Facial Diplegia

DIPLEGIA FACIALIS, bilateral paralysis of the facial nerve, is a relatively rare disease. The etiology is diverse: general acute infection, rheumatic factor, polyneuritis, syphilis, leprosy, tetanus with bulbar localization, trauma (contusion, skull base fracture), the effect of antirabies vaccinations (action of cytoneurotoxins), skull base tumor, basilar artery aneurysm, meningitis, diseases of the pons and medulla oblongata (encephalitis, progressive bulbar paralysis, etc.), bilateral ear processes in the temporal bone, forceps injury during childbirth (congenital facial diplegia). The clinical picture of the morbid phenomena is clear from the symptomatology of unilateral facial nerve paralysis (see Facialis nervus). In some cases there is complete symmetry of phenomena, in others not. The diversity of etiological factors also determines the diversity of pathogenesis: in some cases there is a symmetric effect of the damaging factor on the peripheral trunk on the face, already upon exiting the temporal bone; in others, an ear disease or injury symmetrically affects the nerves passing through the Fallopian canal; in a third group of cases, the morbid process nesting in the base of the skull or in the stem part of the brain spreads broadly to one side or the other; finally, as a fourth method of development of facial diplegia, one must consider the possibility of its occurrence on the basis of bilateral focal lesions in the brain, as a result of which the indicated symptom complex develops by the type of pseudobulbar paralysis. The degree of development of the paralysis and the course of the disease depend on the character and etiology of the process. In some cases (facial diplegia due to infection, rheumatism, syphilis, contusion, antirabies vaccinations, relatively mild ear disease, etc.) complete recovery can be observed, in other cases the morbid phenomena do not undergo reverse development or do so only partially. The diagnosis of the symptom is established easily from a symptomatological standpoint, but ascertaining the etiology and pathogenesis is not always simple; comprehensive examination, radiography, study of the development of morbid phenomena, and the general character of the condition help to sort out the presented difficulties. Therapy depends on the etiology: in some cases, treatment is carried out according to the type of treatment for facial nerve paralysis and neuritis in general, in other cases treatment must proceed along the lines of the underlying disease process.