The anatomy of the sympathetic pathway through the pterygopalatine fossa in humans.

Generally, sympathetic distribution in the pterygopalatine fossa (PPF) is considered to be via the pterygopalatine ganglion (PPG) sympathetic root and branches. We hypothesized that there may be a dual sympathetic path within the PPF, through the vidian nerve and the PPG and through the periarterial plexuses. We dissected 10 human adult cadavers, fixed and unfixed; we applied antibodies for tyrosine hydroxylase (TH) to 5 human adult samples of PPF contents dissected from cadavers at autopsy. We identified TH(+) nerves and fibers distributed through the neuronal clusters of the PPG and also bundles extrinsic to these clusters, distributed along the maxillary artery. Also, TH(+) reactions were identified at the level of the neuronal capsules of the PPG. All the arteries within the PPF presented TH(+) fibers, periadventitial and intramural-the periarterial plexuses were also identified during dissections, a major one being that along the descending palatine artery, distinctive to the greater palatine nerve. Thus, concerning the sympathetic entry to the PPF, this one seems to use both the path of the external carotid artery (via the maxillary artery plexus) and the path of the internal carotid artery, via the vidian nerve supplying the PPG and reinforcing the maxillary artery plexus. The sympathetic exit of the PPF uses the neural scaffolding of the PPG branches and also the arterial scaffolding. The complex trigeminal-autonomic, anatomic content of the PPF may be involved in several distinctive facial algias and thus the pain may be relieved by routine approaches to the PPF, based on updated anatomical knowledge and a correct diagnostic.