Demyelinating Disease

Asymmetric

Symmetric

Midline

Asymmetric Pattern

Multiple Small Ovoid Lesions

Multiple Sclerosis

ADEM

Vascular (SVID, Vasculitis, CADASIL, Susac Syndrome)

Lyme Disease

Multiple Sclerosis

CADASIL

Large Geographic

Tumefactive MS

ADEM

PML, Lyme Disease

Inflammatory Amyloid

Tumefactive MS

Cerebral Amyloid Angiopathy- Inflammatory Subtype

Lyme Disease

PML

Symmetric/Midline Distribution

Symmetric Lobar

Toxic Metabolic

Infectious

Vascular/Hemodynamic

Chemotherapy

Radiation

HIV Encephalopathy

Symmetric Occipital Lobe/Pons

PRES

Tumor

Metabolic

Osmotic Demyelination

Vascular/Hemodynamic

Small Vessel Ischemic Disease

Infarction

Vasculitis: Behçet Disease

PRES

Osmotic Demyelination

Small Vessel Ischemic Disease

Splenium

Toxic: substance abuse e.g. Alcohol, Heroin

Metabolic: Hypoglycemia

Epilepsy: either from seizure or from meds related to treatment for epilepsy

Viral encephalitis

Trauma (DAI)

Inflammatory: MS, ADEM (other lesions should be present)

Tumor: Lymphoma, GBM

Opiate Toxicity