All of the following are the features of Horner's syndrome Except:
Ans. is 'd' i.e. Apparent exophthalmos Horner's syndrome consists of classical triad of ipsilateralPtosisMiosis &Anhidrosis (loss of sweating)Other signs of the Horner's syndromeSlight elevation of the inferior eyelidThe pupillary reactions are normal to both light and accomodation.The pupil is slow to dilateHeterochromia (ipsilateral iris is of lighter color) is seen in congenital Horner's syndromeNote that the anhidrosis is present only if the lesion is below the superior cervical ganglion.Causes of Horner's syndromeHorner's syndrome is caused by a lesion of the sympathetic pathway eitherin its central portion which extends from the posterior hypothalamus through the brainstem to the upper spinal cord.in its preganglionic portion which exits the spinal cord and synapses in the superior cervical (stellate) ganglionin its postganglionic portion which extends from the superior cervical ganglion to the orbit via the carotid plexus and the ophthalmic division of the trigeminal nerveSympathetic fibres supply the Superior tarsal muscle and the iris dilator muscle. Paresis of the Superior tarsal muscle causes ptosis and that of iris dilator leads to miosis. (Some books write that it's the paresis of Muller's muscle that causes ptosis but According to Gray's Anatomy it's the Superior tarsal muscle whose paresis causes ptosis)Melanocyte maturation in the iris of a neonate depends upon sympathetic innervation, thus lack of sympathetic innervation in congenital Horner's syndrome interferes with melanin pigmentation of the iris leading to iris of lighter color (Heterochromia)Note that the Ptosis in Horner's syndrome is mild to moderate and not complete due to preservation of Levator palpebrae superioris muscle function.Horner's syndrome and Enophthalmos Kanski, Yanoff ophthalmology and Vaughan's ophthalmology (a Lange publication) do not include enophthalmos in Homer's syndrome.Articles at above mentioned web addresses clearly write that- though enophthalmos has traditionally been included in Horner's syndrome it is only an illusion of enophthalmos caused by the ptosis.Actual measurement with exophthalmometry clearly demonstrates the lack of enophthalmos. The enophthalmos is only apparent. The small palpebral fissure makes the eye look sunken in on the affected side, but the position of the globe in the orbit remains virtually unchanged.
Ptosis and Miosis in ipsilateral eye
Anhydrosis of ipsilateral face
Hetrochromia irides
Apparent exophthalmos
Cornea