Pediatric Neurosurgery

UBNS' pediatric neurosurgery program is led by Dr. Veetai Li-a fellowship-trained, board certified neurosurgeon and member of the Joint Section on Pediatric Neurosurgery, the American Society of Pediatric Neurosurgeons, and the Children's Oncology Group (COG). Under his leadership, the pediatric neurosurgery team specializes in the practice of minimally invasive neurosurgical techniques that allow for the more precise and less traumatic treatment of brain tumors, brain lesions, and other neurological disorders in children less than 18 years old. Pediatric conditions treated by UBNS include, but are not limited to:

• Arteriovenous malformations & fistulas
• Brain tumors
• Congenital malformations
• Craniofacial anomalies
• Epilepsy
• Hydrocephalus
• Spasticity
• Rhizotomy
• Spinal Dysraphism/Spina Bifida
• Brain & spine trauma

Treatment and diagnostic capabilities include endoscopic neurosurgery, stereotaxis, frameless stereotaxis, intraoperative functional mapping, and a host of specialized treatment programs.

Specialized Programs

Endoscopic Neurosurgery

A variety of brain conditions can now be safely treated using small, minimally invasive endoscopes. These endoscopes allow for the safe and effective treatment of hydrocephalus and other disorders. Children with multi-compartmentalized hydrocephalus requiring multiple shunts can now undergo endoscopic fenestration, reducing the number of shunts, or even eliminating the need for shunts. Endoscopic third ventriculostomy (ETV) can be performed for children with obstructive hydrocephalus from a variety of causes, and may also eliminate the need for a shunt. Small ventricular tumors may be safely removed with minimal exposure, fewer postoperative complications, and shorter hospital stays. To learn more about endoscopic procedures in both children and adults, please visit our endoscopic surgery page.

Center for Developmental Spinal Disorders

UBNS has a strong interest in children with developmental spinal disorders such as spina bifida and related disorders. The Women and Children's Hospital of Buffalo has a coordinated Center for Developmental Spinal Disorders that provides comprehensive neurosurgical, orthopedic, urological, and rehabilitative care for children with these disorders.

Surgical Treatment of Epilepsy

As a participant in the Comprehensive Epilepsy Program, UBNS provides the surgical management of children and adults with intractable epilepsy. Surgical techniques include: resection of epileptiform foci/lesion, implantation of devices for invasive monitoring, use of intraoperative functional mapping and monitoring, and implantation of vagal nerve stimulators.

Comprehensive Craniofacial Program

In association with the craniofacial clinic, our pediatric neurosurgery program offers coordinated and comprehensive care for patients with craniosynostosis and related craniofacial abnormalities. Both surgical and non-surgical options (such as molding helmets) are available for these disorders.

Brain Tumor Program

Using state-of-the-art operating microscopes, micro instruments, computer-aided stereotaxis, and endoscopy, UBNS is ideally suited to provide comprehensive care for children with brain tumors. Our pediatric neurosurgeon, Dr. Li, is a member of the Children's Oncology Group (COG) and actively participates in clinical protocols for a variety of brain tumors. The department also works closely with internationally recognized leaders in pediatric brain tumor research and treatment, and with Roswell Park Cancer Institute.

Treatments for Spasticity: Rhizotomy and Intrathecal Baclofen Pump

Many children with cerebral palsy and lower limb spasticity benefit from selective sensory rhizotomy, which reduces spasticity and improves functional outcome. Others, who are not candidates for rhizotomy, may reduce their spasticity through the insertion of a pump which delivers intrathecal baclofen. The UBNS pediatric neurosurgery team offers the only program in upstate New York for the comprehensive neurosurgical treatment of spasticity.

Tertiary Neurosurgical Trauma Management

In collaboration with the Kiwanis Trauma center, the UBNS pediatric neurosurgery team and the Division of Critical Care Management, provide comprehensive medical and surgical management of children with head and spinal cord injuries.

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The Surgical Management of Spasticity in Children

Spasticity is defined as a disorder of movement characterized by a rate dependent increase in tone, where tone is the resistance to movement. Put simply, children who have spasticity have the resistance set much higher than people without it. As such, when a patient with spasticity wants to use an arm or a leg, the underlying increase in tone will cause them to work harder than normal, as they need to overcome the spasticity in order to accomplish any task.

What we believe happens to cause spasticity is an injury to the motor system that controls the nerve cells in the spinal cord (spinal motor neurons). These cells, when stimulated, allow us to move a muscle. Under normal circumstances, the spinal motor neuron is controlled by two major systems. The first is a set of impulses that come down from the brain that normally serve to inhibit the spinal motor neuron. The second control system is through a reflex arch that travels from the arm or leg to the spinal cord and back to the same arm or leg. Normally, these two systems are appropriately balanced. Spasticity arises when there is an injury to the nervous system, either at the level of the brain or in the spinal cord above the level of the spinal motor neuron, which then affects the first system and its ability to send down the inhibitory impulses to the spinal motor neurons. As a consequence, the balance between the two systems is lost. Now the spinal reflex arch becomes a more significant regulator which leads to a hyper-excitable state causing the spasticity to develop. In children, the most common causes of the injury which leads to spasticity are cerebral palsy, brain injury or spinal cord injury.

Treatment of spasticity is geared towards attempting to create a better balance in the control of the motor neurons in the spinal cord. Possible treatments include physical and/or occupational therapy, oral medications, botulism toxin injections, orthopaedic surgery, selective dorsal rhizotomy (surgery where some of the sensory nerves are cut) and the delivery of intrathecal baclofen through an implanted pump.

Physical or Occupational Therapy

Therapy is geared towards improving range of motion through stretching and by improving strength. To maximize their benefit, exercise programs need to be done at home as well as during therapy sessions. The therapist will often assist in making sure the braces, crutches, walkers or other assistive devices are best suited for the child.

Oral Medications

Medications taken by mouth can help to reduce spasticity by either inhibiting the effects of the reflex arch or acting on the muscle itself to relax it. Although sometimes effective, the problem with these medications is that the dose required to achieve the desired result may lead to intolerable side effects. Because the medication is taken orally, it must pass through the bloodstream. Thus, the whole body is exposed to the medication, and the resulting effects on other parts of the body often outweigh the beneficial effect in reducing spasticity.

Botulism Toxin Injection

Botulism injected directly into the disordered muscle group blocks the impulses from the nerve to the muscle, thus reducing stiffness in patients with spasticity. The downside of this therapy is that its effects are temporary (typically lasting 1-6 months). The injections can be repeated, but the tendency is that over time, the beneficial effects of the injection lessen. Botox injections can be useful in allowing us to see how a child will react to a reduction in spasticity. Furthermore, it can allow us to better measure the strength of the extremity and potentially focus therapy to enhance strength in the period where spasticity is reduced. In essence, in some situations it can give us insight as to how a child will look after a more permanent procedure.

