From the Guidelines
Horner's syndrome is a neurological condition that requires immediate medical attention, especially when it develops suddenly, as it may indicate a serious underlying condition such as stroke or carotid artery dissection. The diagnosis of Horner's syndrome involves a comprehensive ophthalmic examination, including a careful check for other neuro-ophthalmic signs and symptoms, as outlined in the adult strabismus preferred practice pattern 1. This examination should include a complete sensorimotor evaluation, three-step test, and consideration of the additional upright-supine test.
Key elements of the examination include:
- A complete ophthalmic examination with emphasis on sensorimotor evaluation
- Checking for other neuro-ophthalmic signs and symptoms, such as cranial nerve palsy, INO, nystagmus, and hearing loss
- Fundus examination to check for papilledema or optic atrophy
- Visual field testing to provide additional information on the etiology
According to the comprehensive adult medical eye evaluation preferred practice pattern 1, the examination may identify signs of systemic diseases or other serious medical conditions, including Horner's syndrome, which can be associated with systemic infectious, neoplastic, autoimmune, vascular, and nutrition-related diseases. Treatment of Horner's syndrome focuses on addressing the underlying cause, such as surgical removal of a tumor or standard stroke management protocols, rather than the symptoms themselves. The prognosis depends entirely on the underlying cause, and patients should seek immediate medical attention when Horner's syndrome develops suddenly.
From the Research
Definition and Symptoms of Horner's Syndrome
- Horner's syndrome refers to the clinical triad of ptosis, miosis, and anhidrosis resulting from disruption of the ocular and facial sympathetic pathways 2.
- The syndrome consists of unilateral ptosis, an ipsilateral miotic but normally reactive pupil, and in some cases, ipsilateral facial anhidrosis, all resulting from damage to the ipsilateral oculosympathetic pathway 3.
Causes of Horner's Syndrome
- A myriad of etiologies can lead to Horner's syndrome, including trauma, cervical artery dissection, and infarction 2.
- Procedures in the neck, chest, skull base, and paraspinal region accounted for most of the identified causes, with cervical carotid dissection the next most common cause 4.
- Tumors, such as Pancoast tumors, are also a possible cause, although they are discovered only in a small minority of Horner's syndrome cases 2.
Diagnosis and Investigation
- The diagnosis of Horner's syndrome can be difficult, as patients rarely present with the classic triad of ptosis, miosis, and anhydrosis 5.
- Pharmacologic testing, such as apraclonidine, can confirm the presence of Horner's syndrome and direct further testing and management 3, 4.
- Modern imaging modalities have advanced significantly and become more readily available, allowing for a practical and safe combined clinical and radiological diagnostic protocol for Horner's syndrome 5.
Clinical Significance
- Awareness of the underlying anatomy and array of possible etiologies can assist physicians in identifying potential causes and initiating appropriate care 2.
- In an important minority of cases, the identification of Horner's syndrome is critical to the discovery of underlying conditions, such as carotid dissection or tumor 4.