Pediatric CNS Conditions with Characteristic MRI Findings

Neurodevelopmental Disorders

Tuberous Sclerosis Complex (TSC)

• Cortical/Subcortical Tubers:

  T2 hyperintense lesions with:

  • Variable T1 signal intensity
  • Calcification in 50% cases
  • Gyral expansion
• Subependymal Nodules:
  • T1 hyperintense
  • Located along ventricular walls
  • Often calcified
• SEGA:
  • Near foramen of Monro
  • Enhancement with contrast
  • Size >1cm

Lissencephaly Type 1

• Cortical Abnormalities:
  • Smooth brain surface
  • Cortical thickness 10-20mm
  • No visible sulci
• Associated Features:
  • Figure-8 configuration on axial
  • Colpocephaly
  • Corpus callosum dysgenesis

Focal Cortical Dysplasia

• Type I:
  • Subtle cortical thickening
  • Blurred gray-white junction
  • Normal signal intensity
• Type II:
  • Cortical thickening
  • Transmantle sign
  • FLAIR hyperintensity

Metabolic Disorders

Metachromatic Leukodystrophy

• White Matter Changes:
  • Symmetric periventricular involvement
  • T2/FLAIR hyperintensity
  • Tigroid pattern
• Progression Pattern:
  • Starts periventricular
  • Spares subcortical U-fibers initially
  • Splenium involvement early

X-linked Adrenoleukodystrophy

• Classic Pattern:
  • Symmetric parieto-occipital involvement
  • Leading edge enhancement
  • Splenium involvement
• Zones:
  • Zone A: Central uninvolved white matter
  • Zone B: Active demyelination with enhancement
  • Zone C: Peripheral demyelinated white matter

Krabbe Disease

• Early Infantile Form:
  • Symmetric deep white matter involvement
  • Cerebellar white matter changes
  • Thalamic hyperdensity
• Specific Features:
  • Pyramidal tract involvement
  • Optic nerve enlargement
  • Progressive cerebral atrophy

Vascular Disorders

Moyamoya Disease

• Vascular Changes:
  • ICA terminal portion stenosis
  • Basal collateral vessels
  • Ivy sign on FLAIR
• Parenchymal Changes:
  • Watershed infarcts
  • Microhemorrhages
  • Chronic arterial borderzone infarcts

Inflammatory/Demyelinating Disorders

Pediatric Multiple Sclerosis

• Acute Lesions:
  • T2/FLAIR hyperintense plaques
  • Active lesions show enhancement
  • Periventricular perpendicular orientation
• Chronic Features:
  • Black holes on T1
  • Dawson's fingers appearance
  • Corpus callosum involvement

Acute Disseminated Encephalomyelitis (ADEM)

• Typical Pattern:
  • Multifocal white matter lesions
  • Bilateral, asymmetric involvement
  • Gray matter involvement (thalami/basal ganglia)
• Enhancement Pattern:
  • Variable enhancement
  • Complete/incomplete ring pattern
  • Resolution on follow-up

Neuromyelitis Optica (NMO)

• Spinal Cord:
  • Longitudinally extensive lesions
  • Central gray matter predominance
  • Cord swelling in acute phase
• Brain Lesions:
  • Periependymal lesions
  • Area postrema involvement
  • Diencephalic lesions

Neurocutaneous Syndromes

Sturge-Weber Syndrome

• Characteristic Features:
  • Leptomeningeal angioma
  • Cortical calcifications
  • Ipsilateral choroid plexus enlargement
• Contrast Enhancement:
  • Pial enhancement
  • Tramtrack appearance
  • Progressive atrophy

Neurofibromatosis Type 1

• Brain Lesions:
  • FLAIR hyperintense spots (UBOs)
  • Optic pathway gliomas
  • Plexiform neurofibromas
• Specific Locations:
  • Basal ganglia
  • Cerebellum (dentate nucleus)
  • Brainstem

Genetic/Chromosomal Disorders

Alexander Disease

• Frontal Pattern:
  • Frontal white matter involvement
  • Periventricular rim
  • Contrast enhancement
• Additional Features:
  • Caudate involvement
  • Signal abnormalities in brainstem
  • Megalencephaly

Canavan Disease

• White Matter:
  • Subcortical white matter involvement
  • T2 hyperintensity
  • Globus pallidi involvement
• Advanced Features:
  • Cerebellar white matter changes
  • Elevated NAA on spectroscopy
  • Progressive atrophy

