Enlarged Deep (Medullary/Ependymal) Veins

James D. Eastwood, MD

DIFFERENTIAL DIAGNOSIS

Common

Developmental Venous Anomaly
Arteriovenous Malformation

Less Common

Sturge-Weber Syndrome
Thrombosis, Deep Cerebral Venous
Thrombosis, Dural Sinus
Dural A-V Fistula
Glioblastoma Multiforme
Intracranial Hypotension

Rare but Important

Capillary Telangiectasia
Blue Rubber Bleb Nevus Syndrome
Dural Venous Sinus Stenosis
Vein of Galen Malformation
Demyelinating Disease, NOS
Lymphoma, Intravascular (Angiocentric)
Encephalitis (Miscellaneous)
Granulomatous Angiitis

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Urgent: Look for deep (i.e., internal cerebral) vein or dural sinus occlusion!
If not venous occlusion, consider
- Could the lesion be a DVA?
- Are there prominent cortical vessels as well?
- Is there associated cortical abnormality?

Helpful Clues for Common Diagnoses

Developmental Venous Anomaly
- Enlarged medullary veins
- Drains into single dominant transcortical vein
- Empties into dural sinus or deep ependymal vein
- Solitary unless blue rubber bleb nevus syndrome
- Hemorrhage rare unless associated with cavernous malformation
Arteriovenous Malformation
- Parenchymal nidus, prominent cortical vessels
- Enlarged medullary veins less common
- Deep (subependymal) drainage associated with ↑ hemorrhage risk
- On T1 C+ small AVMs may appear as focal “blush” & draining vein

Helpful Clues for Less Common Diagnoses

Sturge-Weber Syndrome
- Facial hemangioma ipsilateral to leptomeningeal (pial) angiomatosis
- Paucity of normal cortical venous drainage causes chronic venous ischemia
- NECT: Cortical Ca++, atrophy
- CECT/T1 C+ MR
  - Enhancing pial angioma
  - Enlarged medullary veins
  - Enlarged choroid plexus ipsilateral to malformation common
- FLAIR MR: “Ivy sign” of ↑ sulcal signal
Thrombosis, Deep Cerebral Venous
- Usually affects both internal cerebral veins (ICVs) ± vein of Galen (VOG), straight sinus (SS)
- Initial findings may be subtle!
- NECT
  - Hyperdense ICVs ± VOG, SS
  - Hypodense thalami, basal ganglia, ± deep white matter
  - ± Petechial hemorrhages
- CECT
  - “Empty delta sign” if clotted SS, venous confluence
  - May see irregular “shaggy” enhancement around ventricles from engorged medullary veins
- MR
  - T1: Deep veins iso- to hyperintense
  - T2: Hypointense clot may mimic “flow voids”
  - T2/FLAIR: Bilateral basal ganglia, thalami hyperintensities
  - T2* (GRE/SWI): Best sequence; clots “bloom”
  - T1 C+: Deep medullary veins may enlarge, enhance
- DSA
  - Absent ICVs ± nonfilling of VOG, SS
Thrombosis, Dural Sinus
- Chronic superior sagittal sinus occlusion → medullary, ependymal veins enlarge as collateral venous drainage
- Can mimic blue rubber bleb nevus syndrome
Dural A-V Fistula
- Higher Cognard grades (IIB and above)
  - Enlarged cortical > > medullary veins
  - Increased flow voids near or in dural venous sinus
Glioblastoma Multiforme
- GBM, other malignant gliomas may develop necrosis, prominent neovascularity
- Draining deep white matter (medullary, ependymal) veins may become very prominent
Intracranial Hypotension
- Orthostatic headaches
- Look for “sagging” floor of 3rd on sagittal, tonsillar herniation
- Passive dural venous congestion common; medullary/deep ependymal vein enlargement less common

Helpful Clues for Rare Diagnoses

Capillary Telangiectasia
- Large capillary telangiectasia (typically > 1 cm) may have prominent central draining vein
- Best seen on T1 C+ scan
- Becomes hypointense on T2* (GRE/SWI) images
Blue Rubber Bleb Nevus Syndrome
- Multiple cutaneous (bluish venous “blebs”), GI hemangiomas
- Diverse CNS vascular malformations, venous variants common
  - Multiple DVAs classic
  - Variant: Sinus pericranii & multiple DVAs
Dural Venous Sinus Stenosis
- Patients often have undiagnosed source of severe chronic recurrent headaches
- Increased collateral flow, venous prominence, variable ↑ ICP
Vein of Galen Malformation
- Infant/child with dilated VOG
- Enlarged ICVs, ependymal veins > > medullary veins
Demyelinating Disease, NOS
- Fulminant demyelinating disease
  - Causes acute perivenular inflammation
  - Increased blood flow, loss of normal BBB
- MS, ADEM, acute necrotizing/hemorrhagic leukoencephalopathy variants
- Enhancement of deep medullary veins may be very prominent
Lymphoma, Intravascular (Angiocentric)
- Clinical presentation
  - Stroke-like symptoms
  - Less common: Dementia, progressive mental status decline
- Intravascular tumor plugs ± extension into perivascular spaces
- Punctate, linear enhancing foci
Encephalitis (Miscellaneous)
- Parenchymal T2/FLAIR abnormality ± mild-moderate enhancement
Granulomatous Angiitis
- Enhancing foci ± mass effect
- May have striking deep perivenular enhancement