Table 2

The MRI pattern and specific imaging findings in neurometabolic diseases and other inherited metabolic disorders with profound CNS manifestations.

Neurometabolic Disorders & other Inherited Metabolic disorders (with profound CNS manifestations)InheritanceBrain Magnetic Resonance Imaging FindingsMagnetic Resonance Spectroscopy
Disorders of Protein metabolismOrganic aciduria (glutaric aciduria)ARBilateral basal ganglia lesions with restricted diffusion during acute encephalopathy, cerebral dysgenesis (enlarged Sylvian fissures, wide CSF spaces anterior to the temporal poles), macrocephalyDecreased N-acetyl-aspartate (NAA)/ creatine (Cr) ratio, lactate peak within basal ganglia acutely
Urea cycle defect(Citrullinemia)ARWhite matter edema as result of hyperammonemia, basal ganglia involvementProminent increase of glutamine/ glutamate and lipid/lactate complexes, decrease of NAA
Aminoacidopathy (MSUD)ARVacuolating myelinopathy (intramyelinic edema), edematous lesions with restricted diffusion in the peri-rolandic white matter, posterior limb of the internal capsules, cerebral peduncles, brainstem, deep cerebellar white matter, and globi pallidiDecreased N-acetylaspartate, methyl resonances of branched amino acids at 0.9–1.0 ppm, and lactate in acute metabolic decompensation
Carbohydrate metabolismGalactosemiaARDiffuse edema, diffusion restrictionGalactitol (Gal-ol) doublet peak at 3.7 parts per million
G6PD deficiencyX-linkedSymmetrical lesions in bilateral globus pallidus, hyperintense on T2/FLAIRKernicterus; increased levels of glutamine and glutamate along with decreased levels of choline and N-acetyl-aspartate
Fatty Acid Oxidation DisorderCarnitine deficiency, Acyl-Coenzyme Dehydrogenase Deficiency, glutaric aciduria type 2ARUnderdeveloped frontal and temporal lobes with enlarged sylvian fissures, delayed myelination,Multifocal parenchymal and intraventricular hemorrhages as well as white matter signal intensity changesNormal N-acetylaspartate and an increased choline-creatine ratio
Peroxisomal disordersAdrenoleukodystrophy (ALD)X-linkedDeep white matter in the parieto-occipital lobes and splenium of the corpus callosum, cortical and subcortical U-fiber sparing, enhancement in 50%Neuronal loss manifested by a decrease in the NAA peak and an elevation in the lactate peak
Zellweger SyndromeARVentricular enlargement, abnormal gyration patterns (pachygyria; especially medial gyri around peri-rolandic regions, polymicrogyria; laterally), cerebral periventricular pseudocysts Nonspecific reduction of N-acetylaspartate with lipid accumulation
Lysosomal disordersMucopolysaccharidosisAR (except Hunter, MP-II; X-linked)Enlarged perivascular spaces (“cribriform” or “spindle-like”), white matter lesions, hydrocephalus, cortical atrophy, ‘honeycomb-like’ appearance in the basal ganglia and thalamiDecreased N-acetylaspartate, total choline and glutamate in the white matter, and an elevation of myo-inositol, glucose-aminoglycans (GAG) peak at 3.7 ppm (higher than myoinositol) 
Metachromatic Leucodystrophy (MLD)ARBilateral symmetrical abnormal high SI on T2 and FLAIR images in the deep periventricular white matter, with sparing of the subcortical U fibers and peripheral “tigroid” or “leopard pattern” of dysmyelinationReduced N-acetyl aspartate (NAA), increased myoinositol, increased lactate
Krabbe disease(Globoid cell Leucodystrophy)ARHigh signal involving periventricular white matter, centrum semiovale and deep grey matter, sparing of subcortical U-fibresMarkedly reduced NAA, Abnormally high Cho/Cr ratio
Neuronal Ceroid Lipofuscinosis (NCL)ARGeneralized brain atrophy and hyperintense white matter changesReduced NAA, elevated lipids
Mitochondrial DisordersLeigh SyndromeAR, X-linkedSymmetrical hyperintense lesions in the basal ganglia and/or brain stem on T2-weighted MR imagesElevated choline, occasionally elevated lactate, reduced NAA
Disorders of purine and pyrimidine metabolismLesch-Nyhan diseaseX-linkedDecreased cerebral volume with a predilection for white matter, cortical and/or brainstem atrophyDecreased metabolites, especially N-acetylaspartate and glutamate/glutamine, only in the prefrontal cortex