Primary intramedullary tumor

　　The main factors affecting the pathological changes of spinal cord compression include:

　　1. Related to the location of tumor compression and the nature of the nerve tissue structure:Different spinal cord nerve tissues have different tolerances to pressure: for example, the tumor first stimulates and then causes damage to the nerve roots; gray matter has greater tolerance to tumor compression than white matter; the nerve fibers in the white matter that convey pyramidal tracts and conduct somatosensory and tactile sensations are thicker (diameter 5μm～21μm), while pain fibers are thinner (diameter less than 2μm). After compression, thin fibers have greater tolerance than thick fibers, and recovery is also faster after relief of compression. Generally speaking, at the initial stage of compression, the nerve roots are pulled, the spinal cord is displaced, followed by deformation under pressure, and finally, the spinal cord undergoes degeneration, gradually causing neural dysfunction in the affected tissue.

　　2. The impact of the tumor on the spinal cord blood circulation:After venous compression, venous dilation, congestion, and edema occur; after arterial compression, the blood supply to the area it支配 is insufficient, leading to hypoxia and nutritional disorders, causing spinal cord degeneration and softening, and finally resulting in spinal cord necrosis. In terms of tolerance to ischemia, gray matter is greater than white matter, and fine nerve fibers are greater than coarse nerve fibers. There are reports that the dorsal surface of the spinal cord seen during surgery is blue, the nutrient arteries are enlarged, and the draining veins are significantly absent, but a small number of small nutrient arteries can be seen under the microscope.

　　The course of intramedullary tumors generally lasts for more than 1 year. The shortest reported symptom duration is 17 days, and the longest is 12 years. Among them, the average course of intramedullary tumors is 11.6 months, and the average course of extramedullary tumors is 19.2 months.

　　3. The hardness of the tumor is closely related to the degree of harm it causes to the spinal cord:Soft tumors, especially those that grow slowly, allow the spinal cord sufficient time to adjust its blood circulation, develop slowly, have mild symptoms, and recover spinal cord function quickly and completely after surgery. Hard tumors, even if small in size, are prone to embed into the spinal cord, and any movement of the spine can cause the tumor to cause contusions and gliosis to the spinal cord, with most postoperative recoveries not ideal.

　　4. Related to the growth pattern and speed of the tumor:Intramedullary tumors may mainly grow by expansion, while others mainly grow by infiltration. The latter can cause greater damage to the spinal cord. Tumors that grow slowly may have mild symptoms even if the spinal cord is significantly compressed, as the spinal cord still has compensatory ability; conversely, tumors that grow quickly, especially malignant tumors, are prone to cause acute complete transverse myelitis symptoms, necessitating emergency surgery to relieve spinal cord compression. Even a delay of 1 to 2 hours can often result in serious consequences.

　　Complications such as acute 'stroke-like' transverse myelitis syndrome and brainstem damage in intramedullary tumors. After transverse myelitis, the muscles, tissues, and sensory and motor sensations below the injury level all disappear. For patients with long-standing paralysis, muscle atrophy can occur due to the loss of neural nutritional support for muscle tissue, and poor翻身 can cause tissue compression and ischemia, which can also lead to bedsores.

　　1. Staging

　　When the spinal cord is compressed, motor disorders appear before sensory disorders. In addition to the compression of the spinal cord tissue, there may also be circulatory disorders, cerebrospinal fluid dynamics disorder, and concurrent inflammation and adhesion factors. Therefore, the clinical manifestations show diversity and complexity. Generally, the development of extramedullary tumor compression symptoms is divided into three stages:

　　1. Early compression period:Radicular pain.

　　2. Progressive compression period:Brown-Séquard syndrome (Brown-Séquard syndrome).

　　3. Complete compression period of the spinal cord:Transverse spinal cord injury, this classification method is still the basis of current clinical classification.

　　2. Clinical symptoms

　　The clinical symptoms of extramedullary tumors are generally manifested in three stages:

　　1. Cervical spinal nerve stimulation period (radicular pain period)

　　In the early stages of the disease, the main manifestations are stimulatory symptoms of the corresponding structures, with the most common symptom being neuralgia. The pain often spreads along the distribution area of the nerve roots, often presents as paroxysmal pain, and activities such as coughing, sneezing, and straining during defecation can exacerbate the pain. 'Night pain and supine pain' is a relatively characteristic symptom of vertebral canal tumors. In addition, there are also abnormal skin sensations, such as numbness and burning sensation. If the tumor compression comes from the ventral side, it may first manifest as twitching, muscle tremors, and weakness in the muscles innervated by the compressed segment or the segments below it. The initial symptom of vertebral canal tumors in 54% of cases is radicular pain (with neurinomas being the most common, accounting for 60.8% of radicular pain cases), presenting as neck and shoulder pain; 35% present with night pain, and 45.9% present with symptoms of compression on the sensory, motor, and autonomic nervous system below the compressed level.

