Parkinson syndrome: a precise localization for abducens palsy

Background: Unilateral isolated abducens palsy can occur due to any lesion from pons to orbit. The precise localization is made through the associated neurological signs. Parkinson syndrome is a symptom complex of unilateral abducens palsy with ipsilateral postganglionic Horner syndrome localizing the lesion to posterior cavernous sinus.

Results: We describe here a 55 year old lady who presented with headache and diplopia for 3 months. On examination she had right lateral rectus palsy and postganglionic Horner syndrome. No other neurological deficit was present. MRI brain and MRA of intracranial vessels showed aneurysm of the right cavernous internal carotid artery which was confirmed on cerebral angiography. Endovascular coiling was advised but refused by the patient and she was treated symptomatically

Conclusions: Parkinson syndrome gives precise localization to unilateral abducens palsy and hence is a valuable clinical pearl.