Post by @Fteranmd

55 yo M active smoker presents to the ED complaining of months of persistent cough, associated with difficulty reading due to inability to fully open his left eye.


Physical exam is remarkable for findings shown in the picture above. Patient is otherwise well-appearing and has normal vitals.

A chest x-ray is obtained as part of the initial work up, and diagnosis is made.

What is the diagnosis?

Answer: Horner’s syndrome (due to Pancoast tumor of the left apex)

Horner’s syndrome (also called oculosympathetic paresis) is a rare clinical syndrome with a classic triad of ptosis, miosis and anhidrosis. It results from an interruption at any point along the cervical sympathetic pathway that supply the head and neck, including the oculosympathetic fibers. The causes of Horner’s syndrome varies with the age of the patient and site of the lesion.


Central: include lesions of the hypothalamus, brainstem and spinal cord such as stroke (classically the lateral medullary syndrome), demyelination (such as multiple sclerosis) and neoplasms (such as glioma). These should present with coexistent neurological deficits.

Preganglionic (second order neuron): lesions of the thoracic outlet (cervical rib, subclavian artery aneurysm), mediastinum (mediastinal tumors) and pulmonary apex (Pancoast’s tumor) like the case of the patient presented above. Other preganglionic causes include neck malignancies and surgical procedures in the subclavian region.

Postganglionic (third order neuron): lesions of the superior cervical ganglion, lesions of the internal carotid artery (ICA) in the neck and skull base (dissection, thrombosis, invasion by tumors or iatrogenic from endarterectomy or stenting, base of skull malignancies), lesions of ICA in the cavernous sinus (thrombosis, aneurysm, inflammation or invasive tumors) and lesions of the sellar and parasellar regions (invasive pituitary tumors, metastatic tumors, paratrigeminal tumors).

Additional presenting symptoms might include headaches, arm pain,  ipsilateral neck pain, symptoms of malignancy and associated neurological symptoms in the setting of brainstem or spinal lesions.

Diagnostic imaging, testing and therapies are based on the underlying etiology. For the emergency physician, the main goal is to identify the clinical syndrome and based on most likely underlying lesion, consult the appropriate service (spine neurosurgery, CT surgery, neurology, ENT, etc.)

Further recommended reading:

Reede DL, Garcon E, Smoker WR, Kardon R. Horner’s syndrome: clinical and radiographic evaluation. Neuroimaging Clin N Am. May 2008;18(2):369-85

Diagram of the oculosympathic pathway

image reproduced from
Image reproduced from





June 2024