3. ETIOLOGY
ďŹ
MATERNAL FACTORS
a) Hypotension
b) Cardiac arrest
c) In utero exposure to cocaine
d) Infection (chorio amnionitis)
ďŹ
UTERO- PLACENTAL FACTORS
a) uterine rupture
b) Umbilical cord-entanglement/prolapse
7. PATHOLOGY
WATER SHED
ZONE/BORDER ZONE:
ISCHAEMIC CHANGES IN
HIE ARE CONCENTRATED
PRIMARILY ALONG THE
ARTERIAL BORDER
ZONES BETWEEN MAJOR
CEREBRAL AND
CEREBELLAR ARTERY
TERRITORIES
CORTICAL LAMINAR
NECROSIS
⢠INFARCTION OF GREY
MATTER OF CORTEX IN
RESPONSE TO ANOXIA
,OFTEN ASSOCIATED
WITH HAEMORRHAGE
8. AXIAL T1 IMAGE SHOWING HYPERINTENSE
SIGNAL ALONG THE GYRUS SHOWING
CORTICAL LAMINAR NECROSIS
9. WATER-SHED ZONES
BORDER OR WATER SHED ZONES ARE
THOSE AREAS BETWEEN THE
TERMINAL CAPILLARY BEDS OF
MAJOR TERRITORIAL ARTERIES.
a)Superficial border zone infarction:
ACA and MCA
MCA and PCA
10. b)Deep medullary zone
infarction
These water shed areas occur b/w cortical
branches of middle cerebral artery and
lenticulostriate arteries of MCA trunck.
Border zones also exist b/w major branches
supplying the cerebellum.
14. Cerebral ischemia
PATHOPHYSIOLOGY:
Can be defined as the diminition of cerebral
blood flow to all or a portion of the brain ,
below the level needed to maintain normal
cerebral function.
Normal regional cerebral blood flow is
approx 54 ml/ 100 gm/min.
The threshold for ischemia is approx 23 ml /
100g/min.
17. PATTERN OF BRAIN INJURY
⢠PRE-TERM (less than 37 weeks)
⢠TERM (37 weeks or more).
18. PRE-TERM:
MILD-TO MODERATE HYPOXIA:
The most common area to undergo ischaemic
injury in the pre-mature infant is the peri-
ventricular white matter,which in the
developing fetus is the vascular watershed
zone and has a relatively high metabolic
demand.
1 periventricular infarction(40%)
2 periventricular haemorrage(15%)-bleed may
occur in the region of germinal matrix which
may break through the ependymal lining
resulting into intra-ventricular bleed.
20. GRADING OF GERMINAL MATRIX
HAEMORRHAGE
⢠DEFINITION:it is a loose network of highly vascularised tissue
with little supporting stroma containing primitive nerve cells.
⢠GRADE 1-haemorrhage confined to germinal matrix.
⢠GRADE 2-haemorrhage extending into ventricle or
subependymal region.
⢠GRADE 3-massive haemorrhage into ventricle causing
hydrocephalous.
21. IMAGING
⢠USG-to exclude dialation of ventricles or
haemorrhage.
⢠CT-to asses ventricular dilation and intra-ventricular
bleed.
⢠T1-intra ventricular bleed seen as hyperintense signal.
⢠T2-gliosis âseen as increased signal intensity in peri-
ventricular white matter.
⢠DWI-shows restriction in peri-ventricular region with
corresponding hypointense signal in ADC map
22. FLAIR
⢠Thinning of periventricular white matter.
⢠Thinning of corpus callosum.
⢠Development of porencephalic cyst.
⢠Ventriculomegaly.
29. PRE-MATURE INFANTS WITH
PROFOUND ASPHYXIA
⢠CAUSE-hypotension or cardiac arrest
followed by resuscitation.
⢠IMAGING-infarction or bleed involving
thalami,basal ganglia and brainstem.
31. ISCHEMIC INJURY IN TERM
Less porfound asphyxia
⢠Cause-birth asphyxia
⢠Injury to cortical and sub-
cortical areas in a water â
shed distribution with
relative sparing of the
peri-ventricular white
matter.
Profound episodes of
asphyxia
⢠Cause-
hypotension/cardiac
⢠injury in the thalami and
basal ganglia.
⢠Cystic encephalomalacia-
32. TERM INFANTS WITH MILD TO MODERATE
HYPOXIA
⢠IMAGING
⢠1)USG-for the assement of ventricular dilation .
⢠2)CT-
⢠24 hrs-hypodensity noted in bilateral cerebral hemisphere with
sparing of cerebellum and thalamus known as reversal sign.
⢠2days-early calcific changes in bilateral basal ganglia.
⢠5 days âventricular dilation.
⢠2 weeks âcoarse calcification.
⢠1 month-calcification resolves ,brain volume loss in cortical
and subcortical region.
33. âŚCONTD
3)T1- hypointense signal in the region of ischaemic grey
matter.
4)T2-hyperintense signal in the region of ischaemic grey
matter .
5)DWI AND ADC MAP-deep gery matter infarction
showing restriction.
36. IMAGING IN TERM INFANTS WITH
PROFOUND ISCHEMIA
1)CT-multicystic areas of fluid collection replacing brain
parenchyma.
2)T1-hypointensity primarily in grey matter.
3)T2-hyperintensity primarily in the grey matter.
4)DWI- high signal intensity in basal ganglia and
thalamus .
5)ADC-hypointensity in basal ganglia and thalamus.
6)FLAIR- shows multicystic encephalomalacia.
38. AXIAL FLAIR IMAGE SHOWING MULTICYSTIC
ENCEPHALOMALACIA IN FRONTAL REGIONS.
39. DWI AND ADC MAP SHOWING INFARCT IN BASAL
GANGLIA AND
40. DIFFERENCES BETWEEN PRE-
TERM AND TERM NEWBORN
PRE-TERM
⢠The water shed zone is
located in deep peri-
ventricular matter.
⢠Collaterals at deep peri-
ventricular matter not
developed.
⢠Auto-regulatory
mechanism not fully
developed.
TERM
⢠The water shed zone is
located in cortical and
sub-cortical region.
⢠Collateral developed.
⢠Auto-regulatory
mechanism developed .
42. PROGNOSIS AND TREATMENT
.. PROGNOSIS
⢠infants with mild
encephalic changes make
full recovery while 20 %
of affected infants die in
neonatal period ,some
develop severe neurologic
sequlae.the prognosis is
even worse in pre-term.
43. TREATMENT
⢠Maintainence of adequate ventilation
,avoidance of hypotension ,maintainence
of metabolic glucose ,fluid and nutritional
status ,control of seizures and control of
brain edema lie the main treatment
44. CONCLUSION
⢠HIE remains an important cause of
morbidity and mortality in the neonatal
period and cerebral palsy is a late
neurologic sequale in the post natal
period .intervention remains supportive
,imaging becomes important for optimal
management and rule out other causes of
encephalopathy
45. REFERENCES
1) CRANIAL MRI AND CT âLEE AND RAO.
2) MRI OF BRAIN AND SPINE âSCOTT.
3) DIAGNOSTIC NEURORADIOLOGY-OSBORN