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Disorders of the brain, spine and nerves commonly treated by neurosurgeons include: Carotid Artery Disease, Carpal Tunnel Syndrome, Cervical Spine Disorders, Chronic Pain, Craniosynostosis, Epilepsy, Head Injury, Herniated Disk, Hydrocephalus, Intra cranial Aneurysm, Lumbar Spinal Stenosis, Meningomyelocele, Parkinson's Disease, Spina Bifida, Spinal Cord Injury, Stroke, Trigeminal Neuralgia, and Tumors. Neurosurgical conditions include primarily brain, spinal cord and peripheral nerve disorders.
Spinal disc herniationA spinal disc herniation, incorrectly called a "slipped disc", is a medical condition affecting the spine, in which a tear in the outer, fibrous ring (annulus fibrosus) of an inter vertebral disc allows the soft, central portion (nucleus pulposus) to bulge out. It is normally a further development of a previously existing disc protrusion, a condition in which the outermost layers of the annulus fibrosus are still intact, but can bulge when the disc is under pressure. Terminology Normal situation and spinal disc herniation in cervical vertebrae. Some of the terms commonly used to describe the condition include herniated disc, prolapsed disc, ruptured disc, and the misleading expression "slipped disc." Other terms that are closely related include disc protrusion, bulging disc, pinched nerve, sciatica, disc disease, disc degeneration, degenerative disc disease, and black disc. The popular term "slipped disc" is quite misleading, as an inter vertebral disc, being tightly sandwiched between two vertebrae to which the disc is attached, cannot actually "slip," "slide," or even get "out of place." The disc is actually grown together with the adjacent vertebrae and can be squeezed, stretched, and twisted, all in small degrees. It can also be torn, ripped, herniated, and degenerated, but it cannot "slip. However, one vertebral body can slip relative to an adjacent vertebral body. This is called spondylolisthesis and damages the disc between the two vertebrae. The spelling "disc" is based on the Latin root discus. Most English language publications use the spelling "disc" more often than "disk." Nomina Anatomica designates the structures as"disci intervertebrales" [plural form] and Terminologia Anatomica as "discus intervertebralis/Inter vertebral disc," [singular form]. REGIONAL DEISTRIBUTIONFrequencyStages of Spinal Disc Herniation
Lumbar disc herniation occurs 15 times more often than cervical (neck) disc herniation, and it is one of the most common causes of lower back pain. The cervical discs are affected 8% of the time and the upper-to-mid-back (thoracic) discs only 1 - 2% of the time. The following locations have no discs and are therefore exempt from the risk of disc herniation: the upper two cervical inter vertebral spaces, the sacrum, and the coccyx. Most disc herniations occur when a person is in their thirties or forties when the nucleus pulposus is still a gelatin-like substance. With age the nucleus pulposus changes ("dries out") and the risk of herniation is greatly reduced. After age 50 or 60, osteoarthritic degeneration or spinal stenosis are more likely causes of low back pain or leg pain. Cervical disc herniationCervical disc herniations occur in the neck, most often between the sixth and seventh cervical vertebral bodies. Symptoms can affect the back of the skull, the neck, shoulder girdle, scapula, shoulder, arm, and hand. The nerves of the cervical plexus and brachial plexus can be affected. Thoracic disc herniationThoracic discs are very stable and herniations in this region are quite rare. Herniation of the uppermost thoracic discs can mimic cervical disc herniations, while herniation of the other discs can mimic lumbar herniations. Lumbar disc herniationLumbar disc herniations occur in the lower back, most often between the fourth and fifth lumbar vertebral bodies or between the fifth and the sacrum. Symptoms can affect the lower back, buttocks, thigh, and may radiate into the foot and/or toe. The sciatic nerve is the most commonly affected nerve, causing symptoms of sciatica. The femoral nerve can also be affected. Can cause the patient to experience a numb, tingling feeling throughout one or both legs and even feet. CausesCauses of a disc herniation can include general wear and tear on the disc over time, repetitive movements, stress on the disc that occurs while twisting and lifting, or other injuries. SymptomsThe chief complaint for spinal disc herniation is leg pain greater than lower back pain, symptoms of a herniated disc can vary depending on the location of the herniation and the types of soft tissue that become involved. They can range from little or no pain if the disc is the only tissue injured to severe and unrelenting neck or low back pain that will radiate into the regions served by an affected nerve root when it is irritated or impinged by the herniated material. Other symptoms may include sensory changes such as numbness, tingling, muscular weakness, paralysis, paresthesia, and affection of reflexes. If the herniated disk is of the Lumbar region the patient may also experience sciatica due to irritation of the sciatic nerve. Unlike a pulsating pain or pain that comes and goes, which can be caused by muscle spasm, pain from a herniated disc is usually continuous. It is possible to have a herniated disc without any pain or noticeable symptoms, depending on its location. If the extruded nucleus pulposus material doesn't press on soft tissues or nerves, it may not cause any symptoms. It has been estimated that as many as 50% of the population have focal herniated discs in their cervical region that do not cause noticeable symptoms. Typically, symptoms are experienced only on one side of the body. If the prolapse is very large and presses on the spinal cord or the cauda equina in the lumbar region, affection of both sides of the body may occur, often with serious consequences. Diagnosis Diagnosis is made by a practitioner based on the history, symptoms, and physical examination. At some point in the evaluation, tests may be performed to confirm or rule out other causes of symptoms such as spondylolisthesis, degeneration, tumors, metastases and space-occupying lesions as well as evaluate the efficacy of potential treatment options. These tests may include the following:
