Spinal Cord Tethering Syndrome

　　1. Various Congenital Spinal Development Abnormalities

　　Such conditions as meningocele, myelomeningocele, and spinal cord meningocele are caused by incomplete closure of the neural tube at the end. Most cases after birth underwent repair surgery within a few days, the purpose of which was to repair the abnormal nerve tissue as much as possible to a normal state. It is important to prevent cerebrospinal fluid leakage, but adhesions during the healing process of the reconstructed spinal cord dura mater tube can cause adhesion at the end of the spinal cord.

　　2. Spinal Cord Lipoma and Dura Mater and Intradural Lipoma

　　It is caused by the premature separation of the neural ectoderm and the epidermal ectoderm, with mesenchymal fat cells entering the unsealed neural ectoderm. The fatty tissue can enter the central part of the spinal cord or connect through the separated vertebral arch and subcutaneous fatty tissue, fixing the spinal cord cone. And in cases after infancy, inflammation occurs in the fat in the subarachnoid cavity, causing fibrosis, adhesion, and scar formation around the nerve roots, leading to adhesion.

　　3. Hair Follicle Sinus

　　It is caused by the poor differentiation of the neural ectoderm and the epidermal ectoderm, forming a cord-like tissue locally from the skin through the subcutaneous tissue and spine, causing adhesion to the spinal cord cone. It can also be caused by the expansion and proliferation of the tissue of the hair follicle sinus wall, producing dermoid cysts, epidermoid cysts, and teratomas, which can wrap around or pull the spinal cord nerves, causing adhesion.

　　4. Spinal Cord Split

　　The occurrence mechanism of spinal cord split is believed by some to be caused by factors other than nerves, namely, the abnormal development of the vertebral bones; some also believe it to be due to the abnormal development of nerves, which then leads to the abnormal development of vertebral bones. The spinal cord is separated into two parts, with the dura mater tube accompanying the split and non-split types. That is, Type I: Double dura mater sac and double spinal cord type, where the spinal cord is completely separated at the longitudinal split by fibrous, cartilaginous, or bony spines, becoming two parts, each with its own dura mater and arachnoid membrane. The spinal cord is pulled by the separator, causing symptoms. Type II: Common dura mater sac and double spinal cord type, where the dura mater is often separated by fibrous septa at the longitudinal split, into two parts, but with a common dura mater and arachnoid membrane, generally without clinical symptoms.

　　5, Taut filum

      It is due to the obstruction in the process of the formation of the filum terminale from the immature terminal part of the spinal cord, causing the filum terminale to be thicker than the normal one, and the remaining part to cause spinal cord tethering.

　　6, Neurogenic enteric cyst

　　So-called neurogenic enteric cysts are a condition where the incomplete closure of the notochordal canal allows the mesentery of the intestinal tract to communicate with the tissues in front of the spine. Depending on the degree of closure and communication of the notochordal canal, there can be bone defects in front of the spine, known as enterocoelus and intestinal cysts within and outside the spinal canal.

　　7, Complications such as adhesions after lumbar sacral meningocele surgery

     Some scholars have statistics that this type of condition can account for 10% to 20% of all surgical cases.

　　Patients with spinal cord tethering syndrome often have various congenital malformations, especially a higher chance of primary spinal cord tethering syndrome with congenital malformations. Spinal deformities include spina bifida, scoliosis, anterior and posterior prominence, forked vertebrae, hemivertebrae, and vertebral fusion. The sacrum often fails to develop, accompanied by an enlarged spinal canal. Lower limb deformities are common, with high-arch feet, followed by clubfoot and incomplete lower limb development. Neurological malformations are common, including various meningocele and myelomeningoceles, hydrocephalus, cerebral palsy, or incomplete brain development. Skin abnormalities include skin sinus tracts, skin spots or nevi, scar-like tissue, skin indentations, abundant hair in the lumbar sacral area, and subcutaneous lipomas or hemangiomas, as well as other systemic malformations such as cleft lip and cleft palate.

　　Some scholars believe that after spinal cord tethering, the activity of the cauda equina at the tip of the spinal cord is restricted, resulting in a series of clinical symptoms. They emphasize that it is of therapeutic significance to release the spinal cord tethering during surgery and allow the cauda equina to rise. However, some people believe that although there is no significant difference in tension involved, the mechanical effects caused by this static extension itself is not the main reason for the appearance of symptoms, and its significance varies according to the pathological condition. In daily movements, the repeated flexion and extension of the spine also cause repeated relaxation and tension of the tethered spinal cord. In fact, dynamic factors play an important role in patients with symptoms caused and exacerbated by posture. In cases of lumbar sacral fatty spinal meningocele, with the progression of the disease, fibrosis is produced due to adhesive arachnoiditis. Due to the attachment and invasion of lipomas in the conus medullaris, not only does it cause tethering, but the contracture around the nerve roots also hinders the rise of the spinal cord. In this case, relying solely on surgical resection of the lipoma in the conus medullaris to allow only a slight rise of the conus medullaris does not have great significance.

　　The dietary treatment for spinal cord tethering syndrome includes a balanced diet, eating more fruits and vegetables with high fiber, eating more eggs and soybeans with high protein, and paying attention to light food. Moderate exercise can also be performed.

