Thoracic or lumbar spinal cord injury

Introduction Thoracic or lumbar spinal cord injury is a clinical manifestation of spinal cord injury. The number of patients with spinal injuries is increasing, depending on the mechanism of damage, and the classification is also different, so it is also difficult to diagnose. However, in fact, as long as the local pathological anatomical features can be grasped, comprehensive diagnosis and judgment can be made under the premise of comprehensive collection of traumatic history, symptoms and signs, and it is not difficult to obtain a correct diagnosis for most cases. On this basis, the treatment problem is also easy to solve. For some patients with clinical difficulties, CT, MRI, CT plus myelography, CTM and other imaging methods can be used.

Cause

Causes of thoracic or lumbar spinal cord injury

(1) Causes of the disease

Due to various spinal fractures, dislocation and injury.

(two) pathogenesis

1. The predilection site of spinal injury: Spinal fracture and dislocation can occur in any vertebra, but 60% to 70% of cases occur in the chest 10 to the waist 2 segment. Among them, the chest 12 to the waist 1 segment is more high, accounting for about 80%; the neck 4 to 6 vertebrae and the neck 1 to 2 are secondary multiple areas, accounting for about 20% to 25%; the remaining cases are scattered in other vertebrae .

2. The incidence of spinal cord injury: Spinal cord injury (SCI) accounted for about 17% of spinal fracture and dislocation, of which the incidence of cervical segment was the highest, followed by the thoracic and lumbar segments. Neck 1 ~ 2 and occipital neck injury are easy to cause death, and most of the time at the injury site. Observed from the mode of action of violence, the proportion of direct violence is the highest, especially the firearms through the injury, almost 100%, followed by overextension. Such as the type of fracture, it is more common in vertebral burst fractures. Of course, the incidence of fractures associated with dislocation and spinal cord injury is higher. Clinically, cases of so-called "lucky spine fractures" with severe vertebral injury but no obvious symptoms of spinal cord injury can be encountered, mainly due to the wider spinal canal.

3. Pathological anatomical features of various types of fractures

(1) Stretch fracture: mainly manifested as a collapse of the articular process or a laminar fracture in the direction of the spinal canal, forming a compression of the dural sac. Lighter people have sensory disturbances, and severe ones can cause paraplegia. It is rare to have an interbody joint isolated from the front or a split in the middle of the vertebral body. The anterior longitudinal ligament can be completely broken, but it is rare in clinical practice. Occasionally, the spinous process fracture can be found and collapsed in front, and many of them are caused by violence directly on the spinous process. At this time, soft tissue contusion is often accompanied. Articular process is common in the cervical spine, followed by the thoracic vertebrae, which is rare in the lumbar segments.

(2) vertebral compression fracture: vertebral compression fracture is the most common in spinal fractures. When the leading edge of the vertebral body is compressed by more than 1/2 of the vertical diameter, an angular deformity of about 18° appears in the segment; when the front edge of the vertebral body is compressed by 2/3, the angle can reach about 25°; When the leading edge of the body is fully compressed, the angle can be up to 40°. Therefore, the more the number of vertebral bodies being compressed, the heavier the degree, the greater the angle, and the following consequences:

1 The sagittal diameter of the spinal canal is reduced: the degree of reduction is proportional to the angle of the deformity, and it is easy to cause spinal cord involvement in the spinal cord tissue and accompanying blood vessels in the spinal canal, especially the posterior small joint loosening. There are severe vertebral instability.

2 spinal canal extension: due to the angular deformity, the posterior wall of the posterior intervertebral facet joint is elongated due to the expansion of the articular capsule, resulting in the spinal canal tissue, especially the posterior ligamentum flavum, the dural wall and The blood vessels are in a state of tension, which is easy to cause damage and affects the spinal cord, especially when the length of the segment exceeds 10%.

3 cause instability of the vertebral node: the more compression of the vertebral body, the worse the stability of the vertebral joint. In addition to the small joints in the subluxation state and the anterior longitudinal ligament relaxation lost the original braking effect, the shortening and angular deformity of the vertebral body itself has changed the normal load line of the spine, which is easy to cause vertebral instability.

