Vascular Myelopathy

Disease/Disorder

Definition

Vascular myelopathy (VM) refers to a set of conditions that result in spinal cord injury (SCI) secondary to ischemia or hemorrhage. These conditions result in spinal cord injury by local interruption of blood flow, spinal cord compression by mass effect, steal phenomenon or venous hypertension.

Etiology

Etiologies of VM are most often secondary to tissue infarction caused by spinal cord ischemia (secondary to lack of blood supply) or by hemorrhage. Bleeding can be within the spinal cord (termed hematomyelia) or in the subarachnoid, epidural, and subdural spaces.

Etiologies of Spinal Cord Ischemia

• Periprocedural/ surgical (AAA repair)
• Spontaneous
  • Atherosclerosis
  • Dissection (Aorta, Vertebral Artery)
  • Embolic
    • Fibrocartilage
    • Atheroma
    • Cardioembolic (atrial fibrillation, endocarditis))
    • Infectious (syphilis, Lyme, varicella Zoster, fungal))
  • Vasculitis
  • Hypoperfusion
    • Hypotension
    • Dissection
    • Venous infarction causing congestion.
    • AVM/ AV fistula / cavernous malformations
  • Hypercoagulable (sickle cell, malignancy, DIC, antiphospholipid antibody syndrome, hemophilia, polycythemia vera)/ Bleeding disorder on Willebrand disease, or factor deficiencies
  • Mechanical
    • AVM
    • Disc
    • Tumor
  • Pharmacologic/drugs: cocaine
  • Other: surfers’ myelopathy, radiation induced myelopathy

Etiologies of Spinal Cord Hemorrhage

• Trauma
• Bleeding disorders
• Iatrogenic
  • Anticoagulants
  • Complications of spine surgery, spine injections, procedures
• Vascular malformations
• Vasculitis
• Bleeding of vascular tumor

Epidemiology including risk factors and primary prevention

• Spinal cord injury due to vascular causes is very rare accounting for an estimated 0.3 to 1% of all strokes and 5–8 % of acute myelopathies.¹ Peak incidence of spinal cord infarction is between the sixth and seventh decades.
• Primary spinal cord ischemia is much less common than brain ischemia and affects both sexes equally. Despite its rarity, it is associated with significant mortality and disability.
• Aortic surgery and spinal procedures are the most common etiology for vascular myelopathy. In patients undergoing thoracoabdominal aneurysm repair the incidence of spinal cord ischemia is between 2.5% to 7.3%.² During surgery blood flow to the spinal cord can be compromised for many reasons, including cross-clamping, surgically induced hypotension, and atheromatous emboli.
• Epidural hematomas should be suspected in patients with new neurological symptoms following spine surgery and procedures involving a spinal dural puncture, especially if the patient was anticoagulated or has blood dyscrasias.
• Unmodifiable factors that predispose individuals to vascular insults are cavernous malformations, hemangioblastomas (von Hippel Lindau syndrome) as well as connective tissue disorders affecting the large vessels (Marfan syndrome and Ehlers-Danlos syndrome) and vasculitides. Spinal cord involvement from vasculitis is exceptionally rare. Patients with these conditions usually present with symptoms during early and mid-adulthood. Preventative screening is performed depending on the underlying condition.
• Modifiable factors that affect vascular integrity include Diabetes Mellitus, smoking, hyperlipidemia, and hypertension. These factors can lead to vascular damage, vascular aneurysm, and dissection, which can result in hypoperfusion of the spinal cord. Treatment of these factors is important in disease prevention. In certain conditions, e.g. aortic aneurysm, routine surveillance guides the need and timing of intervention to prevent neurological sequalae.

