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Table of Contents    
Year : 2020  |  Volume : 68  |  Issue : 5  |  Page : 1238-1241

Spinal Epidural Venous Plexus Enlargement as a Cause of Neurologic Symptoms: Vascular Anatomy and MRI Findings

1 Second Department of Clinical Radiology, Medical University of Warsaw, Warsaw, Poland
2 Department of Neurosurgery, Medical University of Warsaw, Warsaw, Poland
3 Department of Neurology, Medical University of Warsaw, Warsaw, Poland

Date of Web Publication27-Oct-2020

Correspondence Address:
Dr. Edyta Maj
Second Department of Clinical Radiology, Medical University of Warsaw, Ul. Banacha 1A, 02-097 Warsaw
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0028-3886.294546

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 » Abstract 

Pathology of the spinal venous system, unlike that of the spinal arterial system, is rarely considered as a possible cause of clinical symptoms. As the imaging features of the spinal venous anatomy and its diseases are not well-known, related pathologies may be overlooked or misdiagnosed. The major noninvasive technique enabling optimal visualization of spinal venous plexuses is magnetic resonance imaging (MRI). We report MRI findings from three cases of spinal venous plexus engorgement of different etiologies that resulted in neurologic symptoms, including radiculopathy and/or back pain. These cases are discussed in the context of the relevant anatomic and pathophysiologic background.

Keywords: Disc herniation, epidural plexus, inferior vena cava agenesis, intracranial hypotension, magnetic resonance imaging
Key Message: In patients with lumbar back pain and/or radiculopathy, spinal epidural venous plexus enlargement is an under-recognized cause of neurologic symptoms that should be considered in the differential diagnosis. Accurate diagnosis requires spinal MRI, supported by systemic vein assessment or brain MRI if required.

How to cite this article:
Wnuk E, Maj E, Dziedzic T, Podlecka.Piętowska A. Spinal Epidural Venous Plexus Enlargement as a Cause of Neurologic Symptoms: Vascular Anatomy and MRI Findings. Neurol India 2020;68:1238-41

How to cite this URL:
Wnuk E, Maj E, Dziedzic T, Podlecka.Piętowska A. Spinal Epidural Venous Plexus Enlargement as a Cause of Neurologic Symptoms: Vascular Anatomy and MRI Findings. Neurol India [serial online] 2020 [cited 2021 Sep 17];68:1238-41. Available from:

In the differential diagnosis of radiculopathy and/or back pain, the most frequent etiologies include intervertebral disc herniation, followed by hematoma, tumor, and abscess.[1],[2] Epidural venous plexus dilation is an uncommon cause of these symptoms, and it is rarely reported in the literature.[1],[3] As pathological imaging features of the spinal venous system—unlike those of the spinal arterial system—are not well-known, vascular lesions within the epidural space are often overlooked or misdiagnosed. Here, we present imaging findings from three patients with neurologic symptoms caused by epidural venous engorgement of different etiologies.

 » Cases Top

Case 1

A 45-year-old woman was admitted to the neurosurgery department with radiculopathy and severe lumbar pain. Lumbosacral magnetic resonance imaging (MRI) revealed a small, right-sided epidural lesion of mixed-signal intensity on T1-weighted images (T1WIs) and T2WIs, with heterogeneous contrast enhancement, located at the L2–L3 level [Figure 1]. The lesion was diagnosed by neurosurgeons as a disc herniation with slight disc fragment migration, although a radiologist suggested the presence of a coexisting epidural varix. During surgery, a congested and dilated epidural vein compressing the right L2 nerve roots was discovered, which caused massive and persistent bleeding. Slight disc protrusion was also observed. Hemostasis was successfully achieved with thermocoagulation, resulting in the reduction of vein volume and decompression of the dural sac and nerve roots.
Figure 1: Case 1. Lumbar spine MRI showing mixed T1 and T2 signal mass in the anterior epidural space (arrows; a,b and d), with heterogeneous contrast enhancement (arrows; c and e) corresponding to the epidural varix

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Case 2

A 43-year-old woman presented with a prolonged history of lumbar pain and radiculopathy, which were aggravated by activity and alleviated by rest. Lower limb varices were also observed. Lumbosacral MRI revealed numerous serpentine T1- and T2-hypointense lesions located epidurally within the spinal canal and around the vertebral column [Figure 2]. The lesions were diagnosed as dilated spinal venous plexuses. As the cause of the dilation was unclear, a computed tomography (CT) angiography of the abdominal vessels was performed, revealing inferior vena cava agenesis and extensive collateral circulation through the paravertebral veins and spinal venous plexuses [Figure 3]. Further follow-up was recommended.
Figure 2: Case 2 Lumbar spine MRI: Sagittal T2WIs showing longitudinal serpentine flow voids located laterally along the length of the lumbar spine (arrows; a and b) and axial T2-weighed image with flow voids in the anterior epidural space (arrows; c)

