Bilateral Fascicular Third Nerve Palsy in Posterior Circulation Stroke

Area of Science:

• Neuroscience
• Neurology
• Ophthalmology

Background:

• Third nerve palsy typically affects one eye, with bilateral cases being uncommon.
• Brainstem stroke accounts for a significant portion of bilateral third nerve palsy cases.

Observation:

• A rare case of severe bilateral fascicular oculomotor nerve palsy is presented.
• The palsy resulted from a distal basilar artery occlusion leading to midbrain infarction.
• The patient experienced complete ptosis, necessitating mechanical aids and surgery.

Findings:

• Isolated bilateral oculomotor nerve palsy following brainstem stroke is exceptionally rare.
• Cardioembolic events can cause severe neurological deficits, including bilateral fascicular oculomotor nerve palsy.
• Midbrain infarction due to basilar occlusion can manifest with this specific palsy pattern.

Implications:

• This case expands the understanding of potential neurological deficits following cardioembolic stroke.
• It underscores the importance of considering rare presentations of oculomotor nerve palsy in stroke patients.
• Highlights the need for tailored management strategies for severe ptosis resulting from brainstem strokes.