[Arnold-Chiari malformation presenting in adult life].

Eleven patients of Arnold-Chiari malformation (ACM) in adults were reported. Nine of them associated with syringomyelia. The etiology, clinical features, diagnosis, differential diagnosis, the findings of SSEP, MEP, EMG, NCV, and the treatment of ACM in adults were discussed. Our observations lead us to consider that both clinical symptoms and examinations are crucial in the diagnosis. In addition, the delineation of ACM in adults with or without syringomyelia can be somewhat difficult by traditional radiological examinations, but can be readily demonstrated by MRI.