Horner's Syndrome Following Internal Carotid Artery Stent Placement.

A 38-year-old woman presented with acute right hemiplegia and aphasia and initial National Institutes of Health Stroke Scale Score of 18. The patient had past history of Arnold Chiari type I malformation, Attention Deficit Hyperactivity Disorder, fibromyalgia, migraines, and scoliosis. Due to clinical diffusion mismatch on MRI patient underwent an emergent cerebral angiogram which demonstrated left internal carotid artery occlusion secondary to dissection involving the high cervical region and origin of petrous segment. The diagnosis of dissection was made according to the ZQSRC criteria2. The dissection was treated using an 8 x 40 mm Express (Boston Scientific, Natrick, MA) and an 8x20 mm Express self-expanding stents. Post procedure there was successful restoration of the lumen of the left internal carotid artery without evidence of residual stenosis or dissection. The patients demonstrated improvement in aphasia and right hemiplegia in the immediate post procedure period. After 3.5 hours, the patient developed miosis and ptosis of left eye which worsened within the next 2 hours. To differentiate between preand postganglionic symphatetic lesion, we determined the response to 2 drops of topical phenylephrine 1% in the conjuctival sacs of both eyes of the patient. We photographed the pupils in affected and non-affected side with a metric scale at baseline, 2 and 5 minutes post instillation. These images were exported into Analyze Direct 9.0 software (AnalyzeDirect, Inc., Overland Park, KS) and the pupillary diameter was measured. These measurements were then calibrated with the metric ruler within the picture to provide absolute measurements. The affected eye demonstrated an increase of 0.1mm at 5 min. The normal eye demonstrated an increase of 0.2mm at 5 min in pupillary diameter. Given the minimal increase in diameter of affected pupil to phenylepherine drops, the lesion was identified as pre-ganglion in origin.