Syringomyelia
Introduction
Introduction to syringomyelia Due to a variety of reasons, a tubular cavity is formed in the spinal cord, called syringomyelia, and there is often gliosis around the cavity. The incidence of this disease is relatively slow, the clinical manifestations of the affected spinal segmental nerve damage symptoms, with pain, temperature loss and disappearance, and deep sensory preservation of the separation of sensory disturbances, combined with cerebral long-brain damage dyskinesia and nerve Nutritional disorders. basic knowledge The proportion of illness: 0.008% Susceptible people: more common in 31 to 50 years old Mode of infection: non-infectious Complications: scoliosis, recessive spina bifida, cerebellar tonsil, diarrhea, dysphagia, facial paralysis, vertigo
Cause
Cause of syringomyelia
Self-factor (25%)
Greenfield emphasizes that syringomyelia is a tubular cavity in the spinal cord. It extends from the neck to many segments. It should be considered as different from the central cyst of the spinal cord. The empty water is more suitable for the latter. It is considered to be a deformity of the midline of the spinal cord. As a result, the cavity can be transported to the central tube, and the hollow lining can be seen as ependymal cells, which are similar to CSF. Some people think that this disease is due to the proliferation of glial cells, and the central part of the necrosis forms a cavity.
Congenital factors (20%)
It is generally believed that syringomyelia is a congenital dysplasia, because the disease is often accompanied by other congenital anomalies, such as: spinal cord fissure, hydrocephalus, etc., it is considered that syringomyelia is a congenital developmental defect. Some people think that due to congenital fourth ventricle outlet occlusion, cerebrospinal fluid circulation disorder, cerebrospinal fluid pulsating pressure constantly impacts the central canal of the spinal cord, resulting in the continuous expansion of the central tube of the spinal cord, eventually forming a hollow hole.
Trauma factor (15%)
The syringomyelia can be secondary to spinal cord trauma, spinal glioma, cystic lesions, vascular malformations, spinal arachnoiditis, myelitis with central softening and the like.
Pathogenesis
1. There are four general theories about congenital causes:
(1) Gardner's theory of fluid mechanics: In 1958, Gardner reported a large number of cases of Chiari type I malformation with syringomyelia. He speculated that cerebrospinal fluid could not be caused by obstruction in the large area of the occipital region (congenital malformation or arachnoiditis). From the cerebral ventricle, the cerebrospinal fluid under the action of the choroid plexus-derived pulsation will continuously impact the central canal of the spinal cord, expand it, and destroy the gray matter around the central canal, forming a cavity. The fourth ventricle and the central canal are also found during surgery. Traffic; in some patients with ventriculography, it can be observed that the contrast agent enters the central tube through the four ventricles; the air is injected into the cavity through the skin puncture, and the gas can also overflow into the fourth ventricle; and the liquid protein content in the cavity is low, similar to the cerebrospinal fluid. However, there are also different opinions: some patients did not find traffic between the four ventricles and the central canal during angiography, surgery and autopsy; although the contrast agent injected into the lumbar region did not flow into the fourth ventricle, the cavity could be developed; some of the holes were separated from the central tube, and more In the room, some scholars calculated the pressure of the choroid plexus-derived pulsation, and found that the pressure is small, it is impossible to cause a void, and this theory is not Explain to produce bulbar syringomyelia.
(2) Williams' intracranial and intraspinal pressure separation theory: Since 1969, Williams has conducted a series of studies to test the pressure on the ventricles, cavities and subarachnoid space, thinking that when people cough, sneeze and exert force Can cause intracranial and intraspinal venous pressure to rise, so that the pressure of the subarachnoid space of the cerebral spinal cord is increased. At this time, normal people are balanced by the round-trip flow of cerebrospinal fluid in the subarachnoid space, and there is cerebellar tonsil. In patients with mild squats, pressure imbalance occurs due to cerebrospinal fluid circulation disorders. Williams found that in the early stage of cough, the pressure in the lumbar subarachnoid space was higher than that in the basal pool, and later on, contrary to this, he speculated that the cerebellar tonsils might have When the spinal cord subarachnoid pressure is increased, the cerebrospinal fluid can push the lower tonsils into the cranium; as the subarachnoid pressure of the spinal cord decreases, the cerebellar tonsils squat again, so that the cerebrospinal fluid cannot flow back. Causes an increase in intracranial pressure, causing cerebrospinal fluid to perfuse from the fourth ventricle to the central canal. This is the pressure difference between the intracranial and spinal cord, the central canal and the spinal cord. Williams called cerebrospinal fluid. Pressure separation, this pressure difference has been used intermittently for many years, can form a traffic syringomyelia, through the hollow puncture and animal experiments also found that the pressure inside the cavity is high, some patients in the cough force, there are clinical reports of increased symptoms The traffic between the central tube and the cavity of patients with syringomyelia is not always open. Due to the repeated compression of the tissue at the occipital hole and other reasons, it can be closed. Therefore, the cerebrospinal fluid impact theory is proposed in the progress of the cavity, which is obvious in the large hole of the pillow. In a stressed patient, when the cough is forced, the pressure in the subarachnoid space of the spinal cord suddenly rises. Because it cannot be transmitted to the brain, it is transmitted to the cavity in the spinal cord. Because the opening of the cavity is closed or has a flap, the cavity When the liquid can not flow into the cranium, it will hit the gray matter beside the central tube. Over time, the cavity gradually expands upwards and forms a medullary cavity on the basis of the syringomyelia. This indicates that the medullary cavity cannot exist alone, which is consistent with clinical observation. .