MRI Scan of lumbar disc herniation between fourth and fifth lumbar vertebral bodies.TreatmentThe majority of herniated discs will heal themselves in about six weeks and do not require surgery. Pain medications are often prescribed to alleviate the acute pain and allow the patient to begin exercising and stretching. The presence of cauda equina syndrome (in which there is incontinence, weakness and genital numbness) is considered a medical emergency requiring immediate attention and possibly surgical decompression. There are a variety of non-surgical care alternatives to treat the pain, including:
If pain is severe and continuous, or if there are neurological deficits, surgery may be recommended. Surgical options include:
Surgical goals include relief of nerve compression, allowing the nerve to recover, as well as the relief of associated back pain and restoration of normal function. Classical surgery for lumbar disc herniation is carried out by using a vertical median incision over the level which has an herniation. The dorsolumbar fascia is incised about 0.5 cm laterally on the affected side. The paravertebral muscles are dissected free from underlying bony structures, namely the spinous process and laminae, and retracted laterally. The level of disc herniation is identified using C-arm fluoroscopy or palpating the sacrum. The lamina is then fenestrated with bone rongeurs after which the exposed ligamentum flavum (the yellow ligament) is excised. The epidural soft tissue and venous plexus is gently explored to find the nerve root exiting from the associated neural foramina. The herniated disc is usually found beneath the nerve root. The nerve root is protected using root retractors. The posterior longitudinal ligament is incised with a fine blade and herniated disc material and degenerated nucleus pulposus are evacuated using different kinds of disc forcepses. Meticulous control of haemostasis is employed and irrigation with warm saline is essential. The muscle layers and the fascia is repaired, generally, without using a drain. The skin wound is closed. Cervical inter vertebral disc herniations are operated using a horizontal paramedian anterior neck incision parallel to skin folds, a surgical procedure called Anterior cervical discectomy and fusion. After dissecting the neck structures (which are vital organs, such as trachea, esophagus, carotid arteries etc.), the front of the vertebral column is reached and exposure is maintained by automatic retractors. The dissection is blunt and is carried out through natural anatomic planes, thus causing minimal trauma to tissues here. The level is again verified using the C-arm. The disc is evacuated using curettes and high speed drills. The surgeon may place an inter vertebral support, such as autologous bone or allogrefts, or metallic elements for fusion. The incision is then closed layer by layer. Another approach for cervical herniations is the posterior approach, which is basically identical to surgical treatment for lumbar disc surgery. The decision of which route to employ is arrived after complete workup of a patient. Future treatments may include stem cell therapy. Doctors Victor Y. L. Leung, Danny Chan and Kenneth M. C. Cheung have reported in the European Spine Journal that "substantial progress has been made in the field of stem cell regeneration of the inter vertebral disc. Autogenic mesenchymal stem cells in animal models can arrest inter vertebral disc degeneration or even partially regenerate it and the effect is suggested to be dependent on the severity of the degeneration." Spinal stenosisSpinal stenosis is a medical condition in which the spinal canal narrows and compresses the spinal cord and nerves. This is usually due to the natural process of spinal degeneration that occurs with aging. It can also sometimes be caused by spinal disc herniation, osteoporosis, or a tumour. Spinal stenosis may affect the cervical spine, the lumbar spine or both. Lumbar spinal stenosis results in low back pain as well as pain or abnormal sensations in the legs Cervical spinal stenosisThe main causes of cervical spinal stenosis (CSS) include cervical spondylosis, diffuse idiopathic skeletal hyperostosis (DISH), or calcification of the posterior longitudinal ligament. CSS is more common in males than females, and is mainly found in the 40-60 year age group. Signs of CSS include spastic gait; upper extremity numbness; upper extremity, lower extremity weakness or both; radicular pain in the upper limb; sphincter disturbances; muscle wasting; sensory deficits; and reflex abnormalities. The best diagnostic and investigative tool is magnetic resonance imaging (MRI), while computed tomography (CT) is not useful. If the problem is mild, treatment may be as simple as physical therapy and the use of a cervical collar. If severe, treatments include laminectomy, hemilaminectomy, or decompression. Lumbar spinal stenosisThe main causes of lumbar spinal stenosis (LSS) include hypertrophy of the facet joints; spondylolisthesis; diffuse idiopathic skeletal hyperostosis (DISH); and degenerative disc disease. Usually, this condition occurs after the age of 50, and both genders are equally affected. Signs of LSS include neurogenic intermittent claudication that causes leg pain, weakness, tingling and loss of deep tendon reflexes. With lumbar spinal stenosis, the patient's pain usually is worse while walking and will feel better after sitting down. The patient is usually more comfortable while leaning forward, such as walking while leaning on a shopping cart. DiagnosisAs with CSS, MRI is the best imaging procedure, though unlike with CSS, CT may be somewhat useful, and can be used if MRI is unavailable. Slippage is graded on the lateral radiography
