Tethered cord syndrome

Introduction to tethered cord syndrome Tethered cord syndrome (TCS) is a syndrome of a series of neurological dysfunctions and deformities caused by various congenital and acquired causes of spinal cord or cone traction. Because the spinal cord is pulled more often in the lumbosacral medulla, causing the cone to be abnormally low, it is also called the lower spinal cord. basic knowledge Sickness ratio: 0.001%-0.002% Susceptible people: infants and young children Mode of infection: non-infectious Complications: spina bifida, high arch, hydrocephalus, lipoma, hemangioma, cleft lip, cleft palate

Causes of tethered cord syndrome

(1) Causes of the disease

1. Various congenital spinal dysplasia

Such as meningocele, spinal cord fissure, spinal meningocele, etc. due to insufficiency of the end of the neural tube, most of the cases after birth were repaired within a few days, the purpose is to the abnormal nerve Tissue, as much as possible to repair to normal state, it is important to prevent cerebrospinal fluid leakage, but the adhesion produced during the healing process of the spinal dural canal causes the tethering at the end of the spinal cord.

2. Spinal cord lipoma and dural and extrahepatic lipoma

It is caused by the premature separation of the neuroectodermal and epidermal ectoderm. The fat cells of the mesoderm enter the neuroectodermal leaves that are not yet locked. The adipose tissue can enter the center of the spinal cord and can also be separated. The vertebral arch is connected with the subcutaneous adipose tissue to fix the conus of the spinal cord, and the cases after the early childhood are associated with the inflammation of the fat existing in the subarachnoid space, causing fibrosis around the nerve roots, and the tethering caused by adhesion scarring. .

3. Latent sinus

It is the neuroectodermal and epidermal ectoderm that are not well differentiated, and the locally formed cord-like tissue from the skin through the subcutaneous, spinal, causing tethering to the spinal cone, but also by the tissue of the latent sinus wall Proliferation produces dermoid cysts and epidermoid cysts and teratomas, which can surround or pull the spinal cord nerves and cause tethering.

4. Spinal cord longitudinal fissure

The mechanism of the occurrence of longitudinal fissures of the spinal cord is thought to be caused by abnormalities other than the nerves, that is, the developmental abnormalities of the vertebrae. It is also considered to be an abnormality of the nerves, which is followed by an abnormality in the development of the vertebrae. The spinal cord is separated by left and right, and there is a dural tube. With the two types of division and non-split, namely type I: double dural sac double spinal type, that is, the spinal cord is in the longitudinal fissure, completely separated by fibers, cartilage or osteophytes, divided into two, each with its Dura mater and arachnoid, the spinal cord is pulled by the partition, causing symptoms, type II: the common spinal capsule double spinal cord type, the meninges in the longitudinal fissure, separated by fiber septa, 2 parts, but with a common hard ridge Membrane and arachnoid, generally no clinical symptoms.

5. The end of tension

It is due to the process of degeneration of the terminal end of the spinal cord, which is degenerate to form a terminal filament, which causes the terminal filament to be thicker than the normal terminal filament, and the remaining part causes the tethered cord.

6. Neurogenic intestinal cyst

The so-called neurogenic intestinal cyst is a state in which the mesenteric margin of the intestine and the tissue in front of the spine form a traffic due to the patent of the notch of the spinal canal. According to the degree of the patent ductus arteriosus and the communication, the bone defect may be associated with the anterior spine. Intestinal fistula and manifestations of intestinal cysts inside and outside the spinal canal.

7. Postoperative complications such as lumbosacral sulcus

Some scholars estimate that this can account for 10% to 20% of all surgical cases.

(two) pathogenesis

Some scholars believe that after the tethered cord, the activity of the cone-tailed cone is restricted and a series of clinical symptoms appear. They emphasize that it is therapeutic to lift the cone-shaped cone after the spinal cord is removed during surgery, but some people believe that although There is no difference in the tension, but the mechanical effect caused by this static stretching is not the main cause of the symptoms itself, and its meaning varies according to the pathological state. In daily exercise, the spine is repeatedly flexed. Stretching also causes repeated relaxation and tension of the tethered spinal cord. In fact, in patients with symptoms due to posture and aggravation, mainly dynamic factors play an important role in the lumbosacral fat meninges. In the case of bulging, as the disease progresses, fibrosis occurs due to adhesive arachnoiditis. Due to the attachment and invasion of the lipoma in the conical region, not only the tethering, but also the contraction around the nerve root also hinders the rise of the spinal cord. In this case, it relies only on surgical removal of the lipoma of the cone to make the cone rise little, not In a great sense, when the positional change of the spinal cone after tethering is removed by MRI, it is found that the rise of the cone is very limited, and there is no significant correlation between the improvement of the symptoms and the rise of the cone seen by MRI. The significance of surgery is to make the tail of the spinal cord free, and to relieve the blood circulation disorder caused by repeated stretching caused by the movement of the cone. It is more important to consider the blood circulation disorder of the tissue of the tethered tissue. It is an important pathogenesis. It has been confirmed in the practice of tethered animal experiments in practice, and the surface sensory evoked potential is used as an indicator to observe and track, showing progressive neurological pathological abnormalities.