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Figure 3: Case 2 axial contrast-enhanced abdominal CT images showing lack of inferior vena cava in the typical location, with collateral drainage pathways through dilated ascending lumbar veins (arrow; a) and a dilated internal venous plexus (arrows; b)

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Case 3

A 43-year-old woman was admitted with suspected multiple sclerosis (MS). The diagnosis was confirmed by a lumbar puncture and brain MRI. On the second day after the procedure, the patient developed a postural headache and thoracic back pain. Thoracic spinal MRI revealed longitudinal T1- and T2-hypointense lesions located extradurally within the spinal canal [Figure 4] a and [Figure 4]b. The primary diagnosis was postpuncture hematoma; however, there had been no complications during lumbar puncture and the cerebrospinal fluid (CSF) was clear. In addition, the brain MRI revealed subtle thickening and enhancement of the pachymeninges and a slight downward shift of the cerebellar tonsils [Figure 5]. Ultimately, a diagnosis of postpuncture intracranial hypotension syndrome with engorged epidural veins was established. After 7 days of conservative treatment, the symptoms subsided and the epidural lesions were absent on follow-up spinal MRI [Figure 4] c and [Figure 4]d.
Figure 4: Case 3 thoracic postpuncture MRI showing heterogeneous signal intensity in the posterior epidural space on T1WI (a) and T2WI (b) images (arrows), and the same examination performed a week later (c and d) with normalization of the signal intensity

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Figure 5: Case 3 a brain MRI showing features of intracranial hypotension--subtle thickening and enhancement of the pachymeninges

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 » Discussion Top

The venous drainage of the spine and spinal cord is complicated and extremely variable in its anatomy. It can be divided into intradural (intrinsic and extrinsic) and extradural components.[4]

Intradural system

The intrinsic venous system is radially arranged within the spinal cord and drains into the sulcal veins (dorsal and ventral). The extrinsic system located at the level of the spinal pia includes the pial venous plexus, longitudinally oriented venous system, and radiculomedullary (radicular) veins. The pial collectors receive the sulcal veins and drain into the posterior and anterior median veins. The extrinsic system communicates with the epidural system via radicomedullary veins, which receive blood from anterior and posterior median veins and drain into external venous plexus. A unique zigzag course of those veins prevents reflux from the epidural veins into intradural veins.[5]

Extradural system

The extradural system called the vertebral venous plexus (Batson plexus) is an extensive network of valveless veins running throughout the spine. It is divided into the following three sections:

  1. The internal vertebral venous plexuses (anterior and posterior) situated extradurally within the spinal canal
  2. The external vertebral venous plexuses (anterior and posterior) surrounding the vertebral column
  3. The basivertebral veins running horizontally within the vertebrae.[6]

The internal and external vertebral venous plexuses connect at the level of the intervertebral foramen.[5] Finally, this system drains into the inferior vena cava, azygos vein, and pelvic veins. The vertebral venous plexuses also connect via anastomoses with the intracranial venous system and the veins of the scalp, skull, and face, as well as the sacral, pelvic, and prostatic venous plexuses. Spinal venous drainage depends on gravity, body position, and intrathoracic and intraabdominal pressure during phases of the respiratory cycle.[7] The venous outflow from the epidural to extraspinal venous compartment is strictly unidirectional. This is maintained by the functional venous valves, although no such valves exist morphologicaly either in the epidural venous plexus/radicular veins. The epidural plexuses also participate in CSF reabsorption through arachnoid granulations within the spinal nerve roots.[7]

First reported in the 1940s,[8] the lumbar epidural varices occur with an estimated current incidence of 1.2%.[9] The mechanism of their formation has not yet been established. The diagnosis of enlarged venous plexuses may be hindered by the subsidence of symptoms and normalization of the vein diameter in the supine position in patients with normal intracavitary pressure.

Disc herniation is a local factor that may contribute to venous varix formation by causing compression and endothelial injury, leading to thrombotic venous occlusion, as shown in our first case.[1] Hanley et al.[10] divided epidural varices into the following three types based on the MRI findings:

  1. Thrombotic dilated epidural veins
  2. Epidural vein dilation without thrombosis
  3. Submembranous epidurally contained hematoma.

As the T1- and T2-signal intensity in thrombotic lesions is affected by the age of the thrombus, whereas the signal in disc herniation is affected by hydration, lumbar epidural varices can mimic lumbar disc herniation on MRI.

