Intramedullary Tumor

　　The etiology is not yet clear, and may be the result of the single or interactive effects of genetic, physical, chemical, and biological factors. The spinal cord is located within the vertebral canal,呈cylindrical, with a total length of about 42-45cm. From top to bottom, it is divided into 31 pairs of spinal nerve roots; 8 pairs in the cervical segment, 12 pairs in the thoracic segment, 5 pairs in the lumbar segment, 5 pairs in the sacral segment, and 1 pair in the coccygeal nerve.

　　The development of the complete compression stage of the cervical spinal cord in intraspinal tumors leads to transverse damage to the spinal cord substance, and the pathological changes of the spinal cord also gradually become irreversible. The main manifestations are the loss of motor and sensory function of the limbs, dysfunction of autonomic nerves, dysfunction of defecation and urination, and at this stage, it has reached the late stage of paraplegia. Complications such as acute 'stroke-like' transverse myelitis syndrome and brain nerve damage caused by intraspinal tumors should be noted. Active prevention of complications and symptomatic treatment should be carried out.

　　The spinal cord is located within the vertebral canal,呈cylindrical shape, with a total length of about 42-45cm. From top to bottom, it divides into 31 pairs of spinal nerve roots; 8 pairs in the cervical segment, 12 pairs in the thoracic segment, 5 pairs in the lumbar segment, 5 pairs in the sacral segment, and 1 pair in the coccygeal segment. The spinal cord is the primary center of muscle, gland, and visceral reflexes, linking the activities of various parts of the body closely with the activities of various parts of the brain. The main clinical manifestations caused by intraspinal tumors are: motor dysfunction, sensory dysfunction, sphincter dysfunction, and dysfunction of autonomic nerves.

　　1. Radicular pain: caused by stimulation of the nerve root or dura mater. The location is relatively fixed, often localized to one place and radiates along the distribution area of the involved nerve root. The nature is like cutting, piercing, or burning, often呈 intermittent attacks, exacerbated or induced by forceful coughing or sneezing.

　　2. Sensory dysfunction: manifested as decreased or abnormal sensation below the level of the damaged spinal cord (numbness or creeping sensation).

　　3. Motor dysfunction: cervical cord lesions can cause weakness of the limbs; thoracolumbar segment damage is manifested by weakness of the lower limbs, increased muscle tone, and positive pathological reflexes; lumbar sacral segment lesions are manifested by signs of injury to the cauda equina, decreased muscle tone, and decreased tendon reflexes; some patients may be accompanied by muscle atrophy.

　　4. Dysfunction of rectum and bladder: manifested as sphincter dysfunction, constipation, urgency of urination, and even incontinence of urine and feces.

　　Intraspinal tumors can be divided into intramedullary tumors and extramedullary tumors according to their location.

　　1. Intramedullary tumors The main intramedullary tumors are astrocytomas and ependymomas, accounting for about 20% of all spinal tumors. Intramedullary tumors often involve multiple spinal segments and can cause radicular pain when involving the posterior root entry into the spinal cord, although this is rare. Muscle atrophy, fasciculation, and late onset of pyramidal tract signs are common, but usually not prominent. Sphincter dysfunction can appear early, hemisection syndromes of the spinal cord are rare, and changes in cerebrospinal fluid are usually not obvious, and the pressure neck test usually does not show subarachnoid obstruction.

　　2. Extramedullary tumors include subdural and epidural tumors. The former are commonly neurilemmomas (including neurofibromas) and meningeal tumors, accounting for about 55% of all spinal tumors. The latter account for 25%. Extramedullary tumors generally involve fewer spinal segments. Muscle atrophy is rare, but in the late stage of tumors in the cauda equina area, significant muscle atrophy in the lower limbs is evident. Sphincter dysfunction often appears in the late stage, and there are often hemisection syndromes of the spinal cord, early changes in cerebrospinal fluid, and the pressure neck test often shows subarachnoid obstruction. The more complete the obstruction, the more significant the increase in protein.

　　There is no effective preventive measure for this disease.

　　If intraspinal tumors can be detected early and treated surgically 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 compression of the patient's spinal cord.

　　Puncture of the spinal canal and examination of cerebrospinal fluid dynamics and increased protein content are important for the early diagnosis of intraspinal tumors. When there is a suspicion of intraspinal tumor, the Quincke test and cerebrospinal fluid examination should be performed as soon as possible. Routine serial examinations of cerebrospinal fluid in patients with intraspinal tumors can show increased cerebrospinal fluid protein content with normal cell count, and dynamic examination (i.e., Quincke test) can show partial or complete obstruction.