(3) Infiltration of spinal cord parenchyma in cerebrospinal fluid: In 1972, Ball found a significant widening of the perivascular space in the spinal cord parenchyma during autopsy of syringomyelia. He injected ink into the cavity to spread along the perivascular space and formed some localized parts. Koike, especially the dorsal white matter of the spinal cord is obvious. It is speculated that due to the abnormality of the occipital macropore, the venous pressure and the subarachnoid pressure of the spinal cord are repeatedly increased, and the long-term action on the spinal cord makes the perivascular space gradually expand. Infiltrated to form a cavity. In 1979, Aboulker proposed that the axon tissue is permeable to water, and the cerebrospinal fluid can penetrate into the spinal cord along the nerve tissue. Clinically, it has been reported that patients with no communication between the fourth ventricle and the central canal are confirmed. The cavity in the delayed cerebrospinal fluid imaging can be developed, and some of the cavity is away from the central tube, and is mostly located near the rear corner of the spinal cord surface.
(4) Circulatory Disorder Theory: Netsky found intramedullary vascular abnormalities in autopsy of patients with syringomyelia, especially in the posterior horn. He speculated that with age, circulatory disturbances may occur around abnormal blood vessels, resulting in cerebrospinal fluid. The perfusion or impact damage has a protective mechanism, glial fibrosis, which affects the blood supply to the parenchymal parenchyma. Ischemia may be one of the causes of cavitary development and progression. Congenital abnormalities of the spinal cord parenchyma (mainly in the posterior horn) It is not the only factor in the onset of the disease. The congenital anomalies in the posterior horn of the spinal cord, combined with abnormalities in the occipital macropore and venous pressure, make it easy for the cerebrospinal fluid to invade from the posterior root of the spinal cord in the congenital anomaly, forming a cavity in the area, which can be expanded with the expansion of the cavity. Traffic with the central tube, followed by the central tube gradually expanded, and finally can communicate with the fourth ventricle.
2. Acquired causes are caused by factors such as spinal cord tumor, arachnoiditis and trauma. Trauma can cause necrosis in the central part of the spinal cord, resulting in accumulation of exudate and destruction products, resulting in increased osmotic pressure, fluid retention, due to intramedullary pressure. Elevation can destroy the surrounding tissue and gradually enlarge the cavity. In animal experiments, it is found that some tiny cysts appear near the broken end of the spinal cord, which can be speculated that the rupture of these cysts may be the cause of cavity formation. For arachnoid The syringomyelia after inflammation is mainly caused by ischemia and venous thrombosis. The syringomyelia caused by spinal cord tumor is mainly related to the secretion of protein fluid by tumor cells.
The pathogenesis of syringomyelia is complicated, and the malformation or obstruction of the occipital macropore is one of the important factors leading to the formation of cavities. Due to the different causes, physical and body compensatory abilities, the formation and development of cavities are also different. Different causes should be discussed and comprehensively analyzed according to clinical characteristics and disease duration.
Syringomyelia occurs mostly in the vicinity of the central tube of the cervical and upper thoracic segments, close to the posterior horn of one side, forming a tubular cavity that can continue multiple spinal segments, not necessarily connected to the central canal, visible in the cross section of the spinal cord. The cavity cavity occupies most of the medulla, and the dorsal side of the anterior horn can also be affected. The anterior and posterior commissure structures are often destroyed. With the further development of the cavity, the posterior horn can also be affected, even including the ventral side of the posterior cable. Limited to one side of the spinal cord, it can also occupy both sides. The shape of the cavity is different. There may be multiple hollow cavities in the same plane of the spinal cord. They can be separated from each other or connected to each other. Some of these diseases exist simultaneously with the medullary cavity. The cavity is extended to the pons and midbrain. The cavities below the lumbar region are rare. In a few cases, small holes are seen at the end of the spinal cord and coexist with the spina bifida.
