Thoracic spinal stenosis

Introduction to thoracic spinal stenosis In spinal stenosis, thoracic spinal stenosis is far less common than lumbar and cervical vertebrae. However, in recent years, with the development of diagnostic techniques and the improvement of the level of understanding, and the secondary cases are increasing with the aging of the population, the number of confirmed cases is gradually increasing, which should be paid attention to. basic knowledge The proportion of illness: 0.001% Susceptible people: more common in middle-aged men Mode of infection: non-infectious Complications: paraplegia

Causes of thoracic spinal stenosis

(1) Causes of the disease

The disease is more common in middle-aged men, and its etiology mainly comes from the comprehensive factors of developmental thoracic spinal stenosis and acquired degeneration.

(two) pathogenesis

It can be seen from the pathological changes that the bone and fibrous tissues that make up the posterior wall and posterior wall of the thoracic spine (articular processes) are thickened to varying degrees, so that the spinal canal is occupied and the spinal canal is narrowed, and the spinal cord is compressed. In the case of multiple vertebrae and thoracic spinal stenosis, the degree of stenosis in different parts of each vertebral segment is not uniform. The upper part of the above articular process is the heaviest, and the lower part of the articular process is cohesive and occupying into the spinal canal. Less, compression of the spinal cord is lighter, multi-vertebral cases show bee-like or candied haw-like compression (also known as bead-like indentation), MRI and myelography can clearly show the shape of this stenosis.

In addition to the above-mentioned pathological changes of thoracic spinal stenosis degeneration, it can also be found that the intervertebral space is narrowed, and the anterior border of the vertebral body, the lateral margin and the posterior margin have osteophytes formed, and protrude into the spinal canal, which aggravates the compression of the spinal cord.

In addition, thoracic ossification of posterior longitudinal ligament (TOPLL) can also cause thoracic spinal stenosis, which is characterized by thickened and ossified posterior longitudinal ligaments can be several millimeters thick and protrude in the direction of the spinal canal Compression of the spinal cord can be a single section or multiple vertebrae.

Spinal skeletal fluorosis can also cause thoracic spinal stenosis, patients have a long history of drinking high fluoride water, blood fluoride, increased urinary fluoride, blood calcium, urinary calcium, alkaline phosphatase is also increased, and bone changes can be found during examination Hard, as well as ligament degeneration and ossification, can cause extensive, severe spinal stenosis, X-ray film can help the diagnosis and differential diagnosis because it can show the increase of spinal bone density.

The primary congenital thoracic spinal stenosis cases are rare. The pathological anatomy shows that the pedicle is short and thick, and the anteroposterior diameter (sagittal diameter) of the spinal canal is narrow. In this case, the spinal cord can adapt to it when young, and adulthood Mild thoracic spinal canal degeneration or other factors causing thoracic spine injury can constitute the inducement of compression of the spinal cord, thus causing symptoms, and the symptoms are heavier and difficult to treat.

Thoracic spinal stenosis prevention

Early detection and early treatment, there is no effective preventive measures.

Thoracic spinal stenosis complications Complications

In severe cases, you can have a paraplegia in a short time.

Symptoms of thoracic spinal canal stenosis Common symptoms Spinal cord compression kyphosis lumbar spinal stenosis chest tightness back pain bloating paraplegia dyspnea dyspnea urinary incontinence

1. General symptoms The age of onset of thoracic spinal canal stenosis is mostly in middle age. The most common site is the lower thoracic vertebrae, which is mainly located in the 7th to 11th thoracic segments, but it can also be encountered in the upper thoracic segment and even the chest 1 and 2 segments.

The disease develops slowly. At first, it is characterized by lower limb numbness, weakness, coldness, stiffness and inflexibility. Both lower limbs can be diagnosed at the same time. It can also have symptoms on one side of the lower limb and then involve the lower limb on the other side. About half of the patients have an interval. Sexual squatting, after a certain distance, the symptoms are aggravated. You need to bend over or kneel to rest for a while before you can walk. The heavier ones are standing and walking unsteadily. They need to hold a crutches or walk on the wall. In severe cases, they have paraplegia. Tightness or belt sensation, chest tightness, bloating, such as high lesions and severe breathing difficulties, half of patients have low back pain, sometimes for several years, but only 1/4 of patients with leg pain, and The pain is not serious, the dysfunction of the bowel and bladder appears later, mainly to solve the problem of urinary incontinence. Urinary incontinence is rare. Once the patient is ill, the patient is progressively aggravated. The remission period is short and short, and the speed of the disease is different. Paraplegia occurs in the month.