　　2. Partial compression of the cervical spinal cord

　　As the tumor grows, on the basis of the original symptoms, there are gradual symptoms of compression on the spinal cord conducting bundles, such as compression of the spinothalamic tract, which can lead to decreased or absent pain and temperature sensation below the lesion segment on the contralateral side; compression of the posterior tract can result in decreased deep sensation; involvement of the motor conducting bundle can produce upper motor neuron paralysis below the same-sided lesion segment. Brown-Séquard syndrome is a specific symptom of intramedullary spinal cord tumors within the vertebral canal, but it is often atypical. Ni Bin and others reported 137 cases of intramedullary tumors, with 102 cases (74 cases of extramedullary tumors) with ascending paralysis in the medical history, 10 cases with descending paralysis (8 cases of intramedullary tumors), and 4 cases with Brown-Séquard syndrome.

　　3. Complete compression of the cervical spinal cord

　　The progression of the lesion causes transverse damage to the spinal cord substance, and the pathological changes of the spinal cord also gradually become irreversible. Below the lesion, there are limb movement, sensory loss, autonomic nervous system dysfunction, and dysfunctions of urination and defecation, indicating the late stage of paraplegia.

　　There are no effective preventive measures for this disease.

　　If intraspinal tumors can be detected early and treated with surgery early, most patients can achieve good clinical outcomes. Some patients with large intraspinal tumors or located at high cervical levels may die due to respiratory failure after surgery, or may recur after a period of time. As for the recovery of spinal cord nerve function, it is related to the degree and duration of spinal cord compression in the patient.

　　1. Spinal canal puncture and cerebrospinal fluid examination

　　Dynamics of cerebrospinal fluid and increased protein content are important for the early diagnosis of intraspinal tumors. When suspected of having an intraspinal tumor, it is recommended to perform Quincke test and cerebrospinal fluid examination as soon as possible. Routine sequential examination of cerebrospinal fluid in patients with intraspinal tumors can show increased cerebrospinal fluid protein content while the cell count is normal. Dynamics examination (i.e., Quincke test) can show partial or complete obstruction.

　　2. X-ray film examination

　　About 30% to 40% of patients can be seen with bone changes. In routine lumbar spine and lateral radiographs, common signs include: enlargement or destruction of intervertebral foramen. Enlargement of the spinal canal, manifested as widening of the distance between the pedicles. Bone changes in the vertebral bodies and appendages, such as vertebral body bone defects, destruction of the pedicle roots. Calcification within the spinal canal is occasionally seen in a few meningiomas, teratomas, and hemangioblastomas. Soft tissue shadows around the vertebrae, since most intraspinal tumors are benign, there are often no bone abnormalities in the early X-ray films. Sometimes, only in the late stage, there are indirect signs such as widening of the distance between the pedicle roots, thinning of the cortical bone of the spinal canal wall, and enlargement of the spinal canal. For intramedullary tumors such as dumbbell-shaped vertebrae, there can be enlargement of the intervertebral foramen. X-ray film examination can exclude symptoms of spinal cord compression caused by spinal deformities, tumors, and other reasons, and is still an indispensable routine examination.

　　3. Spinal cord myelography

　　It is one of the effective methods for showing intraspinal space-occupying lesions, and contrast medium such as iodine oil (such as iodobenzene) or iodinated water contrast agent (such as AMIPAQUE or OMNIPAQUE) can be used for cervical spinal cord myelography. Especially, the injection and contrast medium myelography through the cerebellar medullary cistern is easy to diagnose, showing cup-shaped defects or obstructions in the non-intervertebral disc plane. Literature reports 180 cases of neurilemmoma, among which 150 cases of contrast findings: 106 cases showed cup-shaped filling defects, 18 cases showed horizontal cross-sectional, 7 cases showed oblique needle-like, 5 cases showed bell-shaped, and 4 cases showed bead-like. OMNIPAQUE is the second-generation non-ionic iodinated water-soluble contrast agent, with clear contrast, safety, and reliability. It can determine spinal cord tumors according to the expansion, displacement, and subarachnoid cavity obstruction of the spinal cord. Combined with increased cerebrospinal fluid protein, a correct diagnosis can be made. Due to adhesions and other reasons, the obstructive plane is not necessarily representative of the true boundary of the tumor. Ni Bin et al. reported that in 137 cases of intraspinal tumors, 4 cases had an obstructive plane that differed from the surgical exploration results by 1/4 to 1 vertebral body. Unless a second contrast study is performed, a single contrast study can only determine the upper or lower limit of the tumor, and it cannot be determined based on the shape of the obstruction and the extent of bone involvement whether the tumor is benign or malignant. However, myelography can determine the location of the lesion, and then perform CT scanning or MRI examination to obtain more information about the tumor lesions.

