Causes of Intraventricular Hemorrhage (IVH)
Intraventricular hemorrhage in adults is most commonly secondary to hypertensive intracerebral hemorrhage involving the basal ganglia and thalamus, occurring in approximately 45% of patients with spontaneous ICH. 1
Primary Classification
IVH can be categorized into two main types 1:
- Secondary IVH (most common): Originates as an extension from an intracerebral hemorrhage, particularly from hypertensive hemorrhages in the basal ganglia and thalamus 1
- Primary IVH (uncommon): Confined to the ventricles without associated intraparenchymal hemorrhage, representing a distinct diagnostic challenge in adults 2
Specific Etiologies
Non-Traumatic Causes
Hypertensive hemorrhage is the most common underlying etiology, typically presenting as deep hemorrhages in the basal ganglia, thalamus, pons, or cerebellum that extend into the ventricular system 1.
Vascular malformations that can cause IVH include 1:
- Arteriovenous malformations
- Dural arteriovenous fistulas
- Aneurysmal rupture (particularly causing subarachnoid hemorrhage with secondary IVH) 3
- Cavernous malformations
Cerebrovascular conditions 1:
- Cerebral amyloid angiopathy (second most common cause of intracerebral hemorrhage)
- Cerebral venous thrombosis or isolated cortical vein thrombosis 2
- Moyamoya disease
- Cerebral hyperperfusion syndromes following carotid revascularization
Coagulopathy-related causes 1:
- Anticoagulant use
- Antiplatelet agents
- Inherited or acquired bleeding disorders
Neoplastic causes 1:
- Primary central nervous system tumors
- Metastatic disease (particularly melanoma, renal cell carcinoma, thyroid cancer, and choriocarcinoma)
Other causes 1:
- Prior ischemic infarction with hemorrhagic transformation
Traumatic Causes
Shearing injury is the primary mechanism in traumatic IVH, occurring in approximately 13.4% of severe head injury cases 4, 5:
- Tears of subependymal veins
- Damage to the fornix or septum pellucidum (anatomically weak points for shearing forces) 4
- Injury to the choroid plexus
- Hemorrhage in the caudate nucleus or thalamus from perforating vessel injury 5
Traumatic IVH typically occurs with frontal or occipital impact and is often detected within 0.5 to 1.5 hours after trauma in cases involving basal ganglia or brain stem injury 5.
Clinical Significance
The presence of IVH dramatically worsens prognosis, with mortality increasing from 20% in ICH without IVH to 51% in ICH with IVH 2, 6. Among patients with spontaneous ICH who develop IVH, 55% will develop hydrocephalus, which independently predicts poor outcome 1.
Diagnostic Approach
When the underlying cause of IVH is not immediately apparent from history and initial imaging, additional workup should include 3:
- Cerebral angiography (particularly for pure intraventricular hemorrhage, which has high prevalence of vascular lesions) 1
- MRI/MRA for detection of vascular malformations, cavernous malformations, or underlying tumors
- Toxicology screening
- Coagulation studies
Common pitfall: In one series of 89 patients with intracerebral hemorrhage in non-typical hypertensive locations who had negative CTA and MRI/MRA, catheter arteriography subsequently identified vascular lesions (arteriovenous malformations and dural arteriovenous fistulas) in 10 patients, emphasizing that noninvasive imaging may miss important lesions 1.