Germinal
matrix hemorrhage
Synonyms
• Grade 4 GMH = periventricular hemorrhagic
infarction (PHI)
• Cerebellar GMH = external granular layer
hemorrhage
• Germinal matrix = ventricular +
subventricular zone (SVZ)
Definitions
• Germinal matrix
○ Highly vascular, neural tube-derived
structure , Dynamic; varies both
temporally, spatially
○ Contains multiple cell types
– Neural stem cells
– Restricted neural progenitor cells
– Ependymal cells
– Premigratory/migrating neurons, glia
Best diagnostic clue
○ Cerebral: Blood products in subependymal
region, usually involving caudothalamic notch
– } intraventricular hemorrhage
– } choroid plexus bleed (often associated with
GMH + intraventricular hemorrhage [IVH])
– } ventriculomegaly
– } PHI
○ Cerebellar: Blood products on cerebellar
surface
Location
○ Cerebral GMH: Hemorrhage into GM along
lateral ventricular wall, most commonly caudothalamic notch
○ Cerebellar GMH: Hemorrhage into cerebellar GM
over cerebellar hemisphere + vermian surface
○ PHI: Hemorrhage in periventricular white
matter adjacent to GM in caudothalamic notch in venous distribution
CT Findings
• NECT
○ High attenuation due to blood products
MR Findings
• T1WI
○ Blood products initially isointense but
become hyperintense after ~ 3 days
• T2WI
○ Blood products hypointense (hyperacute blood
that is hyperintense on T2 not currently reported due to typical
delay in MR > 12 hours)
○ Become centrally hyperintense with
hypointense rim as they evolve
• T2* GRE
○ Blood products "bloom"
• DWI
○ Signal variable (low T2 drives signal down,
low ADC drives signal up)
○ ADC low due to clotted blood
Ultrasonographic Findings
• Grayscale ultrasound
○ Subependymal mass with ↑ echogenicity
– Typically caudothalamic notch
– } intraventricular echogenicity,
ventriculomegaly
Staging, Grading, & Classification
• Papile (based on head ultrasound)
○ Grade 1: GMH (typically caudothalamic notch)
○ Grade 2: GMH + IVH
○ Grade 3: GMH + IVH + ventriculomegaly
○ Grade 4: GMH + IVH + ventriculomegaly +
parenchymal extension
• Volpe (based on head ultrasound)
○ Grade 1: GMH + IVH < 10% ventricular area
on parasagittal view
○ Grade 2: GMH + IVH 10-50% ventricular area on
parasagittal view
○ Grade 3: GMH + IVH > 50% ventricular area
on parasagittal view
○ Periventricular echodensity (probable periventricular
hemorrhagic infarction)
• Color Doppler
○ Helps differentiate echogenic choroid plexus
from avascular echogenic hemorrhage
Imaging Recommendations
• Best imaging tool
○ US is standard of care: Sensitive but not
specific and user dependent
○ MR most sensitive and specific; important,
though, to weigh risks of transport
• Protocol advice
○ US: High-frequency probe, multiple focal
points
PATHOLOGY
• Etiology
○ GMH: Rupture of GM capillaries may occur in
relation to many factors :
– Altered cerebral blood flow (CBF) caused by
□ Rapid volume expansion
□ Hypercarbia
□ ↑ hemoglobin or blood glucose
□ Hypoxic-ischemic events
– Increase in cerebral venous pressure
(delivery, heart failure, positive pressure ventilation, etc.)
– Coagulopathy
– Capillary fragility
– Deficient vascular support
– Increased fibrinolytic activity
–
Hypoxic-ischemic injury
○ PHI: Venous hemorrhagic infarction likely due
to GMH IVH compressing terminal vein
• Associated abnormalities
○ Hydrocephalus
○ Periventricular leukomalacia (high
association with GMH + IVH)
○ Selective neuronal necrosis (pontine >
thalamus, basal ganglia, hippocampus)
CLINICAL ISSUES
○ Silent > stuttering decline >
catastrophic decline --- Stuttering over hours to days
○ Altered consciousness, hypotonia, abnormal
eye movements, abnormal respiration. Catastrophic over minutes to hours
○ Coma, flaccid &/or fixed pupils, apnea,
seizures, decerebrate posturing
○ Most common presentation of GMH + IVH –
Premature infant with respiratory distress syndrome on mechanical ventilation
○ Drop in hematocrit
• Age
○ Most common < 32 weeks GA, < 1,500 g
○ Rare > 34 weeks GA
○ Can occur in utero
Natural History & Prognosis
• > 20 weeks GM gives rise to
oligodendrocytes and astrocytes
• Blood products have adverse effect on
maturing SVZ cells on oligodendrocyte precursors
• about 90% of GM bleeds occur in ≤ 3 days
• Maximal extent reached ≤ 5 days
• Short-term prognosis
○ Grades 1 and 2: Mortality and incidence of posthemorrhagic
ventriculomegaly < 15% if > 750 g
○ Grade 3: Mortality < 35% and incidence of posthemorrhagic
ventriculomegaly > 75%
○ PHI: Mortality up to 45%, and incidence of posthemorrhagic
ventriculomegaly > 80%
• Incidence of long-term neurological sequelae
○ Grade 1: 15%
○ Grade 2: 25%
○ Grade 3: 50%
○ PHI: 75%
Treatment
• Supportive, rarely shunting of secondary
hydrocephalus
•
Current emphasis on prevention
Imaging gallery
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Coronal gross pathology section shows a left germinal matrix hemorrhage (GMH) with intraventricular extension and associated periventricular hemorrhagic infarction in both the left frontal and temporal lobes. Note the clotted blood extending outward from the left lateral ventricle into the medullary veins .
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Para-Sagittal transfontanelle ultrasound in a premature infant shows a focus of increased echogenicity in the caudothalamic notch without intraventricular extension consistent with a grade 1 GMH.
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Axial T2 MR image shows a small focus of hemorrhage in the left germinal matrix and along the right lateral ventricle in this premature infant with a history of oligohydramnios and a grade 2 GMH.
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Axial SWI MR in the previous premature infant shows hypointensity or "blooming" related to hemorrhage in the left germinal matrix and within the lateral ventricles . GMH typically occurs in premature infants less than 32 weeks gestational age.
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Coronal ultrasound in a premature infant shows increased echogenicity in the bilateral caudothalamic notch ſt due to GMH, intraventricular extension of blood , and enlargement of the lateral ventricles, including the temporal horns , diagnostic of a grade 3 germinal matrix hemorrhage (GMH).
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Axial T1WI MR in a premature infant with a grade 3 hemorrhage shows large bilateral GMHs and an extensive mixed intensity intraventricular clot with persistent right lateral ventricle enlargement.
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Coronal T2 HASTE MR in a fetus of 23 weeks gestational age shows decreased signal along the inferomedial surface of the left cerebellar hemisphere, consistent with a cerebellar GMH.
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Coronal T2 HASTE MR in a 33-week premature infant shows bilateral germinal matrix hemorrhages and associated ventriculomegaly . The right germinal matrix hemorrhage has extended into the right frontal lobe with surrounding edema in this patient with a grade 4 GMH.
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Coronal cranial ultrasound in a premature infant shows a small increased echogenicity due to GMH in the right caudothalamic notch .The GMH on the left is obscured by the intraventricular extension and very echogenic associated PHI .
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| Axial T2WI MR in the previous infant shows hypointense hemorrhage in the ventricle and the associated PHI . Note the radiating pattern of the medullary venous thrombosis in the PHI |