Spinal vascular malformation

Introduction to spinal vascular malformation Spinal vascular malformations are less common, the most common manifestations are subarachnoid hemorrhage or spinal cord hemorrhage. Spinal vascular malformations can occur in any segment of the spinal cord, but the most common are the cervical segments and cones. basic knowledge Sickness ratio: 0.0012% Susceptible people: 40-55 years old Mode of infection: non-infectious Complications: Subarachnoid hemorrhage

Cause of spinal vascular malformation

What is the cause of spinal vascular malformation?

(1) Causes of the disease

Spinal vascular malformation is a congenital lesion, which is based on pathological anatomy, with arterial or venous malformation as the main lesion. In the past, the pathophysiological effects of the vein were emphasized. On the basis of magnetic resonance and selective spinal angiography, the combination was general. Pathological findings, spinal cord vascular malformations are now divided into four main types.

(two) pathogenesis

1. Type I is a type of dural arteriovenous malformation. Arteriovenous malformation is located in the dura mater, usually involving the nerve root sleeve or thoracolumbar spinal canal posterior lateral dura mater, located in the nerve hole, dural arteriovenous malformation artery Supplying the dura branch of the segmental arteries derived from the spine, supplying nerve roots and dura mater, the lower blood flow in the dura through the lesion, the venous return to the dura, and then back to the coronary vein of the spinal cord, this The vein is located on the dorsolateral side of the spinal cord without a venous valve. Therefore, arteriovenous fistula is formed between the segmental artery of the spine and the recurrent vein of the spinal cord. This iliac crest also communicates with the posterior and posterior lateral coronary venous fistula. Traffic is also formed between the posterior and posterolateral coronary venous plexus. The blood flow of the coronary venous plexus flows upward to the occipital foramen. The 15% arteriovenous stenosis of the segmental artery supplies the anterior spinal artery or the posterior spinal artery. One nourishes the arteries, but there are more than two nourishing arteries. Anson and Spetzler further classify type I into subtype Ia as a single nourishing artery according to the number of nourishing arteries. Ib is a nourishing artery. Pulse, which is usually at one or two adjacent segments, the average static pressure of the dural arteriovenous fistula is about 74% of the systemic arterial pressure, and hemodynamic evidence shows: type I dural arteriovenous malformation The pathophysiology of the disorder is mainly due to the increase of venous pressure, which is characterized by coronary venous congestion, expansion, followed by compression of the spinal cord, but this spinal nerve dysfunction is reversible damage.

2. Type II is a vascular globular malformation with an arteriovenous vascular mass in the marrow. These lesions are often found in the cervical spinal cord, but can also occur in any part of the thoracolumbar region. Its characteristics are shown as high blood in angiography. Flow and sparse venous return vessels, often with venous tumors and varicose veins.

3. Type III spinal vascular malformation was originally called "immature malformation". It is characterized by high blood flow and extensive and complex dynamic and venous anatomy. The lesion can occupy the entire spinal cord, invade the dura mater, and even extend to the vertebral body and Paravertebral tissue.

4. Type IV spinal vascular malformation is located in the epidural-extraspinal region. A branch of the anterior spinal artery is a nourishing artery of arteriovenous malformation, and then refluxed to the extramedullary vein of varying sizes, arteriovenous fistula and its reflux. The vein is located outside the spinal cord, and the lesion is not in the spinal cord. Such lesions are usually located at the thoracolumbar junction. Anson and Spetzler further classify type IV into subtypes: IVa is relatively small, extramedullary arteriovenous fistula is supplied by a single nourishing artery, usually Located on the ventral side and extending to the conic, IVb type more than one nourishing artery, usually from the anterior spinal artery and multiple nourishing arteries derived from the posterior spinal artery, the blood flow through these lesions is greater than the blood flow through the IVa type, IVc It is characterized by multiple supply arteries connected with sputum. The venous blood flow of the lesions is often very large. The ventral and ventral sides of the thoracolumbar spinal canal often have dilated varicose veins.

Type II, III, and IV spinal vascular malformations, originally belonging to the intradural vascular malformation, in addition to the above type 4, there are still cavernous vascular malformations.

