A patient with internal carotid artery dissection.

Background And Purpose: The purpose of this case report is to raise physical therapist awareness of Horner syndrome as a "red flag" for immediate medical referral.

Case Description: A 45-year-old man sought physical therapy for examination and treatment of neck pain and headache symptoms 5 days after experiencing a whiplash-type injury while waterskiing. His complaints were similar to a prior condition diagnosed as occipital neuralgia that had successfully responded to education, cervical and thoracic joint mobilization, and exercise provided by a physical therapist. The initial examination findings also were similar to those of the previous episode. However, signs consistent with Horner syndrome were noted on the second visit. This finding raised immediate concern on the part of the treating clinician and resulted in prompt physician referral, medical diagnosis, and intervention.

Outcomes: A magnetic resonance imaging angiogram revealed an internal carotid artery dissection. A successful outcome was achieved over the course of 6 months through medical intervention, which consisted of anticoagulant therapy and modification of activity levels.

Discussion: In this case, the patient's sudden onset of signs of Horner syndrome was indicative of a medical emergency-internal carotid artery dissection.