White matterds approach

Predominately

Subcortical White Matter

(early involvement of U-fibers)

Macrocephalic

Canavan Disease:

Ashkenazi Jews, hypotonia (head lag), seizures, spasticity

WM: NEAR-COMPLETE, subcortical/deep

GM: thalami, globi pallidi

MRS: ↑NAA peak

Alexander Disease:

Seizures, developmental delay, spasticity

WM: ANTERIOR-PREDOMINANT, subcortical/deep/periventricular

GM: basal ganglia

ENHANCEMENT

Van der Knaap Disease (MegaloencephalicLeukoencephalopathy with Cysts):

Macrocephaly, seizures, ataxia, spasticity

WM: Subcortical with central sparingDWI: Increased proton movementANTERIOR & FRONTOPARIETAL SUBCORTICAL CYSTS

Vanishing White Matter Disease:

Initially normal motor function with relapsing/remitting but progressive ataxia/spasticity

WM: subcortical, deep, & periventricular; ISOINTENSE TO CSF

Normocephalic

Zellweger (Cerebrohepatorenal) Syndrome:

Facial dysmorphism, mental retardation, hypotonia, hepatic dysfunction/jaundice, small renal cortical cysts

WM: subcortical/deep (internal capsule)

GM: globi pallidi

MRS: ↑lipid peak

POLYMICROGYRIA/PACHYGYRIA, SUBEPENDYMAL GERMINOLYTIC CYSTS IN CAUDOTHALAMIC GROOVE

Galactosemia:

Vomiting, ↑intracranial pressure, hepatic dysfunction, hepatomegaly

WM: diffuse subcortical/periventricular

ASSOCIATED LIVER DISEASE

Kearns-Sayre Disease:

MITOCHONDRIAL INHERITANCE

OPHTHALMOPLEGIA

WM: subcortical with deep sparing

GM: globi pallidi/thalami/dorsal medulla

DWI: restricted diffusion

MRS: ↑Lactate peak/↓NAA peak

BASAL GANGLIA/THALAMIC CA++

Homocystinuria:

Marfanoid body habitus, osteoporosis, mental retardation

WM: Subcortical & deep (anterior limb internal capslule

GM: basal ganglia spared

BILATERAL INFERIOR (vs superior in Marfan’s) LENS DISLOCATION (ECTOPIA LENTIS); INFARCTS

Pelizaeus-Merzbacher disease:

Spasticity, abnormal eye/extrapyramidalmovements, mental retardation

WM: NEAR-COMPLETE subcortical & deep with “TIGROID or LEOPARD” appearance due to sparing of perivascular spaces

Predominately

Deep White Matter

(early sparing of U-fibers)

Thalamic (Gray Matter) Involvement

Krabbe’s Disease:

3-6 months, hypertonia, irritability

WM: deep cerebral & cerebellar

GM: thalami, basal ganglia, cerebellardentate nuclei

HYPERDENSE THALAMI

Gangliosidosis GM1 & GM2 (Tay-Sachs & Sandhoff):

Cherry-red macula, hypotonia, mental retardation, seizures, spasticity

WM: periventricular

HYPERDENSE THALAMI

No Thalamic Involvement

Brainstem (Corticospinal Tract) Involvement

X-linked Adrenoleukodystrophy:

Adolescent ♂, learning difficulty (ADHD), skin hyperpigmentation, adrenal failure, ataxia, seizures

WM: POSTERIOR PERITRIGONAL WITH LEADING EDGE OF ENHANCEMENT, SYMMETRIC, pons/medulla involved

Maple Syrup Urine Disease:

Neonate (< 1 wk) with vomiting, dystonia, & seizures

WM: deep cerebellar, cerebral peduncle, globi pallidi, & dorsal pons

GM: globi pallidi

DWI: RESTRICTION OF DIFFUSION

No Brainstem (Corticospinal Tract) Involvement

Metachromatic Leukodystrophy:

1-1.5 yrs, ↓motor/mentation

WM: symmetric deep/periventricularwith “TIGROID or LEOPARD” appearance due to sparing of perivascular spaces; POSTERIOR PREDOMINANCE; NO ENHANCEMENT

Mucopolysaccharidoses (Hurler’s, Hunter’s, Morquio’s):

Macrocephalic, thick meninges

WM: RADIATING PERIVENTRICULAR & CORPUS CALLOSAL CYSTIC AREAS (dilated perivascular spaces)

Other:

Lowe (Oculocerebrorenal) Disease

Phenylketonuria

Merosin-deficient m. dystrophy

Predominately

Gray Matter

Deep Gray Matter

Leigh Disease:

MITOCHONDRIAL

Respiratory failure, ataxia, visual/auditory problems, weakness

BILATERAL SYMMETRIC T2/FLAIR HYPERINTENSITY & RESTRICTION OF DIFFUSION IN PUTAMINA

MELAS:

MITOCHONDRIAL

Myopathy, Encephalopathy, Lactic Acidosis, Strokes

WM: subcortical, brainstem, deep cerebellum

GM: basal ganglia

MIGRATING INFARCTS MC IN PARIETOOCCIPITAL CORTEX

Other:

Organic Acidopathies

Amino acid metabolic disorders

Cortical Gray Matter

Neuronal ceroid lipofuscinoses:

Vision failure, progressive dementia, seizures

Cerebral/cerebellar atrophy, thalami/globi pallidi involvement

Mucolipidosis type I:

Neonatal (< 1 wk) presentation

Leukodystrophy Mimics

Inflammatory Processes

Subacute SclerosingPanencephalitis:

MEASLES INFECTION

Progressive Multifocal Leukoencephalopathy:

JC PAPOVAVIRUS INFECTION

Acute Disseminated Encephalomyelitis:

Multifocal punctate to large flocculent T2/FLAIR hyperintesnseWM/basal ganglia lesions, which may enhance

10-14 DAYS FOLLOWING VIRAL ILLNESS OR IMMUNIZATION

Lyme Disease:

Imaging findings simulate multiple sclerosis in a patient with skin rash, flu-like symptoms, &/or joint pain

TORCH:

Microcephaly, variable (typically asymmetric) WM demyelination&/or gliosis, periventricular Ca++, subependymal cysts

White Matter Injury

Radiation Injury:

WM: sparing of subcortical U-fibers; scalloped margins

DISTRIBUTION RELATES TO XRT FIELD (unless whole-brain XRT)

6-8 MONTHS FOLLOWING XRT

Periventricular Leukomalacia(WM Injury of Prematurity):

Spastic diplegia, visual/cognitive impairment, associated with PROM/TORCH

Mechanism: ischemic injury to watershed area

WM: deep/periventricular with cystic change & volume loss

Thin corpus callosum, undulating ventricular margin, enlarged ventricles

Axial T2WI in a child with Canavan disease shows periventricular, deep, and subcortical WM involvement, plus thalami (white arrow) and globi pallidi (white curved) involvement; very characteristic.

X-linked adrenoleukodystrophy with preferential involvement of descending pyramidal tract A-C. T2-weighted image shows demyelination of internal capsule, descending pyramidal tract (arrows, A) and cerebellar deep white matter (arrows, B). The peritrigonal white matter is relatively spared(C). D. On gadolinium-enhanced T1-weighted image, enhancing bilateral descending pyramidal tracts (arrows) are shown.

Coronal FLAIR MR shows bilateral and symmetric periventricular and deep white matter signal abnormality but sparing of sub-cortical U-fibers (white arrow) in child with metachromaticleukodystrophy.

Coronal T2WI MR in another case of metachromatic leukodystrophy shows characteristic diffuse deep and periventricular white matter involvement, with sparing of the cerebellar white matter (white arrow).

Axial T2WI shows diffuse high signal in the centrum semiovalewith sparing of the subcortical U-fibers, typical of treatment related leukoencephalopathy. Patient is s/p whole brain XRT.