TreatmentTreatment includes weight loss, and activity modification, such as using a walker to promote a certain posture. Epidural steroid injections may also help relieve the leg pain. If the symptoms are more severe, a laminectomy or foraminotomy may be indicated to take pressure off the spinal nerve. A new procedure, Interspinous Process Decompression (IPD) has recently been approved by the FDA in November of 2005. This procedure promises a less invasive way to treat LSS and maintains motion at the affected level. Recent developments include several new implants used in surgery to treat the symptoms of spinal stenosis, while preserving as much normal motion in the spine as possible. Three newer technologies include the X-Stop, the Wallis, and TOPS implants. These titanium implants act to prevent extension of the stenotic segments and create slight flexion over the segment. Top
HydrocephalusHydrocephalus, sometimes known as Water on the Brain is a condition in which abnormal accumulation of cerebrospinal fluid (CSF) in the brain causes increased intra cranial pressure inside the skull. This is usually due to blockage of CSF outflow in the brain ventricles or in the subarachnoid space at the base of the brain. ExplanationThe elevated intra cranial pressure may cause compression of the brain, leading to brain damage and other complications. The term "hydrocephalus" is derived from the Greek language and means "water-head". Many people with hydrocephalus vary with the conditions that they have. Children who have had hydrocephalus may have very small ventricles, and presented as the "normal case". This is the problem with this condition. Hydrocephalus affects one in every 500 live births, making it one of the most common birth defects, even more common than Down syndrome or deafness. According to the NIH web site, there are an estimated 700,000 children and adults living with hydrocephalus, and it is the leading cause of brain surgery for children in the United States. There are over 180 different causes of the condition, one of the most common being brain hemorrhage associated with premature birth. One of the most performed treatments for hydrocephalus, the cerebral shunt, has not changed since it was developed in 1960. The shunt must be implanted through neurosurgery into the patient's brain, a procedure which itself may cause brain damage. An estimated 50% of all shunts fail within two years, requiring further surgery to replace the shunts. In the past 25 years, death rates associated with hydrocephalus have decreased from 54% to 5% and the occurrence of intellectual disability has decreased from 62% to 30%. In the United States, the health care costs for hydrocephalus exceed $1 billion per year, but is still much less funded than research on other diseases including juvenile diabetes. SymptomsSymptoms of increased intra cranial pressure may include headaches, vomiting, nausea, papilledema, sleepiness, or coma, or death. Elevated intra cranial pressure may result in uncal and/or cerebellar tonsil herniation, with resulting life threatening brain stem compression. For details on other manifestations of increased intra cranial pressure: The triad (Hakim triad) of gait instability, urinary incontinence and dementia is a relatively typical manifestation of the distinct entity normal pressure hydrocephalus (NPH). The triad can easily be remembered as "Wacky, Wet, and Wobbly!" Focal neurological deficits may also occur, such as abducens nerve palsy and vertical gaze palsy (Parinaud syndrome due to compression of the quadrigeminal plate, where the neural centers coordinating the conjugated vertical eye movement are located). Effects Because hydrocephalus injures the brain, thought and behavior may be adversely affected. Learning disabilities are common among those with hydrocephalus, who tend to score better on verbal IQ than on performance IQ, which is thought to reflect the distribution of nerve damage to the brain. However, the severity of hydrocephalus differs considerably between individuals and some are of average or above average intelligence. Someone with hydrocephalus may have motivation and visual problems, problems with coordination, and may be clumsy. They may hit puberty earlier than the average. About one in four develops epilepsy. Because the problem resides inside the head, doctors rely heavily upon computer tomography scanning (CT scans), which may be used frequently to evaluate the condition of the disorder throughout the patient's life. Each CT scan exposes the patient to many times the level of x-ray radiation of a chest x-ray. See CT radiation exposure. TreatmentHydrocephalus treatment is surgical. It involves the placement of a ventricular catheter (a tube made of silastic), into the cerebral ventricles to bypass the flow obstruction/malfunctioning arachnoidal granulations and drain the excess fluid into other body cavities, from where it can be resorbed. Most shunts drain the fluid into the peritoneal cavity (ventriculo-peritoneal shunt), but alternative sites include the right atrium (ventriculo-atrial shunt), pleural cavity (ventriculo-pleural shunt), and gallbladder. A shunt system can also be placed in the lumbar space of the spine and have the csf redirected to the peritoneal cavity(LP Shunt). An alternative treatment for obstructive hydrocephalus in selected patients is the endoscopic third ventriculostomy (ETV), whereby a surgically created opening in the floor of the third ventricle allows the CSF to flow directly to the basal cisterns, thereby shortcutting any obstruction, as in aqueductal stenosis. This may or may not be appropriate based on individual anatomy. Head injury is a trauma to the head, that may or may not include injury to the brain (see also brain injury).The incidence (number of new cases) of head injury is 300 per 100,000 per year (0.3% of the population), with a mortality of 25 per 100,000 in North America and 9 per 100,000 in Britain. Head trauma is a common cause of childhood hospitalization. Contents
