Module 7: Nervous system Pathology Notes

diagnosis of Meningitis

Diagnosis begins with blood tests to look for markers of inflammation. A neurological exam is done and involves a series of tests designed to assess motor and sensory function, nerve function, hearing and speech, vision, coordination and balance and mental status. The most important test in identifying or ruling out meningitis is analysis of the CSF through lumbar puncture. CT, MRI and EEG are also done

diagnosis Herniated nucleus pulposus

A physical examination and history of pain may be all that is needed to diagnose a herniated disk. A neurological examination will evaluate muscle reflexes, sensation, and muscle strength. Often, examination of the spine will reveal a decrease in the spinal curvature in the affected area. EMG may be done to determine the exact nerve root(s) that is (are) involved. Nerve conduction velocity test may also be done. Myelogram may be done to determine the size and location of disk herniation. Spine MRI or spine CT will show spinal canal compression by the herniated disk. Spine x-ray may be done to rule out other causes of back or neck pain. However, it is not possible to diagnosis herniated disk by spinal x-ray alone.

etiology Meningitis

The inflammation is usually caused by infection with viruses, bacteria, or other microorganisms but may also arise due to certain drugs, or other diseases. Most cases are due to infection with viruses, followed by bacteria, fungi, and parasites. Viruses that can cause meningitis include herpes simplex virus 2, varicella zoster virus (known for causing chickenpox and shingles), mumps virus, and HIV. The types of bacteria that cause bacterial meningitis vary by age group. The term aseptic meningitis refers loosely to all cases of meningitis in which no bacterial infection can be demonstrated. This is usually due to viruses, but it may be due to bacterial infection that has already been partially treated, with disappearance of the bacteria from the meninges, or by infection in a space adjacent to the meninges. Meningitis may occur as the result of a number of non-infectious causes: spread of cancer to the meninges, and certain drugs (mainly non-steroidal anti-inflammatory drugs, antibiotics and intravenous immunoglobulins). It may also be encountered in several inflammatory conditions such as sarcoidosis, connective tissue disorders such as systemic lupus erythematosus, and certain forms of vasculitis. Meningitis is potentially life threatening due to the inflammation's proximity to the brain and spinal cord; it is therefore a medical emergency.

describe Glioma

A glioma is a type of cancer that starts in the brain or spine. It is called a glioma because it arises from glial cells. The most common site of gliomas is the brain. Gliomas are classified by cell type, by grade, and by location. By type of cell Gliomas are named according to the specific type of cell they most closely resemble. The main types of gliomas are: • Ependymomas - ependymal cells • Astrocytomas - astrocytes - Glioblastoma multiforme is the most common astrocytoma. • Oligodendrogliomas - oligodendrocytes • Mixed gliomas, such as oligoastrocytomas, contain cells from different types of glia. By grade Gliomas are further categorized according to their grade, which is determined by pathologic evaluation of the tumor. • Low-grade gliomas are well-differentiated (not anaplastic); these are benign and portend a better prognosis for the patient. • High-grade gliomas are undifferentiated or anaplastic; these are malignant and carry a worse prognosis. By location Gliomas can be classified according to whether they are above or below a membrane in the brain called the tentorium. The tentorium separates the cerebrum, above, from the cerebellum, below. They are referred to as supratentorial, or infratentorial.

Herniated nucleus pulposus description

A herniated nucleus pulposus is a slipped disk along the spinal cord. The condition occurs when all or part of the soft center of a spinal disk is forced through a weakened part of the disk. They occur most often in the lumbar spine. They can also occur in the cervical spine, and less frequently in the thoracic spine.

diagnosis of Acoustic neuroma

A special test for hearing which records responses from the brain-stem called the auditory brainstem response test (ABR) may be done. The results of this test detect the cause of a poorly functioning 8th nerve. Once an abnormality in the ABR test suggesting an AN is found, imaging is done to confirm the diagnosis. A majority of the patients can be diagnosed with CT and MRI. The CT scan has proven to be a powerful tool in locating AN's. The only drawback is that small tumors confined to the internal auditory canal may not show on plain CT scan. Such cases require air or contrast materials to be introduced into the body in order to enhance the tumor. MRI has become the gold standard for diagnosis of AN. Gadolinium is the contrast material used to define & enhance the tumor.