(3) vertebral burst fracture: This type of fracture vertebral body posterior margin bone fragments are most likely to enter the spinal canal, and are not easily found on X-ray films. Often the following consequences:

1 Spinal cord compression: The bone fragments behind the fractured vertebral body or the bone fragments of the burst fracture are not easy to shift forward, mainly because the anterior longitudinal ligament is strong and affected by the flexion position. The rear happens to be a lower pressure spinal canal, so that the vertebral body bone piece easily protrudes into the spinal canal and becomes a clinically common frontal spinal cord inducer, and constitutes a pathological anatomical basis for hindering the further recovery of spinal cord function.

2 easy to miss diagnosis: the bone block (slice) protruding in the direction of the spinal canal is not easy to be found on the X-ray film due to the occlusion of various tissues, especially in the thoracic vertebrae segment, so that it is easy to miss the diagnosis and lose the opportunity of early surgical treatment. Therefore, if the condition allows, CT examination or tomography should be performed on the injured person as soon as possible.

3 difficult to repay: when the posterior longitudinal ligament is damaged, if it has not lost the longitudinal connection, the broken bone piece (slice) still adheres to the front of the posterior longitudinal ligament, then the bone can be retracted by traction; but in the case of injury, if When the posterior longitudinal ligament is completely broken, the bone behind the vertebral body is mostly free and loses contact. Even if the vertebral fracture is restored by traction, the bone piece is difficult to return to the original position.

(4) Dissection of the vertebrae: In addition to the cervical vertebrae, the dislocation of the vertebrae can be performed separately. The dislocation of the vertebrae in the thoracic and lumbar segments is mostly accompanied by various types of fractures, especially in the flexion type. Because the lower edge of the upper segment of the vertebral body slides forward on the upper edge of the lower vertebral body, a vertebral step-like pressure is formed in the spinal canal, which may cause stimulation or compression of the spinal cord or cauda equina, which constitutes early spinal cord injury. The main reason. At the same time, this is one of the important factors that hinder the complete recovery of spinal cord function.

(5) Lateral flexion injury: its pathological changes are similar to those of flexion type, mainly manifested by lateral compression of one vertebral body, which is more common in the chest and lumbar segments. The degree of spinal cord damage in a lateral flexion injury is lighter than the anterior flexion in the same violence.

(6) Other types: including the more commonly found acute disc herniation (especially seen in the cervical spine), simple spinous process fractures and transverse process fractures, etc., most of the lesions are more limited, and the degree of damage is also light. It has not been clinically common in recent years to pass through a horizontal fracture of the vertebral body to the posterior lamina.

4. Pathological changes of spinal cord injury: Because the spinal cord tissue is very delicate, any impact, pulling, squeezing and other external forces can cause more serious damage than imagined. The pathological changes are mainly spinal concussion. There are three states of spinal cord parenchymal injury and spinal cord compression, but they are often divided into the following six types in clinical practice.

(1) Oscillation: It is the lightest type of spinal cord injury, similar to concussion. It is mainly transmitted through the back of the spine to the spinal cord, and there are transient sexual loss of several minutes to tens of hours. see. This type of spinal cord injury usually begins with the lower extremity when it is recovered. Because there is no visible pathological change in the morphology of the spinal cord, its physiological dysfunction can be recovered and is reversible.

(2) Spinal cord hemorrhage or hematoma: refers to intraparenchymal hemorrhage, which is more likely to occur in vascular malformations. The degree can range from subtle point bleeding to hematoma formation. A small amount of bleeding, after the hematoma absorption, its spinal cord function may be partially or largely restored; severe hematoma is prone to poor prognosis due to scar formation.

(3) Spinal cord contusion: The degree of spinal cord contusion varies greatly, ranging from very mild spinal cord edema, punctate or flaky hemorrhage to extensive spinal cord contusion (softening and necrosis), and over time, due to nerves Changes in glial and fibrous tissue hyperplasia, which in turn lead to scar formation and spinal cord atrophy leading to irreversible consequences.

(4) Spinal cord compression: extramedullary tissue, including fracture fragments, nucleus pulposus, invaginated ligaments, hematoma and later osteophytes, bone spurs, adhesive bands, scars, etc. and foreign bodies in vitro (shrap, internal fixation) Objects and bone grafts, etc.) can cause direct compression of spinal cord tissue. This compression can cause local ischemia, hypoxia, edema, and congestion, which can change and aggravate the degree of damage to the spinal cord.

