Synonyms of Tethered Cord SyndromeTCStethered spinal cord syndrome
General Discussion
Tethered cord syndrome is a stretch-induced functional disorder associated with the fixation (tethering) effect of inelastic tissue on the caudal spinal cord, limiting its movement. This abnormal attachment is associated with progressive stretching and increased tension of the spinal cord as a child ages, potentially resulting in a variety of neurological and other symptoms. Due to the variation of the growth rate of the spinal cord and the spinal column, the progression of neurological signs and symptoms is highly variable. Some individuals present with tethered cord syndrome at birth (so-called congenital), while others develop the symptomatology in infancy or early childhood. Other individuals may not develop any noticeable symptoms until adulthood. Although some authors call these cases acquired, the majority of these cases are mostly developmental, corresponding to the progressive development of excess fibrous connective tissue (fibrosis) in the filum terminale. The filum terminale is a strand of tissue that bridges the spinal cord tip and the tailbone (sacrum). The inelastic structures in children originated from defective closure of the neural tube (the precursor of the spinal cord) during embryonic development, eventually forming a condition known as spina bifida. Because of its functional (physiological) nature, tethered cord syndrome can be reversible if surgically treated in its early stage.
Signs & Symptoms
The specific symptoms, severity and progression of tethered cord syndrome vary from one individual to another. In most cases, individuals experience symptoms during childhood. In some cases, symptoms are stabilized in childhood, but become apparent only in adulthood.
A high percentage of pediatric cases, with tethered cord syndrome show cutaneous tufts of hair, skin tags, dimples, benign fatty tumors, skin discoloration or hemangiomas. Additional symptoms include lower back pain that worsens with activity and improves with rest (although rarely complained by young children, because of inability to express pain), leg pain or numbness, difficulty walking (gait disturbances), foot and spinal deformities, such as abnormal side-to-side curvature of the spine (scoliosis) or hollow lowback (exaggerated lordosis), high-arched feet and hammertoes, and less commonly difference in leg strength. Tethered cord syndrome can also cause difficulties with bladder and bowel control. Affected children may experience involuntary urination or defecation (incontinence) and repeated urinary tract infections. Symptoms in children may be slowly progressive.
Adult onset of tethered cord syndrome was considered to be rare for many years, but an increasing number of cases have been reported in recent years. This trend is due to improvement in neurological examinations and in the interpretation of imaging studies. Symptoms common to adult tethered cord syndrome include constant, often severe back and leg pain, which may extend to the rectum and genital area in some cases. Progressive sensory and motor deficits may affect the legs potentially resulting in numbness, weakness or muscle wasting (atrophy) in the affected areas. More than 50 percent of the affected individuals experience bladder and bowel dysfunction, manifested by increased frequency or urgency of urination or constipation. In some cases, a fluid-filled cavity (syrinx) is found, sometimes associated with typical signs and symptoms syringomyelia, such as burning pain in the analgesic (painless on examination) area, decreased motor function and loss of muscle mass, or occasional headaches,
Causes
Tethered cord syndrome can be of a congenital (primary) origin or acquired (secondary or developmental).
Various congenital anomalies, particularly spina bifida, are often associated with congenital tethered cord syndrome. Spina bifida is a birth defect due to incomplete closure of the posterior spinal cord and bony vertebral arch (lamina). Many cases with this anomaly leave a portion of the spinal cord protruded through the spinal canal, typically forming a myelomeningocele. Such birth defects, if located in the tail (caudal) end of the spinal cord, can cause tethered cord syndrome. In others, where the anomalous structure is attached to the wide area of the spinal cord, signs and symptoms reflect local effects on the spinal cord, and not stretched-induced dysfunction (tethered cord syndrome).
Types of spina bifida associated with tethered cord syndrome include an abnormal connection of inelastic tissue to the caudal spinal cord, dermal sinus tract, which extends from the intraspinal connective tissue to the skin (dermal sinus tract), a split spinal cord (diastematomyelia), and a benign fatty mass or tumor (lipoma) continuous to the spinal cord. The other fatty anomaly is a lipomyelomeningocele, in which a lipoma extrudes from the spinal canal underneath the lining of the spinal cord (meninges), but covered by normal skin.
In many individuals, tethered cord syndrome is caused mechanically by an inelastic often-thickened filum terminale. This structure, which is composed of glial tissue (the supportive structure of nerve cells) and covered by pia mater, is a delicate strand of fibrous tissue, bridging the spinal cord tip and the sacrum (the tailbone). Due to its high viscoelasticity, the filum allows movement of the spinal cord. If abnormal fibrous tissue grows into the filum and replaces glial tissue, the filum loses its elasticity and abnormally fixes (tethers) the spinal cord, and becomes the mechanical cause of tethered cord syndrome. The inelastic filum is commonly thickened in children, but found less frequently in adolescents and adults.
