Irregular Lateral Ventricles



Irregular Lateral Ventricles


Bronwyn E. Hamilton, MD



DIFFERENTIAL DIAGNOSIS


Common



  • CSF Shunts and Complications


  • Surgical Defects


  • Periventricular Leukomalacia


  • Cerebral Infarction, Chronic


  • Porencephalic Cyst


  • Chiari 2


Less Common



  • Heterotopic Gray Matter


  • Tuberous Sclerosis Complex


  • Metastases, Intracranial, Other


  • Intraventricular Webs or Adhesions


  • CMV, Congenital


  • Schizencephaly


Rare but Important



  • Hemimegalencephaly


  • Holoprosencephaly


  • Holoprosencephaly Variants


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Irregular ventricles may be the result of obstruction, chronic volume loss/or congenital deformities



    • Obstruction: Mass effect, “ballooned” appearing ventricles, & transependymal CSF migration


    • Volume loss: Ventricle irregularity with brain parenchymal loss


    • Congenital: Look for associated findings (colpocephaly, subependymal nodules)


  • Ventricular deformities may become permanent despite relief of obstruction, due to parenchymal atrophy or acquired ventricular non-compliance


  • Enhancement may help differentiate etiologies


Helpful Clues for Common Diagnoses



  • CSF Shunts and Complications



    • Common complications include shunt obstruction/breakage, infection, overdrainage


    • Acquired ventricular non-compliance may result in ventricle deformity


  • Surgical Defects



    • Often evident from prior shunt tract or burr hole


    • Deformity is chronic


    • Overlying skull or scalp also shows defect


  • Periventricular Leukomalacia



    • “Wavy” margins or undulating lateral ventricular contours typical


    • Cysts or ill-defined T2 hyperintensity in periventricular white matter (WM)


    • Colpocephaly common & reflects predominant posterior WM loss


  • Cerebral Infarction, Chronic



    • Vascular territory wedge-shaped area of encephalomalacia


    • Results in compensatory or “ex vacuo” dilation of the regional ventricle, due to volume loss


  • Porencephalic Cyst



    • Cystic space in brain parenchyma with enlarged adjacent ventricle, may communicate with ventricle


    • Cyst may cause mild mass effect (from CSF pulsations)


  • Chiari 2



    • Pointed anterior horns, colpocephaly


    • Small posterior fossa, tectal “beaking”, downward herniation of cerebellar tissue through foramen magnum


    • Associated with a lumbar myelomeningocele


Helpful Clues for Less Common Diagnoses



  • Heterotopic Gray Matter



    • Subependymal nodules follow gray matter signal & do not enhance


    • May be seen with epilepsy or incidental


  • Tuberous Sclerosis Complex



    • Subependymal nodules lining the ventricles characteristic



      • Mostly along striothalamic groove


      • Calcify with increasing age


    • Cortical & subcortical tubers are usually multifocal ± mild mass effect



      • Tubers are most easily seen on FLAIR


      • Rarely tubers may calcify or enhance


    • Enhancing mass at foramen of Monro = subependymal giant cell astrocytoma


  • Metastases, Intracranial, Other



    • CSF seeding of primary CNS tumors, lymphoma or systemic malignancy may cause irregular ventricles


    • May result in ventricular nodules which can deform the ventricles


  • Intraventricular Webs or Adhesions




    • May be congenital or acquired (prior hemorrhage, infection or tumor)


    • Contours of ventricles may be rounded or balloon-like due to obstructive symptoms


    • Contrast ventriculography or cine CSF can be helpful to assess for evidence of physiological flow obstruction


  • CMV, Congenital



    • White matter volume loss


    • Periventricular calcifications are common


    • Polymicrogyria & cortical malformations may be seen


  • Schizencephaly



    • Outward “dimpling” of lateral ventricle suggests schizencephaly


    • Look for gray matter lining the CSF cleft


Helpful Clues for Rare Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Irregular Lateral Ventricles

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