A case of Bell's palsy in a child of four months.

Bell's palsy is defined by Kettel as a collective diagnosis for all cases of peripheral facial paralysis in which it is impossible to demonstrate a local lesion. At present it is considered to be caused by arteriolar spasm in the vasae vasorum supplying the nerve which becomes oedematous and is compressed within the facial canal (Hilgar). Miehlke describes this to be the site when there is no eye movement disability, no apparent vestibular disturbance, and no extra temporal lesion evident. Previously, all cases were considered to be caused by a non-suppurative otitis media, whether the drum head was seen to be involved or not and at one time a tuberculous infection of the middle ear had always to be kept in mind. Kettel noted necrosis in the mastoid process cells in 11 out of 50 cases in which he exposed the nerve but found no round-cell infiltration. He concluded that if the ear drum was injected in a case of Bell's palsy this must be part of the general vascular change and not necessarily of infective origin. It is probable in this case that the antibiotics used were unnecessary, especially considering the absence of other manifestations of infection.