Patho-anatomy/physiology

• Vascular supply to the spinal cord is supplied by radicular spinal arteries originating from the aorta and vertebral arteries, one anterior spinal artery (ASA), and two posterior spinal arteries (PSAs). 
• The ASA supplies the anterior two-thirds of the spinal cord, while the 2 PSAs supply the posterior cord.
• Vascular supply to the lower thoracic and lumbar region of the cord originates from a single large radicular artery, the artery of Adamkiewicz.
• Paramedian vessels (arising from the ASA) and anastomotic vessels between the ASA and PSA penetrate the cord to supply the gray and white matter.
• Blood flow to the spinal cord is regulated by metabolic demands and perfusion pressure (mean arterial pressure minus intraspinal canal pressure), and it is highest within the gray matter.
• Systemic hypotension or increased intraspinal canal pressure may decrease perfusion and put the cord at risk for ischemia.
• With decreased perfusion pressures, watershed ischemia of the penetrating arteries can occur, often at the thoracic levels.
• Spinal infarction syndromes, including anterior and posterior spinal artery syndromes refer to compromise of the respective arteries and lead to distinct patterns of neurologic presentation.
• The degree and duration of hypotension necessary to produce infarction is poorly understood.
• Venous drainage consists of one anterior and one posterior spinal vein that drain into radicular veins, a paravertebral plexus, and finally into the azygos and pelvic venous systems.
• The spinal veins contain no valves. Therefore, Valsalva and increased intra-abdominal pressure can lead to increased venous pressure and decreased spinal cord perfusion.
• The most common location of spinal cord infarction is the lower thoracic cord.
• Surgery to repair aortic aneurysms can cause either systemic or focal hypotension, leading to spinal cord ischemia. Risks are lower in nonemergent surgeries and endovascular (versus open) surgical approach.
• Other factors that cause spinal cord ischemia include aortic dissection, aortic cross-clamping causing decreased arterial perfusion and increased spinal canal pressure, occlusion of radicular or other intercostal arteries (either by ligation, resection, or embolization). Advanced age and history of cerebrovascular disease are risk factors.
• Spinal cord infarction unrelated to surgical intervention is rare. Causes include systemic hypotension (sepsis, trauma, sympathectomy) arterial dissections, emboli (cardiac and fibrocartilaginous), coagulopathies, vasculitis, surfer’s myelopathy.
• Fibrocartilaginous emboli are caused by the embolization of fragments of the nucleus pulposus, often related to minor trauma, exertion and neck loading.¹ Most cases involve the cervical cord or upper thoracic cord.
• Arteriovenous malformations (AVM) are abnormal connection between arteries and veins without an intervening capillary bed, creating dilated vessels that can lead to high venous pressure and reduced spinal cord perfusion, or hemorrhage into the cord.
• AVMs are typically located on the posterior dural surface of the spinal cord, more commonly in the thoracolumbar and upper thoracic regions.
• Subarachnoid hemorrhage (SAH) may cause symptoms due to irritation within the subarachnoid space or blood dissecting into the spinal cord or along nerve root sheaths.
• Spinal epidural hematomas and spinal subdural hemorrhage cause compressive symptoms because of hematomas within these enclosed spaces.

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

Spinal Cord Infarction

• Most cases of spinal cord infarction present with an acute onset and rapid progression of neurologic deficits. The pattern of deficits depends on arteries involved (see table 1) and level of involvement. Back or radicular pain is often an early sign and may be severe. Lower thoracic and lumbar levels are usually affected, and incomplete paraplegia is more common.
• Ischemia typically affects the anterior spinal artery territory with sparing of the posterior column (vibration and proprioception)
• Patients present with acute flaccid paralysis, loss of sensation, bladder or bowel dysfunction, sexual dysfunction, and reduced reflexes below the level of involvement (though hyperreflexia may later develop).
• Many patients experience significant motor recovery, and the nadir of findings is predictive of long-term outcomes.³

Spinal Cord Hemorrhage

• Spinal cord hemorrhages are classified based on their location: intramedullary, subarachnoid (SAH), subdural, and epidural. The most common causes are trauma, iatrogenic causes, bleeding diatheses and vascular malformation.
• Clinical presentations depend on the acuity, size, and rate of hemorrhagic expansion. Symptoms can occur acutely (minutes to days) or subacutely (days to weeks). In fewer than 5%, they present in a stepwise course over months to years.⁴ The most common presentation of a spinal hemorrhage is acute onset of intense pain and progressive neurological symptoms at and below the hemorrhage.⁵  The severity and distribution of deficits can be variable.
• Vascular Malformations are the most common cause of nontraumatic spinal cord bleeding. They can lead to mass effect, venous congestion and hypertension resulting in reduced spinal cord perfusion and progressive myelopathy. They are classified based on their angioarchitecture and location with type 1 AVM (dural arteriovenous fistula) being the most common type. Clinical presentation is variable, ranging from progressive myelopathy to catastrophic hemorrhage. The most common presentation of a spinal AVM is a slowly progressive myelopathy, which may lead to a diagnostic delay.

