Abstrato

A case of Bilateral Third Cranial Nerve Palsy due to Bilateral Thalamic Infarcts

Haritha Vasudevan, Virna M. Shah, Jassim Koya

Purpose: To report a case of bilateral third cranial nerve palsy which is not a common presentation in the standard neuro-ophthalmology clinic, a subset of its various etiologies is immediately life-threatening to the patient and requires through evaluation. A rare case of bilateral complete third nerve palsy with pupillary involvement due to an Artery of Percheron (AOP) infarct in a 70-year-old male patient presenting to a neuro-ophthalmology clinic is reported here. Methods: The patient presented to the ophthalmology clinic and reported a 3-day history of bilateral progressive drooping of upper eyelids, associated with a history of altered level of consciousness from a transient ischemic attack occurring at the time of onset of the primary complaints. Severe ptosis was seen in both eyes with negative fatigability. Both pupils were mid-dilated and fixed. Eye movement examination revealed bilateral restricted elevation and extorsion with mild restriction of adduction and intorsion suggestive of third cranial nerve palsy of both eyes. He was diagnosed to have bilateral oculomotor palsy with pupil involvement, and urgent neuroimaging was done. His MRI brain with cervical and cerebral MRA revealed acute infarcts in both thalami (right >left side) due to infarction of the AOP. Results: Patient was immediately transferred to the emergency room for management by the neurology department. The AOP infarct was thrombolyzed, and patient was further managed with anticoagulants, lipid lowering agents. Conclusion: Pupil-involving third-nerve palsy warrants thorough investigation to investigate a vascular or compressive root cause. The significance of this case is to acknowledge the rarity of this commonly overlooked infarction; to differentiate an AOP infarction from a basilar artery infarction and the rare neuro-ophthalmic presentation of this patient to increase awareness amongst physicians.