secondary adhesive arachnoiditis
Introduction
Introduction to secondary adhesion arachnoiditis The arachnoid membrane is a thin film composed of colloidal, elastic fibers and reticular fibers that adheres to the inside of the dura mater and forms a narrow subdural space between the two. The arachnoid forms many trabeculae that attach to the soft membrane of the outer layer of the spinal cord. The pores between these trabeculae connect to form a wide subarachnoid space in which cerebrospinal fluid flows. The arachnoid membrane belongs to the serosal tissue. When encountering various mechanical, physical, chemical and bacterial stimulating factors, the inflammatory reaction and repair process similar to the serosal tissue appears, thus forming arachnoiditis. There are many causes of secondary adhesive arachnoiditis, including physical factors, chemical factors, biological factors and many other unclear reasons. basic knowledge The proportion of illness: the incidence rate is about 0.004%-0.008% Susceptible people: no special people Mode of infection: non-infectious Complications:
Cause
The cause of secondary adhesion arachnoiditis
(1) Causes of the disease
There are many causes of this disease, including physical factors, chemical factors, biological factors and many other unclear reasons, but the most common reasons for clinically the following are:
Myelography
Because gas angiography is not clear enough and its stimulation of the meninges can cause severe headaches, chemical contrast agents are often used clinically, but both water-soluble and oil-based can cause arachnoiditis. Haughton used to have 80 macaques. This conclusion was reached in the experiment. Therefore, for many years, scholars have been looking for a diagnostic contrast agent that is non-toxic, harmless and can be quickly expelled from the human body, but it has not yet achieved its goal. In recent years, foreign countries have vigorously Recommended for Amipaque and Omnipaque, these non-iodic aqueous solutions are small in irritancy, but when they exceed a certain concentration, they can also cause inflammatory reactions. Therefore, for patients who need angiography, the pros and cons must be weighed and should not be abused to reduce arachnoiditis. The incidence of morbidity, especially in today's widely used MRI technology, can generally be waived unless traditionally necessary.
2. Spinal injury
With the development of industry, agriculture, and the modernization and popularization of transportation tools, especially the rapid development of highways, spinal injuries are bound to increase accordingly. In developed capitalist countries, about 60 out of every 100,000 inhabitants belong to Cases of spasticity with spinal cord injury, the number of cases of spinal injury is more than several times, and the lumbar puncture (including subarachnoid block) and the popularity of spinal surgery constitute the damage factors of the spinal canal. The rupture, hemorrhage, and even the slightest damage of the pia mater and dura mater can also cause arachnoiditis. For cases of spinal injury, accurate X-ray technique or CT, MRI and other auxiliary diagnosis should be used as much as possible. Possible reduction of intraspinal angiography.
3. Compression factors
Mainly refers to disc herniation and spinal stenosis, long-term compression of nerve roots and spinal cord local edema due to blood circulation and nervous tissue dysfunction, cellulose exudation and adhesion formation, especially the arachnoid membrane at the root canal is most likely to occur Adhesion, therefore, for such cases with a long course of disease, attention should be paid to the presence or absence of arachnoiditis. In the case of evidence, the subarachnoid space can be removed at the same time as decompression.
4. Infection of the spinal canal or adjacent areas
Inflammatory lesions near the spinal canal are extensive and severe, and the prognosis is poor, but it is extremely rare. Therefore, those suspected of having intraspinal infections, especially after spinal surgery, must use large-spectrum antibiotics in large doses on the other hand. Should also pay attention to inflammation caused by subacute or low-infection, should be treated as soon as possible.
(two) pathogenesis
The arachnoid membrane consists of a layer of membrane composed of colloidal, elastic fibers and reticular fibers, which adheres to the inside of the dura mater. The narrow subdural space is formed between the two. The arachnoid forms many trabeculae and is connected to the spinal cord. Above the soft membrane of the layer, the pores between the trabeculae are connected to form a cerebrospinal fluid circulation, a wide subarachnoid space, and the arachnoid membrane belongs to the serosal tissue when encountering various mechanical, physical, chemical and bacterial stimuli. In the case of factors, the same inflammatory reaction and repair process as serosal tissue occurs, thereby forming arachnoiditis.
The pathological features of different stages of arachnoiditis: the arachnoid itself lacks blood supply. In the early stage, when the subarachnoid space is caused by various stimuli, the lesion originates from the vascular rich soft spinal membrane and with the infiltration of cellulose. A series of pathophysiological changes such as edema and hyperemia on the pia mater develop into a pathological process centered on arachnoid adhesions, which eventually leads to nerve involvement and loss of function. Generally, this process can be divided into the following four phases (figure 1):
Initial stage
In the early stage, it is also called the period of soft meningitis. The current stage of the lesion is mainly the spinal cord, the nerve root or the outer layer of the horse's tail. The soft meninges are swollen, congested, and there is a little fibroblast proliferation and cellulose precipitation, sedimentation. Reversibility, if handled properly, can return to normal.
