Venous Congestion Myelopathy¶

Definition¶

Venous congestion myelopathy (Foix-Alajouanine syndrome in its most severe form) results from impaired venous drainage of the spinal cord, most commonly caused by a spinal dural arteriovenous fistula. The elevated venous pressure reduces the arteriovenous pressure gradient, causing cord edema, ischemia, and progressive neurological deterioration.

Etiology¶

Spinal dural arteriovenous fistula — The most common cause
Perimedullary arteriovenous fistula
Spinal venous thrombosis — Rare
Epidural venous compression — From tumors or other mass lesions

Imaging Findings¶

MRI¶

Diffuse cord T2 hyperintensity — Extending over multiple segments, typically centromedullary, most prominent in the lower thoracic cord and conus
Flow voids on the cord surface — Dilated perimedullary veins from the underlying vascular malformation
Cord expansion — Mild, from edema
Enhancement — Patchy cord enhancement from breakdown of the blood-cord barrier
Conus involvement — Commonly affected

Clinical Pearl

Venous congestion myelopathy is a treatable cause of progressive paraplegia. The MRI pattern of diffuse cord edema with perimedullary flow voids should trigger urgent evaluation for a dural AVF with spinal angiography. Early treatment (embolization or surgical disconnection) can halt progression and allow recovery, while delayed diagnosis leads to irreversible cord damage.

Key Points¶

Most commonly caused by spinal dural AVF
Diffuse cord T2 hyperintensity with perimedullary flow voids is the classic MRI pattern
Treatable if diagnosed early — irreversible if delayed
Spinal angiography confirms the underlying vascular malformation
Foix-Alajouanine syndrome is the severe, end-stage manifestation with cord necrosis

References¶

Krings T, Geibprasert S. Spinal dural arteriovenous fistulas. AJNR Am J Neuroradiol. 2009;30(4):639-648. https://www.ajnr.org/content/30/4/639
Hurst RW, Grossman RI. Peripheral spinal cord hypointensity on T2-weighted MR images: a reliable imaging sign of venous hypertensive myelopathy. AJNR Am J Neuroradiol. 2000;21(4):781-786. https://pubmed.ncbi.nlm.nih.gov/10782797/
Jeng Y, Chen DYT, Hsu HL, Huang YL, Chen CJ, Tseng YC. Spinal dural arteriovenous fistula: imaging features and its mimics. Korean J Radiol. 2015;16(5):1119-1131. https://pmc.ncbi.nlm.nih.gov/articles/PMC4559784/
Sadighi N, Tajmalzai A, Salahshour F. Spinal arteriovenous malformations causing Foix-Alajouanine syndrome, a case report and review of the literature. Radiol Case Rep. 2021;16(8):2187-2191. https://pmc.ncbi.nlm.nih.gov/articles/PMC8213980/
Spinal dural arteriovenous fistula. Radiopaedia.org. https://radiopaedia.org/articles/spinal-dural-arteriovenous-fistula
Foix-Alajouanine syndrome. Radiopaedia.org. https://radiopaedia.org/articles/foix-alajouanine-syndrome
Expert Panel on Neurological Imaging; Agarwal V, Shah LM, Parsons MS, et al. ACR Appropriateness Criteria® Myelopathy: 2021 Update. J Am Coll Radiol. 2021;18(5S):S73-S82. https://www.jacr.org/article/S1546-1440(21)00116-2/fulltext