2. Physical examination can be found in most patients with gait gait, slow walking, more deformity of the spine, occasional mild hunchback, lateral curvature, increased muscle tension of lower limbs, weakened muscles, hyperreflexia of knee and ankle, and ,, Babinski (Babinski) sign, Oppenheim (Oppenheim) sign, Gordon (Gordon) sign, Chaddock sign positive, such as spinal stenosis plane is very low, while When there is a thoracolumbar stenosis or nerve root damage, it can be soft sputum, that is, low muscle tone, pathological reflex negative; abdominal wall reflex and cremaster reflex weakened or disappeared; chest and lower limbs feel reduced or disappeared, chest skin The sensory segmental distribution is obvious. Accurate positioning examination helps to determine the upper boundary of spinal canal stenosis. Some patients have obvious tenderness of the thoracic vertebrae, and the range of tenderness is large. There are spine and sputum pain and radiation pain, accompanied by leg pain. Leg lift is limited.

3. The clinical classification of thoracic spinal stenosis according to the pathology of thoracic spinal stenosis, including the different planes of stenosis and the different pressures mainly from the direction, the treatment methods are also different, in order to guide the treatment, choose the right Treatment methods, it is necessary to clinically classify thoracic spinal stenosis.

(1) Single vertebra joint type: The pathological changes of spinal stenosis are limited to one intervertebral and facet joint, paraplegic plane, X-ray joint hypertrophy, and other changes in myelography, CT examination, etc., all in the same plane, this type About 1/3 of cases of thoracic spinal stenosis.

(2) Multi-vertebral joint type: The pathological changes of thoracic spinal canal stenosis involve multiple vertebral segments, among which 5-7 vertebrae are mostly, accounting for 1/3 of the whole group. The clinical paraplegia plane of this group is mostly The upper boundary of the stenosis segment, the total obstruction of the myelography is mostly in the lower boundary of the stenosis segment, and in the case of incomplete obstruction, the multiple vertebral stenosis is shown, and the total number of vertebral segments in the stenosis segment is determined mainly based on the X-ray lateral supraorbital process. The number of vertebral segments of hypertrophic hyperplasia into the spinal canal, or the lower boundary of the angiographic complete obstruction, and the number of vertebral segments calculated by the upper plane of the paraplegia plane. CT and MRI examinations can show the stenosis, but the price is expensive.

(3) Jump type: only 1 case in this group, there are 3 vertebral stenosis in the upper thoracic vertebra, no stenosis in the middle 2 vertebral segments, and 3 vertebral stenosis in the lower chest, ie chest 2 ~ 4 and chest 8 stenosis , in the thoracic vertebrae, paraplegia in the upper thoracic vertebrae, incomplete paralysis; lower stenosis is more serious, paraplegia is also heavier, myelography shows incomplete obstruction, the total length of spinal stenosis is determined due to the upper thoracic X-ray Clear and mainly based on CT examination, from the surgical decompression situation, the upper thoracic CT examination has an illusion, which shows that the stenosis is narrower than the actual, due to the inclination of the projection angle.

In addition, some cases have combined with thoracic disc herniation or ossification of the posterior longitudinal ligament, and some scholars recommend it as another two types.

Examination of thoracic spinal stenosis

Others such as blood cell sedimentation rate, rheumatoid factor, serum alkaline phosphatase, blood calcium, blood phosphorus, fluoride check normal, these tests have differential diagnosis, blood glucose should be routinely checked, urine sugar, sometimes due to ossification of the posterior longitudinal ligament With diabetes, untreated can increase the risk of surgery.

