Type I spinal vascular malformation
Introduction
Introduction to type I spinal vascular malformation Spinal dural arteriovenous malformations are more common in men, with a male to female ratio of 4 to 8:1. The onset age of this disease is on average about 45 years old. The lesions occur in the thoracolumbar region, and there is no obvious family morbidity. Statistics show that patients with this type are often associated with acquired diseases, which may be related to traumatic factors, but the exact mechanism is still unclear. basic knowledge The proportion of illness: the incidence rate is about 0.003% - 0.005% Susceptible people: no specific people Mode of infection: non-infectious Complications:
Cause
The cause of type I spinal vascular malformation
(1) Causes of the disease
In the dural arteriovenous malformation, the supply of arteries originates from the dura branch of the spinal segmental artery (Fig. 1). In most cases, arteriovenous fistula occurs in the nerve hole on the lateral side of the nerve root sleeve. There is less blood flowing through the lesion in the membrane. The venous return of the lesion to the dura mater and then back to the coronary venous plexus of the spinal cord. About 90% of the lesions occur in the chest 6-12, and about 10% of the cases occur in the dura mater. The arteriovenous stenosis of the segmental artery supplies the anterior spinal artery or the posterior spinal artery. The lesion usually has only one nourishing artery. This is the type I A. When the lesion has two or more blood vessels, it belongs to the type I B. .
(two) pathogenesis
The direction of blood flow in the coronary venous plexus generally flows upward through the occipital foramen into the cranium. Clinically, if Doppler is used to measure blood flow velocity and pressure to detect hemodynamics at the epidural arteriovenous malformation, It can be found that the local blood flow velocity at the end of the diastolic period is improved after the lesion is removed, and the vascular resistance is increased, which is mainly the result of the increase of the venous pressure. In most cases, the average intravenous pressure of the dural arteriovenous fistula It is about 3/4 of the systemic intra-arterial pressure. From the hemodynamic observation, the pathophysiological changes of neurological dysfunction in patients with spinal dural arteriovenous malformation are mainly due to the increase of local venous pressure. As a result, the sudden deterioration of neurological function in such patients is mostly directly related to the rapid congestion of the venous system, and most of them may be reversible.
Prevention
Type I spinal cord vascular malformation prevention
Pay attention to rest, work and rest, life in an orderly manner, and maintaining an optimistic, positive and upward attitude towards life can be of great help in preventing diseases.
Complication
Type I spinal cord vascular malformation complications Complications
Acute necrotizing myelopathy caused by venous thrombosis can be complicated by sudden deafness.
Symptom
Type I spinal vascular malformation symptoms Common symptoms Sphincter dysfunction Thoracic and lumbar back or hip... Gluteal muscle atrophy Vascular malformation Sensory venous venous thrombosis
1. Pain is the most common symptom of patients with arteriovenous malformation of the spinal cord. This type is also the same. The pain in the back or hip of the thoracolumbar region may be the main symptom, and radiculopathy may also occur, which accounts for 40% of the cases. ~50%.
2. Dyskinesia In patients with spinal dural arteriovenous malformations, 30% to 40% are associated with motor dysfunction, which is usually a combination of upper motor neurons and lower motor neurons associated with the lumbosacral spinal cord. Obstacles, clinical examination can be found in the gluteal and gastrocnemius muscles with signs of atrophy, and often combined with lower limb reflexes, physical labor, long standing and various leaning, bending, stretching or flexion and other postures can aggravate the symptoms, this Mainly due to the increase of pressure in the traffic vein caused by spinal epidural arteriovenous malformation, resulting in increased systemic arterial pressure; it can also be considered that the venous congestion is aggravated when standing.
3. About 1/3 of patients with sensory disturbances may have sensory disturbances, manifested as sensation, skin allergies or other abnormalities, and may also be absent from the sense of touch or position.
4. Other symptoms of spinal dural arteriovenous malformation can also occur in patients with subarachnoid hemorrhage, but less common, in addition to acute necrotizing myelopathy caused by venous thrombosis, and may lead to sudden paralysis (Foix Alajouanine syndrome ), this may be due to a sudden reflow of intravenous thrombosis.
Examine
Examination of type I spinal vascular malformation
1. MRI examination showed abnormal blood vessels on MRI films. Abnormal signals on the T2 weighted images of the lumbosacral spinal cord may be the only abnormal findings. MRI can show blood flow phenomenon, which is related to the tortuous dilated vein around the spinal cord. The performance is consistent. If the patient's MRI findings are normal and highly suspected of having the disease, myelography should be performed. If the angiography is normal, spinal angiography is not necessary. MRI can be used to distinguish it from intramedullary tumors.
2. CTM is often more sensitive and specific to the disease. Compared with no contrast agent, a large, curly-shaped blood vessel can be seen on the CTM scan on the dorsolateral side of the spinal cord. The position was performed to check the venous return in the dura mater, and the arteriovenous malformation on the dura was relatively rare in the CTM image.
3. Selective spinal angiography is the most ideal diagnostic method for the diagnosis of the disease. In angiography, the anterior spinal artery is easily identifiable, and the blood supply associated with arteriovenous malformation on the dura can be determined. All the nourishing arteries in the lesion are It should be clear that the postoperative arteriovenous fistula traffic branch recurrence should be prevented.
Diagnosis
Diagnosis and diagnosis of type I spinal vascular malformation
Diagnostic criteria
1. History and clinical features are mainly mixed development of upper motor neurons and lower motor neurons, and can be combined with pain, sensory disturbances, gluteal muscle atrophy and sphincter dysfunction in middle-aged men, regardless of arteriovenous The sputum is above or below the level of the lumbosacral region. Most of the symptoms are related to the lumbosacral spinal cord. 80% of the patients present with slow-developing myelopathy, and about 10% of the patients have acute onset. The disease is easily misdiagnosed. Only 30% of cases were diagnosed within 1 year after onset, and more than half of the patients were diagnosed 2 to 3 years after symptoms appeared.
2. Imaging findings
(1) MRI examination: manifested as abnormal blood vessels on MRI films, abnormal signals on the lumbosacral spinal cord on the chest 2 weighted image may be the only abnormal findings, MRI can show blood flow phenomenon, which is related to the spinal cord The performance of tortuous dilated veins is consistent. If the patient's MRI findings are normal and highly suspected of having this disease, myelography should be performed. If the angiography is normal, spinal angiography is not necessary. MRI findings can be used with intramedullary tumors. Differentiate.
(2) CTM: It is often more sensitive and specific to the disease. Compared with no contrast agent, a large and curly blood vessel can be seen on the CTM scan on the dorsolateral side of the spinal cord. Take the supine position to check the venous return in the dura, and the arteriovenous malformation on the dura is more common in CTM images.
(3) Selective spinal angiography: the most ideal diagnostic method for determining this disease. In angiography, the anterior spinal artery is easily identifiable, and the blood supply associated with arteriovenous malformation on the dura can be determined. The arteries should be clear to prevent recurrence of the arteriovenous fistula traffic branch after surgery.
