Periventricular Leukomalacia (PVL): Difference between revisions
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== Introduction == | == Introduction == | ||
'''Periventricular Leukomalacia''' (PVL) has been cited as one of the leading causes of brain injury of a non-haemorragic nature in the cerebral white matter of the premature infant. It is an injury which can lead to deficits of physical, cognitive or behavioral deficits and is the leading cause of [[Cerebral Palsy Introduction|cerebral palsy]] in preterm infants..<ref name=":0">Volpe JJ. [https://www.nature.com/articles/pr2001219 Neurobiology of periventricular leukomalacia in the premature infant]. Pediatric research. 2001 Nov;50(5):553-62.</ref>The term leukomalacia has roots in the words 'Leukos' meaning white and 'malacia' meaning softening.<ref name=":2">Ahya KP, Suryawanshi P. [https://www.tandfonline.com/doi/full/10.2147/RRN.S125575 Neonatal periventricular leukomalacia: current perspectives]. Research and Reports in Neonatology. 2018 Jan 10:1-8.</ref> | |||
== Clinically Relevant Anatomy == | == Clinically Relevant Anatomy == | ||
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== Mechanism of Injury / Pathological Process<br> == | == Mechanism of Injury / Pathological Process<br> == | ||
Incidences of PVL have been linked to neonatal hypocarbia, hypotension, prolonged cardiac surgery as well as sick infants where events | Incidences of PVL have been linked to neonatal hypocarbia, hypotension, prolonged cardiac surgery as well as sick infants where events lead to the failure of areolar autoregulation of cerebral perfusion.<ref name=":1">Deng W, Pleasure J, Pleasure D. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2898886/ Progress in periventricular leukomalacia]. Archives of neurology. 2008 Oct 13;65(10):1291-5.</ref> | ||
At 32 weeks and less (gestation age), the germinal matrix (GM) of the neonate is particularly sensitive to bleeding. <ref name=":1" /> | At 32 weeks and less (gestation age), the '''germinal matrix''' (GM) of the neonate is particularly sensitive to bleeding. <ref name=":1" /> | ||
Hemorrhages confined to the GM generally do not have a major effect on the prognostic outcome. When bleeding extends into the ventricles, hydrocephalus may result. If this is severe, distortion of the corticospinal tracts ensues. This has been linked to more severe [[Cerebral Palsy Introduction|spastic diplegic]] presentation in those affected.<ref name=":1" /> | Hemorrhages confined to the GM generally do not have a major effect on the prognostic outcome. When bleeding extends into the ventricles, hydrocephalus may result. If this is severe, distortion of the corticospinal tracts ensues. This has been linked to more severe [[Cerebral Palsy Introduction|spastic diplegic]] presentation in those affected.<ref name=":1" /> | ||
'''There are 2 components of a PVL injury.'''<ref name=":0" /> | '''There are 2 components of a PVL injury.'''<ref name=":0" /><ref name=":2" /> | ||
# The first component is the '''focal component'''. This is characterized by localized necrosis of all cellular elements. This then leads to '''cyst formation'''. | # The first component is the '''focal component'''. This is characterized by localized necrosis of all cellular elements. This then leads to '''cyst formation'''. | ||
# The second component is the '''diffuse component'''. This is cell-specific death of oligodendroglia - those cells which will mature into oligodendrocytes (forming the myelin of the cerebral white matter). | # The second component is the '''diffuse component'''. This is cell-specific death of oligodendroglia - those cells which will mature into oligodendrocytes (forming the myelin of the cerebral white matter). It is characterized by reactive gliosis in the surrounding white matter of the focal site. | ||
When a PVL insult occurs, microglia become activated leading to a release of toxic products thought to lead to the death of premylinating [[Glial Cells|oligodendroglia]] in the periventricular area. There is also the death of [https://www.frontiersin.org/articles/10.3389/fnana.2020.00008/full subplate neurons] (susceptible to ischemia). These subplate neurons are important in the formation of mature thalamocortical connections.<ref name=":1" /> | When a PVL insult occurs, microglia become activated leading to a release of toxic products thought to lead to the death of premylinating [[Glial Cells|oligodendroglia]] in the periventricular area. There is also the death of [https://www.frontiersin.org/articles/10.3389/fnana.2020.00008/full subplate neurons] (susceptible to ischemia). These subplate neurons are important in the formation of mature thalamocortical connections.<ref name=":1" /> | ||
