Delayed Presentation of Horner’s and Harlequin-Like Symptoms Following Interscalene Peripheral Nerve Catheter Placement

Interscalene peripheral nerve catheters are a commonly performed procedure often used to provide continuous outpatient analgesia following orthopedic procedures. In this case report, we present an interesting case of a patient who received an interscalene catheter following an orthopedic procedure and demonstrated an atypical presentation of combined partial Horner's and Harlequin-like syndromes evolving more than 36 hours after block placement. Although several case reports in the literature exist describing incidents in which interscalene catheter migration has led to the late onset of complications, it has never before been observed with either this degree of delay or this combination of symptoms. This case emphasizes the importance of recognizing irregular presentations of interscalene block complications secondary to catheter migration.