Selective Dorsal Rhizotomy (SDR)

This is a surgical procedure where some of the sensory nerves (nerves that supply input to the reflex circuit) are cut. The goal is to reduce the volume of electrical activity being carried by the reflex arch, thereby restoring a more appropriate balance in the control of the motor neuron in the spinal cord. The surgery is done in the lower back. The spine is accessed, the bone is partially removed temporarily, and the spinal sac is open exposing the nerves that connect the legs and the spinal cord. Each nerve has two components. The first is the motor root which transmits the impulse from the spinal motor neuron to the muscles which causes it to contract. The second is the sensory root which carries information from the skin and other tissues back to the spinal cord. Only portions of the sensory root are cut during this procedure. The percentage of each nerve cut depends upon its location and the results of electrical stimulation applied to the nerve during surgery.

After surgery, pediatric patients typically lie in the fetal position. A catheter that is implanted during surgery helps to control pain. This catheter is usually removed 48-hours after surgery. By the third or fourth day, the children become more mobile and start to sit up, can get out of bed, and can begin physical therapy. After five to seven days, the children are transferred to an inpatient rehabilitation service for intensive therapy. This often lasts for four to six weeks and is followed by intensive outpatient therapy for six to twelve months. The focus of therapy is to retrain the child to use his or her legs. To maximize outcome, the surgery and therapy regimen after surgery must go hand-in-hand.

There are two groups of patients that seem to benefit the most from SDR. The first group is those children with spastic diplegia (spasticity in the legs only) or spastic quadriplegia (with only mild involvement of the arms), who have good cognition and are mobile. Treatment in this group is geared towards maximizing functional ability. The second group is comprised of children with severe spastic quadriplegia where the spasticity is hampering the ability of caretakers to provide for the patient's daily care needs, such as bathing, getting dressed or sitting in a chair. In these cases, treatment is offered to allow the children to receive the necessary care with more comfort and ease.

Intrathecal Baclofen (ITB)

Certain patients can be considered for implantation of a pump that delivers baclofen directly to the spinal fluid, allowing for delivery of a much higher concentration of the drug to the desired site (spinal motor neuron), without having to go through the bloodstream first. By doing this, the potential for undesirable side effects is dramatically reduced. Before the pump is implanted, the child is brought into the hospital to receive a spinal tap at which time a small dose of baclofen is given. We monitor the children afterwards to see whether or not there is enough reduction in the spasticity as a result of the dose given. If the response is adequate, a pump can be implanted. If not, the next day a second higher dose is given. Again, if the patient responds appropriately a pump is implanted. However, if an adequate response is not achieved, this form of treatment is not likely to be effective and the child will no longer be considered a good candidate for this procedure.

The pump is implanted by placing the generator in the wall of the abdominal cavity, underneath the skin and sometimes underneath the muscles. The generator is connected to a catheter that is placed into the spinal sac through a small incision in the lower back. The catheter can be guided into the upper part of the lower back if we wish the effects of the drug to be focused on the legs. A second option would be to thread the catheter higher so that the tip would lie between the shoulder blades if we wish to have an effect on both the arms and the legs. The pump can be programmed to deliver baclofen 24-hours a day at any rate we choose. Thus, if the patient is too spastic we can increase the dose or if they are too loose we can lower the dose. The pump can only hold a certain amount of drug and needs to be refilled every 30-90 days. This is accomplished by putting a needle into the pump and filling its reservoir with new medication. Over time the pump battery wears out and will need to be replaced every three to six years.

Spasticity Clinic

UBNS recommends that children with spasticity that are being considered for any interventional treatment should first be evaluated at the Comprehensive Spasticity Clinic at The Women & Children's Hospital of Buffalo. This clinic is staffed by neurosurgeons, physiatrist (doctors in rehabilitative medicine), and physical and occupational therapists. All care providers are specially trained in the care of pediatric patients and specifically in the unique elements of spasticity that are seen in children. Furthermore, pediatric orthopedists are available for consultation.

At the clinic, each patient is thoroughly assessed by each discipline. Upon completion of the independent assessments, the team meets to discuss and recommend the best course of treatment for the patient. Sometimes children are brought back a second time to confirm the findings of the initial assessment.

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Arteriovenous Malformations & Fistulas (AVM/AVF)

Arteriovenous malformations, or AVM, are complex tangles of dilated, thin-walled blood vessel abnormalities. In the case of AVM, large arteries within the brain become directly connected to veins. Resultantly, the rapid, high pressure blood flow that normally occurs in the large arteries is delivered directly into the veins, bypassing the brain. This high pressure causes the thin, fragile blood vessels to expand and push against nearby areas of the brain or "steal" blood away from the surrounding brain tissue which can lead to a stroke or scarring of the brain. Moreover, the malformed arteries or the AVM itself may rupture, causing a type of stroke known as intracranial hemorrhage (bleeding within or around the brain). The blood that escapes from the ruptured AVM may damage the surrounding areas of the brain and/or cutoff or decrease normal blood flow to areas of the brain.

Arteriovenous fistulas or AVF are defined as abnormal connections (shunts) between arteries and veins, and are similar to AVM. AVF more often involve the arteries and veins and the coverings of the brain and spinal cord and cause symptoms either by increasing the pressure in the draining veins of the brain and spinal cord or by causing hemorrhage. Traditionally, the treatment for AVF was largely limited to open surgical procedures, which resulted in significant morbidity and mortality. Over the past 20 years or so, surgeons have perfected the treatment of AVF through minimally invasive endovascular embolization procedures using catheter technology, which is now the more common approach. The goal of treatment is to prevent hemorrhage or remedy the symptoms associated with increased pressure in the brain or on the spine.

Symptoms

There are no symptoms or signs that are completely specific to AVM. Nevertheless, certain neurological symptoms or medical signs may cause a neurosurgeon to request a brain imaging test such as Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) if AVM is suspected. The most common indication of a possible AVM is the abrupt onset of stroke. Other symptoms and signs include headache, weakness, numbness, visual problems, or seizures. Radiological imaging studies are the cornerstone of accurate AVM diagnosis.

When an AVM is diagnosed, an angiogram or arteriogram may be performed. This type of imaging study is used to view the blood vessel anatomy involved in the AVM, and to assist in developing a plan for treatment.

AVM treatment options

There are three major approaches to treating an AVM which can be used either alone or in combination. The type of treatment recommended will depend on the patient's history and symptoms, as well as the features of the AVM including its size, location within the brain, and the arteries and veins involved.

Embolization

Embolization is an endovascular technique that is used to block the vessels of the AVM. A tiny catheter or tube is inserted into the groin and guided via x-ray technology to the affected vessels in the brain that are causing the AVM. Material is then injected into the catheter to permanently block and close off the vessels. These materials might include glue-like substances or small platinum coils.