== Epidemiology == | == Epidemiology == | ||
The incidence of PVL increases with decreasing [https://www.britannica.com/science/gestational-age gestational age]. Peak occurrence is seen between 24 and 32 weeks gestational age and in those infants weighing 1500g or less.<ref name=":2" /> | |||
== Clinical Presentation == | == Clinical Presentation == | ||
Revision as of 20:10, 27 September 2023
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Introduction[edit | edit source]
Periventricular Leukomalacia (PVL) has been cited as one of the leading causes of brain injury of a non-haemorragic nature in the cerebral white matter of the premature infant. It is an injury which can lead to deficits of physical, cognitive or behavioral deficits and is the leading cause of cerebral palsy in preterm infants..[1]The term leukomalacia has roots in the words 'Leukos' meaning white and 'malacia' meaning softening.[2]
Clinically Relevant Anatomy[edit | edit source]
add text here relating to clinically relevant anatomy of the condition
Mechanism of Injury / Pathological Process
[edit | edit source]
Incidences of PVL have been linked to neonatal hypocarbia, hypotension, prolonged cardiac surgery as well as sick infants where events lead to the failure of areolar autoregulation of cerebral perfusion.[3]
At 32 weeks and less (gestation age), the germinal matrix (GM) of the neonate is particularly sensitive to bleeding. [3]
Hemorrhages confined to the GM generally do not have a major effect on the prognostic outcome. When bleeding extends into the ventricles, hydrocephalus may result. If this is severe, distortion of the corticospinal tracts ensues. This has been linked to more severe spastic diplegic presentation in those affected.[3]
There are 2 components of a PVL injury.[1][2]
- The first component is the focal component. This is characterized by localized necrosis of all cellular elements. This then leads to cyst formation.
- The second component is the diffuse component. This is cell-specific death of oligodendroglia - those cells which will mature into oligodendrocytes (forming the myelin of the cerebral white matter). It is characterized by reactive gliosis in the surrounding white matter of the focal site.
When a PVL insult occurs, microglia become activated leading to a release of toxic products thought to lead to the death of premylinating oligodendroglia in the periventricular area. There is also the death of subplate neurons (susceptible to ischemia). These subplate neurons are important in the formation of mature thalamocortical connections.[3]
Epidemiology[edit | edit source]
The incidence of PVL increases with decreasing gestational age. Peak occurrence is seen between 24 and 32 weeks gestational age and in those infants weighing 1500g or less.[2]
Clinical Presentation[edit | edit source]
The presentation of spastic diplegia is most often linked to an incidence of PVL.
Diagnostic Procedures[edit | edit source]
Brain imaging[edit | edit source]
Ultrasonography - Can be used in utero and postnatally. Cystic changes and increased echogenicity are indicators of PVL. After 1 week of birth, ultrasonography which yields no abnormalities can exclude PVL as a diagnosis.[3]
MRI - Can be used earlier than ultrasonography. Repeated MRIs and diffuse tension imaging can be used to determine prognostic information by tracking grey matter atrophy and tract degeneration.[3]
Outcome Measures[edit | edit source]
add links to outcome measures here (see Outcome Measures Database)
Management / Interventions
[edit | edit source]
Prevention is the best form of treatment. An important aspect in this regard is ensuring arterial CO2 (PCO2)does not fall below 35mmHg. [3]
In low-birth-weight infants inhalation of NO has seen to decrease the incidence of PVL. [3]
Cooling, as done for HIE has had little attention in the research and thus has no definable outcomes.[3]
Differential Diagnosis
[edit | edit source]
add text here relating to the differential diagnosis of this condition
Resources
[edit | edit source]
add appropriate resources here
References[edit | edit source]
- ↑ 1.0 1.1 Volpe JJ. Neurobiology of periventricular leukomalacia in the premature infant. Pediatric research. 2001 Nov;50(5):553-62.
- ↑ 2.0 2.1 2.2 Ahya KP, Suryawanshi P. Neonatal periventricular leukomalacia: current perspectives. Research and Reports in Neonatology. 2018 Jan 10:1-8.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Deng W, Pleasure J, Pleasure D. Progress in periventricular leukomalacia. Archives of neurology. 2008 Oct 13;65(10):1291-5.
