Intracranial Cystic Formations in Neonates

INTRACRANIAL CYSTIC FORMATIONS IN NEONATES: TRANSFONTANELLAR SONOGRAPHIC FINDINGS Nakamura, O.K.; Scoppe2a L.R.P.D.; Sameshima, Y.T.; Kim, M.H.; Gasparini, F.F.; Dutenhefner, E.E.; Quadros, M.S.; Francisco Neto, M.J.; Funari, M.B.G. Imaging Department, Albert Einstein Israelite Hospital, Sao Paulo, Brazil CONGENITAL ORIGIN INTRODUCTION Interhemispheric cyst associated with agenesis of the corpus callosum Subependymal cysts Transfontanellar sonography is the most commonly used technique to assess the neonatal intracranial structures, with high sensiUvity and specificity for the diagnosis of major lesions, which primarily include the intracranial hemorrhage and hypoxic-­‐ischemic injury. The aim of this study is to show some examples of intracranial cysUc formaUons in newborns, including the subependymal cyst, arachnoid cyst, periventricular leukomalacia, subependymal cysts following intracranial hemorrhage (ICH) grade I, porencephaly post ICH grade IV, encephalomalacia post cerebellar hemorrhage and congenital anomalies such as Dandy-­‐Walker syndrome and cysUc formaUon associated with Chiari II malformaUon. 1
Le< parasag. Right parasag. 2
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MulUple subependymal cysUc formaUons, with anechogenic content and thin walls, in the frontal horns of lateral ventricles. The largest cyst measures 1.0 cm on the len side (yellow arrow) and 0.8 cm on the right side (blue arrow). •  Cyst located in the interhemispheric midline occurs in approximately 30% of paUents with agenesis of the corpus callosum (arrows). Arachnoid cyst MATERIALS AND METHODS Choroid plexus papilloma in Aicardi Syndrome This study is based on transfontanellar sonographic exams performed rouUnely in our neonatal intensive care unit in preterm and term neonates. 1
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•  Absence of corpus callosum (agenesis), CASES choroid plexus filling the third ventricle with mulUple cysUc spaces (choroid plexus papilloma) (blue arrows) (images POST-­‐ISCHEMIC OR HEMORRHAGIC ORIGIN Sag. Med. Subependymal cysts a<er germinal matrix hemorrhage grade I Ini:al A<er 20 days A<er 3 months 4
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cysUc formaUons (choroid plexus Dandy-­‐Walker malforma:on 1
papilloma) (yellow arrows) (figures 3 and 4). Agenesis of corpus callosum. 2
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Sonographic findings: -­‐ Enlarged posterior fossa with anechogenic cyst (images 1 and 3 -­‐ yellow arrows); -­‐ Cerebellar vermis hypoplasia; -­‐ HypoplasUc cerebellar hemispheres (figure 2 -­‐ red arrows), laterally displaced by the dilated fourth ventricle (figure 2 -­‐ green arrow); -­‐ Small brainstem; -­‐ Hydrocephalus (80%) -­‐ (images 1 to 4). 4
Porencephalic cyst post periventricular hemorrhagic infarc:on (post-­‐ICH grade IV) Le< parasag. T1 Sag. INFECTIOUS ORIGIN Abscess 2
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•  Postnatal infecUon of the Central Nervous System can be caused by bacteria or fungus. Choroid plexus cysts •  MulUple small round areas, well-­‐
d e fi n e d , s u r r o u n d e d b y a hyperechogenic halo, consistent w i t h m i c r o a b s c e s s e s – hematogeneous spread (images 1 to 4 -­‐ arrows). 4
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2 1 E n l a r g e d c h o r o i d p l e x u s , heterogeneous, irregular, with mulUple Subependymal cysts ICH grade I Normal Arachnoid cyst. Presence of anechogenic content cyst with thin walls (arrows), measuring 1.6 x 1.4 x 1.1 cm, located in the posterior fossa on the len. Normal transfontanellar sonography (a). Hyperechogenic subependymal foci along the caudo-­‐thalamic groove bilaterally (blue arrows), showing germinal matrix hemorrhage (GMH), subependymal, grade I (b). Most subependymal hemorrhages disappear completely aner few days or weeks, some leave a small hyperechoic focus, while others have central liquefacUon resulUng in the formaUon of small subependymal cysts with 3 to 5 mm (green arrows) (c), which disappear within 1 year . c b
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1 and 2). T1 Sag. •  Abscesses occur in 4% of neonatal meningiUs cases. FUNGAL MENINGITIS (by Candida albicans) 3 4 • 
periventricular hemorrhagic heterogeneous area adjacent and Le< R
Le< parasag. infarcUon: an irregular and Choroid plexus cysts (arrows), visualized on transfontanellar sonography in right parasagi2al, coronal and len parasagi2al views. communicaUng with the lateral ventricle (arrows). Schizencephaly Encephalomalacia a<er cerebellar hemorrhage 1 2 •  Cerebellar hemorrhage is present in 10-­‐25% of children with low birth weight, more common in premature neonates. •  ExaminaUon through the mastoid fontanelle can be used to assess the cerebellum and posterior fossa with greater resoluUon. Image 4 (red arrow) shows fluid-­‐fluid level of cerebellar hematoma. 3 4 •  The hemorrhagic area is more echogenic in the acute phase and gradually becomes hypoechogenic during its evoluUon (images 1 to 3 -­‐ yellow arrows). Semi-­‐axial 3
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The transiUon of arterial territories (watershed) determines the brain damage regions in hypoxic-­‐ischemic episodes: In premature infants: watershed areas correspond to periventricular regions (deep white ma2er), where the myelinaUon process is more intense; In term infants: corUcal and subcorUcal regions. IniUally we observed diffuse periventricular hyperechogenicity, similar to the plexus choroid echogenicity (images 1-­‐4). This finding is nonspecific. For a definiUve diagnosis of periventricular leukomalacia, caviUes permeaUng these hyperechogenic areas are necessary to be characterized (figures 5 to 8), which occur in 2 to 6 weeks aner the hypoxic-­‐ischemic episode. 6
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T2 coronal Pineal cyst 5 2
REFERENCES Open-­‐lip schizencephaly: voluminous anechogenic extra-­‐cerebral fluid collecUon on the right that communicates with the right lateral ventricle in the parietal region through a open-­‐lip clen (arrows) lined by gray ma2er. Periventricular Leukomalacia 2
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•  Most cysts are small (5-­‐10 mm), round / ovoid, with thin walls (pictures 1 and 2 -­‐ yellow arrows) •  Doppler study shows no flow within the cyst (images 3-­‐5 – white arrows). O
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Transfontanellar sonography is the technique of choice for intracranial evaluaUon of newborns and infants up to the closure of the fontanelles, by the absence of ionizing radiaUon, portability, low cost and real-­‐Ume diagnosis. The technological improvement of new device and the use of addiUonal sonographic windows, such as the posterior and mastoid fontanelles, allow be2er assessment of intracranial structures. Transfontanellar sonography is an important method for intracranial study of preterm and term neonates, allowing differenUal diagnosis of several neonatal intracranial cysUc formaUons. L R
•  Higher mortality and morbidity in premature than term neonate. 1
CONCLUSION P o r e n c e p h a l i c c y s t p o s t T
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