Table 1: Vascular Spinal Cord Syndromes

 Specific secondary or associated conditions and complications

• SCI-related complications found in individuals with VM include neurogenic bowel/bladder, sexual dysfunction, pain, urinary tract infection, pressure ulcers, depression, and spasticity.
• Comorbidities for vascular related SCI include hypertension, cardiovascular disease, diabetes mellitus, and atrial fibrillation.

Essentials of Assessment

History

Past medical history may include history of aortic disease, peripheral vascular disease, vasculitis, radiation therapy exposure near the spine, and coagulopathy. The presentation may vary depending on the location and size of the lesion. Symptoms may include motor weakness, sensory or gait abnormalities, pain, paresthesia, and spasticity. Higher lesions can result in respiratory muscle weakness requiring ventilatory support. Autonomic dysfunction may occur as well, often manifested with hypotension, bowel or bladder dysfunction, or sexual dysfunction.^6-8 Specific syndromes are described in table 1.

Pain can be a presenting symptom of spinal cord hemorrhage and infarction Radicular pain may precede or accompany vascular myelopathy, with location varying depending on the level of SCI.^6,7 In cervical lesions, pain is interscapular, radiating to the shoulder. In thoracic lesions, pain can be localized in the chest, whereas, in more caudal lesions, pain may radiate to the abdomen or anterior thighs. In conus lesions, buttock pain may be seen. Severe tearing pain and abnormal distal pulses suggest aortic tear or dissection; however, 5% to 15% are painless, requiring a high degree of suspicion for this diagnosis.

Physical examination

Physical exams should include a comprehensive evaluation of muscle strength, sensation (including sacral), and reflexes. This should include a rectal examination to assess rectal tone and sensation. Physical exams should also assess for possible SCI-related complications such as spasticity, pressure ulcers, contractures. Additional findings as part of the physical exam may include bladder distension (indicating urinary retention), spinal bruit (indicating a spinal AVM), or cutaneous midline angiomas.

The International Standards for Neurologic Classification of SCI (ISNCSCI) exam developed by the American Spinal Injury Association (ASIA) and the International Spinal Cord Society has specific key muscles and sensory points that can be used to classify the neurologic level and completeness of the SCI (ASIA Impairment Scales A through E).

Examination findings often include flaccid paresis and diminished reflexes in acute presentations. Initially, muscle tone is flaccid, but can evolve over time. A lower motor neuron picture can persist depending on the extent of anterior horn cell and cauda equina involvement. Spinal cord infarction usually presents with anterior cord syndrome with preservation of proprioception, vibratory sense and two-point discrimination that are carried by the dorsal column of the spinal cord.  Preservation of strength and reflexes may suggest involvement of posterior spinal artery.⁸ Common findings for specific vascular spinal cord syndromes are listed in table 1.

Functional assessment

It is important to evaluate patients who have neurologic involvement for their ability to perform self-care and mobility tasks. Various functional evaluation measures can be utilized for individuals with SCI, including the Functional Independence Measure (FIM) and WeeFIM (for children), the Spinal Cord Independence Measure (SCIM), and the Walking Index for Spinal Cord Injury.

Laboratory studies

• Complete blood count with platelets may be helpful to address systemic blood loss in patients with hypotension.
• International normalized ratio or prothrombin time and activated partial thromboplastin time may help to exclude coagulopathy.
• Specific lab tests may be done for vasculitic disorders.
• Vascular risk factors may be assessed with lipid panel and hemoglobin A1c.