CausesCommon causes of head injury are traffic accidents, home and occupational accidents, falls, and assaults. Bicycle accidents are also a common cause of head injury-related death and disability, especially among children. Types of head injuryHead injuries include both injuries to the brain and those to other parts of the head, such as the scalp and skull. Head injuries may be closed or open. A closed (non-missile) head injury is one in which the skull is not broken. A penetrating head injury occurs when an object pierces the skull and breaches the dura mate Brain injuries may be diffuse, occurring over a wide area, or focal, located in a small, specific area. A head injury may cause a skull fracture, which may or may not be associated with injury to the brain. Some patients may have linear or depressed skull fractures. If intra cranial hemorrhage, or bleeding within the brain occurs, a hematoma within the skull can put pressure on the brain. Types of intra cranial hematoma include subdural, subarachnoid, extradural, and intraparenchymal hematoma. Craniotomy surgeries are used in these cases to lessen the pressure by draining off blood. Brain injury can be at the site of impact, but can also be at the opposite side of the skull due to a contrecoup effect (the impact to the head can cause the brain to move within the skull, causing the brain to impact the interior of the skull opposite the head-impact). If the impact causes the head to move, the injury may be worsened, because the brain may ricochet inside the skull (causing additional impacts), or the brain may stay relatively still (due to inertia) but be hit by the moving skull. Specific problems after head injury can include:
ConcussionMild concussions are not associated with any sequelae. However, a slightly greater injury can be associated with both anterograde and retrograde amnesia (inability to remember events before or after the injury). The amount of time that the amnesia is present correlates with the severity of the injury. In some cases the patients may develop postconcussion syndrome, which can include memory problems, dizziness, and depression. Cerebral concussion is the most common head injury seen in children. Epidural hematomaEpidural hematoma (EDH) is a rapidly accumulating hematoma between the dura mater and the cranium. These patients have a history of head trauma with loss of consciousness, then a lucid period, followed by loss of consciousness. Clinical onset occurs over minutes to hours. Many of these injuries are associated with lacerations of the middle meningeal artery. A "lenticular", or convex, lens-shaped extracerebral hemorrhage will likely be visible on a CT scan of the head. Although death is a potential complication, the prognosis is good when this injury is recognized and treated. Subdural hematomaSubdural hematoma occurs when there is tearing of the bridging vein between the cerebral cortex and a draining venous sinus. At times they may be caused by arterial lacerations on the brain surface. Patients may have a history of loss of consciousness but they recover and do not relapse. Clinical onset occurs over hours. A crescent shaped hemorrhage compressing the brain will be noted on CT of the head. Surgical evacuation is the treatment. Complications include uncal herniation, focal neurologic deficits, and death. The prognosis is guarded. Cerebral contusionCerebral contusion is bruising of the brain tissue. The majority of contusions occur in the frontal and temporal lobes. Complications may include cerebral edema and transtentorial herniation. The goal of treatment should be to treat the increased intra cranial pressure. The prognosis is guarded. Diffuse axonal injuryDiffuse axonal injury, or DAI, usually occurs as the result of an acceleration or deceleration motion, not necessarily an impact. Axons are stretched and damaged when parts of the brain of differing density slide over one another. Prognoses vary widely depending on the extent of damage. SymptomsPresentation varies according to the injury. Some patients with head trauma stabilize and other patients deteriorate. A patient may present with or without neurologic deficit. Patients with concussion may have a history of seconds to minutes unconsciousness, then normal arousal. Disturbance of vision and equilibrium may also occur. Common symptoms of head injury include those indicative of traumatic brain injury:
Because brain injuries can be life threatening, even people with apparently slight injuries, with no noticeable signs or complaints, require close observation. The caretakers of those patients with mild trauma who are released from the hospital are frequently advised to rouse the patient several times during the next 12 to 24 hours to assess for worsening symptoms. The Glasgow Coma Scale is a tool for measuring degree of unconsciousness and is thus a useful tool for determining severity of injury. The Pediatric Glasgow Coma Scale is used in young children. Diagnosis and prognosisHead injury may be associated with a neck injury. Bruises on the back or neck, back pain, pain radiating to the arms is a sign of cervical spine injury meriting and application of a cervical collar. It is common for head trauma patients to have drowsiness but to be easily aroused, headaches, and vomiting after injury. If exam and consciousness are preserved, this is of no concern. But if these symptoms persist 1 or 2 days, a CT of the head is needed. In some cases transient neurologic disturbance may occur, lasting minutes to hours and causing occipital blindness and a state of confusion. Malignant post traumatic cerebral swelling can develop unexpectedly in stable patients after an injury, as can post traumatic seizures. Recovery