Demyelinating Diseases

Question 1

Imaging features of NMO

Answer 1

• Aquaporin 4 channel autoantibody
• Optic neuritis + Transverse Myelitis = Blindness and paraplegia
• Long segment of involvement in spine +/- bright spotty lesions on T2
• Can also have lesions in brain (periventricular, sessile, around aqueduct)
• Differs from MS which has classic intracranial findings and short segment of spinal cord involvement

Question 2

What is Machiafava-Bignami disease?

Answer 2

Demyelinating disease of corpus callous in male alcoholics

Question 3

Imaging findings in Wernicke’s encephalopathy

Answer 3

Inc T2 signal in mammillary bodies, medial thalami, tectal plate, periaqueductal grey matter and 3rd ventricle; may have enhancement

Question 4

Imaging findings PRES; causes

Answer 4

Symmetric cortical/ subcortical white matter edema in post parietal and occipital lobes, and post fossa (can also see anteriorly); no enhancement or diffusion restriction

Causes: HTN, eclampsia, sepsis, autoimmune conditions, organ transplant

Question 5

Clinical and imaging findings of CADASIL

Answer 5

Recurrent episodes of stroke/TIA, ass. migraine
Subcortical white matter or basal ganglia
MRI - symmetric high T2 signal in subcortical white matter, ant temporal lobe or paramedial frontal lobe highly sensitive and specific (also external capsules)
**anterior circulation versus posterior in PRES

Question 6

Imaging findings of vasculitis

Answer 6

Multiple subcortical and basal ganglia T2 hyperintense foci, +/- hemorrhagic foci on GRE, beaded irregular vessels (ex: lupus, GCA, Sjogren)

Question 7

Imaging findings PML

Answer 7

Asymmetric white matter lesions in subcortical distribution, may be confluent, involve subcortical U fibres (NB: HIV encephalopathy, which can look similar, does no involve the U fibres), no enhancement

Immunocompromised patient** (immunologics, organ transplant, AIDS, etc.)

Question 8

Imaging findings ADEM

Answer 8

Children; post viral or vaccine
Identical appearance to MS (involves both brain and spine); but can also involve the deep grey structure and brainstem - helpful clue for ADEM
Enhancing ring, peripheral diffusion restriction

** if blood present, think Hurst variant

Question 9

Clinical and imaging findings Susac disease

Answer 9

Rare; affects young women (Susacs seen in young Susans with sensorineural hearing loss)

Subacute encephalopathy, bilateral sensorineural hearing loss, and branch retinal arterial occlusions

Multiple small white matter lesions with predilection for the corpus callosum (‘snow ball’ lesions); lesions enhance