Imaging

Magnetic resonance imaging (MRI) of the spinal region is the preferred test to confirm the presence and location of ischemia, AVM, hemorrhage, or to rule out other nonvascular etiology.

T2-weighted images are more sensitive for acute ischemic lesions which may show hyperintensity, including characteristic “owl eye” appearance on axial images, and increased diameter of the infarcted cord. Diffusion weighted imaging (DWI) should be incorporated to assess for spinal cord infarction, which will show restricted diffusion in infarcted regions of the spinal cord.^6,8-10

MRI techniques such as magnetic resonance angiography (MRA) allow visualization of flow, better vascular anatomy, and intramedullary pathology, and are a good screening modality, especially for AVM. Spinal angiography remains the diagnostic study of choice for AVM and may be helpful in delineating the size, location, configuration, and blood flow of the malformation. Myelography may also be useful to diagnose AVMs (tortuous vessels on the cord’s surface)

MRI findings consistent with fibrocartilaginous emboli include spinal cord edema with a prolapsed disc space at the corresponding level.

Supplemental assessment tools

With hemorrhagic etiology, lumbar puncture can reveal gross blood, increased opening pressure, and increased protein within the cerebrospinal fluid (CSF)

Early predictions of outcomes

There are many factors that can determine prognosis for patients with vascular myelopathy, but the degree of preoperative impairment is the strongest predictor of outcome. Other important factors that determine outcomes include age, hospital length of stay, and level of injury.^3,11

With ischemic myelopathy, more complete motor/sensory deficits (ASIA Impairment Scale A or B), extensive ischemic MRI changes, loss of bladder function or proprioception loss are associated with a worse prognosis for functional improvement.⁹ In studies of individuals with nontraumatic SCI, older age, higher neurologic level of injury, and greater completeness of injury have also been shown to correlate with poorer outcomes.

Etiology also contributes to overall outcomes. Periprocedural spinal cord infarctions have worse outcomes compared to spontaneous spinal cord infarctions.¹² Acute dissection of the descending aorta is often a catastrophic event and is associated with a high mortality (10% to 50%). Recovery and outcomes of spinal cord vascular malformation depends on the type of malformation. The majority of spinal vascular malformations experience either stabilization or improvement of symptoms following surgical or endovascular treatments, with recovery of motor function occurring more frequently than sensory or sphincteric function. There is a higher likelihood of mortality and severe disability, especially loss of ability to ambulate, if lesions are left untreated.⁵

Environmental

Depending on the neurologic level and completeness of injury, modifications may be needed to enhance functional independence within the home, school, or work environment. These may include adaptive devices, home modifications to ensure accessibility, attendants or aids, bath and toilet equipment, and assistive technology.

Social role and social support system

Given that individuals with vascular-related SCI may be older and with additional comorbidities, family, friends, and social support systems will be very important in allowing for return to independent living.

Rehabilitation Management and Treatments

Available or current treatment guidelines

The treatment of ischemic myelopathy includes supportive care, blood pressure maintenance, reversal of causative factors, such as hypovolemia, and reducing risk of recurrence. Improvement of spinal cord perfusion pressure can sometimes be achieved by vasopressor hemodynamic augmentation. Treatment with thrombolysis has been described in case reports but lacks strong evidence.¹² For ischemia secondary to aortic surgery, several techniques have been studied to reduce the risk of spinal cord ischemia during aortic aneurysm repair, including preoperative spinal angiography, intraoperative evoked potential monitoring, placement of lumbar drains, reimplantation of intercostal arteries, draining of cerebrospinal fluid, epidural cooling, and the use of distal aortic perfusion.^6,9,13 Although these interventions appear to improve outcomes, they have not been studied in a randomized or carefully controlled fashion.

The treatment of dural AVMs includes surgical ligation of the fistula or endovascular embolization (using polyvinyl alcohol beads or cyanoacrylate). Rapidly evolving endovascular procedures and techniques have made them the usual early interventional treatment of choice, although in some cases patients may later require surgery. Focal radiation therapy (using a gamma or cold photon knife) is also a consideration.⁵ Treating spinal cord vascular malformations can prevent future hemorrhage.