in children with neurologic deficits will vary. Children with neurologic deficits who improve daily are more likely to recover. Children who are vegetative for months are less likely to improve. Most patients without deficits have full recovery. However, persons who sustain head trauma resulting in unconsciousness for an hour or more have twice the risk of developing Alzheimer's disease later in life. ManagementUnfortunately, once the brain has been damaged by trauma, there is no quick fix. However, there are some steps that can be taken to prevent secondary damage. If left untreated many patients with head injury will rapidly develop complications which may lead to death or permanent disability. Prompt medical treatment may prevent the worsening of symptoms and lead to a better outcome. Medical treatment should begin at the scene of the trauma. Paramedics will generally immobilize the patient to insure no further damage to the spine or nervous system, insert an airway to insure uninterrupted breathing, and perform endotracheal intubation if indicated. One or more IVs will be inserted to maintain perfusion status. In some cases medications may be administered to sedate or paralyze the patient to prevent additional movement which may worsen the brain injury. The patient should be delivered promptly to a hospital with neurosurgical capabilities. The management of brain injury requires the involvement of sub specialists who are generally available only at larger hospitals. TopPhysical traumaIntensive care bed after a trauma intervention, showing the highly technical equipment of modern hospitals .Physical trauma refers to a physical injury. A trauma patient is someone who has suffered serious and life-threatening physical injury potentially resulting in secondary complications such as shock, respiratory failure and death. SPECIALIZED CAREWhat is trauma?Trauma patients require specialized care, including surgery and sometimes blood transfusion, within the so-called golden hour of emergency medicine, the first sixty minutes after trauma occurs. This is not a strict deadline, but recognizes that many deaths which could have been prevented by appropriate care occur a relatively short time after injury. In many places organized trauma referral systems have been set up to provide rapid care for injured people. Research has shown that deaths from physical trauma decline where there are organized trauma systems. TechniquesIn a pre hospital setting, also called the "field", emergency medical technicians, paramedics, specialized nurses, and less trained providers known as 'first responders', use stabilization techniques to improve the chances of a trauma patient surviving the ambulance trip to the hospital. Professionals begin performing a primary survey, consisting of assessment of airway, breathing, and circulation (called the "ABC's"). The purpose of the primary survey is to identify life-threatening problems. Ensuring that the injured person is not disabled by unnecessary movement of the spine is paramount, so the neck and back are secured before moving the patient. Unless the victim is in imminent danger of death, first responders will usually "load and go" transporting the victim immediately to the nearest appropriate trauma-equipped hospital. Upon completion of the primary survey, the secondary survey is begun. This may occur during transport or upon arrival at the hospital. The secondary survey consists of a systematic assessment of the abdominal, pelvic and thoracic viscera, complete inspection of the body surface to find all injuries, and neurological exam. The purpose of the secondary survey is to identify all injuries so that they may be treated. A missed injury is one which is not found during the initial assessment (for example, as a patient is brought into a hospital's Emergency Department), but rather manifests itself at a later point in time, sometimes with baleful consequences (i.e., a liver laceration is sometimes missed and a patient sent home, who will abruptly go into shock shortly thereafter.) The appropriate first aid for a trauma patient is to immediately call for help using the emergency medical service, then treat for shock. Do not move the victim unless failure to do so would create a greater risk to their life (i.e. hazardous chemicals or a spreading fire). Also see wilderness first aid if immediate emergency help is unavailable. In case of traumatic accidents, health care providers use the ABC of life (airway, breathing and circulation) as their primary survey in identifying and assessing the condition of the patient. Airway is considered as the most important factor to be assessed then the breathing and circulation. From this technique the appropriate intervention will be identified immediately and prioritization of action can be done according to the most important aspect to be assessed Recent studiesRecently there has been some new research into how to treat physical trauma by comparing different practices and experiences in military conflicts. For example in the Falklands War the British military lost most of their helicopter support when the Atlantic Conveyor was sunk by an Argentine Exocet, resulting in no fast way to evacuate the wounded from the battlefield. Therefore any soldiers who suffered wounds lay where they fell in bitterly cold weather for hours with no blood transfusion, surgery or medication available. The opposite scenario was known from the Vietnam War in which wounded U.S. soldiers were usually quickly airlifted from the battlefield, kept warm and given aggressive medical treatment. The interesting statistic that is being analysed is why the casualty to fatality ratio in the Falklands War was still significantly lower than in the Vietnam War. See also