(5) Fracture: In addition to firearm injuries, when the spinal dislocation exceeds a certain limit, the spinal cord may also be partially or completely broken, resulting in the loss of most or all of the spinal cord conduction function. In appearance, the dural sac remains mostly intact; A severe type of fracture dislocation is very obvious, and the dural sac can also be broken at the same time.

(6) Spinal shock: Unlike spinal cord concussion, spinal shock is not caused by violence directly affecting the spinal cord. The clinical manifestations are that the muscle tension below the injured vertebrae is reduced, the limbs are flaccid paralysis, the sensory and skeletal muscle reflexes disappear, and no pathological reflex, fecal incontinence and urinary retention are induced. This performance is essentially the result of the loss of advanced central control of the spinal cord below the injured section, generally lasting 2 to 4 weeks, and the duration of the combined infection is prolonged. When the sacral shock disappears, the recovery of the spinal cord varies depending on the degree of injury. The movement, sensation and shallow reflex function of patients with transverse spinal cord injury do not recover, hyperreflexia, and pathological reflexes occur; the spinal cord function of incompletely injured patients can be recovered mostly, partially or slightly.

The above is the type of spinal cord injury, but the pathological changes in the spinal cord vary depending on the length of time after the injury. Substantial spinal cord injury can be divided into three phases: early, middle and late. Within 2 weeks after the early finger injury, the main manifestation was the autolysis process of the spinal cord and reached a peak within 48 hours after the injury. In the medium term, 2 weeks to 2 years after injury, the main manifestation is the process of regression and repair of the acute process. Because the growth rate of fibroblasts is faster than that of spinal cord tissue, the fractured spinal cord is difficult to recanalize. In the later stage, the main manifestation is the degeneration of spinal cord tissue, which has a long change time, generally starting from 2 to 4 years after injury, and lasting for more than 10 years, in which microcirculation changes play an important role.

an examination

Related inspection

Spinal MRI examination of bone and joint soft tissue CT examination chest CT examination of cremaster reflex

Examination of thoracic or lumbar spinal cord injury

1. Clinical features of spinal cord injury According to the location, extent, extent, time and individual specificity of spinal injury, clinical symptoms and signs are quite different. Now explain its common symptoms.

(1) General characteristics:

1 Pain: It has severe pain unique to patients with fractures. Except for cases of coma or severe shock, almost every case occurs, especially when moving the trunk. It is often unbearable. Therefore, patients take more passive positions than any activities. Try to alleviate this symptom during inspection and movement.

2 tenderness, cramps and conduction pain: localized fractures have obvious tenderness and cramps (the latter are generally not checked, so as not to increase the patient's pain), and consistent with the fracture site. In patients with simple vertebral fractures, the tenderness is deeper, mainly through the spinous process. The tenderness of the lamina and spinous process fractures is shallow. In addition to simple spinous processes and transverse process fractures, there are generally indirect ankle pains, and the pain site is consistent with the injury site.

3 Limited activity: no matter what type of fracture, the spine has obvious activity limitation. During the examination, it is forbidden to let the patient sit up or twist the body to prevent the spinal canal from deforming or causing damage to the spinal cord and spinal nerve roots; nor should the patient be allowed to do activities in all directions (both active and passive) to avoid aggravating Dislocation of the fracture and causing secondary damage, and even paraplegia.

(2) Neurological symptoms: The neurological symptoms here refer to the symptoms of spinal cord, cauda equina or nerve root involvement.

1 high cervical spinal cord injury: high cervical spinal cord injury refers to the cervical spinal cord injury caused by neck 1-2 or occipital neck fracture and dislocation. If the life center of this place is directly oppressed and exceeds its compensation limit, the patient will die immediately. Fortunately, the sagittal diameter of the spinal canal is large, and there are still a certain number of survivors. But it can also cause quadriplegia and accidents due to complications.

2 lower cervical spinal cord injury: the lower cervical spinal cord injury refers to the cervical spinal cord injury below the neck 3. In severe cases, not only quadriplegia, but also the chest respiratory muscles are more affected, only abdominal breathing is retained. Complete sputum, the sputum is below the damage plane.

3 thoracic or lumbar spinal cord injury: Thoracic or lumbar spinal cord injury is more common with complete injury, especially in the thoracic segment. There are obstacles to the sensation, movement, and function of the bladder and rectum below the injury plane.

