Horner's syndrome
Horner's syndrome is a clinical syndrome caused by damage to the sympathetic nervous system resulting in ptosis (drooping upper eyelid), miosis (constricted pupil), and occasionally enophthalmos (the impression that the eye is sunk in) and anhidrosis (decreased sweating) on one side of the face. Horner's syndrome is usually acquired but may also be congenital. Although most causes are relatively benign, Horner's syndrome may reflect serious pathology in the neck or chest (such as a Pancoast tumor) and hence requires workup.
It is named after Dr Johann Friedrich Horner (1831-1886), the Swiss ophthalmologist who first described the syndrome in 1869. Several others had previously described cases, but "Horner's syndrome" is most prevalent. In France, Claude Bernard is also eponymised with the condition being called "syndrome Bernard-Horner".
Causes
Horner's Syndrome is due to a deficiency of sympathetic activity. The site of lesion to the sympathetic outflow is on the ipsilateral side that the symptoms are on. The following are examples of conditions that cause the clinical appearance of Horner's Syndrome: Central lesions that involve the hypothalamospinal pathway, i.e., transection of the cervical spinal cord. Preganglionic lesions, i.e., compression of the sympathetic chain by a lung tumor. Postganglionic lesions at the level of the internal carotid artery, i.e, a tumor in the cavernous sinus.
Diagnosis
Three tests are useful in confirming the presence and severity of Horner's syndrome:
- Cocaine test
- Paredrine test
- Dilation lag test
Reference
- Horner JF. Über eine Form von Ptosis. Klin Monatsbl Augenheilk 1869;7:193-8.
External link
- WhoNamedIt entry on Horner's syndrome.