What are the differential diagnoses for intraventricular hemorrhage (IVH) around the choroid plexus?

Differential Diagnoses for Intraventricular Hemorrhage Around the Choroid Plexus

The differential diagnosis for IVH around the choroid plexus depends critically on gestational age: in preterm infants, germinal matrix hemorrhage is the primary etiology, while in term infants, choroid plexus hemorrhage itself becomes the predominant source, with rare vascular malformations requiring consideration in both populations.

Age-Dependent Etiologies

Preterm Infants (<37 weeks gestational age)

Germinal matrix hemorrhage is the most common cause of IVH in premature infants, originating from the fragile capillary network in the subependymal germinal matrix near the caudate nucleus, which then ruptures into the ventricular system 1. This occurs in the context of:

• Prematurity itself - The incidence reaches 30% at 22 weeks gestational age, decreasing to 3% at 28 weeks 2
• Hemodynamic instability - Rapid volume expansion and red blood cell transfusions increase IVH risk 1
• Respiratory distress - Associated with fluctuating cerebral blood flow 1

Primary choroid plexus hemorrhage can occur independently in very low birth weight infants (<1,500g), appearing as the sole bleeding site in 59% of cases with intracranial hemorrhage in this population 3. Diagnostic criteria include:

• Choroid plexus nodularity or enlargement (>12mm anteroposterior diameter) 3
• Asymmetry between sides (>5mm difference) 3
• Associated ipsilateral intraventricular clots or occipital horn dilatation 3

Term Infants (≥37 weeks gestational age)

Choroid plexus venous hemorrhage is the primary source in full-term neonates, typically originating from veins of the choroid plexus rather than germinal matrix 4. These hemorrhages are generally:

• Less frequent than in preterm infants 4
• Smaller in volume 4
• Rarely fatal 4

Rare but Critical Vascular Malformations

Cryptic Arteriovenous Malformations

Choroid plexus AVMs must be considered in cases of unexplained primary IVH, particularly when imaging shows a lesion near the ventricles but angiography is initially negative 5. Key features:

• Extremely rare but potentially treatable cause 5
• May appear as "cryptic" with negative angiography 5
• Can be mistaken for cavernous angioma preoperatively 5
• Complete surgical removal is curative 5

Associated Conditions Requiring Simultaneous Evaluation

Periventricular Hemorrhagic Infarction (PVHI)

PVHI (formerly termed Grade IV IVH) represents venous infarction with secondary hemorrhage extending into the parenchyma, not simply extension of IVH 1. This occurs in:

• 53% of cases develop posthemorrhagic ventricular dilatation 1
• Often unilateral presentation 1

Periventricular Leukomalacia (PVL)

PVL coexists with IVH in 43% of cases and requires different prognostic counseling 2, 6. Critical to recognize:

• 13% of infants with IVH also have PVL 6
• Cannot assume isolated IVH without evaluating for white matter injury 6
• Bilateral cystic PVL predicts nonambulant cerebral palsy 2

Cerebellar Hemorrhage

Cerebellar hemorrhage co-occurs in 10% of preterm infants with IVH and confers a 5-fold increased risk of abnormal neurological outcomes 7, 2, 6. However:

• Ultrasound detects only 23% of cerebellar hemorrhages 7
• MRI is required for definitive diagnosis 7

Diagnostic Approach Algorithm

Cranial ultrasonography is the initial imaging modality for bedside evaluation without transporting critically ill infants 1. The coronal plane best determines IVH presence, while sagittal plane determines extent and grading 1.

When choroid plexus hemorrhage is suspected specifically:

1. Measure choroid plexus anteroposterior diameter (abnormal if >12mm) 3
2. Compare symmetry between sides (>5mm difference suggests hemorrhage) 3
3. Evaluate for ipsilateral intraventricular clots 3
4. Assess occipital horn for dilatation 3

MRI should be obtained once stable to evaluate for:

• Cerebellar hemorrhage (missed by ultrasound in 77% of cases) 7
• Diffuse white matter injury 7
• Cortical malformations 7
• Small infarctions 7

Common Pitfalls to Avoid

Do not assume germinal matrix origin in all preterm IVH - Primary choroid plexus hemorrhage may be the sole source in very low birth weight infants and requires different monitoring 3.

Do not overlook vascular malformations when angiography is negative - Cryptic AVMs of the choroid plexus can cause recurrent hemorrhage and require surgical consideration 5.

Do not diagnose isolated IVH without evaluating for PVL - The 43% coexistence rate mandates assessment for white matter injury, which fundamentally changes prognosis 2, 6.

Serial imaging is essential as early changes may be subtle or absent initially, particularly for PVL and evolving hydrocephalus 6.