Prevention of tethered cord syndrome

There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.

Complications of tethered cord syndrome Complications spina bifida high arch hydrocephalus lipoma hemangioma cleft lip and palate

Patients with tethered cord syndrome often have various congenital malformations, especially primary tethered cord syndrome with congenital malformations. Spinal fractures have spina bifida, scoliosis, anterior and posterior processes, fork type Vertebral body, hemivertebra and vertebral body fusion, humerus often underdeveloped, with spinal canal enlargement, lower extremity deformity is more common with high arch, followed by clubfoot and lower limb dysplasia, nervous system malformation common meninges Spinal cord bulging, hydrocephalus, cerebral palsy or brain hypoplasia, skin abnormalities including skin sinus, skin spots or skin blemishes, skin scar tissue, skin depression, lumbosacral hair, etc., and subcutaneous lipoma or hemangioma And other system malformations such as cleft lip, cleft palate, etc.

Symptoms of tethered cord syndrome Common symptoms Urinary incontinence, urinary reflex, hyperthyroidism, sensory disturbance, constipation, urinary frequency, urgency, weakness, sputum, skin defect,...

The clinical manifestations of tethered cord syndrome are complicated. Because of the different symptoms of patients with tethered cord syndrome, different combinations of symptoms and congenital malformations, the clinical manifestations are complicated, but these clinical manifestations can be summarized. In order to achieve different neurological dysfunctions caused by different times and degrees of traction of the conus of the spinal cord under different causes and incentives, common clinical symptoms and signs are:

Pain

Is the most common symptoms, manifested as difficult to describe pain or discomfort, can be radiation, but often no skin segment distribution characteristics, children's patients often difficult to locate or located in the lumbosacral region, can be radiated to the lower extremities, adults are widely distributed It can be located in the deep rectum, the middle of the anus, the tail, the perineum, the lower limbs and the lower back. It can be unilateral or bilateral. The pain is mostly spread pain, radiation pain and electric shock, less pain, pain often due to sedentary And the body is flexed forward and aggravated, rarely aggravated by coughing, sneezing and twisting. The straight leg raising test is positive, which may be confused with the pain of disc herniation. The lumbosacral spine may cause severe discharge-like pain. Short limb weakness.

2. Movement disorders

Mainly due to progressive weakness and difficulty in walking, can involve unilateral or bilateral, but the latter are more common, sometimes the patient complained of unilateral involvement, but the examination found that both sides have changes, the lower extremities can have both upper motor neurons and lower Motor neuron injury manifestations, namely, amyotrophic muscle atrophy with increased muscle tone and hyperreflexia, no or only lower extremity dyskinesia in early childhood, symptoms appear with age, and progressive exacerbation, can be expressed as Lower limb length and thickness are asymmetrical, valgus deformity, skin atrophic ulcer and so on.

3. Sensory disorder

Mainly in the saddle area, the skin feels numb or the feeling is diminished.

4. Bladder and rectal dysfunction

Bladder and rectal dysfunction often occur at the same time. The former includes enuresis, frequent urination, urgency, urinary incontinence and urinary retention. The latter includes constipation or fecal incontinence. Children with enuresis or urinary incontinence are most common. According to bladder function measurement, it can be divided into sputum. Sexual small bladder and low-tension bladder, the former often combined with squat gait, frequent urination, urgency, stress urinary incontinence and constipation, the performance of motoneuron damage; the latter manifested as low-flow urinary incontinence, residual Increased urine output and fecal incontinence, etc., the performance of damaged motor neurons.

5. Abdominal skin abnormalities

90% of children have subcutaneous masses, 50% have skin sinus, meningocele, hemangioma and hirsutism, about 1/3 of children with subcutaneous lipoma lateral growth, the other side is meningocele, lumbosacral Subcutaneous masses can be very large, and parents pay attention to them due to aesthetic problems. Individuals can have skin lice in the ankles and form tails. The above skin changes are less than half in adults.

6. Promote and aggravate factors

1 the child's growth and development period;

2 Adults are seen in activities that suddenly pull the spinal cord, such as kicking the legs upwards, bending forward, giving birth, exercising or traffic accidents, and the hips are forced to flex forward;

3 spinal stenosis;

4 trauma, such as back injury or fall on the hips when landing.

