KEY FACTS Terminology Mucopolysaccharidoses (MPS): 1-9 Group of lysosomal storage disorders Characterized by inability to break down glycosaminoglycans (GAGs) Undegraded GAGs toxic, accumulate in multiple organs Each type of MPS causes accumulation of particular GAG in lysosomes, extracellular matrix 11…
KEY FACTS Terminology Clinical phenotypes associated with single large-scale mtDNA deletions (SLSMDs) Kearns-Sayre syndrome (KSS) Chronic progressive external ophthalmoplegia Pearson syndrome – Multisystem disorder characterized by bone marrow failure, pancreatic insufficiency – Children who survive develop KSS later in life…
KEY FACTS Terminology M itochondrial myopathy, e ncephalopathy, l actic a cidosis, and s troke-like episodes (MELAS) Inherited disorder of intracellular energy production caused by point mutation in mtDNA Imaging Stroke-like cortical lesions crossing vascular territories Posterior location most common…
KEY FACTS Terminology a.k.a. subacute necrotizing encephalomyelopathy Genetically heterogeneous mitochondrial disorder characterized by progressive neurodegeneration Imaging Best imaging: MR with DWI/MRS Bilateral, symmetric ↑ T2/FLAIR corpora striata (putamen > caudate) > globi pallidi, periaqueductal gray matter, substantia nigra/subthalamic nuclei, dorsal…
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…