acquired cause.
Recognition
Symptoms: what patients report
- New binocular vertical or oblique diplopia.
- Symptoms may improve with a compensatory head tilt.
- Mild peri-orbital discomfort can occur, but severe pain is atypical.
Signs: what the examination shows
- Hypertropia that increases on contralateral gaze and ipsilateral head tilt.
- Pattern of superior oblique weakness.
- In children, longstanding head tilt may reflect congenital superior oblique palsy, but new diplopia or acute head posture needs urgent review.
- No fixed dilated pupil.
What OptoGuide™ covers for cn iv palsy
- Pattern reasoning: what this combination of findings points to, and its differentiators
- Don't-miss risks and escalation triggers
- Management tiers with linked Australian therapeutics
- Referral urgency, specialty, and letter drafting
Sources
- Cranial Nerve 4 Palsy — EyeWiki
- The Neuro-Ophthalmology Survival Guide (Pane, Miller & Burdon) — standard reference text
Standard texts: Kanski's Clinical Ophthalmology: A Systematic Approach, Oxford Handbook of Ophthalmology, Oxford American Handbook of Ophthalmology, Signs in Ophthalmology: Causes & Differential Diagnosis.