There is a large advantage to performing an embolization prior to undergoing other methods of treating AVM. Embolization can often decrease the size of the AVM, rendering radiosurgery or open surgery much safer. In addition, embolization may totally block the AVM's blood flow, causing other types of treatment unnecessary.

Surgery

Surgical treatment of AVM requires removing a portion of the skull so that microsurgical instruments can be used to remove the AVM. This procedure is often done in combination with embolization. Embolization prior to surgery is considered to be a lower-risk option than surgery alone.

Radiosurgery (Gamma Knife)

Despite its name, radiosurgery does not actually involve surgery. Instead, beams of radiation are used to cause scarring within the blood vessels of the AVM, thereby eliminating it. This procedure is recommended for patients with AVMs that are small and located in specific areas of the brain. Radiosurgery is generally successful in completely eliminating the AVM provided that the AVM is sufficiently small. However, a period of 2 to 3 years must pass before the full effect of radiosurgery can be determined. The obvious advantage of this procedure is that treatment can be provided without incision; however, it is not suitable for everyone.

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Brain Tumors in Children

Tumors are masses consisting of abnormal tissue that have a tendency to grow more rapidly than normal, and do not respond to mechanisms set into action by the body to control the growth of the mass. Brain tumors arise within the brain tissue (either from nerve cells or cells that supply support to the nerve cells) or from structures within the skull that are immediately adjacent to the brain. Similarly, spinal cord tumors can arise within the substance of the spinal cord or from the tissue immediately adjacent to it. Tumors of the brain and spinal cord are typically classified as benign (slow growing) or malignant (faster growing). In the pediatric population, either type has the potential of spreading to other sites within the nervous system, but malignant tumors are much more likely to do so. Spread outside of the nervous system is very uncommon in either case.

Background

Brain tumors are the most common form of solid tumors in children. The frequency for newly diagnosed brain tumors is about three to four per 100,000 children per year. The brain is subdivided into two major spaces by a thick sheet of tissue called the tentorium. In one compartment (the supratentorial) lie the cerebral hemispheres (the large halves of the brain) and in the other (the posterior fossa) are the cerebellum and brainstem. In young children (less than two years) tumors are slightly more common in the supratentorial, whereas in older children the posterior fossa is a more common site.

Tumors of the spinal cord or adjacent tissue are much less common in children than brain tumors. About half arise outside the spinal sac, usually from the bone or adjacent structures. Forty percent form within the spinal cord, while 10% grow within the spinal sac but outside of the spinal cord itself thus arise from the tissue adjacent to the spinal cord.

Symptoms

Tumors within the supratentorial space can produce generalized symptoms due to raised pressure within the brain, including:

• Headache
• Nausea/vomiting
• Loss of appetite
• Sleepiness/lack of energy
• Irritability/change in personality
• Drop-off in school performance
• Loss of developmental milestones
• Difficulty walking.

A second way that supratentorial tumors can be noticed is from symptoms that are due to more local effects on the brain, which arise as the growth pushes on specific parts of the brain causing them to function in a less than ideal manner. Included in this category of symptoms are weakness, numbness, tingling, seizures, and change in vision and/or speech difficulties.

Likewise, tumors that grow in the posterior fossa can produce the same generalized symptoms related to globally raised pressures within the brain (generalized) or focal (due to pressure on specific parts of the brain with loss of the function that was normally carried by that part of the brain). Posterior fossa tumors often fill one of the normal fluid filled cavities of the brain (the fourth ventricle) thereby blocking the circulation of the brain fluid causing a build up of fluid within the cavities upstream to the fourth ventricle. This is called hydrocephalus. The effects of focal pressure within the posterior fossa can also lead to:

• Coordination/balance problems
• Jerky eye movements
• Difficulties with speech or swallowing
• Double vision
• Impaired eye movements
• Loss of hearing
• Dizziness/spinning sensations
• Ringing in the ear
• Change in pitch/volume of the voice or cry
• Weakness or neck pain.

Spinal cord tumors usually present with back pain that can extend into the extremities, weakness, difficulty walking, loss of sensation, tingling, change in bowel/bladder control, or curvature of the spine (scoliosis).

Diagnosis

A CT and/or MRI of the brain or spinal cord are essential in establishing the diagnosis of a tumor arising from the nervous system. Often both are required, as they provide complementary information. From these studies we can identify where the tumor is but cannot tell with certainty what type of tumor it is; that can only be determined by the pathologist examining tissue taken from the tumor itself. The imaging studies allow us to formulate a treatment strategy based upon the appearance of the lesion. In many cases of newly diagnosed brain tumors in children, an MRI of the spine is also obtained to evaluate for possible spread of the tumor to other sites within the nervous system.

Treatment

The treatment of nervous system tumors very much depends upon the location, age of the patient, and tumor type. Except for the most benign forms of tumor, cases are discussed in a group setting (called a tumor board). In attendance at the tumor board are representatives from neurosurgery, neurology, hematology/oncology, pathology, and radiation therapy who have specialized training in the treatment of pediatric patients. The board discusses and then decides as a group how to best manage each case. Often, existing protocols established by The Children's Oncology Group are used.

The following is a brief overview describing the management of some of the more common tumors, by location. Please be aware that these are generalized descriptions, and may not apply to individual cases.

Supratentorial

1. Juvenile Pilocytic Astrocytoma (JPA): These are the most benign of intrinsic brain tumors. In general, JPA's are best managed with surgery, and a complete removal of the tumor will often lead to a cure. In cases where the entire tumor cannot be removed, the patient's condition is simply monitored with sequential MRIs. If growth of the residual tumor is demonstrated, or if there is a large residual tumor, treatment options can include more surgery, chemotherapy, or radiation therapy.
2. Anaplastic Astrocytoma or Glioblastoma Multiforme: Tumors in these categories are malignant and fast growing. Treatment often utilizes a combination of maximal surgical resection (when possible) with radiation and/or chemotherapy.
3. Ependymoma: These tumors arise from cells that normally line the fluid filled spaces in the brain called the ventricles. Surgery is the mainstay of treatment, especially if a complete removal is possible. If not, radiation therapy and possibly chemotherapy can often be added.
4. Primitive Neuroectodermal Tumor (PNET): PNET's are tumors arising from very primitive cells and often grow rapidly. Most supratentorial PNET's arise in children less than three years of age. These children are treated with surgery with the intent of removing as much of the tumor as possible, keeping in mind the delicate balance between risks and benefits. Surgery is usually supplemented with chemotherapy and/or radiation therapy.
5. Ganglioglioma, Dysembryoplastic Neuroepithelial Tumor: These two forms of tumor are distinct types that represent benign growths that usually are diagnosed after the child develops seizures. Patients with these lesions can typically be treated with radical surgery.
6. Craniopharyngioma: Craniopharyngioma's are slow growing tumors and thus can be quite large by the time they reach diagnosis. The tumors arise from the region known as the infundibular stalk, which is a strand of tissue that connects the brain to the pituitary gland (a major hormone secreting gland). Children with these tumors can present with headaches, visual loss, alterations in hormone regulation, memory problems, changes in personality, or a drop-off in school performance. There are two ways to manage patients with craniopharyngioma's. The first is an attempt to remove the tumor completely. The second is subtotal (incomplete) removal followed by radiation therapy. There are certainly pros and cons to each of these strategies, which go far beyond the scope of this article. There is, at this time, not a clear-cut advantage of one strategy over the other.