Brain tumorsA brain tumor is any intracranial tumor created by abnormal and uncontrolled cell division, normally either found in the brain itself (neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells), lymphatic tissue, blood vessels), in the cranial nerves (myelin-producing Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors). Primary (true) brain tumors are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain. In the United States in the year 2005, it was estimated that there were 43,800 new cases of brain tumors<Central Brain Tumor Registry of the United States, Primary Brain Tumors in the United States, Stastical Report, 2005 - 2006. which accounted for 1.4 percent of all cancers, 2.4 percent of all cancer deaths, and 20–25 percent of pediatric . Ultimately, it is estimated that there are 13,000 deaths/year as a result of brain tumors CLASSIFICATIONPrimary tumorsMostprimarybrain tumors originate fromglia(gliomas), astrocytes (astrocytomas), oligodendrocytes (oligodendrogliomas), or ependymal cells (ependymoma). There are also mixed forms, with both an astrocytic and an oligodendroglial cell component. These are called mixed gliomas or oligoastrocytomas. Additionally, mixed glio-neuronal tumors (tumors displaying a neuronal, as well as a glial component, e.g. gangliogliomas, disembryoplastic neuroepithelial tumors) and tumors originating from neuronal cells (e.g. gangliocytoma, central gangliocytoma) can also be encountered. Other varieties of primary brain tumors include: primitive neuroectodermal tumors (PNET, e.g. medulloblastoma, medulloepithelioma, neuroblastoma, retinoblastoma, ependymoblastoma), tumors of the pineal parenchyma (e.g. pineocytoma, pineoblastoma), ependymal cell tumors, choroid plexus tumors, neuroepithelial tumors of uncertain origin (e.g. gliomatosis cerebri, astroblastoma), etc. From a histological perspective, astrocytomas, oligondedrogliomas, and oligoastrocytomas may be benign or malignant. Glioblastoma multiforme represents the most aggressive variety of malignant glioma. At the opposite end of the spectrum, there are so-called pilocytic astrocytomas, a distinct variety of astrocytic tumors. The majority of them are located in the [posterior cranial fossa], affect mainly children and young adults, and have a clinically favorable course and prognosis. Another type of primary intracranial tumor is primary cerebral lymphoma, also known as primary CNS lymphoma, which is a type of non-Hodgkin's lymphoma that is much more prevalent in those with severe immunosuppression, e.g. AIDS. In contrast to other types of cancer, primary brain tumors rarely metastasize, and in this rare event, the tumor cells spread within the skull and spinal canal through the cerebrospinal fluid, rather than via bloodstream to other organs. There are various classification systems currently in use for primary brain tumors, the most common being the World Health Organization (WHO) brain tumor classification, introduced in 1993. Secondary tumors and non-tumor lesionsSecondary or metastatic brain tumors originate from malignant tumors (cancers) located primarily in other organs. Their incidence is higher than that of primary brain tumors. The most frequent types of metastatic brain tumors originate in the lung, skin (malignant melanoma), kidney (hypernephroma), breast (breast carcinoma), and colon (colon carcinoma). These tumor cells reach the brain via the blood-stream. Some non-tumoral lesions can mimic tumors of the central nervous system. These include tuberculosis of the brain, cerebral abscess (commonly in toxoplasmosis), and hamartomas (for example, in tuberous sclerosis and von Recklinghausen neurofibromatosis). Symptoms of brain tumors may depend on two factors: tumor size (volume) and tumor location. The time point of symptom onset in the course of disease correlates in many cases with the nature of the tumor ("benign", i.e. slow-growing/late symptom onset, or malignant, i.e. fast growing/early symptom onset). Many low-grade (benign) tumors can remain asymptomatic (symptom-free) for years and they may accidentally be discovered by imaging exams for unrelated reasons (such as a minor trauma). New onset of epilepsy is a frequent reason for seeking medical attention in brain tumor cases. Large tumors or tumors with extensive perifocal swelling edema inevitably lead to elevated intracranial pressure (intracranial hypertension), which translates clinically into headaches, vomiting (sometimes without nausea), altered state of consciousness (somnolence, coma), dilatation of the pupil on the side of the lesion (anisocoria), papillede prominent optic disc at the funduscopic examination). However, even small tumors obstructing the passage of cerebrospinal fluid (CSF) may cause early signs of increased intracranial pressure. Increased intracranial pressure may result in herniation (i.e. displacement) of certain parts of the brain, such as the cerebellar tonsils or the temporal uncus, resulting in lethal brainstem compression. In young children, elevated intracranial pressure may cause an increase in the diameter of the skull and bulging of the fontanelles. Depending on the tumor location and the damage it may have caused to surrounding brain structures, either through compression or infiltration, any type of focal neurologic symptoms may occur, such as cognitive and behavioral impairment, personality changes, hemiparesis, (hemi) hypesthesia, aphasia, ataxia, visual field impairment, facial paralysis, double vision, tremor etc. These symptoms are not specific for brain tumors - they may be caused by a large variety of neurologic conditions (e.g. stroke, traumatic brain injury). What counts, however, is the location of the lesion and the functional systems (e.g. motor, sensory, visual, etc.) it affects. A bilateral temporal visual field defect (bitemporal hemianopia—due to compression of the optic chiasm), often associated with endocrine disfunction—either hypopituitarism or hyperproduction of pituitary hormones and hyperprolactinemia is suggestive of a pituitary tumor. DiagnosisAlthough there is no specific clinical symptom or sign for brain tumors, slowly progressive