Horner syndrome

Specialty: Neurology.

• oculo-sympathetic paralysis
• triad of miosis, ptosis and anhidrosis

Why it occurs

• Dissection of the internal carotid artery (damage to the postganglionic sympathetic fibers that ascend through the carotid adventitia)
• Apical lung tumor (Pancoast tumor that invades the lower cervical sympathetic stellate ganglion)
• Syringomyelia or cervical spinal tumors affecting the mediolateral column
• Lateral bulbar ischemic stroke (Wallenberg Syndrome)
• Giant multinodular goiter or traumatic thyroid/cervical surgery

Initial workup

Pharmacological test with 0.5% apraclonidine eye drops (pupil dilation affected by denervation hypersensitivity, confirming the syndrome) or 4% cocaine test (failure to dilate the pathological pupil); hydroxyamphetamine test to differentiate preganglionic from postganglionic lesions; CT angiography or MR angiography of the skull and neck from the aortic arch; Chest CT if apical pulmonary tumor pathology is suspected.

Standard management

• Antiplatelet aggregation (Aspirin 100-300 mg/day) or anticoagulation with low molecular weight Heparin if carotid dissection is confirmed without contraindications
• Surgical or oncological management of the underlying Pancoast tumor.