Posterior Fossa

1. Juvenile Pilocytic Astrocytoma (JPA): Like the tumors found in the supratentorial space, these are very benign. Complete surgical removal will often cure the patients of these tumors. If there is residual tumor, options are similar to those found in the supratentorial form.
2. PNET (medulloblastoma): These are similar to the PNET's found elsewhere. Treatment consists of maximal removal, chemotherapy, and radiation therapy.
3. Ependymoma: Ependymoma of the posterior fossa are a little different than those found in the supratentorial space. Like the counterparts found in the supratentorial space, surgery plays a major part in the management of these patients and those that do the best over the long term are those in whom the tumor can be completely removed. This fact is so clear that current thinking is that if a complete removal is not possible in the first surgery, chemotherapy is given for a few cycles followed by a second look operation to try and remove the remaining tumor. Radiation, or sometimes chemotherapy, is used to supplement surgery.
4. Brainstem Glioma: These are tumors that grow within the brainstem, which is a vitally important neurologic structure that houses controls for virtually every neurologic function. The brainstem is subdivided into three parts: the midbrain, the pons, and the medulla. Tumors that arise within the midbrain or medulla are generally benign and can be treated with surgery (removal or biopsy), and possibly radiation or chemotherapy. Tumors within the pons are usually aggressive, malignant tumors, especially if the MRI characteristics satisfy the criteria of a "diffused pontine glioma." In these cases, a biopsy is usually unnecessary, and chemotherapy and radiation therapy are used. For atypical pontine tumors, therapy might be guided by a biopsy.

Spinal Cord

1. Astrocytoma: There is a range of aggressiveness seen in these tumors from benign to malignant. For benign tumors, surgery is geared towards maximal removal. If there is tumor still remaining after surgery, treatment options include observation, chemotherapy, or radiation therapy. If the tumor is malignant, surgery is generally limited to a biopsy or subtotal removal followed by chemotherapy and/or radiation therapy.
2. Ependymoma: These tumors often have distinct margins that allow for complete removal. Thus, surgery is the mainstay of treatment.
3. Ganglioglioma: Ganglioglioma are benign tumors that are very much like the benign astrocytomas of the spinal cord and thus are managed in a similar fashion.

Long-term follow-up for children with nervous system tumors

Children who require more than just surgery are followed in the Comprehensive Neuro-oncology Clinic at Women & Children's Hospital of Buffalo. Neurosurgeons, neurologists, and oncologists, all with special training in pediatrics, attend this clinic. Prior to seeing patients in the clinic, the team sits down to review the most recent MRI's as a group. In addition to reviewing the MRI's, the team discusses each case to help outline the best treatment plan for each child. This form of comprehensive care enables us to establish a treatment plan that is individualized to each patient.

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Craniofacial Anomalies

Background

Infant skulls are made up of five major plates of bone with gaps (called sutures) between the plates, allowing the skull to grow as the child's brain grows. There are six major sutures: metopic, sagittal, coronal (one on each side) and lambdoid (one on each side). The metopic suture runs from the bridge of the nose to the soft spot in the front (anterior fontanelle) and separates the two frontal bones. The sagittal suture courses from the anterior fontanelle to the posterior fontanelle and separates the two parietal bones. Each coronal suture run from the anterior fontanelle to a point just behind the eye and partitions the frontal and parietal bones. Each lambdoid suture separates the parietal and occipital bones and extends from the posterior fontanelle to a point just behind the ear.

Craniosynostosis occurs when one of these gaps (sutures) doesn't form properly. This ultimately results in an abnormal skull shape, as growth cannot occur along that suture line. The most common form involves the sagittal suture. In Sagittal synostosis the characteristic head shape is one that is very narrow and elongated (scaphocephaly). There may be accompanying prominence of the forehead and/or formation of a knob at the back of the head.

Coronal synostosis is the next most common form of craniosynostosis, and may involve one or both coronal sutures. In the case of one-sided involvement (frontal plagiocephaly), the forehead just above the eye becomes flattened and is taller than normal. The opposite side of the forehead may stick out a bit more than normally. The top of the nose is shifted towards the side that is flattened and the tip is pointed towards the opposite side. If both coronal sutures are fused, the head is very short from front to back and tall, particularly in the front (brachycephaly). Both sides of the forehead are quite flattened.

Metopic synostosis results in a head shape that has been described as "triangular" or "keel-like". The midline of the forehead is quite prominent and often ridged. The outer forehead is retracted so that when you look down onto the top of the head, it is like the top of a triangle (trigonocephaly). Often the eyes are set more closely together than normal. This form of craniosynostosis exhibits the greatest variability in severity. A range can be from just a slightly prominent ridge that runs from the anterior fontanelle to the top of the nose to a very triangularly shaped forehead, which creates a quite abnormal head shape.

Lambdoid synostosis has been a very controversial subject. When the recommendations were made to have newborns sleep on their backs rather than their stomachs to minimize the risk of crib death, there was thought to be a rash of "lambdoid synostosis" where one or both of the sides of the back of children's head became quite flattened. We now know that this has come about because some newborns have a strong tendency to lie on one side or another (more commonly the right side). When this occurs, that side of the head becomes flattened. The ear on the same side is often pushed forward, and sometimes the forehead on the same side protrudes forward as well. Skull x-rays in these children show that the sutures are still open but there may be "sclerosis" or thickening of the bone along the lambdoid suture. This entity almost never requires surgical treatment (reserved only for the most severe cases that don't respond to conservative treatment). Often all that is needed is to aggressively change the position that the baby lies, keeping them from resting on the flat portions of their head. If this fails, a trial with a molding band or helmet may be useful. This device needs to be worn for 23 out of 24 hours a day for somewhere between 12-16 weeks. One important point to make is that this entity, (known as occipital plagiocephaly, positional molding, occipital flattening, or deformational plagiocephaly) does not seem to have any affect on how a child develops and it merely affects the shape of their heads.

