The spinal cord is located in the spinal canal, and as people grow and develop, the spinal canal grows faster than the spinal cord, so the lower end of the spinal cord rises gradually in relation to the lower end of the spinal canal. Spinal cord tethering is a condition in which the lower end of the spinal cord cannot rise normally due to various reasons, making its position lower than normal. It is one of the main pathological mechanisms leading to neurological symptoms due to various congenital developmental abnormalities, and the resulting series of clinical manifestations is called spinal cord tethering syndrome, also known as spinal cord tethering syndrome.
Etiology
Various congenital developmental abnormalities of the spinal cord and spinal ends can lead to spinal cord tethering, such as occult spina bifida, spondylolisthesis, spinal cord spondylolisthesis, spinal cord end filament tension, lumbosacral spinal canal lipoma, congenital cysts and latent hair sinus. In addition to the aforementioned congenital factors, postoperative adhesions in the lumbosacral spinal bulge can also lead to spinal cord reembolization. It is generally believed that spinal cord embolism causes blood circulation disorders at the end of the spinal cord, resulting in the corresponding neurological symptoms.
Clinical manifestations
The clinical manifestations of spinal cord embolism syndrome (spinal cord tethering syndrome) are similar to those of spina bifida, mainly in the following aspects.
Skin changes in the lumbosacral region
Lumbosacral skin bulges or depressions, possibly with discharge or infection; hirsutism; large bulging masses. These predict the presence of occult spina bifida, latent hair sinus, spinal bulge, etc., which may be combined with spinal cord embolism.
Motor disorders of the lower extremities
These include abnormal walking, weakness, deformity, and pain in the lower extremities, and may be combined with scoliosis.
Sensory disorders of the lower extremities
The symptoms include abnormal sensation and pain in the lower extremities, perineum and low back.
Dysfunction of urination and defecation
The common manifestations are urinary retention, difficulty in urination, urinary incontinence, more frequent urination, less than normal volume each time, etc.; constipation, constipation, or incontinence.
Diagnosis and examination
Magnetic resonance imaging (MRI) is the main method to diagnose spinal cord embolism, it can not only clarify the presence of spinal cord embolism, but also understand the coexistence of other pathological changes, such as lipoma, spinal cord longitudinal bifida, etc. X-ray plain film can determine the presence of spina bifida. Ultrasound and urodynamic examination of the urinary tract are performed to evaluate the degree of urinary tract involvement and spinal cord neurological impairment in conjunction with urinary and fecal function.
Treatment
Surgery to loosen the embolus and remove lesions such as lipoma.
Our principles of surgical treatment for spinal cord embolism syndrome]
The spinal cord embolism is already organically altered by the time symptoms appear, so we cannot restore it to normal, but can only treat it appropriately so that it does not progress. The symptoms of spinal cord embolism syndrome may be the result of destructive damage to the nervous system, which is usually irreparable, and treatment is simply to keep the damage from getting worse. Symptoms may also be the result of irritative or incomplete damage to the nervous system, when surgical treatment may have the dual effect of reducing symptoms and preventing progression.
Therefore, the fundamental goal of surgical treatment of spinal cord tethering syndrome (spinal cord tethering syndrome) is to prevent the progression of the disease, and some patients may have improved motor and sensory function of the lower extremities, and even urinary and fecal function as a result. In general, the presence of bowel and urinary dysfunction is often indicative of a poor prognosis, and surgery usually does not result in improvement of bowel and urinary dysfunction, lower extremity and foot deformities, but may result in some improvement of pain and incomplete muscle strength loss. The deformities of the lower extremities and feet can be partially improved by orthopedic surgery. Therefore, for many patients with spinal cord embolism syndrome, especially in children, a combination of spinal cord spine surgery or neurosurgery, urology and orthopedic surgery is required.
For patients with normal spinal cord embolism, including those with skin changes in the lumbosacral region and sensory and motor deficits in the lower extremities, early systematic examination, evaluation, and surgery are recommended; for patients who already have urinary and fecal dysfunction, surgery should be selected in the context of their general condition and relevant investigations, and most of these patients can and need surgery.
Patients should be operated with the concept of minimally invasive surgery, insist on microsurgery, and cooperate with neurophysiological monitoring if necessary, in order to release the embolism as completely as possible, avoid nerve damage, reduce re-adhesion and embolism, and prevent postoperative wound complications.
Postoperative patients are followed up and given the best possible guidance on the prevention and treatment of urinary tract dysfunction, rehabilitation of lower limb movement and sensation, and correction of lower limb deformities. We believe it is detrimental to patients to focus solely on embolization surgery and to neglect proper guidance for the continued treatment of these dysfunctions.
The concept of spina bifida usually encompasses multiple congenital pathologic changes that occur in the spine. These pathologic forms include congenital defects on the posterior aspect of one or more segments of the spinal canal, spinal cord spondylolisthesis (overt spina bifida), spinal cord hypoplasia (i.e., spinal cord embolism), lipomas, skin latent sinuses alone or in association with tumors, and longitudinal spinal bifida. A posterior congenital defect of one or more segments of the spinal canal, known as spinal closure insufficiency, is the initial origin of the term spina bifida and is its accepted diagnostic criterion. Spinal cord spondylolisthesis is a dominant spina bifida.
Occult spina bifida usually takes the following pathological forms: spinal cone hypoplasia (spinal cord embolism), lipoma, shortened and thickened end filaments, fibrous tangles, spinal longitudinal fissures, cutaneous sinus tracts, spinal cavities, dermatomal cysts, and epithelioid cysts. Spinal cord embolism is basically the common pathology of most lumbosacral occult spina bifida, and it is the main pathophysiological mechanism of neurological damage caused by spina bifida.
Clinicians, especially in China, are accustomed to separately describing the various pathological forms of occult spina bifida and giving a diagnosis based on them, such as spinal cord embolism syndrome, lipoma, spinal cord cavernosity, terminal filament tension syndrome, and spinal longitudinal bifida. However, in fact, the diagnosis of these pathological forms often does not reflect the full picture of the disease, and the actual pathological forms may often be more complex and tend to occur simultaneously.
In summary, spinal cord embolism syndrome is part of the disease of spina bifida, and it is rare to have a separate spinal cord embolism without spina bifida. While spinal cord tethering is the main pathologic form of neurological damage caused by spina bifida, the diagnosis of spinal cord tethering syndrome alone is often incomplete in many cases because it often coexists with other pathologic forms, and it is important to recognize this and to perform a detailed analysis of the various pathologic forms with the necessary preoperative tests to improve the surgical outcome.