4 horsetail injury: the range of visual impairment is different, the symptoms of horsetail injury are quite different, in addition to lower limb movement and feeling different degrees of obstacles, rectal and bladder function can also be affected.

5 root damage: root damage and spinal cord symptoms occur at the same time, often caused by intense compression of nerve roots, especially in patients with complete spinal cord injury, and often become one of the main reasons for this type of surgery.

(3) Clinical judgment of the spinal cord injury plane: The plane of the spinal cord injury is generally consistent with the fracture plane, but the order number is different from the plane sequence of the spinal cord injury due to the anatomical features of the adult spinal cord ending at the lower end of the first lumbar vertebrae. In the spinal cord injury, the plane of the vertebra should be: cervical vertebra +1, upper thoracic vertebra +2, lower thoracic vertebra +3, and the cone is located between chest 12 and waist 1. In addition, it is clinically possible to infer the damaged plane of the spinal nerve root based on the location of the affected muscle.

(4) Other symptoms: According to the location of the fracture, the degree of injury, the involvement of the spinal cord and other various factors, some other symptoms and signs may occur in patients with spinal cord injury, including:

1 Muscle spasm: refers to the defensive contracture of the paravertebral muscles of the damaged vertebrae. In essence, it fixes and brakes the fractured vertebrae.

2 abdominal muscle spasm or pseudo acute abdomen: common in chest and lumbar fractures. The main reason is that the retroperitoneal hematoma caused by vertebral fractures stimulates local nerve plexus, causing reflex abdomen tension or spasm. Individual cases may even appear as symptoms and signs like acute abdomen, so that they are surgically diagnosed because they are misdiagnosed. Finally, the retroperitoneal hematoma is found during surgery.

3 fever reaction: more common in high spinal cord injury. Mainly due to the imbalance of heat dissipation in the whole body, it is also related to central reflex, stimulation of metabolites and inflammatory reaction.

4 acute urinary retention: In addition to spinal cord injury, patients with simple chest and lumbar fractures can also develop acute urinary retention. The latter is mainly due to the reflex response caused by retroperitoneal hemorrhage.

5 systemic reactions: In addition to systemic traumatic reactions, other such as shock, traumatic inflammatory response and other various complications may occur, should be fully observed.

2. Determination of the degree of spinal cord injury

(1) Standards for general judgment: There are different opinions on the general criteria for the degree of spinal cord injury. In the country, according to the movement, feeling and urination function of the injured person, the degree of spinal cord injury is divided into 6 grades according to whether it is a partial disorder or a complete disorder. Although this method is simple and easy to perform, it is difficult to accurately reflect the degree of injury of the patient, which needs further improvement and improvement. Foreign countries use the Frank classification standard, which is divided into five levels, namely:

Class A: No sensory or motor function below the damaged plane.

Class B: There is a feeling below the damaged plane, but there is no motor function.

Grade C: There is muscle movement but no function.

Class D: There are useful motor functions, but not resistance.

Class E: Exercise and feeling are basically normal.

It has also been proposed to divide it into four categories: complete spinal cord injury, Brown-Séguard syndrome, acute spinal cord injury and acute cervical spinal cord syndrome.

Differential diagnosis

Symptoms of confusion in the thoracic or lumbar spinal cord injury

1. Identification of complete and incomplete spinal cord injury: The identification of complete and incomplete spinal cord injury is generally more difficult.

2. Identification of severe incomplete spinal cord injury and spinal cord transection injury: This identification is a major clinical problem, and it is difficult to distinguish it with special examinations such as MRI and myelography. The authors believe that the following points may be helpful in the identification of the two during clinical examination.

(1) Autonomous hyperactivity in the toes indicates incomplete spinal cord injury.

(2) In the saddle area, there is an incomplete spinal cord injury.

(3) The presence of an anal reflex is mostly incomplete spinal cord injury in the acute phase.

(4) Those with urethral bulbal caver reflex are mostly incomplete spinal cord injury.

(5) The residual position of the toe is incomplete spinal cord injury.

(6) Stimulation of the soles of the feet and toes with multiple flexion and extension of the spinal cord.

3. Identification of sputum caused by upper motor neurons and lower motor neurons: Each clinician should have a clear understanding of the different sputum characteristics of upper and lower neuron damage for easy identification.

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