True lambdoid synostosis is actually quite rare and produces a head shape that is very different from the head shape that is typical of occipital plagiocephaly (OP). Whereas the head in OP is shaped like a parallelogram the head shape and true lambdoid synostosis is akin to a trapezoid. The ear on the affected side is pushed further back and the forehead on the affected side is pulled back rather than pushed forward as in OP.

Diagnosis

Craniosynostosis is most often recognized by the characteristic head shape abnormality. The diagnosis is confirmed by skull x-rays which usually reveal that the affected suture is not visible on x-ray (normal sutures appear as dark gaps between the whitish bone on each side). There is also often heaping of the bone at the site of the fused suture. A computed tomography (CT) scan, as well as 3-dimensional CT can supplement skull x-rays and provide information that helps the surgeon plan the safest and most effective correction possible for each patient.

Treatment

Treatment for craniosynostosis is generally reserved only for those patients in whom the disorder has resulted in a significant alteration in their head shape. In other words, the rationale for treatment is primarily to improve head shape. Craniosynostosis by itself only infrequently causes developmental problems or raised intracranial pressure. For true synostosis, the treatment is almost always corrective surgery (a molding helmet or band alone without surgery is of no use in these cases). Surgery is geared towards creating a "new" suture while also correcting the head shape. Infants with sagittal synostosis are usually treated by 3-4 months of age. In these cases a strip of bone, where the sagittal suture should have been, is removed. The theory here is that, once this is done, continued growth will allow the head to take on a more normal shape. This surgery can be done open (under direct vision) or by using an endoscope. The open procedure is the tried and true method whereas the latter is a newer approach. The potential advantage of the latter is a reduced need for blood transfusions. The major disadvantage is that it requires the use of a molding helmet after surgery for up to twelve months.

The treatment of coronal (one side or both) and metopic synostosis is very similar. A craniofacial team, consisting of a pediatric neurosurgeon and a plastic surgeon, does these procedures. In these cases, a more involved procedure is necessary, as the forehead needs to be reshaped. We usually wait until these children reach about six months of age so the bone is sturdy enough to withstand the reconstruction that is necessary to reshape the head.

Rarely, all the sutures can be fused or more than two sutures can be fused, which carries an increased risk for developmental delay or learning disabilities. In these children, surgery must be done to help take the pressure off the brain. If there is a concern about this, sometimes an intracranial monitor is placed first to give us a better sense on whether or not this is truly ongoing. Treatment for this condition is complete cranial vault reconstruction, which is again performed with a craniofacial team.

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Endoscopic Neurosurgery

An endoscope is a device that allows a surgeon to operate through a limited opening by providing remote visualization, illumination, and manipulation. The typical endoscope used in neurosurgery features a lens and camera for visualization, a light source for illumination, and one or more channels through which instruments can be directed for surgical manipulation. Most of the current applications of endoscopy in neurosurgery are directed at hydrocephalus.

While an endoscope can be helpful to the neurosurgeon in many ways, most neurosurgical procedures cannot be performed solely through an endoscope for a variety of reasons. The endoscope is most helpful when used to open a membrane, place a catheter at a precise location, or biopsy lesions associated with the brain's fluid chambers (ventricles).

Endoscopic Cyst Fenestrations

Other thin membranes and cyst walls within or around the brain can be opened using the endoscope to relieve pressure caused by the blockage of CSF circulation. The technique is similar to an ETV but the hole is made to release an isolated (trapped) pocket of CSF into a ventricle or the subarachnoid space. Sometimes a small tube (stent) is left to keep the hole open after it is made.

Endoscope-Assisted Shunt Insertion

Endoscopes small enough to fit inside shunt tubes are sometimes used to achieve the best possible placement of the catheter tip within the patient's ventricle. This technique can be applied to both new shunt insertion and the revision of shunts whose ventricular catheters are blocked.

Endoscopic Tumor Surgery

Brain tumors located within or adjacent to the lateral or third ventricles can often be reached with an endoscope. Only the smallest tumors can be removed through the endoscope and complete removal remains unlikely. A more reasonable goal in these situations is tumor biopsy. Many tumors that occur in these areas are either impossible to cure by any surgical treatment or can be cured with non-surgical means making complete removal unnecessary. As tumors in these locations frequently cause obstructive hydrocephalus, the biopsy can be combined with a simultaneous fenestration procedure.

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Hydrocephalus

Background

Under normal circumstances, there is fluid within the brain and the spinal cord, as well as outside of these structures. This fluid is known as cerebral spinal fluid (CSF); in appearance it is a clear, water-like fluid. CSF undergoes constant turnover and has a specific flow pattern. In the brain CSF is in cavities known as ventricles (see Figure 1). There are two lateral ventricles (one on each side of the brain) that flow into the third ventricle, which in turn flows into the fourth ventricle. From the fourth ventricle CSF escapes into the space around the brain and spinal cord known as the subarachnoid space (SAS). In this space, the fluid gets absorbed back into the blood stream primarily through connection to a large vein that runs between the two halves of the brain (sagittal sinus).

Definition of Hydrocephalus

CSF is produced primarily in the brain, by tissue known as the choroid plexus. Normally we make about 4-5 teaspoons of CSF an hour, regardless of age. The fluid then flows through the pathways as described above and ultimately gets resorbed back in the bloodstream. We should be absorbing the same 4-5 teaspoons an hour, such that the volume of CSF really doesn't change much over time. Hydrocephalus is defined by excessive CSF, as a consequence of imbalance between the production and absorption of CSF. Most commonly it is absorption of CSF that is the problem. When this imbalance occurs, the ventricles and perhaps the SAS become enlarged as the fluid builds up. An analogous situation is like a sink with a faucet that is always on at a constant rate. As long as the drain at the bottom of the sink is open, there is no build-up of fluid. If the drain starts to get plugged then fluid will start to well up within the sink.

Types of Hydrocephalus

Hydrocephalus can be broken down into two major types based upon where the blockage of flow of CSF occurs. If it occurs anywhere within the ventricular system (within the brain itself) it is known as non-communicating or obstructive hydrocephalus. If blockage occurs outside the brain (usually at the level of where the CSF gets absorbed into the venous system) it is called communicating hydrocephalus. This differentiation can be important when it comes to treatment and this will be discussed in more detail below. Typical causes of non-communicating hydrocephalus are tumors, cysts, blood within the ventricles, infection or inflammation. In the case of communicating hydrocephalus the culprit is usually bleeding, infection, inflammation, spread of tumor cells or trauma.