According to the typical medical history, clinical manifestations and auxiliary examination, it is not difficult to diagnose the tethered cord syndrome. Because the disease is often asymptomatic or the symptoms develop in the early stage, a small number of patients have acute onset, although the treatment can not improve the neurological dysfunction, therefore, improve The understanding of this disease, to achieve early diagnosis and timely treatment is essential, for those with the following clinical manifestations, especially children, should be alert to this disease may: 1 lumbosacral skin hairy, abnormal pigmentation, hemangioma, skin sputum , sinus or subcutaneous mass; 2 feet and legs asymmetrical, weakness; 3 recessive spina bifida; 4 unexplained urinary incontinence or repeated urinary tract infection.

Diagnosis of tethered cord syndrome:

1 The pain is extensive and cannot be explained by a single nerve damage;

2 adults have obvious incentives before symptoms appear;

3 bladder and rectal dysfunction, frequent urinary tract infections;

4 feeling dyskinesia progressively worse;

5 have different congenital malformations, or have a history of lumbosacral surgery;

6MRI and/or CT angiography revealed abnormalities in the conic position of the spinal cord and/or thickening of the terminal filaments.

Examination of tethered cord syndrome

No special abnormalities.

1.MRI

It is the best and preferred method for the diagnosis of tethered cord syndrome. It can not only find the low spinal conus, but also clearly cause the cause of tethered cord syndrome (Figure 1).

The advantages of MRI in the diagnosis of tethered cord syndrome:

(1) MRI can clearly show the position of the conus of the spinal cord and the thickened terminal filament. It is generally believed that the conus of the spinal cord is lower than the lower edge of the lumbar 2 vertebral body and the diameter of the final filament is >2 mm, which is the difference between the lipoma and the terminal fat infiltration. At high rates, they have high signals in T1-weighted images and T2-weighted images. Sagittal imaging can determine the relationship between cones and lipomas (Fig. 2). MRI can also detect spina bifida, mitotic spinal deformities, syringomyelia and other abnormalities.

(2) Non-invasive.

MRI also has some shortcomings in the diagnosis of tethered cord syndrome, such as: 1 poor display of bone, in the relationship between skeletal malformation and tumor, spinal cone and spinal nerve root is not as clear as CT myelography; 2 postoperative Follow-up was not sensitive to changes in the position of the spinal cone.

2. CT angiography

CT myelography can show the relationship between lipoma, spinal cone, cauda equina and dura mater, which can guide the development of surgical approach. In addition, CT can show skeletal deformity, spina bifida, intraspinal tumor, etc., but CT The sensitivity and reliability of diagnosis of tethered cord syndrome are not as good as MRI. CT vertebral angiography is an invasive procedure. Therefore, for patients with typical tethered cord syndrome, MRI diagnosis is sufficient, because MRI and CT have their own advantages. Disadvantages, for patients with complex tethered cord syndrome or MRI diagnosis, combined with MRI and CT angiography.

3. X-ray film

Because MRI and CT angiography have become the main diagnostic methods of this disease, X-ray plain film and conventional spinal canal angiography have been rarely used. Currently, X-ray plain film examination is only used to understand whether there is scoliosis and preoperative vertebral body. Positioning.

4. Other inspections

(1) Neurophysiological examination: It can be used as a means to diagnose tethered cord syndrome and to judge the recovery of postoperative neurological function. Hanson et al. measured the electrophysiological condition of tendon reflex in patients with tethered cord syndrome and found that the latency of tendon reflex was shortened. It is one of the electrophysiological features of tethered cord syndrome. Boor measured SSEPs in the posterior tibial nerve of patients with secondary tethered cord syndrome and found that SSEPs were decreased or negative. After reoperation, the SSEPs of the posterior tibial nerve increased. The recovery of neurological function after terminal silk release was confirmed.

(2) B-ultrasound: For patients aged <1 year old, the posterior structure of the spinal canal is not fully matured and ossified. B-ultrasound can show the conus of the spinal cord, and it can be judged according to the pulsation of the spinal cord.

(3) bladder function test: including intravesical pressure measurement, cystoscopy and urethral sphincter electromyography, patients with tethered cord syndrome may have sphincter-detrusor ataxia, elevated intravesical pressure (sexual) Or to reduce (low-tension) and abnormal changes in bladder residual urine volume, preoperative and postoperative bladder function tests can help determine the curative effect.

Diagnosis and differentiation of tethered cord syndrome

Tethered cord syndrome needs to be differentiated from lumbar disc herniation, lumbar muscle strain, myalgia, spinal cord tumor, etc. Adults also need to be differentiated from spinal stenosis. CT and MRI scans can help to confirm the diagnosis.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.