Neuro-Ophthalmic
Dorsal Midbrain Syndrome
Also known as: dorsal midbrain syndrome, Parinaud syndrome, Parinaud's syndrome, pretectal syndrome, upgaze palsy, convergence retraction nystagmus, light-near dissociation mid-dilated pupils, pineal tumour eye signs
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
A group of eye signs caused by a lesion pressing on or damaging the back of the midbrain, also called Parinaud syndrome. The classic signs are mid-dilated pupils that react poorly to light but constrict to a near target, loss of upgaze, and convergence-retraction nystagmus when the patient tries to look up. The commonest causes are a tumour of the pineal region and other midbrain lesions; hydrocephalus, stroke and demyelination can do the same. Every new case needs neurological investigation with brain imaging. The optometrist's job is to recognise the combination and refer, and to send the patient the same day when there are signs of raised intracranial pressure.
Recognition
Symptoms: what patients report
- Difficulty looking up, noticed when reading signs overhead or looking up at shelves
- Double vision or blur, often worse at near
- Oscillopsia or a pulling sensation on trying to look up
- Headache, nausea or vomiting when the pressure inside the skull is raised
- In a child: a chin-up head posture, tiredness, or a fall in school performance
Signs: what the examination shows
- Mid-dilated pupils, usually both, with minimal or no light response
- Intact constriction to a near target (light-near dissociation)
- Limited upgaze, most obvious on rapid upward refixation; downgaze is usually preserved
- Convergence-retraction nystagmus: on attempted upgaze the eyes jerk inwards and pull back into the orbits
- Lid retraction in primary gaze may be present
- Optic disc swelling when hydrocephalus is present
What OptoGuide™ covers for dorsal midbrain syndrome
- 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