In this case, HS associated with basilar skull fractures is most likely caused by trauma to the
postganglionic pericarotid plexus as it traverses the carotid canal within the petrous bone.
Only a few cases of pheochromocytoma have been reported in horses, but it has been well described in dogs, cattle, and humans the adrenal medulla, which are
postganglionic neurons of the autonomic nervous system [5,7].
Without this receptor, primary afferent neurons and
postganglionic sympathetic fibers, which are dependent on NGF for growth and survival, are lost, and their loss induces both autonomic disturbance and loss of pain sensation [1, 2].
The vague nerve further divides into the superior and inferior cardiac nerves, finally merging with the
postganglionic sympathetic neurons to form a plexus of nerves at the base of the heart, known as the cardiac plexus [3].
Efferent vagal fiber terminals form synaptic contacts with
postganglionic neurons, primarily in the myenteric nervous plexus, allowing a variety of information collected from intestinal tract to be transmitted to the brain and connecting paroxysmal migraine and gastrointestinal symptoms.19
Preganglionic and
postganglionic neurons responsible for cerebral vasodilation mediated by nitric oxide in anesthetized dogs.
(1) Norepinephrine also is released from
postganglionic neurons of the sympathetic nervous system.
In addition, it is also known to promote the synthesis of endogenous motilin, and subsequently stimulate cholinergic nerves of the gut at both preganglionic and
postganglionic levels, which leads to the release of calcium and contraction of smooth muscle cells (2).
Approximately 8 months after her SCT she developed orthostatic hypotension, confirmed by an autonomic reflex screen which showed significant adrenergic failure with mild cardiovagal and probable distal
postganglionic sudomotor impairment.
In line with this observation, sudomotor denervation has been reported in patients with MSA indicating
postganglionic impairment of the sympathetic nervous system which may contribute alongside degeneration of central autonomic structures to dysautonomia in these patients [16].
Third-order or
postganglionic (at or distal to the superior cervical ganglion) Horner's syndrome often indicates lesions of the internal carotid artery, typically seen with aneurysm or carotid dissection and generally spares facial sweating.