Periventricular leukomalacia
Updates to Article Attributes
Periventricular leukomalacia (PVL), or or white matter injury of prematurity affecting the periventricular zones, typically results in cavitation and periventricular cyst formation.
It is important to note that both periventricular and subcortical leukomalacia correspondscorrespond to a continuous disease spectrum. Please refer to the article on patterns of neonatal hypoxic-ischaemic brain injury for a relation between perinatal brain maturation process and these lesions.
Epidemiology
PVL is most common in premature neonates (less than 34 weeks gestational age with a median gestational age of 30 weeks) and <1500 grams at birth.
Clinical presentation
PVL may manifest as cerebral palsy (>50% in the setting of cystic PVL), intellectual disability or visual disturbance.
Pathology
It likely occurs as a result of hypoxic-ischaemic lesions resulting from impaired perfusion at the watershed areas, which in premature infants are located in a periventricular location. It is likely that infection or vasculitis also playplays a role in pathogenesis.
early: periventricular white matter necrosis
subacute: cyst formation
late: parenchymal loss and enlargement of the ventricles
Distribution
The white matter necrosis often occurs in a characteristic distribution with the pattern being dorsal and lateral to the lateral ventricles and with the involvement of the centrum semiovale, the optic (trigone and occipital horns) and acoustic (temporal horn) radiations.
Radiographic features
Ultrasound
Cranial ultrasound provides a convenient, non-invasive, relatively low-cost screening examination of the haemodynamically-unstable neonate at the bedside. The examination also imparts no radiation exposure. Sonography is sensitive for the detection of haemorrhage, periventricular leukomalacia, and hydrocephalus.
On ultrasound, hyperechoic areas are firstly identified in a distinctive fashion in the periventricular area, more often at the peritrigonal area and in an area anterior and lateral to the frontal horns (periventricular white matter should be less echogenic than the choroid plexus).
These are watershed areas that are sensitive to ischaemic injury. Follow Follow-up scans in the more severely affected patients may reveal the development of cysts in these areas, known as cystic PVL (when cystic PVL is present, it is considered the most predictive sonographic marker for cerebral palsy).
Classification
See sonographic grading of PVL.
MRI
Initial MR images depict areas of T1 hyperintensity within larger areas of T2 hyperintensity.
Subsequent cavitation and periventricular cyst formation, features that are required for a definitive diagnosis of PVL, develop 2-6 weeks after injury and are easily seen on sonograms as localised anechoic or hypoechoic lesions. Progressive necrosis of the periventricular tissue with resulting enlargement of the ventricles is called end-stage PVL. CT and MR imaging findings of end-stage PVL include ventriculomegaly with with irregular margins of the bodies and trigones of the lateral ventricles, loss of periventricular white matter with increased T2 signal, and thinning of the corpus callosum.
Differential diagnosis
The differential for periventricular echogenicity in neonates on ultrasound include
cerebral oedema: from various underlying causes
-<p><strong>Periventricular leukomalacia (PVL),</strong> or white matter injury of prematurity affecting the periventricular zones, typically results in cavitation and periventricular cyst formation. </p><p>It is important to note that both periventricular and <a href="/articles/subcortical-leukomalacia">subcortical leukomalacia</a> corresponds to a continuous disease spectrum. Please refer to the article on <a href="/articles/patterns-of-neonatal-hypoxicischaemic-brain-injury">patterns of neonatal hypoxic-ischaemic brain injury</a> for a relation between perinatal brain maturation process and these lesions.</p><h4>Epidemiology</h4><p>PVL is most common in premature neonates (less than 34 weeks gestational age with a median gestational age of 30 weeks) and <1500 grams at birth. </p><h4>Clinical presentation</h4><p>PVL may manifest as cerebral palsy (>50% in the setting of cystic PVL), intellectual disability or visual disturbance. </p><h4>Pathology</h4><p>It likely occurs as a result of hypoxic-ischaemic lesions resulting from impaired perfusion at the watershed areas, which in premature infants are located in a periventricular location. It is likely that infection or vasculitis also play a role in pathogenesis. </p><ul>-<li><p>early: periventricular white matter necrosis </p></li>- +<p><strong>Periventricular leukomalacia (PVL),</strong> or white matter injury of prematurity affecting the periventricular zones, typically results in cavitation and periventricular cyst formation. </p><p>It is important to note that both periventricular and <a href="/articles/subcortical-leukomalacia">subcortical leukomalacia</a> correspond to a continuous disease spectrum. Please refer to the article on <a href="/articles/patterns-of-neonatal-hypoxicischaemic-brain-injury">patterns of neonatal hypoxic-ischaemic brain injury</a> for a relation between perinatal brain maturation process and these lesions.</p><h4>Epidemiology</h4><p>PVL is most common in premature neonates (less than 34 weeks gestational age with a median gestational age of 30 weeks) and <1500 grams at birth. </p><h4>Clinical presentation</h4><p>PVL may manifest as cerebral palsy (>50% in the setting of cystic PVL), intellectual disability or visual disturbance. </p><h4>Pathology</h4><p>It likely occurs as a result of hypoxic-ischaemic lesions resulting from impaired perfusion at the watershed areas, which in premature infants are located in a periventricular location. It is likely that infection or vasculitis also plays a role in pathogenesis. </p><ul>
