The term Bell's palsy has been used indiscriminately for almost every kind of peripheral facial palsy, regardless of its nature.In this paper the term is restricted to cases in which facial palsy is the only clinical symptom, and in which it has not been possible to demonstrate a local cause.The advances in understanding and treatment of this disease are especially due to Ballance and Duel 4 , Cawthorne 8 , Collier 9 , Hilger 18 and Sullivan 41 .
ANATOMYDescriptions of the anatomy of the facial nerve throughout its course can be tound in any textbook. There are also the excellent papers by Lathrop 2 3, Sullivan and Smith 42 and Tschiassny 45. In Bell's palsy the facial nerve is affecied in its intratemporal course between the posterior end of the lateral semicircular canal and the stylomastoid foramen. Certain details of the pathway should be stressed.In its peripheral part the nerve is superficially situated, but in its temporal course becomes enclosed by the rigid Fallopian canal, connected with the wall by fibrous strands running to the nerve sheath. Within the stylomastoid foramen and at its exit the nerve is compactly bound down and intimately surrounded by a cíense periosteal sheath, which leaves it very little space to expand A description of the blood supply is important for clinical reasons. The intratympanic part of the nerve, the mastoid cells, the semicircular canals and the tympanic cavity are mainly nourished by the stylomastoid artery, a branch of the posterior auricular, which enters the Fallopian canal at the stylomastoid foramen and runs proximally. There are two principal anastomoses. At the knee of the facial canal, posterior to the tympanum, the stylomastoid artery anastomoses with the superior petrosal branch of the middle meningeal, which enters the canal by the hiatus facialis. The second anastomosis concerns the posterior tympanic branch of the stylomastoid artery; this follows the chorda tympani in the posterior part of the tympanic cavity and on the tympanum before joining with branches to the tympanum from the internal maxillary, ascending pharyngeal, middle meningeal and carotid arteries.Relatório apresentado ao XIX Congresso Internacional de Oto-Neuro-Oftalmo¬ logia, reunido em São Paulo em 11-17 de junho de 1954, subordinado ao 2º tema oficial: Fisiopatologia do nervo facial.* Chief-Surgeon, Frederiksborg County Hospital, Hillerod, Denmark.Sullivan and Smith 42 have described the arterial supply of nerves on micro scopical examination. On reaching a nerve, the nutritient vessels divide into ascend ing and descending branches, which course in the epineurium. From these primary divisions secondary branches are given off penetrating more deeply and dividing further, being predominately arranged in longitudinal fashion in the perineural or interfascicular connective tissue and forming a longitudinal vascular bed. No one nutrient artery may be considered as dominating any portion of this plexus. But the facial nerve presents a special problem, as Hilger points out: "In the case of end-...
