Abstract:  Objective To analyze the clinical features and etiology of non-traumatic and non-iatrogenic Horner syndrome (HS) in adults. Design Retrospective case series. Participants From January 2018 to June 2020, hospitalized 7 patients with HS were collected in Beijing Tongren Hospital. Methods Their clinical and imaging data of characteristics, location and etiology of the disease were reviewed and analyzed. Main Outcome Measures The patient's onset form, HS three main signs, other clinical manifestations, imaging and other examination results. Results There were 6 males and 1 female with pituitary apoplexy. The age of onset ranged from 41 to 60 years. All patients had obvious neuro-ophthalmic signs, including exophthalmos in 2 cases, oculomotor nerve involvement in 2 cases, abducent nerve involvement in 2 cases, and the first branch of trigeminal nerve involvement in 2 cases. There were 6 cases of acute or subacute onset, 1 case of chronic course. The difference in the size of the difference of fissure size was 2-4 mm, and the difference of the pupil was 1-1.5 mm. The lesions of the third-order neurons of the cervical sympathetic nerve involved the internal carotid artery and cavernous sinus was in 3 cases, including malignant tumor, apoplexy and arteriovenous fistula. The all 3 cases were no abnormal secretion of facial sweat glands, and 2 cases had obvious local pain. There were 2 cases of secondary neuron involvement, all of which were malignant tumors, 1 case of pulmonary apex lesion and 1 case of thyroid lesion involving common carotid artery. There were abnormal secretion of facial sweat glands, but there were no pain and other signs of neuro ophthalmology and nervous system. There were 2 cases of pathological changes in the first level neurons of sympathetic pathway, which was from thalamus to cervical 8 or thoracic 2 (spinal ciliary center). 1 case was medulla oblongata infarction and 1 case was demyelinating disease of nervous system. All patients had abnormal secretion of facial sweat glands and other positive signs of nervous system. Conclusion The onset form, symptoms and other manifestations of nervous system damage of non-traumatic HS play very important roles in the localization and qualitative diagnosis of the disease. Detailed neuro-ophthalmic examination and early confirmation of physical signs are particularly important for the diagnosis of malignant tumor disease, invasive artery and cavernous sinus with HS. (Ophthalmol CHN, 2021, 30: 112-117)

Key words: Horner syndrome, location diagnosis, etiological diagnosis