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Chiari Malformations Chiari Malformations are hindbrain (back of the skull) anomalies involving displacement of the tonsils of the cerebellum into the spinal canal. Chiari type I is a quite common malformation, and only rarely needs surgical intervention (only when causing symptoms such as headache or pressure on the brainstem). The headaches caused by a Chiari malformation are often associated with laughing, straining, coughing and sometimes physical activity. A syrinx or syringomyelia (cavity in the spinal cord tissue) and scoliosis (curvature of the spine) can be associated with Chiari. Chiari type II is associated with Spina Bifida. Tethered Cord Syndrome What is a Tethered Spinal Cord? Tethered spinal cord syndrome is a condition caused by tissue attachments that restrict the movement and growth of the spinal cord within the spinal column. As the spinal column grows, the restricted cord stretches beyond its tolerance which can then result in lower spinal cord dysfunction. The result is a spinal cord that is stretched beyond its tolerance which damages nerve cells, nerve fibers, and blood vessels. Tethered spinal cord syndrome may go undiagnosed until adulthood, when sensory and motor problems and loss of bowel and bladder control emerge. This delayed presentation of symptoms is related to the degree of strain placed on the spinal cord over time. Disorders which can lead to tethered cord syndrome include:
The most common signs of tethered cord syndrome include loss of function in the legs and/or loss of bladder or bowel control. The symptoms and signs of a tethered cord are not always obvious and may result in a delayed diagnosis. The neurological defect that results from abnormal stretching of the spinal cord may not be reversed by surgery, so it is important to diagnose this condition as soon as possible. Some signs and symptoms include:
Patients suspected of having tethered cord may go through the following steps for evaluation and treatment:
What is the prognosis? With treatment, individuals with tethered spinal cord syndrome have a normal life expectancy. However, some neurological and motor impairment may not be fully correctable. Myelomeningocele / Spina Bifida Myelomeningocele is one of the most common birth defects of the nervous system. It is a neural tube defect in which the bones of the spine do not completely form, and the spinal canal is incomplete. This allows the spinal cord and meninges (the membranes covering the spinal cord) to protrude out of the child's back. The spinal cord is exposed through the opening in the spine, resulting in partial or complete paralysis of the parts of the body below the spinal opening. The affected individual may be unable to walk and may have bowel and urinary dysfunction. Causes The cause of myelomeningocele is unknown. However, folic acid deficiency is thought to play a part in neural tube defects. Also, if a child is born with myelomeningocele, subsequent children in that family have a higher risk than the general population. A viral cause or trigger has been theorized because there is a higher incidence of the defect in children born in the early winter months. Research also indicates possible environmental factors such as radiation. Other congenital disorders may also be present in the child, usually disorders of the spinal cord or the musculoskeletal system such as hydrocephalus (which may effect as many as 90% of children with myelomeningocele), syringomyelia, hip dislocation, or similar disorders. Symptoms Symptoms include partial or complete paralysis of the legs, with partial or complete lack of sensation, and may include loss of bladder or bowel control. The exposed spinal cord is susceptible to infection (meningitis). Visible sac-like protrusion on the mid to lower back of a newborn (not translucent when a light is shone from behind the sac) Weakness of the hips, legs, or feet of a newborn. Myelomeningocele is a visible defect after the child is born. Neurologic examination may indicate loss of neurologic functions below the defect. For example, response of the infant to pinpricks at various locations may indicate the level where sensation is maintained. Diagnosis
Before surgery, the infant must be handled carefully to reduce damage to the exposed spinal cord. This may include positioning, protective devices, and modifications in the methods of handling, feeding, bathing and caring for the infant. Orthopedic intervention or physical therapy may be needed to treat musculoskeletal symptoms. Other neurologic losses are treated according to the type and extent of the loss of function. The goal of these interventions is to minimize future disability and maximize functioning. Occasionally, surgical shunting to correct hydrocephalus causes the myelomeningocele to spontaneously reduce, and normal growth of the child may cover the defect. Lipomas and Lipomyelomeningoceles Spinal cord lipomas are a fatty mass or tumor within the spinal cord and are usually associated