- +<li><p>early: periventricular white matter necrosis </p></li>
-</ul><h5>Distribution</h5><p>The white matter necrosis often occurs in a characteristic distribution with the pattern being dorsal and lateral to the lateral ventricles and with the involvement of the centrum semiovale, the optic (trigone and occipital horns) and acoustic (temporal horn) radiations.</p><h4>Radiographic features</h4><h5>Ultrasound</h5><p><a href="/articles/head-ultrasound">Cranial ultrasound</a> provides a convenient, non-invasive, relatively low-cost screening examination of the haemodynamically-unstable neonate at the bedside. The examination also imparts no radiation exposure. Sonography is sensitive for the detection of haemorrhage, periventricular leukomalacia, and hydrocephalus.</p><p>On ultrasound, hyperechoic areas are firstly identified in a distinctive fashion in the periventricular area, more often at the peritrigonal area and in an area anterior and lateral to the frontal horns (periventricular white matter should be less echogenic than the choroid plexus).</p><p>These are watershed areas that are sensitive to ischaemic injury. Follow-up scans in the more severely affected patients may reveal the development of cysts in these areas, known as cystic PVL (when cystic PVL is present, it is considered the most predictive sonographic marker for <a href="/articles/cerebral-palsy">cerebral palsy</a>).</p><h6>Classification</h6><p>See <a href="/articles/periventricular-leukomalacia-classification">sonographic grading of PVL</a>.</p><h5>MRI</h5><p>Initial MR images depict areas of T1 hyperintensity within larger areas of T2 hyperintensity.</p><p>Subsequent cavitation and periventricular cyst formation, features that are required for a definitive diagnosis of PVL, develop 2-6 weeks after injury and are easily seen on sonograms as localised anechoic or hypoechoic lesions. Progressive necrosis of the periventricular tissue with resulting enlargement of the ventricles is called end-stage PVL. CT and MR imaging findings of end-stage PVL include <a href="/articles/ventriculomegaly-1">ventriculomegaly</a> with irregular margins of the bodies and trigones of the lateral ventricles, loss of periventricular white matter with increased T2 signal, and thinning of the corpus callosum.</p><h4>Differential diagnosis</h4><p>The differential for periventricular echogenicity in neonates on ultrasound include</p><ul>- +</ul><h5>Distribution</h5><p>The white matter necrosis often occurs in a characteristic distribution with the pattern being dorsal and lateral to the lateral ventricles and with the involvement of the centrum semiovale, the optic (trigone and occipital horns) and acoustic (temporal horn) radiations.</p><h4>Radiographic features</h4><h5>Ultrasound</h5><p><a href="/articles/head-ultrasound">Cranial ultrasound</a> provides a convenient, non-invasive, relatively low-cost screening examination of the haemodynamically-unstable neonate at the bedside. The examination also imparts no radiation exposure. Sonography is sensitive for the detection of haemorrhage, periventricular leukomalacia, and hydrocephalus.</p><p>On ultrasound, hyperechoic areas are firstly identified in a distinctive fashion in the periventricular area, more often at the peritrigonal area and in an area anterior and lateral to the frontal horns (periventricular white matter should be less echogenic than the choroid plexus).</p><p>These are watershed areas that are sensitive to ischaemic injury. Follow-up scans in the more severely affected patients may reveal the development of cysts in these areas, known as cystic PVL (when cystic PVL is present, it is considered the most predictive sonographic marker for <a href="/articles/cerebral-palsy">cerebral palsy</a>).</p><h6>Classification</h6><p>See <a href="/articles/periventricular-leukomalacia-classification">sonographic grading of PVL</a>.</p><h5>MRI</h5><p>Initial MR images depict areas of T1 hyperintensity within larger areas of T2 hyperintensity.</p><p>Subsequent cavitation and periventricular cyst formation, features that are required for a definitive diagnosis of PVL, develop 2-6 weeks after injury and are easily seen on sonograms as localised anechoic or hypoechoic lesions. Progressive necrosis of the periventricular tissue with resulting enlargement of the ventricles is called end-stage PVL. CT and MR imaging findings of end-stage PVL include <a href="/articles/ventriculomegaly-1">ventriculomegaly</a> with irregular margins of the bodies and trigones of the lateral ventricles, loss of periventricular white matter with increased T2 signal, and thinning of the corpus callosum.</p><h4>Differential diagnosis</h4><p>The differential for periventricular echogenicity in neonates on ultrasound include</p><ul>
-<li><p><a href="/articles/cns-infectious-diseases">cerebral infection</a>: e.g. <a href="/articles/congenital-infections-mnemonic">TORCH infection</a></p></li>- +<li><p><a href="/articles/cns-infectious-diseases">cerebral infection</a>: e.g. <a href="/articles/congenital-infections-mnemonic">TORCH infection</a></p></li>
Image 7 Ultrasound ( update )
Image 8 MRI (FLAIR) ( update )
Image 9 MRI (FLAIR) ( update )
Image 10 Ultrasound (Coronal) ( update )
Image 11 Ultrasound (Transverse) ( update )
Image 12 MRI (T2) ( update )
Image 13 MRI (FLAIR) ( update )
Image 14 MRI (T2) ( update )
Image 15 MRI (FLAIR) ( update )
Image 16 Ultrasound (Multiple projections) ( update )
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