5. Cavernous vascular malformation cavernous vascular malformation can occur in the form of a single lesion or in the form of a part of the cranial spinal cavernous hemangioma. These low blood flow lesions are caused by stratified blood vessels or multiple segments within the spinal cord parenchyma. The vascular channel is composed of intra-root canal hemorrhage or compression symptoms. Cavernous hemangioma can occur in the entire central nervous system. These lesions are composed of some vascular blood vessels with no obvious elastin or smooth muscle wall. These thin-walled pipes Lined with endothelial cells, often with the appearance of old bleeding, there is no visible distribution of normal spinal cord or brain parenchyma between the vessel walls.

Spinal vascular malformation prevention

How should spinal vascular malformation be prevented?

There are no major problems, mainly early detection of early treatment, better recovery of the patient's body.

Spinal vascular malformation complications Complications subarachnoid hemorrhage

What diseases can be complicated by spinal vascular malformations?

Spinal vascular malformations may be associated with subarachnoid hemorrhage.

Symptoms of spinal vascular malformation Common symptoms Motor dysfunction Extracranial headache Thoracic and lumbar back or hip... Congestive sphincter dysfunction Sensory hypersensitivity Sensory gluteal muscle atrophy Limb growth, excessive thickening

What are the manifestations of spinal vascular malformations and how to diagnose them?

According to the location of the spinal cord vascular malformation in the epidural and epidural areas, the clinical manifestations are different. The epidural spinal vascular malformation belongs to type I, and the intradural vascular malformation is divided into intramedullary and extramedullary, and the classification belongs to II, III. Type IV, including spongy vascular malformations.

1. Type I clinical manifestations of spinal dural arteriovenous malformation more men than women, male to female ratio of 4:1, the average age of patients is 40 to 50 years old, lesions mostly in the thoracolumbar segment, no obvious family morbidity, population Statistics show that spinal dural arteriovenous malformations may be acquired diseases, which may be related to traumatic factors.

Pain is the most common symptom of patients with spinal arteriovenous malformation. Pain in the back or hip of the thoracolumbar region may be the main symptom. Sometimes the patient may have radicular pain. Aminoff and Logue report that 42% of patients complain of pain a pain as their main symptom. 33% of patients have sensory disturbances rather than pain. Some patients often feel hypersensitivity in the vicinity of the acne-producing area of the acupuncture-sensing area, with a lack of light touch and positional sensation.

One-third of patients with spinal dural arteriovenous malformations have motor dysfunction. These patients usually have mixed dysfunction of upper motor neurons and lower motor neurons associated with the lumbosacral spinal cord, gluteal and gastrocnemius. Atrophy often combines the reflexes of the lower extremities, physical labor, standing for a long time and various postures such as bending over, bending, stretching or flexing can aggravate the symptoms of the veins.

Subarachnoid hemorrhage is rare in patients with spinal dural arteriovenous malformations. Acute necrotizing myelopathy may cause sudden paralysis (Foix-Alajouaine syndrome), which may be caused by sudden reflux venous thrombosis.

One of the typical medical history of patients with spinal dural arteriovenous malformation is a progressive development of mixed sputum with upper motor neurons and lower motor neurons, combined with pain, sensory disturbances, gluteal muscle atrophy and middle-aged men. Sphincter dysfunction, although arteriovenous fistula may be above or below the level of the lumbosacral region, symptoms are often associated with the lumbosacral spinal cord, 80% of patients may be slowly progressing spinal cord disease, less than 10% to 15% of patients are severe Spinal cord dysfunction, acute diagnosis, diagnosis of spinal dural arteriovenous malformation is often delayed, only 1/3 of patients diagnose within 1 year, and about 2/3 of patients diagnose after 3 years of symptoms .

2. Type II, III clinical manifestations of spinal cord vascular malformations occurring in the dura include type II, III, and IV, with type II (spheroidal vascular malformations) and type III (immature or extensive vascular malformations) located in the spinal cord.

Intramedullary lesions account for 10% to 15% of all spinal vascular malformations. Compared with spinal dural arteriovenous malformations, intramedullary lesions are similar in gender distribution, intramedullary lesions can also occur in young patients, and foreign studies report 75%. Patients with intramedullary lesions are younger than 40 years old, 46% of lesions occur in the cervical spinal cord, and 44% occur in the thoracolumbar spinal cord.

