Observations on the Pathology of the Moebius Syndrome.

The first report of the congenital facial diplegia syndrome, or Moebius syndrome, was that of Graefe (1880). Moebius reported cases in 1888 and 1892 and reviewed the prior case reports, thus gaining eponymic distinction. Since that time, some authors have broadened the definition of the Moebius syndrome, as for example, Henderson (1939), who considered some cases of congenital unilateral facial palsy to belong to the syndrome. We would agree with the definition of Van Allen and Blodi (1960) that the syndrome consists of varying degrees of facial paresis, usually a facial diplegia, associated with an apparent paralysis of lateral gaze. This is frequently associated with paresis of other muscles supplied by the motor cranial nerves, and with other deformities such as micrognathia, talipes, and the congenital absence of various muscles, particularly the pectoral group. The condition is congenital and not progressive; the clinical features have been reviewed in detail by Henderson (1939). Cases of congenital unilateral facial paralysis without other facial muscular weakness or musculo-skeletal anomalies (Richter, 1958 and 1960) and a case of congenital bilateral sixth nerve palsy (Phillips, Dirion, and Graves, 1932) possibly represent a forme fruste of the syndrome. The syndrome of congenital flaccid bulbar palsy (Graham, 1964) probably represents essentially the same disorder with prominent bulbar symptoms. Some cases of congenital laryngeal abductor paralysis could represent a variant of the Moebius syndrome, as pointed out by Plott (1964). Only three histological examinations of undisputed cases of the complete syndrome could be found (Heubner, 1900; Spatz and Ullrich, 1931; Wallis, 1960); the last author did not report the pathological findings in detail. Two other pathological reports (Fenyes, 1937; Riggs, 1958) have been challenged by some (Henderson, 1939; Richter, 1958) as representing intrapartum brain-stem