1. Thoracic X-ray examination X-ray film can show different degrees of degenerative signs, the range of which varies, vertebral bone hyperplasia can be very wide, or only 1 to 2 knots. The pedicle is short and thick. Most of the posterior joints showed hypertrophy, cohesion, and superior articular process; the lamina was thickened, the interlaminar space was narrowed, and sometimes the posterior joint space and lamina were blurred, the density was increased, and some plain films showed narrowing of the intervertebral space. A few cases have anterior longitudinal ligament ossification, intervertebral disc calcification, intraspinal calcification or intraspinal free body, in which the hypertrophic hyperplasia of the articular process can be found on the lateral radiograph, which is an important basis for the diagnosis of this disease.

Another prominent feature on the X-ray film is ossification of the ligamentum flavum and ossification of the posterior longitudinal ligament. The vertebral space is narrowed or blurred on the anteroposterior slice, and the density is increased. Lateral slices, especially the tomogram can be displayed. The posterior plane of the lamina is formed by the posterior wall of the spinal canal and forms a triangular bone shadow that occupies into the spinal canal. The light is obtuse. The upper and lower lamina are ossified to the middle, and the intermediate density is low. The weight is similar to the equilateral triangle. High, close to the density of the joint, when the ligament of the ligamentum flavum is several, the posterior wall of the spinal canal is large jagged, the "sawtooth" tip is opposite to the intervertebral space, and the spinal canal is severely stenotic here. X-ray plain film of about half of the patients There are signs of ossification of the posterior longitudinal ligament. The intervertebral space and the posterior margin of the vertebral body have longitudinal sacral occlusion into the spinal canal. The ossification of the ligamentum flavum and the posterior longitudinal ligament can occur in the thoracic vertebrae of each segment, but the lower the rate, the higher the incidence And the severity of the lesion is also greater.

In addition, individual patients can show spinal deformity on the X-ray film, including round-back deformity, spinal cord segmentation, spine cracking, spinous process bifurcation and lateral bending deformity, etc., and cervical and lumbar X-ray films sometimes have degenerative signs. And ossification of the posterior longitudinal ligament, ligamentum flavum, ligament or anterior longitudinal ligament.

2. CT examination CT examination is crucial for the diagnosis and localization of the disease, but the location should be accurate, the scope should be appropriate, otherwise it is easy to miss diagnosis, CT examination can clearly show the degree of thoracic spinal stenosis and the changes of the wall of the spinal canal, vertebra Posterior wall hyperplasia, ossification of the posterior longitudinal ligament, shortening of the pedicle, thickening of the lamina, thickening of the ligamentum flavum and ossification can reduce the sagittal diameter of the spinal canal; pedicle thickening and cohesion The transverse diameter becomes shorter; the posterior articular hyperplasia hypertrophy and the joint capsule are thickened, and the ossification makes the spinal canal be triangular or clover-shaped, but avoiding the illusion during the examination, the CT scan should be perpendicular to the long axis of the spinal canal, especially For multi-segment scanning, if it is not perpendicular to the long axis of the spinal canal and is slightly inclined, the sagittal diameter of the spinal canal is narrower than the actual situation.

3. Other inspections

(1) Quaker test and laboratory tests: Quebec test can be performed first in lumbar puncture, most of them are incomplete obstruction or complete obstruction, a small number of patients have no obstruction, cerebrospinal fluid examination, protein content is mostly increased, cell count occasionally increases Glucose and chloride levels were normal, and cytology was normal. Most of the tests were performed simultaneously with myelography.

(2) myelography: myelography can determine the location and extent of stenosis, provide more reliable information for surgical treatment, often use lumbar puncture retrograde angiography, head low foot high to observe the flow of contrast agent, only show the vertebra when completely obstructed The lower boundary of the tube is narrow, the brush is often on the positive position, or the contrast agent is completely obstructed after rising a short distance from one side or both sides; the lateral position is a bird's beak, which often shows that the main compression comes from the back or the front, not complete. Obstruction can show the whole process of stenosis, the compression site is a segmental filling defect, the symptoms are mild or the symptoms of one side of the lower extremity are severe, positive, lateral observation or when the film is difficult to find the lesion, from the left or right anterior oblique position or Left or right posterior oblique level observation or projection can show the posterior lateral or anterior lateral filling defect, that is, the lesion site, cerebellar medullary puncture can also be used as appropriate.