focal neurologic signs and signs of elevated intracranial pressure, as well as epilepsy in a patient with a negative history for epilepsy should raise red flags. However, a sudden onset of symptoms, such as an epileptic seizure in a patient with no prior history of epilepsy, sudden intracranial hypertension (this may be due to bleeding within the tumor, brain swelling or obstruction of cerebrospinal fluid's passage) is also possible. Imaging plays a central role in the diagnosis of brain tumors. Early imaging methods—invasive and sometimes dangerous—such as pneumoencephalography and cerebral angiography, have been abandoned in recent times in favor of non-invasive, high-resolution modalities, such as computed tomography (CT) and especially magnetic resonance imaging (MRI). Benign brain tumors often show up as hypodense (darker than brain tissue) mass lesions on cranial CT-scans. On MRI, they appear either hypo- (darker than brain tissue) or isointense (same intensity as brain tissue) on T1-weighted scans, or hyperintense (brighter than brain tissue) on T2-weighted MRI. Perifocal edema also appears hyperintense on T2-weighted MRI. Contrast agent uptake, sometimes in characteristic patterns, can be demonstrated on either CT or MRI-scans in most malignant primary and metastatic brain tumors. This is due to the fact that these tumors disrupt the normal functioning of the blood-brain barrier and lead to an increase in its permeability. Electrophysiological exams, such as electroencephalography (EEG) play a marginal role in the diagnosis of brain tumors. The definitive diagnosis of brain tumor can only be confirmed by histological examination of tumor tissue samples obtained either by means of brain biopsy or open surgery. The histologic examination is essential for determining the appropriate treatment and the correct prognosis. Treatment and prognosisMeningiomas, with the exception of some tumors located at the skull base, can be successfully removed surgically, but the chances are less than 50%. In more difficult cases, stereotactic radiosurgery, such as Gamma Knife radiosurgery, remains a viable option. Most pituitary adenomas can be removed surgically, often using a minimally invasive approach through the nasal cavity and skull base (trans-nasal, trans-sphenoidal approach). Large pituitary adenomas require a craniotomy (opening of the skull) for their removal. Radiotherapy, including stereotactic approaches, is reserved for the inoperable cases. Although there is no generally accepted therapeutic management for primary brain tumors, a surgical attempt at tumor removal or at least cytoreduction (that is, removal of as much tumor as possible, in order to reduce the number of tumor cells available for proliferation) is considered in most cases However, due to the infiltrative nature of these lesions, tumor recurrence, even following an apparently complete surgical removal, is not uncommon. Postoperative radiotherapy and chemotherapy are integral parts of the therapeutic standard for malignant tumors. Radiotherapy may also be administered in cases of "low-grade" gliomas, when a significant tumor burden reduction could not be achieved surgically. Survival rates in primary brain tumors depend on the type of tumor, age, functional status of the patient, the extent of surgical tumor removal, to mention just a few factors. Patients with benign gliomas may survive for many years while survival in most cases of glioblastoma multiforme is limited to a few months after diagnosis. The main treatment option for single metastatic tumors is surgical removal, followed by radiotherapy and/or chemotherapy. Multiple metastatic tumors are generally treated with radiotherapy and chemotherapy. Stereotactic radiosurgery, such as Gamma Knife radiosurgery, remains a viable option. However, the prognosis in such cases is determined by the primary tumor, and it is generally poor. Symptoms include phantom odors and tastes. Often, in the case of metastatic tumors, the smell of galvanised vulcan rubber is prevalent. This claim needs references to reliable sources since March 2007"citation needed A shunt operation is used not as a cure but to relieve the symptoms. The hydrocephalus caused by the blocking drainageof the cerebrospinal fluid can be removed with this operation. TopCerebral aneurysmA cerebral aneurysm or brain aneurysm is a cerebrovascular disorder in which weakness in the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel. LocationsA common location of cerebral aneurysms is on the arteries at the base of the brain, known as the Circle of Willis. Approximately 85% of cerebral aneurysms develop in the anterior part of the Circle of Willis, and involve the internal carotid arteries and their major branches that supply the anterior and middle sections of the brain. The most common sites include the anterior communicating artery (30-35%), the bifurcation of the internal carotid and posterior communicating artery (30-35%), the bifurcation of the middle cerebral artery (20%), the bifurcation of the basilar artery, and the remaining posterior circulation arteries (5%). Causes of cerebral aneurysmsAneurysms may result from congenital defects, preexisting conditions such as high blood pressure and atherosclerosis (the buildup of fatty deposits in the arteries), or head trauma. Cerebral aneurysms occur more commonly in adults than in children but they may occur at any age. They are slightly more common in women than in men. The pursuit to identify Genetics of Intracranial Aneurysms has identified a number of locations, most recently 1p34-36, 2p14-15, 7q11, 11q25, and 19q13.1-13.3. Classification of cerebral aneurysmsCerebral aneurysms are classified both by size and shape. Small aneurysms have a diameter of less than 15mm. Larger aneurysms include those classified as large (15 to 25mm), giant (25 to 50mm), and super giant (over 50mm). Saccular aneurysms are those with a saccular outpouching and are the