describe Acoustic neuroma

An acoustic neuroma (AN) (sometimes termed a vestibular schwannoma or neurolemmoma) is a benign (non-cancerous) growth that arises on the eighth cranial nerve leading from the brain to the inner ear. This nerve has two distinct parts, one part associated with transmitting sound and the other with sending balance information to the brain from the inner ear. The eigth nerve, along with the facial or seventh cranial nerve, lie adjacent to each other as they pass through the internal auditory canal. This canal is approximately 2 cm (0.8 inches) long and it is generally here that acoustic neuromas originate from the sheath surrounding the eighth nerve. The seventh or facial nerve provides motion to the muscles of facial expression. Acoustic neuromas usually grow slowly over a period of years. They expand in size at their site of origin and when large can displace normal brain tissue. The brain is not invaded by the tumor, but the tumor pushes the brain as it enlarges. The slowly enlarging tumor protrudes from the internal auditory canal into an area behind the temporal bone called the cerebellopontine angle. The tumor now assumes a pear shape with the small end in the internal auditory canal. Larger tumors can press on another nerve in the area (the trigeminal nerve) which is the nerve of facial sensation. Vital functions to sustain life can be threatened when large tumors cause severe pressure on the brainstem and cerebellum. Tumors are typically described as small (less than 1.5 cm), medium (1.5 cm to 2.5 cm) or large (more than 2.5 cm).

etiology Acoustic neuroma

An acoustic neuroma is caused by a change or absence of both of the NF2 tumor suppressor genes in a nerve cell. Every person possesses a pair of NF2 genes in every cell of their body including their nerve cells. One NF2 gene is inherited from the egg cell of the mother and one NF2 gene is inherited from the sperm cell of the father. The NF2 gene is responsible for helping to prevent the formation of tumors in the nerve cells. In particular the NF2 gene helps to prevent acoustic neuromas. Only one unchanged and functioning NF2 gene is necessary to prevent the formation of an acoustic neuroma. If both NF2 genes become changed or missing in one of the myelin sheath cells of the vestibular nerve then an acoustic neuroma will usually develop. Other studies have hinted at exposure to loud noise on a consistent basis may contribute to the formation of AN. One study has shown a relationship of acoustic neuromas to prior exposure to head and neck radiation. There are even controversies over hand-held cellular phones. Whether or not the radiofrequency radiation has anything to do with acoustic neuroma formation remains to be seen. To date, no environmental factor (such as cell phones and diet) has been scientifically proven to cause these tumors.

etiology for Encephalitis

Because encephalitis can be caused by many types of germs, the infection can be spread in several different ways. One of the most dangerous and most common causes of encephalitis is the herpes simplex virus (HSV). HSV is the same virus that causes cold sores around the mouth, but when it attacks the brain it may occasionally be fatal. Fortunately, HSV encephalitis is very rare. Encephalitis can be a very rare complication of Lyme disease transmitted by ticks, or of rabies spread by rabid animals. Mosquitoes can also transmit the viruses for several types of encephalitis, including West Nile encephalitis, St. Louis encephalitis, and Western Equine encephalitis. Over the last several years in the United States, there's been concern about the spread of West Nile virus, which is transmitted to humans by mosquitoes that pick up the virus by biting infected birds. Milder forms of encephalitis can follow or accompany common childhood illnesses, including measles, mumps, chickenpox, rubella (German measles), and mononucleosis. Viruses like chickenpox spread mostly via the fluids of the nose and throat, usually during a cough or sneeze. Less commonly, encephalitis can result from a bacterial infection, such as bacterial meningitis, or it may be a complication of other infectious diseases like syphilis. Certain parasites, like toxoplasmosis, can also cause encephalitis in people with weakened immune systems. Brain inflammation itself is not contagious, but any of the various viruses that cause encephalitis can be.

diagnosis of Glioma

Diagnosing a brain tumor usually begins with an exam by a neurologist, which includes checking vision, hearing, balance, coordination and reflexes. Depending on those results, the physician may request one or more of the tests described below. A biopsy is usually required to diagnose a brain tumor and confirm its type. Imaging tests include: MRI - these are particularly useful because they outline the normal brain structures in detail. CT - using contrast media helps to better distinguish tumors. Angiography - this helps locates blood vessels in and around a tumor Magnetic resonance spectroscopy (MRS), single-photon emission computed tomography (SPECT) or positron emission tomography (PET) scanning also help physicians gauge brain activity and blood flow. These scans can be combined with MRIs to help physicians understand a tumor's effects on brain activity and function. If a brain scan detects a tumor, especially multiple tumors, physicians may test for cancer elsewhere in the body. An X-ray of the head may show skull alterations indicating a tumor or calcium deposits sometimes associated with brain tumors. However, an X-ray is far less sensitive than brain scans and is used less often. A biopsy is usually required to diagnose a brain tumor and confirm its type.