Signs and symptoms

The way in which children with hydrocephalus are affected is dependent upon their age at the time of diagnosis. In children less than two years, the most common way it is detected is an abnormally rapid head growth. Rather than following a normal growth curve on a head circumference chart, these children start to cross curves and often ultimately exceed the curve for the 95th percentile. This occurs since the young child's skull bones are not yet fused. Thus as the fluid builds up, it separates the bones and causes the skull to expand too quickly. Less frequently, children in this age group develop vomiting, excessive sleepiness, unexplained irritability, loss of development milestones or even developmental delay, downward deviation of their eyes and seizures. When examined, the soft spot tends to be full and the gaps between the skull bones are often split wider than normal. Children older than five years have skull bones that are less likely to expand as fluid builds up thus they tend to show signs of raised pressures within the brain itself. This typically causes them to complain of headaches, nausea with or without vomiting, listlessness or lethargy, unexplained irritability, loss of developmental milestones, change in behavior, change in school performance and rarely seizures. Medical examination of these children can range from normal to showing pressure induced changes in the eye nerves (papilledema), problems with eye movements, gait disorders and/or problems with cognition. Children between 2-5 may have a mixture of clinical findings that fall somewhere between the older and young age groups.

Diagnosis

Several studies can be helpful in establishing the diagnosis of hydrocephalus, including ultrasound, computed tomography (CT) scan and magnetic resonance imaging (MRI). Ultrasounds are only useful in the very young children that still have open soft spots. This study is very good at looking at the size of the ventricles but doesn't provide as much detail as a CT or MRI does about the structure of the brain tissue itself. A CT is sort of the middle-tiered study that gives both good views of the ventricles and brain tissue and can potentially identify sites of blockage within the brain. Sometimes the addition of intravenous contrast (dye) can add further information. The advantage of CT is that the study itself is quick so that sedation is not needed and thus can be scheduled in relatively short order. The most elaborate way of imaging the brain is MRI and this is certainly the best study to look at specific sites of blockage within the brain. A MRI, however, does require sedation or anesthesia if the child can not hold still for at least 30-45 minutes. As a consequence it cannot be as easily scheduled as a CT scan. Thus, patients may have at least two of these studies done during the course of their evaluation.

Treatment

The decision of whether or not to treat hydrocephalus depends how confident one is that the increased ventricular size is creating problems for the child. If the level of confidence is high, the hydrocephalus certainly needs to be treated, whereas if there is some uncertainty careful and close observation may be reasonable. This is particularly true for an infant who does not get into problems with raised pressures within the brain as frequently as older children for the reasons that were described above. In these cases, frequent clinical assessments with developmental evaluations and head circumference measurements will allow us to monitor the child and reserve treatment only if there is evidence of progression of this disorder.

Unfortunately, there is not reliable long-term non-surgical treatment for hydrocephalus. There are some pills available that might reduce production of CSF but they often cause significant side effects and are not effective over the long-term. There are two forms of surgical treatments that can be employed; the first is a ventricular shunt and the second is an endoscopic third ventriculostomy. The former can be used on all patients with hydrocephalus, whereas the latter is reserved for only those with non-communicating hydrocephalus.

Ventricular Shunt

A shunt is a device made of silastic that is placed under the skin and runs from the head to the belly (peritoneum), chest (pleura) or heart (atrial). Every shunt has three parts; the catheter that goes into the brain, the valve, and the tubing that goes to one of the three above mentioned distal sites. The shunt serves as a separate pathway to drain CSF in the brain that will ultimately be absorbed by the lining of the belly cavity, chest cavity or directly into the heart. The valve serves as a regulator of CSF flow through the shunt system. Surgery for placement of a shunt requires an incision in the head and over the site for the distal catheter (belly, chest or around the neck or collarbone). The surgery takes about one hour and children are usually discharged the next day. It is important to note these shunts are self-sufficient and do not require that you do anything to keep them working. You will see parts or all of the shunt as it bulges underneath the skin, particularly evident in the neck. This should not be of concern.

Shunts are mechanical devices and as such, are prone to malfunctioning. About 30-40% of all shunt failures occurs within one year of placement, 50% by 5-6 years; however, some can last a lifetime. If the shunt malfunction occurs the shunt will need to be "revised" to get it working again. There is no way of predicting how long any particular individual can go before the shunt needs to be revised. The signs and symptoms of shunt failure are similar to those that can be present at the time of the original diagnosis of hydrocephalus. If shunt malfunction is a concern then a evaluation will likely include some or all of the following: careful review of the symptoms, medical examination, a CT scan of the head, a series of x-rays to follow the course of the shunt to make sure it's not broken (shunt series), abdominal ultrasound and maybe a shunt tap (where a small needle is inserted into part of the shunt to measure pressure within the brain and assess shunt flow). The most important feature in evaluation is review of the problems that the patient is experiencing followed by the results of the CT scan and shunt tap. Of note, in the presence of shunt malfunction, the CT scan does not necessarily have to show enlarged ventricles.

Another potential problem related to a shunt is infection of the device, which occurs in about 5-10% of all shunt surgeries. Patients with an infection can present with fever, redness along the shunt tract or at one of the shunt incisions, pus-like drainage, abdominal pain, or evidence of shunt malfunction. The diagnosis is established by culturing fluid drawn from the shunt for bacteria by "tapping" it. Most shunt infections occur within 30-days of surgery and 90-95% by 6-months of surgery. Treatment most often requires removal of the shunt, placement of a temporary drainage tube, intravenous antibiotics and ultimately reinsertion of a new shunt once the infection has cleared. This usually takes at least seven days.

Once a functioning shunt is in place, we will see your child back in one month with a CT scan, which we will use as a baseline study to which further studies can be compared. Routine CT scans are not helpful unless the child has significant developmental delay and cannot communicate well. If stable, patients are usually followed on a once a year basis.

Endoscopic Third Ventriculostomy

An alternative treatment for non-communicating hydrocephalus is a surgery known as endoscopic third ventriculostomy (ETV). In these cases the blockage of CSF flow occurs beyond the third ventricle and presumes that the ability to absorb CSF back into the bloodstream is normal. Thus, if a communication between the ventricle upstream from the site of the blockage and the subarachnoid space can be made, the hydrocephalus could be effectively treated. This is done by placing an endoscope (which is a small rod with a light source and a camera) into the lateral ventricle, and then under direct vision the tip of the device is guided into the third ventricle. At the base of this ventricle there is normally a very thinned out area that is further thinned by the hydrocephalus. On the other side of this thinned out area is the subarachnoid space. This area does not house any critical brain function so that a small hole can be made in this region safely. Now the fluid within the ventricle can escape through the hole into the subarachnoid space and ultimately get absorbed back into the bloodstream through the normal pathways. In properly selected patients, about 80% can be effectively "cured" of the hydrocephalus by an ETV. The remaining 20% will need to be treated with a shunt. The patients that seem to do the best are those with non-communicating hydrocephalus that develop a bit later in life and are typically older than two years of age. However, even patients who are born with non-communicating hydrocephalus fare well with this procedure but it is generally reserved for when they reach an age older than six months and in my experience it is probably better to wait until they are older than two years of age. The reason for this is that in many children it takes up to two years to fully develop the channels to absorb CSF back into the bloodstream. Thus, if an ETV is done before the channels are adequately developed, the failure rate becomes higher since the CSF cannot be effectively resorbed back into the bloodstream. In children less than two years of age who present with non-communicating hydrocephalus, it is therefore reasonable to suggest that a shunt be placed first then if their shunt malfunctions and they are older than two years old an ETV can be done at that point.