2. Medium term
This period, also known as adhesive arachnoid period, due to increased proliferation of fibroblasts, cellulose deposition also increased, and formed a film, resulting in adhesion between the arachnoid and nerve tissue.
3. Late
This period is based on the former, there is a large amount of collagen fiber between the arachnoid and the soft meninges, and even between the dura mater, except for the membrane-like adhesions, with a strip-like band and the subarachnoid space It is divided into multiple capsules so that it is completely or largely occluded. At this time, the nerve tissue and the dura mater can be deformed by the pulling of the band.
Late stage
This period is the end stage of the disease, also known as the neurodegenerative stage. The scar formed by the late stage of the band is wrapped and pulled by the spinal cord or cauda equina, and the direct compression of the cyst causes the hypoxia of the nerve tissue. In addition, mechanical compression and blood supply are gradually interrupted, and finally the nerve tissue is progressively atrophic. In this period, various treatments, including surgical release, are difficult to achieve, and the risk of surgery is large.
Although the disease has primary and secondary points, the former is rare, accounting for only about 5%. In fact, most of the cases in this group are due to other reasons that have not yet been discovered.
Prevention
Secondary adhesion arachnoiditis prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.
Complication
Secondary adhesive arachnoiditis complications Complications
Severe cases can be complicated by convulsions.
Symptom
Secondary adhesions of arachnoiditis common symptoms, sensory disturbances, hyperesthesia, muscle atrophy, gait, unstable, intervertebral disc, ant colony
History
Refers to previous history of intraspinal angiography, puncture, anesthesia, surgery and trauma. It should also be noted that long-term chronic intraspinal pressure-induced lesions are also a common cause of this disease, especially spinal canal stenosis and intervertebral disc prolapse. And vertebral instability.
2. Symptoms
(1) Root pain: It is the early symptom, mainly caused by the adhesion of the adhesion to the spinal nerve root. Since the root sleeve is the earliest part of arachnoiditis, root pain is also manifested first.
(2) Sensory disturbance: more or less with root pain at the same time or later, including ant walking, feeling allergic, feeling dull and numb, etc., rarely feeling completely lost.
(3) dyskinesia: mainly for weakened muscles, severe cases may have spastic paralysis, more common in patients with longer course.
(4) Others: including reduced reflex, muscle atrophy and gait instability, etc., can be found in the physical examination.
3. X-ray inspection
Generally, there are no positive findings in the plain film, but those who have previously performed iodized oil angiography may have a candle-like tear or cystic shadow on the X-ray film; those with this syndrome can basically confirm the diagnosis, but they have not previously performed iodized oil. It is not advisable to emphasize myelography to confirm the diagnosis.
4. MRI examination
The adhesive band in the subarachnoid space can show a lighter shadow on the MRI cross-sectional scan image, especially for those with longer disease duration, which is helpful for diagnosis.
5. Lumbar puncture
The initial pressure is lower, the cerebrospinal fluid is mostly yellow or normal color, the protein is increased more, and lymphocytosis is accompanied. The Quckenstedt test may show partial or complete obstruction.
6. Intraoperative dural sac incision detection judgment According to the above examination, most cases can be diagnosed, and a few are still unclear and have no MRI examination conditions, or the image is not clear, can not make a judgment, you can choose irritating A small contrast agent is used for angiography, but the disease may be performed, for example, because of the primary disease, or may have an indication for surgical exploration. The dura mater may be incision during surgery, and the diagnosis may be observed outside the arachnoid.
Intraoperative dural sac incision exploration indications:
(1) The dura mater has obvious fibrous changes or even contractures.
(2) Although the lamina has been extensively resected, the spinal cord beat has not recovered.
(3) After the epidural adhesion is released, the dural capsule is still deformed.
(4) There is a release of iodized oil.
(5) Intraoperative subarachnoid puncture proved that there was obstruction or the extracted cerebrospinal fluid was pale yellow, and there were partial depressions.
(6) When the dura mater is cut, if the arachnoid opacity is found, thickened, and adhesion has formed, or has been directly fused with the dura mater, the arachnoid lysis is performed.
Examine
Secondary adhesion arachnoiditis examination
1. Lumbar puncture: the initial pressure is lower, the cerebrospinal fluid is more yellow or normal color, the protein is increased more, and accompanied by lymphocytosis, the Quckenstedt test may show partial or complete obstruction.
2. X-ray inspection
Generally, there are no positive findings in the plain film, but those who have previously performed iodized oil angiography may have a candle-like tear or cystic shadow on the X-ray film; those with this syndrome can basically confirm the diagnosis, but they have not previously performed iodized oil. It is not advisable to emphasize myelography to confirm the diagnosis.
3. MRI examination
The adhesive band in the subarachnoid space can show a lighter shadow on the MRI cross-sectional scan image, especially for those with longer disease duration, which is helpful for diagnosis.
Diagnosis
Diagnosis and identification of secondary adhesive arachnoiditis
There are many diseases that need to be differentiated from secondary adhesive arachnoiditis. In addition to causing the primary disease of the disease (due to the principle of treatment, it is not necessary to identify before surgery), it should be differentiated from spinal cord tumors. .
