MRI features of acquired abducens nerve palsy

Objective To explore MRI features of acquired abducens nerve palsy to provide reliable imaging basis for clinical diagnosis and treatment. Design Retrospective case series. Participants Forty-two patients with acquired abducens nerve palsy. Methods The MRI of 42 cases with acquired abducens nerve palsy were analyzed retrospectively. The MRI features of lesions were observed,including location, morphology, extent, signal intensity and the characteristics of contrast. Main Outcome Mearsures MRI findings.Results Sixteen cases were diagnosed with ischemic abducens nerve palsy, the main findings of MRI was multiple ischemic focus in brain. Tumor was found in 15 patients and the main locations were at prepontine cistern, tip of petrous bone or cavernous sinus, with corresponding segments of abducens nerve afflicted. Five patients got acquired abducens nerve palsy after head trauma, including 1 case of left abducens nerve palsy after multiple fractures of right skull and 4 cases with no fracture in skull bones. Four patients were diagnosed with nonspecific inflammation, in which 3 cases were manifested as cavernous sinus thickening. Other rare causes included 1case of myasthenia gravis and 1 case who was after cerebellopontine cholesteatoma surgery. Conclusion The etiology of acquired abducens nerve palsy is quite diverse and MRI is useful to define the causes and original locations and help to guide specific treatment.