Spinal compression and degeneration is often the inevitable result of the expansion of the cavity. The spinal cord of the cavity is fusiform, the color is lightened, the soft-membrane vessels are reduced, and the cavity can be located at the center or on one side, or biased to the front or back, making the spinal cord gray. The lateral cord, the posterior cord is subjected to pressure-denatured, and the wall of the cavity is smooth. It is a proliferating gelatinous and nerve fiber that tends to be denatured. The color becomes white, the surrounding nerve fibers are edematous, and the late spinal cord is huge, and the spinal cord tissue is thin, which can cause Obstruction of the spinal canal.
According to the pathological condition, syringomyelia can be divided into two types: one is traffic syringomyelia, that is, syringomyelia and fourth ventricle, subarachnoid cerebrospinal fluid communication, often combined with cerebellar tonsil sputum type I and type II Malformation, which may be caused by some abnormal factors during growth and development. For example, the central canal of the spinal cord may under the pressure of high cerebrospinal fluid, the fluid continuously leaks into the peripheral nerve tissue, causing it to expand continuously. The disease is formed; the other type is non-communicative syringomyelia, the cavity and cerebrospinal fluid circulation pathway are not in communication, and its formation is related to intramedullary tumor, traumatic paraplegia and some degenerative diseases.
Prevention
Syringomyelia prevention
1. Maintain an optimistic and happy mood, a strong long-term or repeated mental stress, anxiety, irritability, pessimism and other emotional changes, can make the balance of the cerebral cortex excitability and inhibition process imbalance, so that muscle jump is aggravated, so that muscle atrophy develops.
2. Reasonable diet, maintain normal digestive function, patients with dystrophic muscle atrophy maintain normal digestive function, rational allocation of diet structure is the basis of rehabilitation, patients with syringomyelia muscle atrophy need high protein, high energy diet supplement, provide nerve cells and bones The necessary substances for muscle cell reconstitution to strengthen muscle strength, increase muscle mass, early use of high protein, foods rich in vitamins, phospholipids and trace elements, and actively cooperate with medicated diets such as yam, glutinous rice, lotus seed, dried tangerine peel, and radix ginseng , lily, etc., fasting spicy food, quit smoking, alcohol, middle and late patients, high protein, high nutrition, energy-rich semi-liquid food and liquid food, and use small meals to maintain patient nutrition and water and electrolytes balance.
3. Pay attention to prevent colds, infections, syringomyelia patients with muscle atrophy due to low autoimmune function, or there is some kind of immune deficiency, once the cold, the disease worsens, the disease course is prolonged, the muscle weakness is weak, the muscle jump is aggravated, especially the ball paralysis patients Easy to have pulmonary infection, if not timely prevention and treatment, poor prognosis, and even endanger the life of patients, gastroenteritis can lead to dysfunction of intestinal bacteria, especially viral gastroenteritis has different degrees of damage to the anterior horn cells of the spinal cord, thus enabling The patient's muscle jump is aggravated, the muscle strength is decreased, and the condition is repeated or aggravated.
Complication
Complications of syringomyelia Complications Scoliosis, recessive spina bifida, cerebellar tonsillar palsy, swallowing difficulty, facial vertigo
Syringomyelia often associated with other congenital malformations, such as scoliosis or kyphosis, recessive spina bifida, neck occipital deformity, cerebellar tonsil sac and arched foot.
After the lesion development damages the pyramidal tract and the extrapyramidal bundle, the lower extremity gradually develops spastic paralysis, and the lower limbs have a positive pyramidal tract sign. When one cervical spinal cord is damaged, the descending sympathetic fibers are destroyed, and Hornor can appear on the same side. Syndrome, more common autonomic disorders, skin dystrophies such as skin keratosis, hair loss, vasomotor disorders, etc., in the later stages of the disease, the cavity often involves the facial onion skin-like pain and temperature loss in the trigeminal nucleus From the lateral to the nasolabial development; involving the suspected nucleus caused by dysphagia, drinking water and cough; involving the sublingual nerve nucleus and fasciculation; involvement of the facial nucleus with peripheral facial paralysis; vestibular cerebellar pathway involvement with dizziness, nystagmus and steps Steady.