Genetic factors are involved in development of anomalous caudal spine and spinal cord, e.g. myelomeningocele, and in some cases of lipomyelomeningocele. Since tethered cord syndrome is a physiological disorder and develops only when it is abnormally stretched, it cannot be connected to genetic factors, unless the congenital susceptibility of spinal cord to oxidative metabolic impairment is proven.
Secondary causes of tethered cord syndrome include tumors, infection or the development of scar tissue (fibrosis) connected to the spinal cord. Tethered cord syndrome may develop as a complication of spinal surgery. Trauma to the spine results in a band of scar formation attached to the spinal cord and can cause tethered cord syndrome. However, some researchers believe that trauma alone is not enough to cause the disorder. They propose that tethering and abnormal tension were already present before the trauma, which worsened the condition.
Some researchers have speculated that some cases of tethered cord syndrome that occur due to anomalies that can cause stretching of the spinal cord may have a genetic basis or that some individuals are genetically predisposed to developing the disorder in these specific cases. Although genetic factors are found in patients with myelominingocele, more research is necessary to determine the exact role that genetic factors play in the development of stretch-causing anomalies.
Pathophysiologically, neuronal dysfunction in tethered cord syndrome results partly from inability for the spinal cord neurons to utilize oxygen, that is, the impaired oxidative metabolism, partly due to lack of oxygen supply (ischemic effect), and partly to ion channel dysfunction directly related neuronal membrane stretching. The spinal cord consists of a long bundle of neuronal fibers (axons) and the interneurons that connect sensory and motor fibers within the cord. During gestation, the spinal cord is continuous to the brain and runs in the spinal canal to the tailbone area. In general, the spinal cord is protected from external insult by two mechanisms; 1) encased in the spinal column, that is, a rigid structure, 2) floating free in the spinal fluid space of the spinal canal. In addition, the spinal cord is continuous to the filum terminale, which is extremely extensible because of its high viscoelasticity. If the spinal cord is tethered at its caudal end, and if the spinal cord is unable to grow as fast as the vertebral column in childhood, the spinal cord is stretched beyond its physiological tolerance. In turn, this causes various metabolic abnormalities in the spinal cord and, ultimately, the various neurological symptoms of this disorder.
Normally, the spinal cord ascends in the spinal canal as the spinal column starts to grow faster than the spinal cord at 9th weeks of gestation. Consequently, the spinal cord is pulled upwards due to this growth difference. By three months of age, the tip of the spinal cord reaches the normal level between T12 and L2 vertebrae. An elastic, extremely extensible filum allows for the ascension of the less elastic spinal cord. If the filum becomes inelastic in an embryo, then the spinal cord tip is anchored and ceases to ascend. Compensatory to the stretching force, the lower (lumbosacral) spinal cord naturally grows more than seen in normal subjects, and becomes elongated. Associated with tethered cord syndrome, the elongated cord is often noted in children, but less often in adults.
In most cases, the abnormal tension of the spinal cord increases over time, but disturbing symptoms often develop quickly during a few weeks. Certain activities such as flexing or extending the lower spinal column can put additional tension on the spinal cord and often worsen tethered cord syndrome. Participation in physical activities such as strenuous sports and ballet dancing with high kicks can worsen the signs and symptoms. Special physical features such as abnormal curvature of the spine (scoliosis and exaggerated lordosis) are the potential for symptomatic acceleration. It should be warned that slight flexion of the lower (lumbosacral) spine always aggravates back pain by spinal cord stretching.