Subdural and epidural hemorrhages may require surgical intervention to relieve pressures on the cord. Treatment of spinal subarachnoid hemorrhage consists of bed rest and surgical resection of extramedullary angiomas, if present. In coagulopathy-induced hemorrhage, reversal of the bleeding is important.  Warfarin-induced bleeds can be reversed with Vitamin K; protamine sulfate for heparin-induced bleeds; platelet transfusions for thrombocytopenia; and specific clotting factor concentrates or fresh frozen plasma for clotting factor deficiencies.¹⁴

At different disease stages

• Motor and sensory deficits below the level of injury can lead to functional impairment of mobility (bed, transfer, ambulation, wheelchair) and self-care activities (feeding, grooming, bathing, dressing). Physical and occupational therapy, along with the use of orthoses and assistive/adaptive devices, can help increase independence.
• Impaired sensation and mobility may predispose to pressure ulcers. Patients and caregivers must be educated in pressure relief strategies and routine skin inspection. Pressure mapping along with appropriate mattress and wheelchair cushions may be required.
• Bladder dysfunction (neurogenic bladder) may require a specific program designed to maintain continence, bladder emptying, and reduced incidence of urinary tract infections. Long-term urinary tract assessment may include lab studies, urodynamic testing, renal ultrasound, and urology follow-up.
• Bowel dysfunction (neurogenic bowel) may require a specific bowel program (including medications, diet, timing, positioning, digital stimulation, manual disimpaction, and physical activity designed to maintain continence and reduce constipation and fecal impaction.
• Neuropathic pain is common after SCI, either at or below the level of injury, and may require medications, and non-pharmacological interventions.
• Sexual dysfunction may be present, requiring education and discussion of treatment options.
• Spasticity can be seen following VM. Treatment depends on how much it contributes to discomfort or interferes with function and may include range of motion, positioning, orthotics, medications, intrathecal baclofen pumps, local neuromuscular injections, or surgery.

Coordination of care

Rehabilitation strategies for individuals with VM should focus on a coordinated interdisciplinary team approach to maximize outcomes while minimizing complications.

Patient & family education

Patient and family education are important to manage ongoing medical and functional comorbidities and to prevent secondary SCI-related complications.

Cutting Edge/Emerging and Unique Concepts and Practice

• Monitoring spinal cord perfusion during aortic procedures remains a challenge but Non-invasive near-infrared spectroscopy is gaining popularity in the detection of spinal cord ischemia following aortic aneurysm repair.^13,15 Other promising imaging modalities to assess spinal cord perfusion in-vivo include Phase-contrast X-ray tomography, contrast enhanced ultrasound, and cone beam computed tomography.⁴
• A study performed by Archer et al.² found that SCI can be significantly reduced by using proactive intraoperative and postoperative neuroprotective interventions that prolong spinal cord ischemic tolerance and increase spinal cord perfusion and oxygen delivery.

Gaps in the Evidence-Based Knowledge

• The pathophysiology of spinal stroke is not nearly as well understood as cerebral infarction.
• Specific rehabilitation outcomes after VM have not been studied as often as in those with traumatic SCI.¹¹ Future studies are encouraged to examine differences in complication rates, long-term functional outcomes, and mortality between these two SCI populations because of differences in demographics and comorbidities.