diagnosis for Encephalitis

Doctors use several tests to diagnose encephalitis, including: • CT scans or MRI, to check the brain for swelling, bleeding, or other abnormalities • electroencephalogram (EEG) to check for abnormal brain waves • blood tests to confirm the presence of bacteria or viruses in the blood, and whether a person is producing antibodies in response to a germ • lumbar puncture, or spinal tap, in which cerebrospinal fluid is checked for signs of infection

describe Encephalitis

Encephalitis is an acute inflammation of the brain.

etiology Hydrocephalus

Hydrocephalus can be caused by impaired cerebrospinal fluid (CSF) flow, reabsorption, or excessive CSF production. • The most common cause of hydrocephalus is CSF flow obstruction, hindering the free passage of cerebrospinal fluid through the ventricular system and subarachnoid space (e.g., stenosis, tumors, infections). • Hydrocephalus can also be caused by overproduction of cerebrospinal fluid. Based on its underlying mechanisms, hydrocephalus can be classified into communicating, and non-communicating (obstructive). Both forms can be either congenital, or acquired. Communicating Communicating hydrocephalus, also known as non-obstructive hydrocephalus, is caused by impaired cerebrospinal fluid resorption in the absence of any CSF-flow obstruction. Various neurologic conditions may result in communicating hydrocephalus, including subarachnoid/intraventricular hemorrhage, meningitis, Chiari malformation, and congenital absence of arachnoidal granulations. Non-communicating Non-communicating hydrocephalus, or obstructive hydrocephalus, is caused by a CSF-flow obstruction (either due to external compression or intraventricular mass lesions). Congenital The cranial bones fuse by the end of the third year of life. For head enlargement to occur, hydrocephalus must occur before then. The causes are usually genetic but can also be acquired and usually occur within the first few months of life. In newborns and toddlers with hydrocephalus, the head circumference is enlarged rapidly and soon surpasses the 97th percentile. Since the skull bones have not yet firmly joined together, bulging, firm anterior and posterior fontanelles may be present even when the patient is in an upright position. The infant exhibits fretfulness, poor feeding, and frequent vomiting. As the hydrocephalus progresses, torpor sets in, and the infant shows lack of interest in his surroundings. Later on, the upper eyelids become retracted and the eyes are turned downwards. Movements become weak and the arms may become tremulous. There may be reduction of vision. The head becomes so enlarged that the child may eventually be bedridden. About 80-90% of fetuses or newborn infants with spina bifida-often associated with meningocele or myelomeningocele-develop hydrocephalus. Acquired This condition is acquired as a consequence of CNS infections, meningitis, brain tumors, head trauma, intracranial hemorrhage and is usually extremely painful. Another form of hydrocephalus is called normal pressure hydrocephalus. Normal pressure hydrocephalus can happen to people at any age, but it is most common among the elderly. It may result from a subarachnoid hemorrhage, head trauma, infection, tumor, or complications of surgery. However, many people develop normal pressure hydrocephalus even when none of these factors are present for reasons that are unknown.

diagnosis of Hydrocephalus

Hydrocephalus is diagnosed through clinical neurological evaluation and by using cranial imaging techniques such as ultrasonography, CT, MRI, or pressure-monitoring techniques. A physician selects the appropriate diagnostic tool based on an individual's age, clinical presentation, and the presence of known or suspected abnormalities of the brain or spinal cord.

treatment of Hydrocephalus

Hydrocephalus treatment is surgical. It involves the placement of a ventricular shunt system, 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.