Symptom
Symptoms of syringomyelia common symptoms spinal cavity formation localization neurological signs paraplegic segmental sensory dysfunction nystagmus urinary tract infection keratitis gait instability vertigo nausea
The age of onset is 31 to 50 years old. Children and the elderly are rare. There are more men than women. There have been family history reports. The clinical manifestations of syringomyelia have three aspects. The degree of symptoms has a great relationship with the development of the cavity, and the progress of the disease is slow. The early symptoms are mostly segmental distribution, which affects the upper limb first. When the cavity is further enlarged, the gray matter in the marrow and the white matter conduction bundle outside it are also involved, and the conduction beam dysfunction occurs below the cavity. Therefore, Symptoms of early patients are more limited and mild, and late symptoms are widespread and even paraplegic.
1. The sensory symptoms are located in the cervical and upper thoracic segments of the spinal cord according to the cavity, and are located on one side or in the center. There is a segmental sensory disturbance of the unilateral upper limb and the upper thoracic segment, which is often characterized by segmental dissociative sensory disturbance. The sense of temperature subsides or disappears, and the deep feeling exists. The symptom can also be bilateral.
2. Sports symptoms of the neck, chest cavity cavity affects the anterior horn of the spinal cord, there is a symptom of flaccid part of the upper limb on one or both sides, manifested as muscle weakness and decreased muscle tone, especially in the two-handed intermuscular muscle, the most obvious interosseous muscle atrophy In severe cases, the claw-shaped hand deformity is present. When the descending root of the trigeminal nerve is affected, the central side of the same facial sensation is characterized by central pain, temperature sensation, and facial dissociative sensation, forming a so-called "onion-like distribution" with weak chewing muscle strength. If the vestibular cerebellar conduction bundle is involved, dizziness, nausea, vomiting, gait instability and nystagmus may occur, and metacarpal partial spasm occurs on one or both lower extremities, hypertonia, abdominal wall reflex and Babinski sign positive Late cases are more severe.
3. The symptoms of autonomic nerve damage involve the sympathetic spinal cord center of the spinal cord (neck 8 cervical and thoracic 1 chest) lateral angle, Horner syndrome appears, lesions damage the corresponding segments, limb and trunk skin may have abnormal secretion, sweating Or hypohidrosis is the only sign of abnormal secretion. Less sweat can be confined to one side of the body, called "half side sweating", and more common in one side of the upper body, or one side of the upper limb or half of the face Usually corneal reflex can also weaken or disappear, because neurotrophic keratitis can cause bilateral corneal perforation, another strange sweating phenomenon is increased sweating after cold, accompanied by temperature decrease, fingertip, nail keratinization Excessive, atrophy, loss of luster, due to pain, temperature loss disappears, prone to burns and bumps, trauma, advanced patients with dysfunction and recurrent urinary tract infections.
Examine
Examination of syringomyelia
Laboratory inspection
There are no characteristic changes in routine and kinetic examination of cerebrospinal fluid. Large voids can cause mild obstruction of the spinal canal and increased CSF protein.
Film degree exam
1. CT scan 80% of the cavity can be found in the plain scan of the CT, showing a low-density cystic cavity with clear intramedullary border, the CT value is the same as the corresponding subarachnoid cerebrospinal fluid, and the average CT value of the corresponding segmental spinal cord Low 15Hu, the corresponding shape of the spinal cord is enlarged, and the pressure in a few cavities is low and atrophic. At this time, its shape is not regular. When the cavity is small or the protein content is high, the plain scan may be missed. The iodine angiography CT in the spinal canal is performed. Delayed scanning can be seen in the syringomyelia. When the cavity is directly connected to the subarachnoid space, the contrast agent can enter the cavity through the spinal vascular space or the fourth ventricle. Therefore, the contrast agent is delayed. Scanning found that the intramedullary high-density shadow has a higher chance. When the spinal cord tumor is involved, the spinal cord is irregularly enlarged, the density is uneven, and the cavity wall can be thick. After the trauma, the syringomyelia is often eccentric, and the separation is often seen.