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Benign Extra-Axial Fluid Collection

This diagnosis is one of the most common reasons for referrals of new patients to our practice. This entity occurs in infants and becomes apparent as head growth begins to accelerate abnormally, typically beyond the age of three months. This abnormally accelerated head growth continues until about 9-12 months of age. At this point head growth usually returns to a normal rate. Development proceeds normally in a great majority of these patients. In these cases, a head CT scan or MRI will show abnormally prominent fluid spaces (filled with CSF) between the brain and it's covering. Up to 45% may show a mild to moderate concomitant increase in ventricular size.

The theory beyond why BEFI develops is that in many infants the channels to absorb CSF do not develop early enough so that now more CSF is being made then can be absorbed. In this entity, the CSF accumulates in the subarachnoid space outside the brain rather than within the ventricles. Fortunately, BEFI almost always resolves on it's own without treatment by two years of age. All that is recommended is that these children be watched closely in terms of their development and head growth pattern.

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Spinal Dysraphism/Spina Bifida

Normal Development

The nervous system of the human fetus undergoes rapid change, particularly in the very early part of development. The tissue that ultimately forms the spinal cord starts off as a sheet but by 3-4 weeks after conception, the edges of the sheet roll upward towards one another to form a tube. This tube then goes on to form the nervous system.

Abnormal Development Leading to Spinal Cord Malformations

At different points during this process, errors in formation can occur resulting in anomalies of the spinal cord. These are often called spina bifida, spinal dysraphism, tethered cord or birth defects of the spinal cord. The most accurate terms are spinal dysraphism or spina bifida. Spina bifida is a commonly used term, but it is somewhat confusing as there are three forms, one that only refers to malformations of the spine bone (spina bifida occulta). Normally, the spine bones form a ring that completely encircles the sac that covers the spinal cord. Spina bifida occulta is actually defined as a malformation of the spine bones, where the back of the spine does not come together completely (incomplete formation of the bony spine ring). The second refers only to myelomeningoceles (spina bifida aperta) and are considered to be "open" (not covered by skin) lesions. Finally, there is spina bifida clausus which represent skin covered or "closed" lesions. There are various forms of spinal dysraphism which will be discussed in more detail below.

Myelomeningocele

A myelomeningocele (MMC) is the most severe form of spinal dysraphism. In this entity, the sheet of nerve tissue never makes it into a tube thus the skin, bone, muscle and other soft tissue layers are also unable to form over the nervous tissue. At birth, the spinal cord is covered only by a thin sheet of transparent tissue. This is considered to be an "open" lesion as there is no skin covering the nerve tissue. In addition, the spinal cord itself doesn't form normally thus the function that would normally be controlled by that part of the spinal cord is lost. This usually includes some or all of leg movement and control of bowel and bladder function. As this is an open lesion, the threat of infection is a very real one. As such, it is typically recommended that babies with these lesions be operated upon to "close" the myelomeningocele by bringing soft tissue and skin to cover the lesion. This procedure is typically done in the first 48-72 hours of life. The goal of this surgery is to minimize the risk of infection. Unfortunately, nothing can be done to recover nerve function that is lost as a consequence of the myelomeningocele.

Hydrocephalus

About 80-85% of patients with MMC have hydrocephalus (excess water in the brain cavities). This will require placement of a device called a ventricular shunt to drain the excess fluid. This procedure might be done at birth, if the condition is severe, but sometimes it is delayed until it becomes absolutely necessary (see information at this website on Hydrocephalus).

Chiari Malformation

Nearly all (about 90-95%) of patients with MMC also have a malformation of the back part of the brain, called a Chiari malformation (CM) type II. In this condition, the space for the brain stem and cerebellum is insufficient causing downward displacement of these tissues through the opening at the base of the skull called the foramen magnum. Although virtually all patients with MMC have this malformation, only about 25-30% require treatment for it. Treatment is reserved only for patients who develop problems directly related to the Chiari malformation. There are countless problems that can arise from a CM, but the most common are neck pain, visual disturbances, change in pitch/volume of the voice or cry, difficulty with swallowing (especially liquids), worsening of arm/leg strength, sleep apnea or syringomyelia (fluid build-up within the spinal cord).

Tethered Cord

Another problem that occurs in a delayed fashion seen in about 20-40% of patients with MMC, is worsening of neurologic function related to a tethered cord. These patients develop back/leg pain, worsening of leg weakness, new numbness, new problems with gait, scoliosis (curvature of the spine), worsening of leg/foot bone abnormalities, or worsening of bowel/bladder control. If these develop, an evaluation process to diagnosis a tethered cord is undertaken. Having said that, the diagnosis is made purely on clinical grounds. What happens is that scar tissue forms at the site of repair of the MMC which causes the spinal cord to stick to the walls of the spinal sac. As the child grows, because the spinal cord is anchored to the sac by the scar tissue (normally the end of the spinal cord is free and somewhat mobile and can slide up and down), the cord gets stretched. As this occurs, the blood vessels that feed nutrients to the nerve cells also get stretched, which in turn reduces blood flow to the nerve cells. This ultimately results in impaired function of the nerve cells. Studies have shown that patients with previous repair of spinal dysraphism will show evidence of a tethered cord on MRI in almost 100% of the cases. Thus, the MRI itself does not help us diagnosis the tethered cord but is done mostly to exclude other lesions that might explain the patient's clinical picture. Like in the Chiari malformations, only patients who develop problems directly related to the tethering need to have treatment. Treatment is an operation to release the scar tissue and to allow the spinal cord to become free from its attachments to the spinal sac.

Comprehensive Clinic

The best way to follow patients with MMC is in a comprehensive "Spina Bifida" clinic where all the specialists who care for their chronic needs can see them at one time. The clinic in Buffalo is called The Spina Bifida Clinic of Western New York. Specialists included in this program are pediatric physiatrists (rehabilitative medicine doctors), pediatric orthopaedic surgeons, pediatric urologists, physical therapists and pediatric neurosurgeons. In addition to routine examinations by each specialist, patients will be followed with urodynamics (bladder studies) and manual muscle tests (detailed strength assessments done by the physical therapist). This cooperative effort will allow for collaboration between specialists and has been proven in studies to be the best way to care for these patients. This will allow us to detect, as early as possible, problems that might arise from a CM or tethered cord.