symptom of Hydrocephalus

In infancy, the most obvious indication of hydrocephalus is often a rapid increase in head circumference or an unusually large head size. Other symptoms may include vomiting, sleepiness, irritability, downward deviation of the eyes, and seizures. Older children and adults may experience different symptoms because their skulls cannot expand to accommodate the buildup of CSF. Symptoms may include headache followed by vomiting, nausea, papilledema (swelling of the optic disk which is part of the optic nerve), blurred or double vision, sunsetting of the eyes, problems with balance, poor coordination, gait disturbance, urinary incontinence, slowing or loss of developmental progress, lethargy, drowsiness, irritability, or other changes in personality or cognition including memory loss. Symptoms of normal pressure hydrocephalus include, problems with walking, impaired bladder control leading to urinary frequency and/or incontinence, and progressive mental impairment and dementia. Because some of these symptoms may also be experienced in other disorders such as Alzheimer's disease, Parkinson's disease, and Creutzfeldt-Jakob disease, normal pressure hydrocephalus is often incorrectly diagnosed and never properly treated. Doctors may use a variety of tests, including brain scans (CT and/or MRI), a spinal tap or lumbar catheter, intracranial pressure monitoring, and neuropsychological tests, to help them accurately diagnose normal pressure hydrocephalus and rule out any other conditions. Symptoms vary significantly from one person to the next.

etiology of Herniated nucleus pulposus

In most known cases, pain begins with an injury, after lifting a heavy object, or after making a sudden movement. Not all people have back pain after such injuries, however. In the majority of back pain cases, the causes are unknown. Intervertebral disks begin deteriorating and growing thinner by age 30. One-third of adults over 20 show signs of herniated disks (although only 3% of these disks cause symptoms). As people continue to age and the disks lose moisture and shrink, the risk for spinal stenosis increases. The incidence of low back pain and sciatica increases in women at the time of menopause as they lose bone density. Jobs that involve lifting, bending, and twisting into awkward positions, as well as those that cause whole-body vibration (such as long-distance truck driving), place workers at particular risk for herniated disks. The longer a person continues such work, the higher their risk.

diagnosis of Multiple sclerosis

MS diagnosis is based upon an individual's history of clinical symptoms and neurological examination. Lab studies include blood work to exclude other diseases and abnormalities. The examination of cerebrospinal fluid has been used to support the diagnosis of MS. MRI remains the imaging procedure of choice for diagnosing and monitoring disease progression in the brain and spinal cord. This test can show brain abnormalities in 90-95% of patients and spinal cord lesions in up to 75% of cases, especially in elderly patients. However, MRI alone cannot be used to diagnose MS. Evoked potential tests that measure how quickly and accurately a person's nervous system responds to certain stimulation have been the most useful neurophysiological studies for evaluation of MS.

describe Multiple sclerosis

MS is a nerve disorder caused by destruction of the insulating layer surrounding neurons in the brain and spinal cord. This insulation, called myelin, helps electrical signals pass quickly and smoothly between the brain and the rest of the body. When the myelin is destroyed, nerve messages are sent more slowly and less efficiently. Patches of scar tissue, called plaques, form over the affected areas, further disrupting nerve communication. The symptoms of MS occur when the brain and spinal cord nerves no longer communicate properly with other parts of the body. MS causes a wide variety of symptoms and can affect vision, balance, strength, sensation, coordination, and bodily functions.

describe Meningitis

Meningitis is a medical condition that is caused by inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges

symptoms of Multiple sclerosis

Multiple sclerosis signs and symptoms may differ greatly from person to person and over the course of the disease depending on the location of affected nerve fibers. They may include: Numbness or weakness in one or more limbs that typically occurs on one side of your body at a time, or the legs and trunk Partial or complete loss of vision, usually in one eye at a time, often with pain during eye movement Prolonged double vision Tingling or pain in parts of your body Electric-shock sensations that occur with certain neck movements, especially bending the neck forward (Lhermitte sign) Tremor, lack of coordination or unsteady gait Slurred speech Fatigue Dizziness Problems with bowel and bladder function

describe Hydrocephalus

People with hydrocephalus have abnormal accumulation of cerebrospinal fluid (CSF) in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head, convulsion, and mental disability. The ventricular system is made up of four ventricles connected by narrow passages.. Normally, CSF flows through the ventricles, exits into cisterns (closed spaces that serve as reservoirs) at the base of the brain, bathes the surfaces of the brain and spinal cord, and then reabsorbs into the bloodstream. CSF has three important life-sustaining functions: 1) to keep the brain tissue buoyant, acting as a cushion or "shock absorber"; 2) to act as the vehicle for delivering nutrients to the brain and removing waste; and 3) to flow between the cranium and spine and compensate for changes in intracranial blood volume (the amount of blood within the brain). The balance between production and absorption of CSF is critically important. Because CSF is made continuously, medical conditions that block its normal flow or absorption will result in an over-accumulation of CSF. The resulting pressure of the fluid against brain tissue is what causes hydrocephalus.