Infectious Conditions

Herpes Simplex Encephalitis

• Early Findings:
  • Temporal lobe involvement
  • Insular cortex changes
  • Orbital frontal involvement
• Signal Changes:
  • DWI restriction
  • Gyral enhancement
  • Hemorrhagic changes

Congenital CMV Infection

• Brain Changes:
  • Periventricular calcifications
  • Migration abnormalities
  • Temporal lobe cysts
• Additional Features:
  • Ventriculomegaly
  • White matter changes
  • Cerebellar hypoplasia

Posterior Fossa Abnormalities

Dandy-Walker Malformation

• Posterior Fossa:
  • Cystic dilatation of 4th ventricle
  • Vermian hypoplasia/agenesis
  • Elevated tentorium
• Associated Features:
  • Hydrocephalus
  • Cerebellar hemispheric hypoplasia
  • Absent cerebellar vermis

Chiari I Malformation

• Key Features:
  • Cerebellar tonsils >5mm below foramen magnum
  • Crowding at foramen magnum
  • Syringohydromyelia (30%)
• Additional Findings:
  • CSF flow abnormalities
  • Basilar invagination
  • Medullary kinking

Joubert Syndrome

• Classic Signs:
  • Molar tooth sign
  • Vermian hypoplasia
  • Deep interpeduncular fossa
• Brain Stem:
  • Thick superior cerebellar peduncles
  • Fourth ventricle bat-wing appearance
  • Elongated midbrain

Epilepsy-Associated Conditions

Hemimegalencephaly

• Hemispheric Changes:
  • Unilateral enlargement
  • Cortical dysplasia
  • White matter signal abnormality
• Associated Features:
  • Ventricle enlargement
  • Straight gyri pattern
  • Midline shift

Rasmussen Encephalitis

• Early Changes:
  • Unilateral T2/FLAIR hyperintensity
  • Cortical swelling
  • Insular involvement early
• Late Features:
  • Progressive hemispheric atrophy
  • Caudate head atrophy
  • Contralateral hemisphere normal

Toxic/Metabolic Conditions

Leigh Syndrome

• Characteristic Pattern:
  • Bilateral basal ganglia lesions
  • Brainstem involvement
  • Periaqueductal gray matter changes
• Signal Features:
  • T2/FLAIR hyperintensity
  • Restricted diffusion in acute phase
  • Lactate peak on spectroscopy

Maple Syrup Urine Disease

• Acute Phase:
  • Cerebellar white matter edema
  • Dorsal brainstem involvement
  • Thalamic edema
• Imaging Pattern:
  • Restricted diffusion
  • FLAIR hyperintensity
  • Branched-chain amino acids peak on MRS

Neurodegenerative Disorders

Neuronal Ceroid Lipofuscinosis

• Brain Changes:
  • Cerebellar atrophy
  • Cerebral atrophy
  • T2 hyperintense white matter
• Progressive Features:
  • Thalamic hypointensity on T2
  • Hippocampal atrophy
  • Corpus callosum thinning

Vanishing White Matter Disease

• White Matter:
  • Diffuse white matter signal change
  • Cystic degeneration
  • CSF-like signal intensity
• Specific Signs:
  • Sparing of U-fibers
  • Progressive rarefaction
  • Central>peripheral involvement

Brain Malformations

Schizencephaly

• Cleft Characteristics:
  • Gray matter lined cleft
  • Extension from ependyma to pia
  • Unilateral or bilateral
• Associated Features:
  • Polymicrogyria along cleft
  • Absent septum pellucidum
  • Type I (closed lip) vs Type II (open lip)

Holoprosencephaly

• Types:
  • Alobar: Single ventricle, fused thalami
  • Semilobar: Partial hemispheric separation
  • Lobar: Anterior separation defect
• Key Features:
  • Absent falx cerebri (alobar)
  • Monoventricle
  • Dorsal cyst formation

Septo-optic Dysplasia

• Classic Triad:
  • Absent septum pellucidum
  • Optic nerve hypoplasia
  • Pituitary abnormalities
• Additional Findings:
  • Schizencephaly (15%)
  • Empty sella
  • Corpus callosum dysgenesis