The clinical manifestations of patients with intramedullary arteriovenous malformations are significantly different from those of dural arteriovenous malformations. Intramedullary and subarachnoid hemorrhage often occurs in patients with intramedullary arteriovenous malformations, with or without acute neurological dysfunction, 76% Patients have had bleeding at a certain time, 24% of patients have neurological dysfunction due to hemorrhage, intramedullary hemorrhage seems to be more common in cervical venous malformation, and some patients show progressive weakness, sensory disturbance, sphincter dysfunction And impotence, often with intramedullary hemorrhage, about 20% of patients with intramedullary arteriovenous malformations can occur intramedullary aneurysms, these spinal aneurysms are often located in the main nourishing blood vessels supplying intramedullary arteriovenous malformations, lesions in the middle thoracic segment Patients have a worse prognosis than patients with other lesions, which may be related to less collateral vessels in the segment. Patients with lesions in the cervical segment have a better prognosis.

3. Type IV clinical manifestations Type IV lesions are rare, and Barrow and colleagues report that type IV lesions account for 17% of spinal cord vascular malformations treated at the medical center.

Patients with type IV lesions are usually younger than patients with type I disease and often develop symptoms before the age of 40. In the Barrow study, half of the arteriovenous malformations were type IVa, but Mourier and colleagues noted 63% of patients. For type IVc malformations, most patients present with progressive development of myelopathy with pain, weakness, sensory and sphincter dysfunction, or subarachnoid hemorrhage, which is not different between men and women.

The spinal cord dysfunction in these patients is similar to type I lesions. The vascular congestion is due to an increase in intradural venous pressure. The compression of IVc lesions significantly affects the function of the spinal cord and nerve roots. Barrow speculates that some of these lesions The patient may have acquired the day after tomorrow. There have been several reports of intraspinal surgery and/or cranial spine trauma before the onset of symptoms, suggesting that in some patients, the onset of the disease is acquired and other patients are congenital.

4. Clinical manifestations of cavernous vascular malformations These lesions are estimated to account for 5% to 12% of all spinal vascular malformations. They may be familial or multiple, and the incidence of cavernous vascular malformations in the central nervous system is 0.2% to 0.4. %, it is estimated that 3% to 5% of cerebrospinal spongiform vascular malformations occur in the spinal canal.

The average age of patients with spongiform vascular malformation is 35 years old. Patients may present with acute neurological dysfunction, which is often associated with hemorrhage. Due to the acute expansion of blood vessels, blood is often emitted. Other patients can be progressive and progressive. Neurological dysfunction, and a tendency to improve neurological function after the onset of more severe dysfunction, repeated bleeding may occur, and deterioration of neurological function after hemorrhage may last for hours or days.

The diagnosis of spinal vascular malformation, in addition to medical history, physical signs, is mainly imaging diagnosis.

1. Type I diagnosis abnormal blood vessels can be seen on MRI, but in the lumbosacral spinal cord, abnormal T2-weighted signals are often the only abnormal findings. The diagnosis of spinal dural arteriovenous malformation is often more sensitive and specific in CTM. Sexuality, compared with no contrast, a large, curly-shaped blood vessel can be seen on the dorsolateral side of the spinal cord on the enhanced CT. The patient should be placed in the supine position during the angiography to check the venous return in the dura, the dura mater. Intensive CT in arteriovenous malformations is very rare in patients with complete obstruction. It can be distinguished from intramedullary tumors on MRI. MRI can show blood flow phenomenon, which is consistent with the performance of tortuous and dilated veins around the spinal cord. MRI in patients with arteriovenous malformations is often normal. If the patient's MRI results are normal and he is highly suspected of having a spinal dural arteriovenous malformation, myelography should be performed. If the angiography is normal, spinal arteriography is usually not necessary.

Selective spinal angiography is the method of definitive diagnosis when intensive CT or MRI is indicated. In the process of angiography, the anterior spinal artery is identifiable, and the blood supply associated with dural arteriovenous malformation is also acceptable. It is determined that all the nourishing arteries of the lesion should be clearly defined to prevent recurrence of postoperative arteriovenous fistula. Sometimes, the dura venous fistula near the skull may have spinal venous traffic and may cause spinal venous hypertension and myelopathy. In these patients, in order to diagnose such uncommon diseases, it is necessary to perform selective carotid angiography with selective external carotid artery and internal carotid artery injection.