　　First, X-ray film examination:About 30% to 40% of patients can be seen with bone changes. On routine anteroposterior and lateral X-ray films and oblique films, common signs include:

　　1. Expanding or destroying intervertebral foramina;

　　2. Spinal canal expansion, manifested as widening of the pedicle distance;

　　3. Bone changes of the vertebral bodies and appendages, such as vertebral body bone defects, destruction of pedicle roots, and so on;

　　4. Intraspinal calcification, occasionally seen in a few neurinomas, teratomas, and hemangioblastomas;

　　5. Paravertebral soft tissue shadow. Since most intraspinal tumors are benign, there is often no bone abnormality on the X-ray film in the early stage, and sometimes only indirect signs such as widening of the pedicle distance, thinning of the cortical bone of the spinal canal wall, and expansion of the spinal canal can be seen in the late stage. For dumbbell-shaped vertebral bodies and other intraspinal tumors, there can be widening of the intervertebral foramen. X-ray film examination can exclude symptoms of spinal cord compression caused by spinal deformity, tumor, and other reasons, and is still an indispensable routine examination.

　　Second, myelography:It is one of the effective methods for showing intraspinal space-occupying lesions, and iodine oil or iodine water contrast agent can be used for cervical spinal canal myelography, especially when the drug is injected into the cisterna magna, it is easy to make a diagnosis. It shows that the contrast agent appears as a cup-shaped defect or blockage on the non-intervertebral disc plane. Literature reports 180 cases of neurilemmoma, among which 150 cases showed: 106 cases with cup-shaped filling defect, 18 cases with horizontal cross-sectional shape, 7 cases with oblique needle-like shape, 5 cases with bell-shaped, and 4 cases with bead-like. OMNIPAQUE is the second-generation non-ionic iodine water-soluble contrast agent, with clear imaging, safety, and reliability. It can determine spinal cord tumors according to the expansion, displacement, and subarachnoid obstruction of the spinal cord, and combined with increased cerebrospinal fluid protein, make an accurate diagnosis. Due to adhesions and other reasons, the obstruction 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 obstruction plane that differed from the surgical exploration results by 1/4 to 1 vertebral body. Unless a second myelography is performed, a single myelography can only determine the upper or lower limit of the tumor, and it cannot determine the nature of the tumor solely based on the obstruction shape and bone involvement. 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.

　　Three, CT examination:CT scanning has sensitive density resolution and can clearly display 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 the diagnosis of intraspinal tumors, which is not available in traditional imaging methods. However, the location of CT scanning, especially when it is used as the first imaging examination, needs to be determined 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 lesion range of intraspinal tumors, but it is difficult to distinguish them from the normal spinal cord substance. CTM can show the entire relationship between the spinal cord and the tumor and distinguish between intramedullary tumors and spinal cord cysts.

　　Four, MRI: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 and display the boundary between tumor tissue and normal tissue, the location, size, and extent of the tumor, and directly outline the tumor, showing its longitudinal and transverse extension and its relationship with surrounding tissue structures. It has become the preferred method for diagnosing spinal cord tumors. MRI has its advantages in distinguishing intramedullary and extramedullary tumors. The MRI imaging of intramedullary tumors shows the expansion of the spinal cord in this area, with different signal intensities displayed by the tumor 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. Sagittal MRI imaging shows the tumor as a clear, long T1, long T2 signal area, but mainly long T1, with a significant enhancement effect, and some show cystic changes. Axial imaging shows the cervical spinal cord being 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 masses 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, so MRI is very important for diagnosis and surgical localization, which is far inferior to MRI in terms of CT or CTM.

　　Patients with intramedullary tumors should pay attention to nutritional balance in their diet, and try to make their food diverse. They should eat more high-protein, vitamin-rich, low-animal-fat, easily digestible foods, fresh fruits, and vegetables, avoid spicy and刺激性 foods, avoid smoking and drinking, avoid high-salt and high-fat foods, avoid drinking strong tea, and avoid eating contaminated or spoiled foods.

　　Patients with intramedullary tumors with mild symptoms or spontaneous remission can be treated conservatively and 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 the surgical resection of the tumor. Since primary intramedullary tumors are predominantly benign, about 3/4 of the cases can be cured by surgical resection. Therefore, efforts should be made to surgically resect intramedullary tumors, even if they cannot be completely removed, and partial or large-scale resection should be performed to alleviate or relieve the compression and damage of the tumor on the spinal cord. Once a clear diagnosis is made, 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, symptoms can recur, and the risk of surgery varies depending on its functional location. Exogenous tumors have fewer postoperative defects. Appropriate treatment methods should be chosen, and intraoperative monitoring of spinal cord evoked potentials can help reduce neurological complications.