Vascular Malformations

Vein of Galen Malformation

• Vascular Features:
  • Dilated median prosencephalic vein
  • Multiple feeding arteries
  • Flow voids on T2
• Complications:
  • Hydrocephalus
  • White matter calcifications
  • High-output cardiac failure

Cerebral Cavernous Malformation

• Classic Appearance:
  • Popcorn-like lesion
  • Hemosiderin rim
  • Mixed signal intensity core
• Sequences:
  • Blooming on SWI
  • No enhancement
  • Development stages on T1/T2

Spinal Cord Conditions

Spinal Dysraphism

• Open Forms:
  • Myelomeningocele
  • Neural placode exposure
  • Associated Chiari II
• Closed Forms:
  • Lipomyelomeningocele
  • Dermal sinus tract
  • Split cord malformation

Syringomyelia

• Cavity Features:
  • CSF signal intensity
  • Central canal dilation
  • String sign on sagittal
• Associated Findings:
  • Chiari malformation
  • Tethered cord
  • Post-traumatic changes

Additional Metabolic Disorders

Glutaric Aciduria Type 1

• Key Features:
  • Wide CSF spaces anterior to temporal lobes
  • Bilateral striatal lesions
  • Subdural collections
• Additional Signs:
  • Fronto-temporal atrophy
  • White matter changes
  • Acute striatal necrosis

MELAS Syndrome

• Acute Lesions:
  • Stroke-like cortical lesions
  • DWI/ADC mismatch
  • Non-vascular territory distribution
• Chronic Changes:
  • Basal ganglia calcification
  • Cerebral atrophy
  • Lactate peak on spectroscopy

Inherited White Matter Disorders

Pelizaeus-Merzbacher Disease

• Early Findings:
  • Diffuse T2 hyperintense white matter
  • Tigroid pattern preservation
  • No enhancement
• Advanced Features:
  • Progressive brain atrophy
  • Thin corpus callosum
  • Cerebellar atrophy

Megalencephalic Leukoencephalopathy with Subcortical Cysts

• White Matter:
  • Diffuse supratentorial involvement
  • Swollen appearance
  • Anterior temporal cysts
• Characteristic Signs:
  • Subcortical cysts location
  • Spared central white matter
  • Preserved myelination of corpus callosum

Mitochondrial Disorders

MERRF Syndrome

• Brain Changes:
  • Cerebellar atrophy
  • Bilateral basal ganglia lesions
  • Subcortical white matter changes
• Advanced Imaging:
  • Elevated lactate on MRS
  • Progressive atrophy
  • Dentate nucleus involvement

Pearson Syndrome

• Early Features:
  • Delayed myelination
  • Symmetric white matter lesions
  • Basal ganglia involvement
• Progressive Changes:
  • Global atrophy
  • Vacuolating myelinopathy
  • Lactate elevation on spectroscopy

Rare Neurodegenerative Conditions

Progressive Familial Intrahepatic Cholestasis Type 1

• Brain Findings:
  • High T1 signal in globus pallidus
  • Cerebellar atrophy
  • White matter changes
• Progressive Features:
  • Bilateral thalamic involvement
  • Brainstem signal abnormalities
  • Cerebral atrophy

Infantile Neuroaxonal Dystrophy

• Early Signs:
  • Cerebellar atrophy
  • T2 hyperintense globus pallidus
  • Thin corpus callosum
• Late Features:
  • Eye-of-the-tiger sign
  • Progressive cerebral atrophy
  • White matter signal changes

Complex Brain Malformations

Rhombencephalosynapsis

• Cerebellar Features:
  • Absent vermis
  • Fused cerebellar hemispheres
  • Diamond-shaped fourth ventricle
• Associated Findings:
  • Fusion of dentate nuclei
  • Hydrocephalus
  • Corpus callosum dysgenesis

PHACE Syndrome

• Brain Abnormalities:
  • Posterior fossa malformations
  • Dandy-Walker variants
  • Cerebellar hypoplasia
• Vascular Changes:
  • Arterial anomalies
  • Persistent embryonic vessels
  • Cervical arch abnormalities

Disclaimer

The notes provided on Pediatime are generated from online resources and AI sources and have been carefully checked for accuracy. However, these notes are not intended to replace standard textbooks. They are designed to serve as a quick review and revision tool for medical students and professionals, and to aid in theory exam preparation. For comprehensive learning, please refer to recommended textbooks and guidelines.