Etiological evaluation of Horner syndrome in the modern imaging era and proposal for a practical algorithm
Ayse Betul Acar1
, Hale Zeynep Batur Caglayan1,2, Ayse Ilksen Colpak3, Murat Ucar4, Taylan Altiparmak1, Bijen Nazliel1
1Department of Neurology, Gazi University Faculty of Medicine, Ankara, Türkiye
2Neuroscience and Neurotechnology Center of Excellence Joint Application and Research Center (NÖROM), Ankara, Türkiye
3Department of Neurology, Hacettepe University Faculty of Medicine, Ankara, Türkiye
4Department of Radiology, Gazi University Faculty of Medicine, Ankara, Türkiye
Keywords: Horner syndrome, miosis, oculosympathetic syndrome, ptosis, pupil.
Abstract
Objectives: This study aimed to investigate the etiology in patients with Horner syndrome (HS) using neuroimaging studies based on demographic and clinical characteristics and to contribute to clinical practice by developing a practical algorithm based on our findings and integrating current neuroimaging techniques.
Patients and methods: This retrospective, two-center study evaluated 54 patients (28 males, 26 females; mean age: 49.3 ± 14.1 years; range, 21 to 76 years) with HS between January 2013 and February 2022. Demographic and clinical features of the patients, the response to apraclonidine, and neuroimaging study findings were evaluated.
Results: Of the cases included in the study, 18 (33.3%) were idiopathic, three (5.5%) were congenital, 13 (24.1%) were central (first-order neuron), 11 (20.4%) were preganglionic (second-order neuron), and nine (16.7%) were postganglionic (third-order neuron). Localized etiology was affirmed in 33 (61.8%) of 54 patients.
Conclusion: This study showed that neuroimaging methods easily identified etiology in patients with additional neurological findings in HS. The underlying causes could not be defined in a significant part of patients with isolated HS. However, it is essential to carry out detailed neuroimaging studies according to clinical findings to exclude life-threatening causes in patients with HS.
Cite this article as: Acar AS, Batur Caglayan HZ, Ilksen Colpak A, Ucar M, Altiparmak T, Nazliel B. Etiological evaluation of Horner syndrome in the modern imaging era and proposal for a practical algorithm. Turk J Neurol 2026;32(1):11-18. https://doi.org/10.55697/tnd.2026.573.
The data that support the findings of this study are available from the corresponding author upon reasonable request.
AI Disclosure:
The authors declare that artificial intelligence (AI) tools were not used, or were used solely for language editing, and had no role in data analysis, interpretation, or the formulation of conclusions. All scientific content, data interpretation, and conclusions are the sole responsibility of the authors. The authors further confirm that AI tools were not used to generate, fabricate, or ‘hallucinate’ references, and that all references have been carefully verified for accuracy.
A.B.A., H.Z.B.Ç.: Idea/ concept, design, literature review; H.Z.B.Ç., B.N.: Control/supervision, critical review; A.B.A., A.İ.Ç.: Data collection and/or processing; A.B.A., M.U.: Analysis and/ or interpretation; A.B.A.: Writing the article, references and fundings; H.Z.B.Ç., A.İ.Ç., M.U.: Materials.
The authors declared no conflicts of interest with respect to the authorship and/ or publication of this article.
The authors received no financial support for the research and/or authorship of this article.