KEY FACTS Terminology Adult hypoglycemic encephalopathy Imbalance between glucose supply, utilization → brain injury Hypoglycemia: Sudden decrease in serum glucose level < 50 mg/dL Imaging Stroke/coma in adult diabetic on insulin replacement therapy (IRT) Parietal/temporal/occipital lobes, basal ganglia, ± hippocampi…
Approach to Toxic and Metabolic Disorders Acquired toxic and metabolic disorders of the brain result from a wide variety of agents, including toxic exposures, substance abuse, radiation, and chemotherapy, as well as metabolic alterations, including hypertension, hepatic failure, hypoglycemia, and…
KEY FACTS Terminology Wilson disease is also known as hepatolenticular degeneration Autosomal recessive disorder of copper metabolism Abnormal accumulation of copper in various tissues Particularly in liver, basal ganglia (BG), midbrain Imaging Usually normal MR in presymptomatic patients T1WI: Normal…
KEY FACTS Terminology Autosomal dominant neurodegenerative disease Loss of GABAergic neurons of basal ganglia (BG) Imaging Diffuse cerebral atrophy Caudate nucleus (CN) atrophy → frontal horns enlarged ↑ “Bicaudate” ratio (BCR) or Evans ratio Intercaudate distance divided by distance between…
KEY FACTS Terminology Pantothenate kinase-associated neurodegeneration (PKAN) Most common form of neurodegeneration with brain iron accumulation (NBIA) Mutated pantothenate kinase 2 gene ( PANK2 ) Formerly known as Hallovorden-Spatz disease Imaging Best diagnostic clue Highly suggestive of PKAN is eye-of-the-tiger…
KEY FACTS Terminology Group of neurodegenerative disorders characterized by dystonia, parkinsonism, and spasticity Caused by mutations in L-ferritin gene FTL All characterized by abnormal Fe accumulation in basal ganglia – Lewy bodies, axonal swellings, hyperphosphorylated tau in some subtypes Includes…
KEY FACTS Terminology Rare inherited leukoencephalopathy characterized by Rosenthal fibers (eosinophilic intracytoplasmic inclusions) 3 clinical forms Infantile (most common) Juvenile Adult Imaging Infantile: Symmetric ↑ T2 bifrontal white matter (WM) including subcortical U fibers Juvenile/adult: ↑ T2 brainstem (especially medulla),…
KEY FACTS Terminology Progressive autosomal-recessive spongiform leukodystrophy a.k.a. spongy degeneration of infancy Aspartoacyclase deficiency (autosomal recessive) Imaging White matter Involves subcortical U fibers Spares internal capsule and corpus callosum Gray matter Thalami, globi pallidi (GP), ± dentate nuclei Spares caudate,…
KEY FACTS Terminology Abbreviations X-linked adrenoleukodystrophy (X-ALD) Classic childhood ALD (CCALD) Inherited peroxisomal disorder ABCD1 mutation → impaired β-oxidation of very-long-chain fatty acids (VLCFAs) Accumulation of VLCFAs in white matter causes severe inflammatory demyelination Several clinical forms of ALD and…
KEY FACTS Terminology Fabry disease (FD) Imaging NECT Ca++ in lateral pulvinar, globus pallidus, putamen, substantia nigra, dentate nuclei MR may show earlier changes ↑ T1 signal in deep gray nuclei T1 lateral pulvinar hyperintensity considered pathognomonic of FD T2/FLAIR…