Idiopathic inflammatory demyelinating diseases of the brainstem.

Idiopathic inflammatory demyelinating diseases (IIDDs) represent a broad spectrum of central nervous system disorders that can be differentiated on the basis of severity, clinical course, and lesion distribution, as well as imaging, laboratory and pathologic findings. The spectrum includes monophasic, multiphasic, and progressive disorders, ranging from highly localized forms to multifocal or diffuse variants. All forms of IIDDs may affect the brainstem usually in association with involvement of other areas of the central nervous system but only rarely in isolation. In this article, we will review the main clinical and imaging features of the different IIDDs which may involve the brainstem.