Möbius and Möbius-like syndromes (TTV-OFM, OMLH)

There exists a spectrum of syndromes characterized by cranial nerve palsies, limb anomalies, and craniofacial malformations. Criteria based on type and severity of limb anomaly or presence or absence of cranial nerve palsy may alter the syndrome nomenclature due to a selection bias but do not appear to benefit syndrome delineation to any extent. Patients with seventh nerve palsy and abduction weakness are usually diagnosed as having Möbius syndrome by ophthalmologists. The observed ocular motility findings range from primarily abduction deficiencies to patients who have a Duane or gaze palsy pattern of horizontal movements. Some cases previously described as "sixth nerve and partial third" may better fall into one of the latter groups, since an isolated adduction deficit as a manifestation of third nerve involvement is rare. The presence of clinical appearance of Duane syndrome in these Möbius-type patients raises the possibility of abnormal innervation of the lateral rectus as an explanation of some patterns of motility observed.