Isolated oculomotor nerve palsy: a rare manifestation of internal carotid artery dissection

Abstract

A 58-year-old man reported sudden-onset binocular double vision that appeared 3 days earlier. He denied history of headache/cervical pain or trauma. He had a medical history of well-controlled diabetes, hypertension and dyslipidaemia. Neurological examination revealed a left-sided ptosis and binocular horizontal diplopia in dextroversion without apparent extraocular-muscle paresis or pupillary involvement. Other cranial nerves were spared as well as motor, sensory and coordination systems. There were no signs of ocular erythema, proptosis or palpable orbital mass. Brain MR angiography revealed a crescent-shaped mural hyperintensity in left internal carotid artery (ICA) at skull base, extending to intrapetrous segment, with reduced calibre and flow, suggesting a left ICA dissection. The patient was started on antiaggregation therapy. A year later he was asymptomatic and CT angiography confirmed ICA recanalisation.

Figure 1

MR angiography showing irregularities in left internal carotid artery lumen.

Figure 2

Fat-suppressed T1-weighted MRI showing a crescent-shaped haematoma within the wall of the left internal carotid artery, adjacent to the eccentric lumen.