Group III Möbius syndrome: CT and MR findings.

Mobius syndrome is a congenital neuromuscular disorder characterized by both inability to abduct the eyes and facial weakness [1] . It is classified into four groups on the basis of whether the primary abnormalities are diffuse (group 1), in the abducens and facial nerves (group II), or nuclei (group Ill), or lie outside the CNS (group IV) [2]. Although the radiologic findings of the musculoskeletal abnormalities associated with Mobius syndrome have been reported [3] , no prior imaging studies of the primary CNS abnormalities have been published. We report a case of a child with clinical and pathologic evidence of group Ill Mobius syndrome whose CT and MR studies showed a hypoplastic brainstem and calcification in the abducens nerve nuc:ei . Radiologic-pathologic correlation is presented .