Horner's syndrome

The following set of findings, involving sympathetic dysfunction:
1) unequal pupils, with more constricted pupil on side of lesion. 2) mild drooping of the eyelid (weak tarsal muscles in upper lid produce little "ptosis") on side of lesion. 3) hot, flushed, dry skin on same side of face as lesion. The lesion is always on the same side as the findings. However the lesion can interrupt the sympathetic system at different levels: laterally-located sympathetic
"command" (hypothalamospinal) tract in brainstem/cervical spinal cord; intermediolateral column at T1-2; superior cervical ganglion; postganglionic sympathetic fibers in carotid plexus, etc.