DÄ internationalArchive5/2026Painful Horner Syndrome as a Warning Sign

Clinical Snapshot

Painful Horner Syndrome as a Warning Sign

Dtsch Arztebl Int 2026; 123: 128. DOI: 10.3238/arztebl.m2025.0147

Mattern, J; Weyrauch, N; Majolk, J

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a: Horner syndrome with discrete ptosis on the left side (arrow); miosis not visible under bright light conditions. b: Axial time-of-flight magnetic resonance angiography: dissection of the left internal carotid artery (long arrow) with a mural hematoma causing stenosis (short arrow).
Figure
a: Horner syndrome with discrete ptosis on the left side (arrow); miosis not visible under bright light conditions. b: Axial time-of-flight magnetic resonance angiography: dissection of the left internal carotid artery (long arrow) with a mural hematoma causing stenosis (short arrow).

A 48-year-old female patient with no known pre-existing conditions presented to our interdisciplinary emergency department with an approximately 14-day history of new-onset, left-sided frontotemporal facial pain that was moderately pressure-like in character and well controlled with self-administered ibuprofen. Physical examination revealed discrete Horner syndrome on the left side (Figure a), with otherwise normal neurological status. The patient reported that she had not experienced neck trauma or severe coughing, nor had she undergone chiropractic treatment or forceful head rotation. Emergency computed tomography (CT) angiography of the neck vessels showed subacute dissection of the left internal carotid artery (ICA). The patient was transferred to a specialist neurological department for further evaluation. Supplementary magnetic resonance (MR) angiography confirmed ICA dissection at the typical prepetrosal site with high-grade stenosis due to a mural hematoma (Figure b) without signs of cerebral ischemia. The patient was discharged with secondary prophylaxis comprising acetylsalicylic acid and a follow-up appointment scheduled for 3 months later. With an annual incidence of 2.5/100 000, spontaneous carotid dissection is rare. Early detection is crucial as, if left untreated, over 50% of patients experience stroke.

Acknowledgments: We would like to thank the Department of Neurology at Ludwigshafen Hospital for their kind support and prompt transfer of the patient, as well as the Central Institute for Diagnostic and Interventional Radiology, also at Ludwigshafen Hospital, for providing the MRI image.

Dr. med. Juri Mattern, Nadine Weyrauch, Dr. med. Jürgen Majolk, Interdisziplinäre Zentrale Aufnahme, Diakonissen-Stiftungs-Krankenhaus Speyer, jurimattern@web.de

Conflict of interest statement: The authors declare that no conflict of interest exists.

Translated from the original German by Christine Rye.

Cite this as: Mattern J, Weyrauch N, Majolk J: Painful Horner syndrome as a warning sign. Dtsch Arztebl Int 2026; 123: 128. DOI: 10.3238/arztebl.m2025.0147

a: Horner syndrome with discrete ptosis on the left side (arrow); miosis not visible under bright light conditions. b: Axial time-of-flight magnetic resonance angiography: dissection of the left internal carotid artery (long arrow) with a mural hematoma causing stenosis (short arrow).
Figure
a: Horner syndrome with discrete ptosis on the left side (arrow); miosis not visible under bright light conditions. b: Axial time-of-flight magnetic resonance angiography: dissection of the left internal carotid artery (long arrow) with a mural hematoma causing stenosis (short arrow).