References

1. AbdelRazek MA, Mowla A, Farooq S, Silvestri N, Sawyer R, Wolfe G. Fibrocartilaginous embolism: a comprehensive review of an under-studied cause of spinal cord infarction and proposed diagnostic criteria. J Spinal Cord Med. 2016;39(2):146-54. doi:10.1080/10790268.2015.1116726
2. Acher C, Acher CW, Marks E, Wynn M. Intraoperative neuroprotective interventions prevent spinal cord ischemia and injury in thoracic endovascular aortic repair. J Vasc Surg. Jun 2016;63(6):1458-65. doi:10.1016/j.jvs.2015.12.062
3. Bonavita J, Torre M, Capirossi R, et al. Outcomes Following Ischemic Myelopathies and Traumatic Spinal Injury. Top Spinal Cord Inj Rehabil. Fall 2017;23(4):368-376. doi:10.1310/sci2304-368
4. Bonnet B, Kobeiter H, Pescatori L, et al. Preoperative Spinal Arterial Supply Mapping Using Non-Selective Cone Beam Computed Tomography before Complex Aortic Repair. J Clin Med. Jan 30 2024;13(3)doi:10.3390/jcm13030796
5. Flores BC, Klinger DR, White JA, Batjer HH. Spinal vascular malformations: treatment strategies and outcome. Neurosurg Rev. Jan 2017;40(1):15-28. doi:10.1007/s10143-016-0713-z
6. Takayama H, Patel VI, Willey JZ. 31 – Stroke and Other Vascular Syndromes of the Spinal Cord. In: Grotta JC, Albers GW, Broderick JP, et al, eds. Stroke (Seventh Edition). Elsevier; 2022:466-474.e3.
7. Kumral E, Polat F, Gulluoglu H, Uzunkopru C, Tuncel R, Alpaydin S. Spinal ischaemic stroke: clinical and radiological findings and short-term outcome. Eur J Neurol. Feb 2011;18(2):232-239. doi:10.1111/j.1468-1331.2010.02994.x
8. Lyerly MJ. Spinal Cord Vascular Disease. In: Jankovic J, C. MJ, L. PS, Newman NJ, eds. Bradley and Daroff’s Neurology in Clinical Practice. 8 ed. Elsevier; 2022:chap 69.
9. McEntire CR, Dowd RS, Orru’ E, et al. Acute Myelopathy: Vascular and Infectious Diseases. Neurologic Clinics. 2021/05/01/ 2021;39(2):489-512. doi:https://doi.org/10.1016/j.ncl.2021.01.011
10. Weidauer S, Nichtweiß M, Hattingen E, Berkefeld J. Spinal cord ischemia: aetiology, clinical syndromes and imaging features. Neuroradiology. 2015/03/01 2015;57(3):241-257. doi:10.1007/s00234-014-1464-6
11. Gedde MH, Lilleberg HS, Aßmus J, Gilhus NE, Rekand T. Traumatic vs non-traumatic spinal cord injury: A comparison of primary rehabilitation outcomes and complications during hospitalization. The Journal of Spinal Cord Medicine. 2019/11/02 2019;42(6):695-701. doi:10.1080/10790268.2019.1598698
12. Stenimahitis V, Fletcher-Sandersjoo A, El-Hajj VG, et al. Long-term Outcomes After Periprocedural and Spontaneous Spinal Cord Infarctions: A Population-Based Cohort Study. Neurology. Jul 11 2023;101(2):e114-e124. doi:10.1212/WNL.0000000000207377
13. Khachatryan Z, Haunschild J, von Aspern K, Borger MA, Etz CD. Ischemic Spinal Cord Injury-Experimental Evidence and Evolution of Protective Measures. Ann Thorac Surg. May 2022;113(5):1692-1702. doi:10.1016/j.athoracsur.2020.12.028
14. Shaban A, Moritani T, Al Kasab S, Sheharyar A, Limaye KS, Adams HP, Jr. Spinal Cord Hemorrhage. J Stroke Cerebrovasc Dis. Jun 2018;27(6):1435-1446. doi:10.1016/j.jstrokecerebrovasdis.2018.02.014
15. Vanpeteghem CM, Van de Moortel LMM, De Hert SG, Moerman AT. Assessment of Spinal Cord Ischemia With Near-Infrared Spectroscopy: Myth or Reality? J Cardiothorac Vasc Anesth. Mar 2020;34(3):791-796. doi:10.1053/j.jvca.2019.06.041

Original Version of the Topic

William O. McKinley, MD. Vascular Myelopathy. 9/20/2013

Previous Revision(s) of the Topic

William O. McKinley, MD. Vascular Myelopathy. 8/16/2016

Kareen Velez, MD. Vascular Myelopathy. 5/12/2021

Author Disclosures

Marika Hess, MD
Nothing to Disclose

Brijend Shrestha, MD
Nothing to Disclose