Overview Inherited metabolic disorders (IMD) are very difficult to diagnose. Affected patients can present at any age; symptoms vary depending on age of onset and severity of the biochemical defect. Completely different parts of the brain may be involved in…
KEY FACTS Terminology C hronic l ymphocytic i nflammation with p ontine p erivascular e nhancement r esponsive to s teroids (CLIPPERS) Predominantly involving brainstem, adjacent rhombencephalic structures Shows clinical, imaging response to glucocorticosteroids Imaging Location: Predominately pons May extend…
KEY FACTS Terminology Autoimmune-mediated white matter (WM) demyelination of brain &/or spinal cord, usually with remyelination Imaging Best diagnostic clue: Multifocal WM and deep gray lesions days to weeks following infection/vaccination May involve both brain and spinal cord; WM >…
KEY FACTS Terminology Synonyms: Devic disease, optic-spinal multiple sclerosis Definition: Autoimmune inflammatory disorder involving myelin of neurons of optic nerves and spinal cord, with limited brain parenchymal involvement Imaging Longitudinally extensive (> 3 vertebral segments) T2 hyperintensity within cord +…
KEY FACTS Imaging Multiple perpendicular callososeptal T2 hyperintensities characteristic of multiple sclerosis (MS) Perivenular extension: “Dawson fingers” Bilateral, asymmetric linear/ovoid FLAIR hyperintensities > 85% periventricular/perivenular 50-90% callososeptal interface May also commonly involve subcortical U fibers, brachium pontis, brainstem, spinal cord…
KEY FACTS Terminology HIV/AIDS-related opportunistic infections and neoplasms Imaging Findings Primary CNS lymphoma: Enhancing lesions, often hemorrhagic/necrotic within basal ganglia, periventricular white matter Kaposi sarcoma: Intense enhancing soft tissue mass in scalp Bacterial abscesses: Ring-enhancing lesion with ↑ signal on…
KEY FACTS Terminology I mmune R econstitution I nflammatory S yndrome (IRIS) Atypical/worsening opportunistic infection HIV/AIDS patients following commencement of HAART Patients with MS, immunomodulatory therapy Imaging Progressive multifocal leukoencephalopathy (PML)-IRIS White matter (WM) hypodensities with ↑ mass Patchy atypical…
KEY FACTS Terminology Progressive multifocal leukoencephalopathy (PML) Subacute opportunistic infection caused by DNA virus JC polyomavirus (JCV) JCV infects oligodendrocytes, causes demyelination in immunocompromised patients Associated with immunosuppression, often AIDS Organ transplant, cancer, chemotherapy, myeloproliferative disease, and steroid treatment Reported…
KEY FACTS Terminology Cryptococcus neoformans infection Opportunistic fungal infection that typically affects HIV and other immunosuppressed patients Cryptococci spread along perivascular spaces (PVS) to deep brain: Basal ganglia, thalamus, brainstem, cerebellum, dentate nucleus, periventricular WM Imaging Dilated PVS in deep…
KEY FACTS Terminology Coccidioidomycosis, histoplasmosis (sporadic, common) Blastomycosis (rare, sporadic, generally lungs/skin) Invasive fungal infection (immunocompromised) Candidiasis (common) Aspergillus, mucormycosis (angioinvasive) Imaging Varies with type, site of infection, immune status MR ± contrast (add T2* for hemorrhage) Invasive fungal sinusitis…