How to Examine Horner's Syndrome
Hi, Motor supply of pupil movements is by the autonomic nervous system, with the sympathetic nervous system supplying the pupil dilation, and the parasympathetic system controlling constriction. A defect of the sympathetic supply to the eye, also called an oculosympathetic palsy is horner's syndrome. It makes the affected pupil smaller or meiotic, causing the pupils to be unequal in size. This pupillary size difference is termed anisocoria. Here, the right pupil is slightly smaller than the left. When the lights are switched off this anisocoria becomes more obvious as the normal left pupil dilates. The affected right pupil may also dilate, but more slowly, this is called a dilation lag. The anisoria may therefore be greatest a few seconds after switching off the room lights. Another feature of horner's, illustrated here, is an upper and lower lid ptosis, making the upper and lower eyelids slightly closer together and making the eye appear smaller. The patient may also notice a...