Venous varices in epidural space are occasioned also by varied vascular anomalies, malformations, and vascular tumors. In such circumstances, not only is there single varix visible on imaging but most likely there are also extensive arterialized venous lakes, such as in epidural arteriovenous fistulas (AVFs).[11]

Increased intrathoracic or intra-abdominal pressure caused by large masses (e.g., tumors, lymphadenopathy, etc.) or pregnancy can obstruct the inferior vena cava.[3] Other causes of varices include systemic factors, such as vascular anomalies; thrombosis of the iliac, superior, or inferior vena cava; Budd–Chiari syndrome;[12] intracranial hypotension; and portal hypertension. In our second case, numerous multilevel serpentine varices within and around the spinal canal were considered highly likely to be a part of a more extensive vascular pathology. CT angiography revealed inferior vena cava agenesis with the formation of collateral pathways and dilation of epidural plexuses, resulting in intermittent compression of the spinal nerves.

Our third case illustrates a spinal manifestation of postlumbar puncture intracranial hypotension syndrome, which typically presents with postural headaches, but can also cause back pain. The MRI revealed dilated epidural plexuses and dural thickening and enhancement. According to the Monro–Kellie doctrine, epidural venous plexus engorgement in such cases results from decreased CSF volume.

 » Conclusion Top

In patients with back pain or radiculopathy of unclear etiology, venous plexus engorgement should be considered as a potential cause of neurologic symptoms. A spinal MRI is crucial for correct diagnosis. If necessary, detailed diagnostic imaging with systemic vein assessment and brain visualization should be performed. In many cases, a tailored spinal angiography allows to fully understand the vascular abnormality. Accurate diagnosis prevents unnecessary treatment and surgical complications.[13],[14]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.


The formatting and language assistance were provided by Proper Medical Writing Sp. z o.o., Warsaw, Poland.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

 » References Top

Zimmerman GA, Weingarten K, Lavyne MH. Symptomatic lumbar epidural varices. J Neurosurg 1994;80:914-8.  Back to cited text no. 1
Wong CH, Thng PL, Thoo FL, Low CO. Symptomatic spinal epidural varices presenting with nerve impingement. Spine (Phila Pa 1976) 2003;28:E347-50.  Back to cited text no. 2
Paksoy Y, Gormus N. Epidural venous plexus enlargements presenting with radiculopathy and back pain in patients with inferior vena cava obstruction or occlusion. Spine (Phila Pa 1976) 2004;29:2419-24.  Back to cited text no. 3
Griessenauer CJ, Raborn J, Foreman P, Shoja MM, Loukas M, Tubbs RS. Venous drainage of the spine and spinal cord: A comprehensive review of its history, embryology, anatomy, physiology, and pathology. Clin Anat 2015;28:75-87.  Back to cited text no. 4
Santillan A, Nacarino V, Greenberg E, Riina HA, Gobin YP, Patsalides A. Vascular anatomy of the spinal cord. J Neurointerv Surg 2012;4:67-74.  Back to cited text no. 5
Groen RJM, Du Toit DF, Phillips FM, Hoogland PVJM, Kuizenga K, Coppes MH, et al. Anatomical and pathological considerations in percutaneous vertebroplasty and kyphoplasty: A reappraisal of the vertebral venous system. Spine (Phila Pa 1976) 2004;29:1465-71.  Back to cited text no. 6
Lasjaunias P, Berenstein A. No Title. In: Surgical Neuroangiography. Functional Vascular Anatomy of Brain, Spinal Cord and Spine. Berlin: Springer-Verlag; 1990.  Back to cited text no. 7
Cohen I. Extradural varix simulating herniated nucleus pulposus. J Mt Sinai Hosp 1941;8:136-8.  Back to cited text no. 8
Endres S. Epidural varicosis as a possible cause of radicular pain: A case report. J Med Case Rep 2011;5:537.  Back to cited text no. 9
Hanley EN Jr, Howard BH, Brigham CD, Chapman TM, Guilford WB CJ. Lumbar epidural varix as a cause of radiculopathy. Spine (Phila Pa 1976) 1994;19:2122-6.  Back to cited text no. 10
Krings T, Mull M, Bostroem A, Otto J, Hans FJ, Thron A. Spinal epidural arteriovenous fistula with perimedullary drainage. Case report and pathomechanical considerations. J Neurosurg Spine 2006;5:353-8  Back to cited text no. 11
Bozkurt G, Çil B, Akbay A, Türk CÇ, Palaoǧlu S. Intractable radicular and low back pain secondary inferior vena cava stenosis associated with Budd-Chiari syndrome: Endovascular treatment with cava stenting-Case report and review of the literature. Spine(Phila Pa 1976) 2006;31:E383-6.  Back to cited text no. 12
Kansal R, Mahore A, Kukreja S. Cervical intradural disc herniation and cerebrospinal fluid leak. Neurol India 2011;59:447-50.  Back to cited text no. 13
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Mahapatra AK, Gupta PK, Pawar SJ, Sharma RR. Sudden bilateral foot drop: an unusual presentation of lumbar disc prolapse. Neurol India 2003;51:71-2.  Back to cited text no. 14
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  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


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