Imaging CNS autoimmune and inflammatory disease
This is the first lecture in a case based review of imaging of the brain and spine for autoimmune and inflammatory conditions. We will cover the MRI findings of some of the common conditions and some potential pitfalls and mimics.
This first lecture covers demyelinating disease, with the most common being multiple sclerosis (or MS), neuromyelitis optica (NMO), and acute disseminated encephalomyelitis (ADEM). These are all demyelinating/autoimmune conditions in which the brain loses its normal myelination.
MS is the most common demyelinating disease, affecting women more than men, with 2 age distribution peaks in younger and middle age women. MS commonly presents with optic nerve or visual symptoms, affects the brain more commonly than the spine, and can result in short segment spine lesions.
Neuromyelitis optica, or NMO, is an autoimmune disease characterized by predominantly optic nerve and spine lesions. It is often associated with an antibody to aquaporin 4.
Acute disseminated encephalomyelitis (ADEM)
ADEM is an acute fulminant demyelinating syndrome characterized by acute onset and often many supratentorial lesions. The majority of patients recover, although some may have residual symptoms and it can even progress to death.
Acute hemorrhagic encephalomyelitis (AHEM)
AHEM is a closely related variant of ADEM which is associated with hemorrhage.
Susac syndrome is a small vessel vasculitis with small vessel infarcts, most commonly in the retina, cochlea, and periventricular white matter and corpus callosum. It can frequently mimic demyelinating disease because the distribution of lesions is similar.
Summary and Conclusion
The level of this lecture is appropriate for radiology residents, radiology fellows, and trainees in other specialties, such as neurology, who have an interest in neuroradiology or may see patients with CNS demyelinating or inflammatory conditions.