2. Type II, III diagnosis of intramedullary arteriovenous malformation lesions can be identified by the airflow signs on the T1-weighted image. In the T2-weighted images, abnormal signals appear in the spinal cord, and the signs of airflow around the spinal cord suggest the surrounding spinal cord lesions. In part, spinal angiography is necessary to determine intramedullary lesions, but it is not always helpful in distinguishing between type II and type III lesions, selective aortic cannulation and vertebral artery, carotid artery and iliac crest Intubation angiography is necessary to determine the nourishing arteries supplied by intramedullary lesions. The dorsal and ventral root vessels supply arteriovenous malformations through the anterior spinal cord and posterior spinal cord branches. The anterior spinal artery may terminate in the intramedullary arteriovenous Malformation or still possible as a segment of blood vessels, can determine spinal aneurysms and varicose veins.

3. Type IV diagnostic magnetic resonance imaging sometimes shows large signs of airflow around the spinal cord, mainly characterized by dilated epidural venous return, which often occurs at the thoracolumbar junction, near the cone and at the proximal end of the horse's tail, selective Angiography can show the distribution of the anterior spinal artery to the arteriovenous fistula and the reflux vein.

4. The radiographic image of cavernous vascular malformation for the diagnosis of cavernous vascular malformation is characteristic. The center of a mixed signal intensity can be seen on T1 weighted, T2 weighted and proton density imaging. This center can be seen on the T1 weighting. Surrounded by a low-density hemosiderin ring, these lesions are usually not significantly enhanced. Continuous magnetic resonance imaging is performed on patients with fluent symptoms. The volume of the lesion may vary. Myelography and angiography are rare, usually Can not make a diagnosis of cavernous vascular malformation, sometimes it is necessary to perform spinal angiography, the difference between spongy vascular malformation and other types of vascular malformations.

Examination of spinal vascular malformations

What tests should be done for spinal vascular malformations?

Abnormal blood vessel rupture may be associated with subarachnoid hemorrhage, and bloody cerebrospinal fluid may be found during lumbar puncture.

1. Plain vertebral hemangioma can be seen in the vertebral body with grid-like loose, intramedullary vascular malformation can be seen widening of the spinal canal and pedicle spacing, similar to intramedullary tumors, Cobb syndrome can be seen vertebral and pedicle destruction.

2. Myelography This is the most important first step in the diagnosis of spinal cord lesions. It not only provides an indirect image of the spinal cord itself, but also displays a direct image of the pericardial vessels. A non-ionic water-soluble contrast agent should be used for angiography. With fewer side effects, it can be well dispersed in the subarachnoid space, fully showing the lesions, and at the same time, it can be absorbed quickly, without affecting the angiography again. If necessary, CT scan or spinal tomography can be added.

(1) normal periarthritis: normal medullary angiograms are often seen in the peri-medullary and post-medullary stenosis, the straight line is the anterior spinal cord, and the curved is the posterior venous spinal cord, mostly located in the thoracic 4-8 segment, orthotopic The needle can be seen in the thoracolumbar region with a needle-like root draining vein.

(2) Myelography of the lesion: thickening of the spinal cord, suggesting intramedullary vascular malformation, venous mass on the surface of the spinal cord can cause obstruction, vertebral hemangioma can cause epidural compression, in addition, visible around the spinal cord or in the cone of the spinal canal An enlarged or distorted blood vessel shadow.

3. CT scan after CT imaging to confirm the lesion segment, and then CT scan, will have a more comprehensive understanding of the lesion, plain scan can detect intramedullary hematoma and calcification, intrathecal injection of contrast agent can be seen arachnoid, hard There is an abnormal filling defect in the sub-membrane cavity. After contrast enhancement, it can show abnormal vascular clusters inside and outside the marrow.

4. Magnetic resonance imaging can comprehensively understand the location of intramedullary vascular malformation, the size of vascular mass, the presence or absence of venous thrombosis from sagittal, coronal, and transverse three-dimensional tomographic images, and follow up after surgery or after angiography, gradually replacing Spinal iodine angiography, except for cavernous hemangioma, all types of vascular malformations in the MRI image, showed a distortion of low signal flow phenomenon, distributed in the subarachnoid space or spinal cord, with venous congestion When the spinal cord is enlarged, the signal is strong or weak, the intramedullary cavernous hemangioma appears as a typical "black ring" sign in the T1-weighted image, that is, the middle is a high signal, suggesting the deposition of methemoglobin after hemorrhage. There is a low signal around.

5. Spinal angiography is the only method for the diagnosis and classification of spinal vascular malformations, and it can also provide valuable information for treatment.

Diagnosis and diagnosis of spinal vascular malformation

What diseases are easily confused with spinal vascular malformations?

There are no diseases that need special identification.

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