Blunt internal carotid artery trauma leading to oculomotor nerve palsy and abducens nerve palsy: a report of 2 cases

Ocular motor nerve palsy is rarely reported as isolated manifestation of blunt internal carotid artery (ICA) injury. This case report describes two young patients who suffered from craniofacial trauma after a car accident. Both presented with ocular motor nerve palsy (third cranial nerve in Case 1, sixth cranial nerve in Case 2) revealing blunt internal carotid artery injury. Case 1: a 17-year-old boy was referred to our unit for exotropia and vision loss in the right eye a few days following a severe non-penetrating craniofacial trauma. Best-corrected visual acuity was hand movement in the right eye and 20/20 in the left eye. Ocular motor examination demonstrated an isolated, incomplete right third cranial nerve palsy with pupillary involvement. Fundus examination of the deviated eye revealed sequelae of postcontusion neuroretinopathy. CT angiography (CTA) and magnetic resonance angiography (MRA) demonstrated dissection of the right internal carotid artery with occlusion of the cavernous segment. The patient was managed only with long-term antiplatelet therapy. Six-month follow-up showed a partial recanalization of the carotid artery, a slight improvement in visual acuity to count fingers, and a partial regression of the oculomotor nerve palsy. Residual strabismus was surgically corrected two years later. Case 2: an 11-year-old child was admitted in our unit for esotropia following a severe blunt craniofacial trauma. Visual acuity was 20/20 and slit lamp examination was normal in both eyes. Complete neuro-ophthalmological evaluation revealed right sixth cranial nerve palsy with sensory loss in the territory of the ipsilateral ophthalmic nerve (V1). MRA showed a pseudoaneurysm in the right cavernous internal carotid artery and early endovascular treatment was performed. On a 2-year follow-up, the patient’s condition remained stable, with complete regression of the abducens and ophthalmic nerve disturbances. Blunt internal carotid artery injuries are uncommon, but potentially dangerous conditions that require prompt diagnosis and management. Their recognition is often delayed. However, the occurrence of premonitory focal neuro-ophthalmologic signs and symptoms, such as ocular motor nerve palsies observed in our cases, following blunt trauma may be suggestive of these lesions. CTA and MRA remain the essential first-line diagnostic modalities.