　　4. CT examination

　　CT scanning has sensitive density resolution, which can clearly show the tissue structures such as the spinal cord and nerve roots in cross-sections. It can clearly show the soft tissue shadow of the tumor, which is helpful for diagnosing intraspinal tumors, which is not available in traditional imaging methods. However, when CT scanning is performed, especially as the first imaging examination, it is necessary to locate according to clinical signs. There is a possibility of missing the tumor location due to inaccurate localization. CT can basically determine the segmental distribution and extent of intraspinal tumors, but it is difficult to distinguish them from the normal spinal cord substance. CTM (CT with myelography) can show the entire relationship between the spinal cord and the tumor and distinguish intramedullary tumors from syringomyelia.

　　5. MRI examination

　　Magnetic Resonance Imaging (MRI) is an ideal examination method with no side effects of ionizing radiation. It can observe the spinal cord in three dimensions, showing the boundary between tumor tissue and normal tissue, the location, size, and extent of the tumor, and directly outline the tumor, displaying its longitudinal and transverse extension and its relationship with surrounding tissue structures. It has become the first choice for diagnosing spinal cord tumors. MRI has a unique advantage in distinguishing intramedullary and extramedullary tumors. The MRI imaging of intramedullary tumors shows the spinal cord in that area to be dilated, with different signal intensities in different pulse sequences, which can be distinguished from syringomyelia. Extramedullary tumors can be localized according to their relationship with the dura mater, with a high accuracy rate. MRI sagittal imaging shows the tumor as a clear boundary, long T1, long T2 signal area, but mainly long T1, with a significant enhancement effect. Some may present as cystic changes. Axial imaging shows the cervical spinal cord compressed to one side, with the tumor appearing elliptical or crescent-shaped. For dumbbell-shaped tumors that protrude outward through intervertebral foramina, the continuity of intraspinal and extraspinal tumors can be seen. Since MRI directly performs sagittal imaging, the range of spinal cord examination is larger than that of CT scanning, which is unparalleled by CT. Moreover, MRI can show the size, location, and tissue density of the tumor, especially the application of paramagnetic contrast agent GD-DTPA can clearly show the outline of the tumor. Therefore, MRI is very important for diagnosis and surgical localization, and it is far superior to CT or CTM in this aspect.

　　2. Eat a balanced and reasonable diet, and eat more foods that have an anti-spinal cord tumor effect: oysters, sandworms, chrysanthemum flowers, etc.

　　1. Avoid smoking and drinking, which are absolute taboos for primary liver cancer patients.

　　2. Avoid overeating, greasy foods, and foods that are salted, smoked, roasted, and fried, especially charred and carbonized foods, which are things that primary liver cancer patients need to pay attention to.

　　3. Avoid spicy and刺激性 foods such as scallions, garlic, Sichuan pepper, chili, cinnamon, etc.

　　4. Avoid moldy, pickled vinegar foods, such as moldy peanuts, moldy soybeans, salted fish, pickled vegetables, which all primary liver cancer patients must pay attention to.

　　5. Avoid foods with many bones, rough and hard, sticky and difficult to digest, and foods with rough fibers.

　　6. Patients with primary liver cancer should avoid heavy taste, overly sour, overly sweet, overly salty, cold, hot, and foods with too much gas in their diet.

　　8. Abdominal fluid should avoid foods with high salt and water content.

　　Patients with mild symptoms or spontaneous remission can be treated conservatively, and they should undergo repeated and multiple physical examinations and MRI reviews (note: there is a risk of recurrence and hemorrhagic injury to the spinal cord). However, the only effective treatment is surgical resection of the tumor. Since primary intramedullary tumors are mostly benign, about 3/4 of the cases can be cured by surgical resection. Therefore, efforts should be made to resect intramedullary tumors, even if they cannot be completely removed, partial or large resection should be performed to alleviate or relieve the compression and damage of the tumor on the spinal cord. Once the diagnosis is confirmed, active efforts should be made to create surgical conditions, and timely surgical treatment should be carried out regardless of the degree of spinal cord compression. Surgery has risks, and symptoms can recur. The risk of surgery varies depending on its functional location, and there are fewer postoperative defects in exogenous tumors. Appropriate treatment methods should be chosen. Intraoperative spinal cord evoked potential monitoring can help reduce neurological complications.