　　It is best to avoid cold and raw foods, smoking, drinking, spicy foods, coffee, and other刺激性 foods with the spinal cord tethering syndrome. Pay attention to eat less chili, raw garlic, and other刺激性 foods or spicy foods, and do not eat cold foods.

　　1. MRI is the best and first choice for diagnosing tethered cord syndrome.It can not only detect a low conus medullaris but also identify the etiology of tethered cord syndrome.

　　Advantages of MRI in the diagnosis of tethered cord syndrome:

　　(1) MRI can clearly show the position and thickening of the conus medullaris, and it is generally considered that a low position of the conus medullaris below the inferior margin of the L2 vertebral body and a diameter of the filum greater than 2mm are abnormal. MRI has high resolution for lipoma and fatty infiltration of the filum, which appear as high signals in T1-weighted and T2-weighted images. Sagittal imaging can determine the relationship between the conus medullaris and the lipoma. MRI can also detect other abnormalities such as spina bifida, split cord malformation, syringomyelia, etc.

　　(2) Non-invasive

　　There are some limitations in the diagnosis of tethered cord syndrome with MRI. For example: ① The display of bones is poor, and it is not as clear as CT myelography in distinguishing the relationship between skeletal deformities, tumors, conus medullaris, and spinal nerve roots; ② postoperative follow-up is not sensitive to changes in the position of the conus medullaris.

　　2. CT myelography

　　CT myelography can show the relationship between lipoma, conus medullaris, cauda equina, and dura mater, which has a guiding effect on the planning of surgical approaches. In addition, CT can show skeletal deformities, spina bifida, intraspinal tumors, and other conditions. However, the sensitivity and reliability of CT in diagnosing tethered cord syndrome are not as good as MRI, and CT myelography is an invasive examination. Therefore, for patients with typical tethered cord syndrome, MRI diagnosis is sufficient. Due to the respective advantages and disadvantages of MRI and CT, for complex tethered cord syndrome or cases with suspected MRI diagnosis, the combined application of MRI and CT myelography is required.

　　3. X-ray film

　　As MRI and CT myelography have become the main diagnostic methods for this disease, X-ray films and routine myelography are rarely used. Currently, X-ray film examination is only used to understand whether there is a spinal curvature deformity and to locate the vertebrae before surgery.

　　4. Other examinations

　　(1) Neuroelectrophysiological examination: It can be used as a means of diagnosing tethered cord syndrome and judging the recovery of postoperative neurological function. Hanson et al. measured the electrophysiological condition of the sacral reflex in patients with tethered cord syndrome and found that the shortening of the sacral reflex latency is one of the electrophysiological characteristics of tethered cord syndrome. Boor measured the SSEPs of the posterior tibial nerve in patients with secondary tethered cord syndrome and found that SSEPs were reduced or negative. After the second operation to release the filum, the SSEPs of the posterior tibial nerve increased, confirming the recovery of neurological function after the operation.

　　(2) Ultrasound: for age

　　(3) Bladder function examination: including bladder pressure measurement, cystoscopy, and electromyography of the urethral sphincter muscle. Patients with tethered cord syndrome may exhibit abnormalities such as coordination disorders between the sphincter and detrusor muscles, increased bladder pressure (spastic), or decreased bladder pressure (hypotonic), as well as changes in the amount of residual urine in the bladder. Preoperative and postoperative bladder function examinations are helpful in determining the efficacy of surgery.

　　1. Pay attention to a balanced diet and nutrition in daily life, eat more fruits and vegetables, high-fiber foods, more eggs, soybeans, and other high-protein foods, and pay attention to eating light and easily digestible foods. Avoid eating cold, spicy, and刺激性 foods, avoid smoking and drinking, avoid drinking coffee and other stimulating foods.

　　2. Pay attention to avoid overexertion, avoid staying up late, maintain an optimistic attitude, and actively adopt symptomatic treatment.

　　With the improvement of diagnostic levels, the improvement of surgical instruments, the increase of anesthetic safety, and the continuous development of microsurgical operations, the timing of surgical treatment for tethered cord syndrome has been greatly advanced at present. The only means of treatment for tethered cord is surgical release. The purpose of the surgery is to remove osteophytes, fibrous septa, the dural sleeve, and release the fibrous neurovascular bundles and their adhesions, relieve the tethering of the spinal cord, correct local twists and compressions, restore the microcirculation of the damaged area, and promote the maximum recovery of nerve function. Some scholars believe that persistent standing and lumbar flexion activities can potentially cause damage to the spinal cord in patients with tethered cord syndrome, exacerbating symptoms. Experimental and surgical findings indicate that spinal cord circulation disorders are an important cause of the disease. After the tethering is released, the local blood supply of the spinal cord is significantly improved. Most doctors advocate that except for children with severe hydrocephalus and other serious complications, surgical treatment should be adopted as soon as the diagnosis is confirmed, and the earlier the surgery, the better. Some scholars have compared the follow-up of surgical patients in the pediatric and adult groups and found that the pediatric group has better postoperative effects, suggesting that asymptomatic patients with tethered cord syndrome should also undergo surgery to prevent ischemic degeneration of nervous tissue. However, many doctors also believe that before other symptoms appear, close observation can be conducted, and surgery should be performed promptly once symptoms appear.