(3) Magnetic resonance examination: This is a non-invasive examination. The current trend of replacing myelography shows that the spinal cord signal is clear, and it can be observed whether the spinal cord is under pressure and whether there is internal change, so as to correlate with the internal spinal cord lesion or tumor. Identification, the change of thoracic spinal stenosis on MRI is: longitudinal section imaging can be seen in the posterior longitudinal ligament ossification, ligamentum flavum and spinal cord anterior or posterior gap shrinkage or even disappear, in the presence of disc herniation, it can also show the prominent site compression spinal cord; In the facet imaging, hypertrophy of the joint protrusion and thickening of the ligamentum flavum can be seen, but it is not as clear as CT examination.

(4) Examination of cerebral cortical evoked potential (CEP): Stimulation of the posterior or posterior tibial nerves of the lower extremities, scalp reception, in cases of incomplete paraplegia or complete paraplegia, CEP changes, the peak amplitude decreases and disappears, and the incubation period is prolonged. After laminectomy, CEP showed peak recovery and paraplegia improved. Therefore, CEP can be used not only for preoperative examination of spinal cord injury, but also for the appearance of postoperative CEP peaks, indicating that the spinal cord can recover better.

Diagnosis and diagnosis of thoracic spinal stenosis

Diagnostic criteria

The diagnosis of this disease is not very difficult. When patients with paraplegia of the lower extremity are treated, thoracic spinal canal stenosis should be considered. The diagnosis of this disease is mainly based on the following points:

1. The general symptoms of patients are mostly middle-aged people. There is no clear cause of lower extremity numbness, weakness, stiffness and inflexibility, such as early sputum symptoms, which are chronic progressive and can be aggravated by mild trauma.

2. Clear X-ray film shows degeneration and hyperplasia of the thoracic vertebrae. Special attention should be paid to the presence or absence of joint protuberance hyperplasia on the lateral radiograph, hypertrophy, protrusion into the spinal canal, and presence of thoracic ligamentum flavum (OYL) and/or on the lateral tomographic slice. Thoracic posterior longitudinal ligament ossification (OPLL), and exclude spinal trauma and destructive lesions.

3. CT examination showed that the joint hypertrophy protruded into the spinal canal, the pedicle was short, and the OYL or OPLL caused the spinal canal stenosis.

4. MRI examination showed spinal stenosis and spinal cord compression.

5. Myelography showed incomplete obstruction or complete obstruction. Incomplete obstruction showed segmental stenosis changes, compression of the articular process and/or OYL from the posterior hypertrophy, or ossification of the posterior longitudinal ligament.

Differential diagnosis

1. (simple) thoracic disc herniation clinical symptoms and thoracic spinal stenosis are basically similar, but the incidence is fast, mostly in an acute state, but X-ray, CT and MRI and other examinations, easy to identify.

2. Syringomyelia is more common in young people, and it occurs in the neck and upper thoracic segments. It develops slowly and has a long course of disease. It has obvious and long-lasting sensory separation, pain, temperature loss, tactile and deep sensory preservation, subarachnoid space. No obstruction, cerebrospinal fluid protein content is generally normal, MRI examination showed lesions in the spinal cord.

3. Lateral sclerosis is mainly characterized by more severe upper motor neuron and lower motor neuron damage symptoms, but no sensory disturbance.

4. The symptoms and signs of patients with thoracic disc herniation are similar to those of thoracic spinal stenosis, but the clinical manifestations are variable, the incidence is more urgent, often sudden, no typical syndrome, CT myelography and MR examination Conducive to the identification of the two, it is generally not difficult to make a correct diagnosis.

5. In patients with intraspinal tumors, the symptoms of progressive spinal cord compression, lumbar puncture examination of cerebrospinal fluid, can be found that the increase in protein content is much more obvious than patients with thoracic spinal stenosis, often more than 1000mg / L, through the spinal cord Special forms of angiography (such as inverted cup, fusiform, etc.) and CT myelography, magnetic resonance examination can often make a definite diagnosis. In addition, patients with thoracic metastatic tumors have poor general condition and may find primary lesions.

6. Other thoracic spinal stenosis needs to be differentiated from traumatic epidural hematoma, unilateral posterior articular process fracture, arachnoid cyst, thoracic tuberculosis, spinal arachnoiditis and spinal cord disease caused by poisoning.

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