Ipsilateral Pupillary Dilation Following Carotid Endarterectomy: A Temporary and Benign Phenomenon.

BACKGROUND AND

IMPORTANCE

Cases of post carotid endarterectomy (CEA) Horner's syndrome have been reported, with symptoms attributed to manipulation of the sympathetic plexus situated along the carotid artery; however, these patients presented with the typical constricted pupil. We report the first 3 cases to our knowledge of mydriasis following CEA.

CLINICAL PRESENTATION: We present 3 cases of CEA followed by immediate postoperative development of ipsilateral mydriasis. The patients were otherwise at their neurologic baseline and the mydriasis resolved over the ensuing few days.

CONCLUSION

We suggest that these cases are secondary to an ischemic phenomenon, specifically to parasympathetic structures such as the ciliary ganglion and/or oculomotor nerve, resulting in autonomic dysfunction manifested by pupillary dilation. A similar finding of mydriasis occurring subsequent to other carotid pathology has been reported, with ischemia to parasympathetic structures also proposed as the underlying etiology. Although pupillary dilation often represents a worrisome neurosurgical sign indicating herniation, it should be recognized that after CEA this finding may be a transient, benign occurrence.