2. The MRI MRI sagittal image can clearly show the whole cavity. The T1-weighted image shows the tubular expansion of the low signal in the central part of the spinal cord. The T2 weighted image shows a high signal in the cavity. The T1 or T2 weighted image, the cavity liquid signal is uniform. Consistently, the cross-section of the cavity is mostly round, sometimes irregular or double-cavity, the edge is clear and smooth, and there are often glial hyperplasia on the upper and lower ends of the cavity, when the proliferating colloidal tissue forms a separation in the cavity. The cavity is multi-atrial or sausage-like, and the spinal cord of the corresponding segment of the cavity is uniformly enlarged. Due to the pulsation of cerebrospinal fluid, the T2-weighted image shows a low signal on the cerebrospinal fluid. This phenomenon is called cerebrospinal fluid flow phenomenon, and the syringomylium fluid and cerebrospinal fluid phase Traffic, and can have pulsation, so these patients can see the low signal flow phenomenon on the T2-weighted image, which is quite similar to the T1 weighting. Due to the different degree of fluid pulsation in the cavity, the shape of the missing signal region can be weighted with T1. The range of time is inconsistent. The multi-atrial cavity is weak due to the existence of separation, and the occurrence of airflow is low, but when it is traffic, the phenomenon of emptying occurs in the cavity. The rate is obviously increased. Therefore, if the phenomenon of emptying is found, the presence of multi-room separation is suggested. The non-pulsating cavity is often single-shot, and its length and diameter are small. After the shunt, the amplitude of the pulsation in the cavity is weakened or even disappeared. The observation of empty phenomenon can also be used as one of the indicators for the observation of surgical outcomes. MRI is the most effective tool for diagnosis. In most cases, the syringomyelia and its extent and size can be displayed.
3. Others use induced current to detect muscle contraction. For those with severe muscle paralysis, the electrical degeneration reaction may occur. The value of exercise is often increased. Electromyography is meaningful for any level of damage to the motor neuron pathway under the spinal cord.
Diagnosis
Diagnosis and diagnosis of syringomyelia
diagnosis
According to the characteristics of chronic pathogenesis and clinical manifestations, there are segmental separation sensory disturbances, motor neuron dyskinesia in upper limbs, motor neuron dyskinesia in lower limbs, etc., can make a definite diagnosis, combined with imaging Performance can further confirm the diagnosis.
Differential diagnosis
1. Spinal cord tumors Extramedullary and intramedullary tumors can cause localized muscle atrophy and segmental sensory disturbance. In tumor cases, astrocytomas or ependymoma secreted from the gray matter of the spinal cord accumulate in the tumor. The upper and lower sides make the diameter of the spinal cord widened. The posterior column of the spine and the nervous system symptoms can be similar to syringomyelia. Especially in the lower cervical spinal cord, it is sometimes difficult to identify, but the tumor case progresses rapidly, the root pain is common, and the nutritional disorder Rarely, the protein in the early cerebrospinal fluid is increased, which can be distinguished from the disease. CT and MRI can be identified for difficult cases.
2. Cervical vertebrae joint disease can cause upper limb muscle atrophy and long beam signs, but root pain is common, segmental sensory disturbance with obvious lesion level is rare, cervical vertebrae, if necessary, for myelography and cervical CT or MRI help To confirm the diagnosis.
3. Cervical ribs can cause localized atrophy of the small muscles of the hand and sensory disturbances, with or without evidence of compression of the subclavian artery, and because of the neck ribs often associated with syringomyelia, the diagnosis can be confused, but The sensory disturbance caused by the neck rib is usually limited to the ulnar side of the hand and forearm. The tactile dysfunction is more serious than the pain dysfunction. The upper arm tendon reflex is not affected, and there is no long beam sign. When it can be identified, the cervical spine film also has Helps establish a diagnosis.
4. Ulnar nerve palsy can produce localized atrophy of the interosseous muscle and the middle two sacral muscles, but the sensory disturbance is relatively mild and limited, and the sense of touch and pain are affected. The nerve in the back of the elbow usually has tenderness.
5. Leprosy can cause feelings to disappear, upper limb muscle atrophy, finger ulcers, but there is a middle, ulnar and radial nerve and brachial plexus trunk thickening, there may be scattered depigmentation on the trunk.
6. Syphilis can be suspected of syringomyelia in two aspects. In rare proliferative dural meningitis, upper limb sensory disturbance, atrophy and weakness and lower limb pyramidal tract signs may occur, but myelography may show subarachnoid obstruction. Moreover, the progression of the disease is also more rapid than that of syringomyelia. The syphilis of the spinal cord can show signs of intramedullary tumors, but the progression of the disease is rapidly disrupted and the syphilis seropositive.
7. Amyotrophic lateral sclerosis is not easily confused with syringomyelia because it does not cause paresthesia or loss of sensation.
8. Puncture injury or fracture displacement can sometimes cause intramedullary hemorrhage, which is concentrated in the same plane of the spinal cord as syringomyelia, but the history of injury and the evidence of spinal injury in X-ray films are sufficient to provide a basis for identification.