Spinal Lipoma (lipomyelomeningocele)

Another form of congenital spinal malformation occurs if during the process of rolling into a tube, fat tissue breaks through the normal tissue layers and becomes stuck to the back of the spinal cord. This entity is known as a spinal lipoma or lipomyelomeningocele. Children with this disorder typically have a visible lump in their lower backs at birth. The lump is covered by skin, although sometimes there are strawberry colored birthmarks over the lump. MRI of the spine will reveal the fat tissue and its relationship to the spinal cord. Generally, these children will have normal neurologic function. This lesion produces a tethered cord thus children with spinal lipomas are at risk for deterioration in their neurologic function. Surgery is geared toward detaching the fat from the surrounding tissue, thereby "untethering" the spinal cord. Patients with spinal lipomas, like those with myelomeningocles, are at risk for rethering (tethered from scar tissue), again with the frequency of about 20-40%.

Dermal Sinus Tract

This entity develops if there is incomplete separation of the layers of the sheet that rolls up to become the spinal cord. Normally there are three layers that separately form the nervous tissue, bone, underlying soft tissue and skin. If these layers do not separate completely what results is tissue that would otherwise form skin being pulled into the tube that forms a spinal cord. This creates a tract of abnormal tissue that runs from the spinal cord to the skin. These abnormalities are known as a dermal sinus tract (DST). Children with a dermal sinus tract often have a dimple in their lower backs. Like patients with spinal lipomas, these children typically demonstrate normal spinal cord function at birth. These lesions can also lead to a tethered spinal cord or can become a source of serious infections, thus are surgically treated by detaching the connection of the DST to the spinal cord, and excising the tract. Retethering is, again, a potential problem in these patients.

Split Cord Malformation

Split cord malformations (SCM) are very complex disorders where part of the spinal cord forms as two tubes (spinal cords) rather than just one. These can either be in a single spinal sac or two distinct sacs. In the form with the two sacs, there is usually a piece of bone that is wedged in between the two sacs. Whereas, in the form with the single sac, the cords are separated only by fibrous tissue. Both types create a situation where the spinal cords are tethered and typically need to be treated with surgery.

Low Conus, Thickened Filum Terminale

Early in the development of a fetus the spinal cord typically runs all the way down to the lowest portion of the spine. As the fetus grows, the spinal cord doesn't grow as much as the body does, thus, the spinal cord "rises" within the spinal canal. At birth, the lowest portion of the spinal cord is usually at the space between the 2nd and 3rd lumbar spine bones (L2-3). There are five lumbar spine levels with L1 being towards the chest and L5 towards the tailbone. By 2-12 months the lowest portion of the spinal cord rises further to typically lie at the junction between L1-2. In some instances when the spinal cord fails to rise to the expected level, a diagnosis of a tethered cord needs to be considered. Most commonly, the cause of the lack of proper ascension of the spinal cord is thickening of the filum terminale, which is a band of fibrous (non-nerve) tissue that runs from the bottom of the spinal cord and anchors it to the bottom of the spinal sac. Often, the filum is infiltrated with fat tissue, making it thicker and less elastic, thus preventing the expected ascension of the spinal cord. This in turn creates tension on the spinal cord resulting in insufficient delivery of nutrients to the nerve cells (for a more detailed description of the effects of this on the spinal cord see the section on tethered cord in the patients with myelomeningocele as listed above).

Patients with a tethered cord can have any of the following: abnormalities of the skin overlying the spine (dimples, strawberry birth marks, skin tags, lumps), back and/or leg pain, weakness of the legs, numbness/tingling in the legs, scoliosis, bone deformities of the feet and problems with bowel/bladder control. This entity is quite treatable with a relatively simple operation where the filum terminale is cut.

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Trauma Care

Neurologic trauma continues to be a major public health problem, even with modern trauma care in the 21st century. Appropriate management of a traumatic brain or spinal injury requires knowledge of the pathophysiology involved.

Brain injury

The brain has several features that distinguish it from other organ systems. The most important of these differences is that the brain is contained within the skull, a rigid and inelastic container. Because of this, only small increases in volume within the intracranial compartment can be tolerated before pressure within the compartment rises dramatically, causing neurological sequelae. This concept is known as the Monro-Kellie doctrine, which states that the total intracranial volume is fixed by the inelastic volume of the skull. This volume is divided into three compartments: the brain parenchyma, the blood volume, and the cerebrospinal fluid (CSF). When a significant head injury occurs, cerebral edema often develops, which increases the relative volume of the brain parenchyma. Because the intracranial volume is fixed, the pressure within this compartment rises unless some compensatory action occurs, such as a decrease in the volume of one of the other intracranial components.

In pediatric head trauma, maturational differences impact directly on evaluation and prognosis. The child's brain presents a different developmental substrate for injury. It has greater water content than the adult's, and is relatively resistant to damage from hypoxia. However, coma may still result from diffuse axonal injury, brainstem injury, or bilateral hemispheric damage.

Spine injury

The diagnosis of an unstable spinal injury and its subsequent management can be difficult, and a missed spine injury can have devastating long-term consequences. Therefore, spinal column injury must be presumed until it is excluded. The main concerns are which patients can be cleared by clinical exam alone, which imaging studies are necessary, and when should additional imaging be used. An assessment for ligamentous injury in the absence of a fracture is also important, especially in unconscious patients who are unable to complain of neck pain or tenderness.

Imaging

Imaging studies have become of increasing importance in the evaluation and treatment of head and spinal trauma in the past 20 years, and recent advances have made CT and MRI more accurate and quicker for the assessment of traumatic injury. CT remains the investigation of choice even following the advent of MRI, due both to the ease of monitoring injured patients and the better demonstration of fresh bleeding and bony injury. MRI is the more sensitive of the imaging studies, having better resolution and greater sensitivity than a CT scan. However, it can't be used if the patient has IV lines and ventilation equipment or pacemakers, because of its magnetic field; and the confined space of the MRI make it difficult to use in emergent situations. Yet, as valuable as these diagnostic tools have been in guiding intervention in acute management of the severely injured brain, normal scans do not rule out even life threatening brain trauma.

Treatment

Goals of brain and spine trauma management in the acute setting include securing the airway, correcting hypovolemia and hypotension, management of intracranial pressure, stabilization of neurological deficits, and surgical intervention as indicated. If the patient is unresponsive or has an obstructive hydrocephalus, then intracranial pressure monitoring may be required. Indications to operate on skull fractures include an open fracture, a posterior table sinus fracture, an underlying hematoma compressing the brain, or a bony fragment compromising eloquent cortex. Spinal surgery may be required if the injury involves mechanical and/or neurological instability of the spine. Treatment protocols vary widely depending on the location and extent of the injury. They can range from simple bracing and supplemental analgesics, to surgical decompression and stabilization.

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