most common form of cerebral aneurysm. Berry aneurysms are saccular aneurysms with necks or stems resembling a berry. Fusiform aneurysms are aneurysms without stems. Symptoms of aneurysmsA small, unchanging aneurysm will produce no symptoms. Before a larger aneurysm ruptures, the individual may experience such symptoms as a sudden and unusually severe headache, nausea, vision impairment, vomiting, and loss of consciousness, or the individual may be asymptomatic, experiencing no symptoms at all. Onset is usually sudden and without warning. Rupture of a cerebral aneurysm is dangerous and usually results in bleeding into the meninges or the brain itself, leading to a subarachnoid hemorrhage (SAH) or intracranial hematoma (ICH), either of which constitutes a strke. Rebleeding, hydrocephalus (the excessive accumulation of cerebrospinal fluid), vasospasm (spasm, or narrowing, of the blood vessels), or multiple aneurysms may also occur. The risk of rupture from an unruptured cerebral aneurysm varies according to the size of an aneurysm, with the risk rising as the aneurysm size increases. The overall rate of aneurysm rupture is estimated at 1.3% per year. The risk of short term re-rupture increases dramatically after an aneurysm has bled, though after approximately 6 weeks the risk returns to baseline. In outlining symptoms of ruptured cerebral aneurysm, it is useful to make use of the Hunt and Hess scale of subarachnoid hemorrhage severity:
The Fischer Grade classifies the appearance of subarachnoid hemorrhage on CT scan:
The Fischer Grade is most useful in communicating the description of SAH. It is less useful prognostically than the Hunt-Hess scale. VasospasmOne complication of aneurysmal subarachnoid hemorrhage is the development of vasospasm. Approximately 1 to 2 weeks following the initial hemorrhage, patients may experience 'spasm' of the cerebral arteries, which can result in stroke. The etiology of vasospasm is thought to be secondary to an inflammatory process that occurs as the blood in the subarachnoid space is resorbed. Vasospasm is monitored in a variety of ways. Non-invasive methods include transcranial Doppler, which is a method of measuring the velocity of blood in the cerebral arteries using ultrasound. As the vessels narrow due to vasospasm, the velocity of blood increases. The amount of blood reaching the brain can also be measured by or MRI or nuclear perfusion scanning. The definitive, but invasive method of detecting vasospasm is cerebral angiography. It is generally agreed that in order to prevent or reduce the risk of permanent neurological deficits, or even death, vasospasm should be treated aggressively. This is usually performed by early delivery of drug and fluid therapy, or 'Triple H' (hypertensive-hypervolemic-hemodilution therapy) (which elevates blood pressure, increases blod volume, and thins the blood) to drive blood flow through and around blocked arteries. For patients who are refractive (resistant) to Triple H therapy, narrowed arteries in the brain can be treated with medication delivered into the arteries that are in spasm and with balloon angioplasty to widen the arteries and increase blood flow to the brain. Although the effectiveness of these treatments is well established, angioplasty and other treatments delivered by interventional radiologists have been in evolution over the past several years. It is generally recommended that aneurysms be evaluated at specialty centers which provide both neurosurgical and interventional radiology treatment and which also permit angioplasty, if needed, without transfer. TreatmentEmergency treatment for individuals with a ruptured cerebral aneurysm generally includes restoring deteriorating respiration and reducing intracranial pressure. Surgery is usually performed within the first three days to occlude the ruptured aneurysm and reduce the risk of rebleeding. Traditionally this was performed by neurosurgeons clipping the aneurysm, but increasingly this is performed by interventional neuroradiologists placing coils in the aneurysm. This new technique is less invasive. During these procedures, a thin, hollow tube (catheter) is inserted in the groin area and threaded through the blood vessels to the site of the aneurysm in the brain. Once the catheter reaches the aneurysm, tiny platinum coils are placed inside blocking blood flow and preventing rebleeding. PrognosisThe prognosis for a patient with a ruptured cerebral aneurysm depends on the extent and location of the aneurysm, the person's age, general health, and neurological condition. Some individuals with a ruptured cerebral aneurysm die from the initial bleeding. Other individuals with cerebral aneurysm recover with little or no neurological deficit. The most significant factors in determining outcome are grade (see Hunt and Hess grade above) and age. Generally patients with Hunt and Hess grade I and II hemorrhage on admission to the emergency room and patients who are younger within the typical age range of vulnerability can anticipate a good outcome, without death or permanent disability. Older patients and those with poorer Hunt and Hess grades on admission have a poor prognosis. Generally,about two thirds of patients have a poor outcome, death or permanent disability. |
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Neurosurgery is the medical specialty concerned with the diagnosis and treatment of the entire nervous system, composed of the brain, spinal cord and spinal column, as well as the nerves that travel through all parts of the body. A neurological surgeon may provide either surgical or non-surgical care, depending on the nature of the injury or illness.
Disc herniation can occur in any disc in the spine, but the two most common forms are the cervical disc herniation and the lumbar disc herniation. The latter is the most common, causing lower back pain (lumbago) and often leg pain as well, in which case it is commonly referred to as sciatica.