People push your buttons because they know they can, regardless of whether theyâre aware of it. What theyâre looking for is a negative reaction; they want you damaged and on the defensive, for whatever reason.
Horner syndrome is caused by damage to a certain pathway in the sympathetic nervous system. The sympathetic nervous system regulates heart rate, pupil size, perspiration, blood pressure and other functions that enable you to respond quickly to changes in your environment.
There are a number of potential causes of Hornerâs syndrome, each affecting a different place in the sympathetic chain: 1  First order neuron lesion: brainstem stroke. 2  Second order neuron lesion: apical lung tumor, neck trauma, other. 3  Third order neuron lesion: orbital trauma or inflammation, carotid dissection, other.