Intraspinal tumors, also known as spinal cord tumors, include a general term for primary or metastatic tumors that occur in the spinal cord itself and various tissues within the spinal canal adjacent to the spinal cord (such as nerve roots, dura mater, blood vessels, adipose tissue, congenital embryonic remnants, etc.). Intraspinal tumors can compress the spinal cord and nerves, causing motor and sensory disorders in the limbs. Etiology and classification: Primary spinal cord tumor has an incidence of 2 or 5 per 100,000 population per year. The incidence is similar in men and women, but spinal meningiomas are more common in women and ventricular meningiomas are more common in men. The incidence of thoracic spinal cord segments is higher, but the incidence is approximately the same according to the proportion of the length of each segment. The nature of intraspinal tumors is most common in adults with nerve sheath tumors; followed by spinal meningiomas; and the rest are congenital tumors, gliomas, and metastases in that order. In children, congenital tumors (dermatomal cysts, epithelioid cysts and teratomas) and lipomas are most common; followed by gliomas; and in third place, nerve sheath tumors. Symptoms and hazards: General clinical manifestations of spinal canal tumors: The spinal cord is located in the spinal canal and is cylindrical in shape, with a total length of about 42-45 cm. 31 pairs of spinal nerve roots are divided from top to bottom; 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 caudal nerve. The spinal cord is the primary center for muscular, glandular and visceral reflexes, the intermediate unit that closely links the activities of the various parts of the body with those of the brain. The main clinical manifestations caused by spinal cord lesions are: motor disorders, sensory disorders, sphincter dysfunction and disorders of vegetative nerve function. The main manifestations are nerve root damage in the plane where the tumor is located and symptoms and signs of involvement of the pyramidal tract below that level. 1.Nerve root pain: It is caused by the irritation of nerve root or dura mater. The location is fixed, often confined to one place and radiates along the distribution area of the involved nerve root, with the nature of cutting, stabbing or burning. 2.Sensory impairment: It is manifested as hypesthesia or abnormal sensation (numbness or ankylosis) below the plane of the damaged spinal cord. 3.Motor disorders: cervical medullary lesions may show reduced muscle strength of the limbs; thoracolumbar segment damage shows weakness of the lower limbs, increased muscle tone and positive pathological reflexes; lumbosacral segment lesions show signs of damaged cauda equina, low muscle tone and tendon reflexes; some patients may be accompanied by muscle atrophy. 4. Rectal and bladder dysfunction: manifested as sphincter function impairment, constipation, urinary urgency and even urinary and fecal incontinence. Spinal canal tumors can be divided into intramedullary tumors and extramedullary tumors according to their locations. Extramedullary tumors include extramedullary subdural tumors and epidural tumors. 1.Intramedullary tumors Intramedullary tumors are mainly astrocytomas and ventricular meningiomas, which account for about 20% of all spinal cord tumors. Intramedullary tumors often invade multiple segments of the spinal cord and can cause radicular pain by involving the posterior root into the medullary area, but it is less common. It may cause radicular pain in the posterior roots of the spinal cord, but it is less common. Myasthenia and tremor of the muscle bundles are often seen, and the cone bundle signs appear later and are not significant. Sphincter dysfunction can appear early, spinal cord hemisection syndrome is rare, cerebrospinal fluid changes are not obvious, and pressure neck test does not show subarachnoid obstruction. Extramedullary tumors include subdural and epidural tumors. The former is common for nerve sheath tumor (including neurofibroma) and spinal meningioma, accounting for about 55% of all spinal cord tumors. The latter accounts for 25%. Extramedullary tumors involving spinal cord segments are generally less common. Most of them do not have muscle atrophy, but the lower limb muscle atrophy is obvious in the advanced stage of cauda equina tumor. Sphincter impairment mostly appears in late stage, often with spinal cord hemisection syndrome. Cerebrospinal fluid changes appear earlier, and pressure neck test mostly shows subarachnoid obstruction, the more complete the obstruction, the more significant the protein increase. Neurological localization signs: here refers to longitudinal localization, i.e. neurological signs of lesions in different segments. 1. Cervical spinal canal tumor: lesions in the upper cervical medullary region may have occipital and cervical pain and sensory abnormalities. Spastic quadriplegia and hyperactive biceps tendon reflexes may be seen below the lesioned segment. The 5th cervical medullary lesion may cause atrophic paralysis of the deltoid and biceps, and posterior rotator muscle. Sensory impairment extends to the lateral arm, and the biceps and posterior rotator reflexes are absent. The sixth cervical medullary lesion causes paralysis of the triceps and wrist extensor muscles, partial wrist droop, and sensory disturbance in the corresponding dermatomes. The seventh cervical medullary lesion causes wrist flexor and finger flexor-extensor paresis with sensory disturbances involving the ulnar side of the midline of the arm. The 8th cervical medullary lesion causes atrophic palsy of the intrinsic muscles of the hand, claw-shaped hand deformity, and may have Horner’s sign, with sensory disturbance involving the medial arm and the 4th and 5th fingers. 2.Thoracic spinal canal tumor Clinical localization usually relies on the level of sensory impairment and is difficult to determine by intercostal muscle strength. The lower abdominal muscles are paralyzed, while the upper abdominal muscles are normal. Beevor’s sign may appear, which means that the umbilicus moves upward when the patient, lying supine, sits up against the resistance added to the chest. The lower abdominal wall reflex is absent. There may be a clear sense of thoracoabdominal fasciculation. 3.Lumbar spinal canal tumor: Involvement of the 1st and 2nd lumbar medulla can cause loss of the tachycardia reflex. When the 3rd and 4th lumbar medulla are not involved, the quadriceps muscle is weakened and the knee reflex disappears, while the Achilles tendon reflex is hyperactive and ankle clonus appears. Involvement of the cauda equina at this level causes bradykinetic paralysis of the lower legs and loss of the knee and ankle reflexes. If the spinal cord and cauda equina are involved at the same time, it may show spastic paralysis of the calf on one side and bradykinetic paralysis on the other side. 4. Conus and cauda equina: Early symptoms may include low back pain, saddle area and lower extremity pain or numbness, which is often diagnosed as sciatica. Sphincter dysfunction appears earlier. There may be lower extremity chronically paralyzed, muscle atrophy, foot drop, loss of sensation in the lumbosacral cortex, especially in the saddle area, and occasional lumbosacral, hip, hip or heel ulcers.