Ptosis, anisocoria and hemifacial anhidrosis are symptoms related to the abnormal function of the oculosympathetic pathway of the autonomic nervous system. This tract consists of a three-neuron arc that runs from the hypothalamus to the eye and the sweat glands of face and neck. If it is disrupted at any point along its length, it results in Horner syndrome like in this clinical case.
The first order neuron, also called central, originates in the posterolateral part of the hypothalamus, runs through the brainstem, to finally reach the intermediolateral nucleus at level C8-T2 (ciliospinal center of badge – grey matter).
Then it synapses with the second order …show more content…
Anisicoria is the different dilation measure of the pupils. When the sympathetic fibers of the iris dilator muscle are compromised, then there will be unopposed parasympathetic constriction of the pupil. That is the reason why on the ipsilateral side the pupil is 3 mm smaller.
Hemifacial anhidrosis is the lack or decrement of sweat on one part of the face. The ipsilateral side will result drier, because the sympathetic fibers are not optimally providing the sweat glands. In the diagnostic procedure of Horner syndrome, this symptom can sometimes help to determine whether a preganglionic damage or a postganglionic one affects the patient, but it has not a real clinical value. Anhidrosis tends to not appear in the case of a postganglionic lesion Horner syndrome because, as previously described, the fibers that supply the sweat glands do not follow a path directed to the