II. Symptoms: Red Flags for CNS Cause
- Sudden change in Vision (or worsening over hours to days)
- Unilateral Vision Loss with Eye Pain or pressure
- Vision Loss with Vomiting, severe Headache or Altered Level of Consciousness
- Distorted or blurry Vision without ocular cause (e.g. Cornea abrasion, anterior chamber, lens, Retina)
- Acute Retinal Artery Occlusion
- Evaluate as stroke variant with emergent carotid imaging including aortic arch (CT Head, CT Angiogram head and neck)
- Central Retinal Artery Occlusion (CRAO)
- Branch Retinal Artery Occlusion (BRAO)
- Ophthalmic Artery Occlusion
- Amaurosis Fugax (Transient Monocular Blindness)
- Binocular Diplopia (acute onset)
- Diplopia only with both eyes open
-
Internuclear Ophthalmoplegia (Conjugate Gaze Palsy)
- Medial Longitudinal Fasciculus lesion results in discordance between CN 3 and CN 6
-
Afferent Pupillary Defect
- Intact Consensual Light Reflex (but not to direct light)
- Ischemic Optic Neuropathy
- Multiple Sclerosis
- Acute Cranial Nerve Palsy (CN 3, 4, 6)
- Oculomotor Nerve Palsy (CN 3 Palsy)
- Pupil-involving acute CN 3 Palsy may be expanding Cerebral Aneurysm (esp. Posterior Communicating Artery)
- Abducens Nerve Palsy (Cranial Nerve 6 Palsy)
- Long, thin nerve subject to injury
- Bilateral palsy may occur in Increased Intracranial Pressure, Wernicke's Encephalopathy, Botulism
- Trochlear Nerve Palsy (CN 4 Palsy)
- Long, thin nerve also subject to injury
- Oculomotor Nerve Palsy (CN 3 Palsy)
-
Horner's Syndrome
- Miosis, Ptosis and Anhidrosis
III. References
- Marcolini in Herbert (2020) EM:Rap 20(8): 8-9
- Marcolini in Herbert (2021) EM:Rap 21(1): 6