with spina bifida but will, in rare circumstances occur among adult men and women who do not have spina bifida. Lipomyelomeningoceles, congenital lesions due to the failure of closure of spinal bones associated with spina bifida, usually emerge within the first year of life. Lipomyelomeningoceles affects females more frequently than males. Symptoms of Spinal Cord Lipomas A gradual compression of the spinal cord causes numbness or tingling for the patient. In extreme cases, there is weakness, difficulty in urination or bowel movements, incontinence and stiffness of the extremities. Symptoms of Lipomyelomeningoceles Identified by abnormal fat accumulation that starts below the level of the skin and extends through the bony opening to the spinal cord, more than 90 percent of patients will have an obvious soft tissue swelling over the spine in the lumbosacral region. While not painful, patients can lose neurological function over a broad range of time. Typical neurological symptoms for adolescents and adults are weakness and bladder and bowel incontinence. Pain may be the force behind seeking treatment. Diagnosing and Treating Spinal Cord Lipomas and Lipomyelomeningoceles MRI's give exceptional anatomical details and can help surgeons plan the operative procedure. Conventional x-rays will show spina bifida in most cases. Lipomas are removed the same as other spinal cord tumors, through a laminectomy which debulks the fatty mass. There is no other recommended treatment method. Surgical treatment is indicated at two months of age or at the time of diagnosis if the patient is older. The goals of surgery are to release the attachment of the fat to the spinal cord and reduce the bulk of the fatty tumor. Dermal Sinus Tract What is a dermal sinus? A Congenital Dermal Sinus is a tract lined by stratified squamous epithelium found in, or very near, the midline anywhere from the nasal bridge to the coccyx (tailbone). The tract may end just below the skin surface or may extend to the conus medullaris (part of the spinal cord) or the central canal of the spinal cord from the back, the fourth ventricle from the occipital region, or the crista galli from the nasal bridge. Symptoms A Spinal Dermal Sinus may appear as a dimple or a sinus (open tract), with or without hairs, usually very close to the midline, with an opening of only 1-2 millimeters. The surrounding skin may be normal, pigmented, or distorted by an underlying mass. These tracts are a potential pathway for intradural infections, which may result in meningitis and/or an abscess. The contents of the dermal sinus causing sterile (chemical) meningitis may also irritate the superficial skin. If the tract expands into the thecal sac (the sac that contains the spinal cord) to form a cyst, the mass may present as a tethered cord. In these circumstances bladder dysfunction is usually the first manifestation. Diagnosis If the tract is seen initially following birth, a MRI should be obtained. MRI also shows masses within the canal. Treatment Sinuses above the lumbosacral region should be surgically removed. Although approximately 25% of presumed sacral sinuses seen at birth will regress to a deep dimple on follow-up, it is recommended that all dermal sinuses should be surgically explored and fully excised prior to the development of neurologic deficit or signs of infection. The results following intradural infection are never as good as when undertaken prior to infection. Sinuses that terminate on the tip of the coccyx rarely penetrate the dura, and may not need to be treated unless local infection occurs. Diastematomyelia - Split Cord Malformation What is Diastematomyelia? Split cord malformation (diastematomyelia) is a complex congenital condition where the spinal cord is split into two halves, each half usually functioning normally. The split is in a plane running front to back. The split in the cord can occur at any level and the split cords may reunite or not at some point below the split. Occasionally there is no obvious cause of the split but usually there is bone, cartilage or fibrous tissue that is between the two halves of the spinal cord. The presence of the tissue splitting the spinal cord causes tethering. The surgical procedure is to remove any tissue that is between the two split cords, thus releasing any tethering that is present. What are the symptoms? The signs and symptoms of diastematomyelia, as well as tethered spine (which often occurs with diastematomyelia), may appear at any time of life, although females are affected much more commonly than males. Pain is the number one reason patients will visit their doctor for this problem. Other common symptoms include a decrease in strength of the legs; loss of bowel and bladder control; sexual dysfunction; deformity of the legs, feet or hips; back or leg pain; loss of reflexes and sensation in the legs; and curvature of the spine. Often there are skin abnomalities overlying the tethered cord such as midline dimples, sinuses or tracts leading from the skin toward the