Affect
คำเหมือนของกลุ่มอาการสันหลังคุณสาย SyndromeTCStetheredสนทนาทั่วไปคุณสายเป็นความยืดที่เกิดทำงานผิดปกติเกี่ยวข้องกับปฏิกิริยาการตรึง (tethering) ผลของเนื้อเยื่อ inelastic caudal สันหลัง การจำกัดการเคลื่อนย้าย สิ่งที่แนบนี้ผิดปกติที่สัมพันธ์กับการยืดแบบก้าวหน้าและความตึงเครียดที่เพิ่มขึ้นของสันหลังเป็นเด็กอายุ อาจเกิดอาการของระบบประสาท และอื่น ๆ ให้เลือกมากมาย ความก้าวหน้าของอาการและอาการแสดงของระบบประสาทจะไม่ผันแปรสูงเนื่องจากความผันแปรของอัตราการเติบโตของสันหลังและในสันหลัง บางคนนำเสนอสายทุกอาการที่เกิด (เรียกว่าธา), ใน ขณะที่คนอื่นพัฒนา symptomatology ที่ในวัยเด็กหรือปฐมวัย บุคคลอื่น ๆ อาจพัฒนาอาการใด ๆ อย่างเห็นได้ชัดจนถึงวัยผู้ใหญ่ได้ แม้ว่าผู้เขียนบางเรียกกล่าวมา ส่วนใหญ่ของกรณีเหล่านี้ได้ส่วนใหญ่พัฒนา ที่สอดคล้องกับการพัฒนาก้าวหน้าเกินข้อเนื้อเยื่อเกี่ยวพัน (fibrosis) ใน filum terminale Filum terminale เป็นสาระของเนื้อเยื่อที่สะพานปลายสันหลังและ tailbone (sacrum) โครงสร้าง inelastic ในเด็กมาจากปิดข้อบกพร่องของท่อ neural (สารตั้งต้นของสันหลัง) ในระหว่างการพัฒนาตัวอ่อน เป็นเงื่อนไขที่เรียกว่าบูล bifida ในที่สุด เนื่องจากการทำงาน (สรีรวิทยา) ธรรมชาติ กลุ่มอาการสายคุณสามารถกลับผ่าตัดรักษาในระยะแรก ๆ ของSigns & SymptomsThe specific symptoms, severity and progression of tethered cord syndrome vary from one individual to another. In most cases, individuals experience symptoms during childhood. In some cases, symptoms are stabilized in childhood, but become apparent only in adulthood.A high percentage of pediatric cases, with tethered cord syndrome show cutaneous tufts of hair, skin tags, dimples, benign fatty tumors, skin discoloration or hemangiomas. Additional symptoms include lower back pain that worsens with activity and improves with rest (although rarely complained by young children, because of inability to express pain), leg pain or numbness, difficulty walking (gait disturbances), foot and spinal deformities, such as abnormal side-to-side curvature of the spine (scoliosis) or hollow lowback (exaggerated lordosis), high-arched feet and hammertoes, and less commonly difference in leg strength. Tethered cord syndrome can also cause difficulties with bladder and bowel control. Affected children may experience involuntary urination or defecation (incontinence) and repeated urinary tract infections. Symptoms in children may be slowly progressive.ผู้ใหญ่เริ่มมีอาการของกลุ่มอาการทุกสายถือว่าหายากหลายปี แต่หลายกรณีมีการรายงานในปีที่ผ่านมา แนวโน้มนี้เนื่องจากการปรับปรุงตรวจระบบประสาท และการตีความภาพศึกษาได้ อาการทั่วไปทุกสายผู้ใหญ่อาการรวมกลับคง มักจะรุนแรงและปวดขา ซึ่งอาจลุกลามไปยังบริเวณรูตูดและอวัยวะเพศในบางกรณี การขาดดุลทางประสาทสัมผัส และการเคลื่อนที่ก้าวหน้าอาจมีผลต่อขาอาจเกิดอาการ อ่อนแอ หรือกล้ามเนื้อเสีย (ฝ่อ) ในพื้นที่ได้รับผลกระทบ มากกว่าร้อยละ 50 ของบุคคลที่ได้รับผลกระทบพบกระเพาะปัสสาวะและลำไส้ผิดปกติ ประจักษ์โดยเพิ่มความถี่ของการปัสสาวะหรือท้องผูก ในบางกรณี เป็นช่องที่เติมน้ำมัน (หอยสังข์) พบ บางครั้งเกี่ยวข้องกับอาการทั่วไปและอาการ syringomyelia เช่นเขียนปวดบริเวณยาระงับปวด (เจ็บปวดในการตรวจสอบ) ลดฟังก์ชันมอเตอร์และสูญเสียมวลกล้ามเนื้อ หรือปวดหัวเป็นครั้งคราวทำให้เกิดกลุ่มอาการทุกสายสามารถเป็นจุดเริ่มต้น (หลัก) แต่กำเนิด หรือมา (รอง หรือพัฒนา)Various congenital anomalies, particularly spina bifida, are often associated with congenital tethered cord syndrome. Spina bifida is a birth defect due to incomplete closure of the posterior spinal cord and bony vertebral arch (lamina). Many cases with this anomaly leave a portion of the spinal cord protruded through the spinal canal, typically forming a myelomeningocele. Such birth defects, if located in the tail (caudal) end of the spinal cord, can cause tethered cord syndrome. In others, where the anomalous structure is attached to the wide area of the spinal cord, signs and symptoms reflect local effects on the spinal cord, and not stretched-induced dysfunction (tethered cord syndrome).Types of spina bifida associated with tethered cord syndrome include an abnormal connection of inelastic tissue to the caudal spinal cord, dermal sinus tract, which extends from the intraspinal connective tissue to the skin (dermal sinus tract), a split spinal cord (diastematomyelia), and a benign fatty mass or tumor (lipoma) continuous to the spinal cord. The other fatty anomaly is a lipomyelomeningocele, in which a lipoma extrudes from the spinal canal underneath the lining of the spinal cord (meninges), but covered by normal skin.In many individuals, tethered cord syndrome is caused mechanically by an inelastic often-thickened filum terminale. This structure, which is composed of glial tissue (the supportive structure of nerve cells) and covered by pia mater, is a delicate strand of fibrous tissue, bridging the spinal cord tip and the sacrum (the tailbone). Due to its high viscoelasticity, the filum allows movement of the spinal cord. If abnormal fibrous tissue grows into the filum and replaces glial tissue, the filum loses its elasticity and abnormally fixes (tethers) the spinal cord, and becomes the mechanical cause of tethered cord syndrome. The inelastic filum is commonly thickened in children, but found less frequently in adolescents and adults.Genetic factors are involved in development of anomalous caudal spine and spinal cord, e.g. myelomeningocele, and in some cases of lipomyelomeningocele. Since tethered cord syndrome is a physiological disorder and develops only when it is abnormally stretched, it cannot be connected to genetic factors, unless the congenital susceptibility of spinal cord to oxidative metabolic impairment is proven.Secondary causes of tethered cord syndrome include tumors, infection or the development of scar tissue (fibrosis) connected to the spinal cord. Tethered cord syndrome may develop as a complication of spinal surgery. Trauma to the spine results in a band of scar formation attached to the spinal cord and can cause tethered cord syndrome. However, some researchers believe that trauma alone is not enough to cause the disorder. They propose that tethering and abnormal tension were already present before the trauma, which worsened the condition.
Some researchers have speculated that some cases of tethered cord syndrome that occur due to anomalies that can cause stretching of the spinal cord may have a genetic basis or that some individuals are genetically predisposed to developing the disorder in these specific cases. Although genetic factors are found in patients with myelominingocele, more research is necessary to determine the exact role that genetic factors play in the development of stretch-causing anomalies.
Pathophysiologically, neuronal dysfunction in tethered cord syndrome results partly from inability for the spinal cord neurons to utilize oxygen, that is, the impaired oxidative metabolism, partly due to lack of oxygen supply (ischemic effect), and partly to ion channel dysfunction directly related neuronal membrane stretching. The spinal cord consists of a long bundle of neuronal fibers (axons) and the interneurons that connect sensory and motor fibers within the cord. During gestation, the spinal cord is continuous to the brain and runs in the spinal canal to the tailbone area. In general, the spinal cord is protected from external insult by two mechanisms; 1) encased in the spinal column, that is, a rigid structure, 2) floating free in the spinal fluid space of the spinal canal. In addition, the spinal cord is continuous to the filum terminale, which is extremely extensible because of its high viscoelasticity. If the spinal cord is tethered at its caudal end, and if the spinal cord is unable to grow as fast as the vertebral column in childhood, the spinal cord is stretched beyond its physiological tolerance. In turn, this causes various metabolic abnormalities in the spinal cord and, ultimately, the various neurological symptoms of this disorder.
Normally, the spinal cord ascends in the spinal canal as the spinal column starts to grow faster than the spinal cord at 9th weeks of gestation. Consequently, the spinal cord is pulled upwards due to this growth difference. By three months of age, the tip of the spinal cord reaches the normal level between T12 and L2 vertebrae. An elastic, extremely extensible filum allows for the ascension of the less elastic spinal cord. If the filum becomes inelastic in an embryo, then the spinal cord tip is anchored and ceases to ascend. Compensatory to the stretching force, the lower (lumbosacral) spinal cord naturally grows more than seen in normal subjects, and becomes elongated. Associated with tethered cord syndrome, the elongated cord is often noted in children, but less often in adults.
In most cases, the abnormal tension of the spinal cord increases over time, but disturbing symptoms often develop quickly during a few weeks. Certain activities such as flexing or extending the lower spinal column can put additional tension on the spinal cord and often worsen tethered cord syndrome. Participation in physical activities such as strenuous sports and ballet dancing with high kicks can worsen the signs and symptoms. Special physical features such as abnormal curvature of the spine (scoliosis and exaggerated lordosis) are the potential for symptomatic acceleration. It should be warned that slight flexion of the lower (lumbosacral) spine always aggravates back pain by spinal cord stretching.
Affect
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