spinal cord, birthmarks, fatty lumps, or small tufts of hair. What is the prognosis? The presence of diastematomyelia has no influence on the prognosis when spina bifida is present. When diastematomyelia presents as a closed neural tube defect, the prognosis for neurological function may be enhanced by early surgical removal of the septum, dural reconstruction into a single tube, excision of associated developmental masses and division of the tethering filum. Syringomyelia Syringomyelia (SM) is a disorder in which a cyst forms within the spinal cord. This cyst, called a syrinx, expands and elongates over time, destroying the center of the cord. Since the spinal cord connects the brain to the nerves in the extremities, this damage may result in pain, weakness, and stiffness in the back, shoulders, arms or legs. Other symptoms may include headaches and loss of the ability to feel extremes of hot or cold, especially in the hands and disruption in body temperature. SM may also adversely affect sweating, sexual function and bladder and bowel control. Symptoms Each patient experiences a different combination of symptoms. Magnetic resonance imaging (MRI) has significantly increased the number of syringomyelia cases diagnosed in the beginning stages of the disorder. Signs of the disorder tend to develop slowly, although sudden onset may occur with coughing or straining. If not treated surgically, syringomyelia often leads to progressive weakness in the arms and legs, loss of hand sensation, and chronic, severe pain. In most cases, the disorder is related to a congenital abnormality of the brain called a Chiari I malformation. This malformation occurs during the development of the fetus and causes the lower part of the cerebellum to protrude from its normal location in the back of the head into the cervical or neck portion of the spinal canal. Syringomyelia may occur as a complication of trauma, meningitis, hemorrhage, a tumor, or arachnoiditis. Symptoms may appear months or even years after the initial injury, starting with pain, weakness, and sensory impairment originating at the site of trauma. How is Syringomyelia diagnosed? MRI (Magnetic Resonance Imaging) is the leading diagnostic tool used in determining SM. The MR imager takes pictures of body structures, such as the brain and spinal cord, in vivid detail. MRI Testing will show the syrinx in the spine or any other conditions, such as the presence of a tumor. MRI is safe, painless, and informative and has greatly improved the diagnosis of syringomyelia. Is there any treatment? Surgery is usually recommended for syringomyelia patients. Recurrence of syringomyelia after surgery may make additional operations necessary; these may not be completely successful over the long term. In some patients it may be necessary to drain the syrinx, which can be accomplished using a catheter, drainage tubes, and valves. In the absence of symptoms, syringomyelia is usually not treated. In addition, a physician may recommend not treating the condition in patients of advanced age or in cases where there is no progression of symptoms. Whether treated or not, many patients will be told to avoid activities that involve straining. What are the different forms of SM? Generally, there are two forms of SM. The disorder may be related to a congenital abnormality of the brain called Arnold Chiari malformation. A syrinx may then develop in the cervical region of the spinal cord; this is referred to as communicating syringomyelia. Some people with this form of the disorder also have hydrocephalus (water on the brain), a condition in which CSF accumulates in the skull, or arachnoiditis, in which a covering of the spinal cord is inflamed. The second major form of SM occurs as a complication of trauma, meningitis, hemmorrhage or tumor. Here, the cyst or syrinx develops in a segment of the spinal cord damaged by one or more of these conditions. The syrinx may start to expand; this is sometimes referred to as noncommunicating syringomyelia. What is the prognosis? Symptoms usually begin between the ages of 25 and 40 and may worsen with straining or any activity that causes cerebrospinal fluid pressure to fluctuate. Some patients, however, may have long periods of stability. Surgery results in stabilization or modest improvement in symptoms for most patients. Delay in treatment may result in irreversible spinal cord injury. The condition may lie dormant and undetected for months or years until a symptom or variety of symptoms become bothersome enough to warrant medical attention. Many people with 8M are not diagnosed until mid-life. A number of medical conditions can cause an obstruction in the normal flow of cerebrospinal fluid (CSF), redirecting it to the spinal cord itself. This results in the formation of a syrinx (cyst that fills with CSF). Pressure differences along the spine cause the fluid to move within the cyst. It is believed that this continual movement of fluid results in cyst growth and further damage to the spinal cord and connecting nerves. |