treatment of Meningitis

Routine immunizations can go a long way toward preventing meningitis. The vaccines agains Hib, measles, mumps, polio, and meningococcus can protect against meningitis caused by these mocroorganisms. Meningitis is potentially life threatening and has a high mortality rate if untreated; delay in treatment has been associated with a poorer outcome. Thus treatment with wide-spectrum antibiotics should not be delayed while confirmatory tests are being conducted. If meningococcal disease is suspected in primary care, guidelines recommend that benzylpenicillin be administered before transfer to hospital. High-flow oxygen should be administered as soon as possible, along with intravenous fluids if hypotension or shock are present. Given that meningitis can cause a number of early severe complications, regular medical review is recommended to identify these complications early, as well as admission to an intensive care unit if deemed necessary.

symptoms for Herniated nucleus pulposus

SYMPTOMS OF HERNIATED LUMBAR DISK Muscle spasm Muscle weakness or atrophy in later stages Pain radiating to the buttocks, legs, and feet Pain made worse with coughing, straining, or laughing Severe low back pain Tingling or numbness in legs or feet SYMPTOMS OF HERNIATED CERVICAL DISK Arm muscle weakness Deep pain near or over the shoulder blades on the affected side Neck pain, especially in the back and sides Increased pain when bending the neck or turning head to the side Pain radiating to the shoulder, upper arm, forearm, and rarely the hand, fingers or chest Pain made worse with coughing, straining, or laughing Spasm of the neck muscles

treatment for Encephalitis

Some children with very mild encephalitis can be monitored at home, but most will need care in a hospital, usually in an intensive care unit. Doctors will carefully monitor their blood pressure, heart rate, and breathing, as well as their body fluids, to prevent further swelling of the brain. Because antibiotics aren't effective against viruses, they aren't used to treat encephalitis. However, antiviral drugs can be used to treat some forms of encephalitis, especially the type caused by the herpes simplex virus. Corticosteroids may also be used in some cases to reduce brain swelling. If a child is having seizures, anticonvulsants may also be given. Over-the-counter medications, like acetaminophen, can be used to treat fever and headaches.

symptoms for Encephalitis

Symptoms in milder cases of encephalitis usually include: • fever • headache • poor appetite • loss of energy • a general sick feeling In more severe cases of encephalitis, a person is more likely to experience high fever and any of a number of symptoms that relate to the central nervous system, including: • severe headache • nausea and vomiting • stiff neck • confusion • disorientation • personality changes • convulsions (seizures) • problems with speech or hearing • hallucinations • memory loss • drowsiness • coma It's harder to detect some of these symptoms in infants, but important signs to look for include: • vomiting • a full or bulging soft spot (fontanel) • crying that doesn't stop or that seems worse when an infant is picked up or handled in some way • body stiffness

symptoms for Glioma

Symptoms of gliomas depend on which part of the central nervous system is affected. A brain glioma can cause headaches, nausea and vomiting, seizures, and cranial nerve disorders as a result of increased intracranial pressure. A glioma of the optic nerve can cause visual loss. Spinal cord gliomas can cause pain, weakness, or numbness in the extremities. Gliomas do not metastasize by the bloodstream, but they can spread via the cerebrospinal fluid. High-grade gliomas are highly-vascular tumors and have a tendency to infiltrate. They have extensive areas of necrosis and hypoxia. Often tumor growth causes a breakdown of the blood-brain barrier in the vicinity of the tumor. As a rule, high-grade gliomas almost always grow back even after complete surgical excision. On the other hand, low-grade gliomas grow slowly, often over many years, and can be followed without treatment unless they grow and cause symptoms

etiology for Glioma

The cause of primary brain tumors is unknown. Some tumors tend to be hereditary so people who inherit specific genes may be more likely to develop a brain tumor. In other cases, a person's genes may change as they grow. Environmental factors such as food, radiation, or chemicals may cause these changes to genes.

etiology of Multiple sclerosis

The causes of multiple sclerosis remain unknown, but it is widely accepted that susceptibility to MS is determined by a complex interaction between susceptibility genes and environment. The most popular current theory is that the disease occurs in people with a genetic susceptibility, who are exposed to some environmental assault (a virus or a toxin) that disrupts the blood-brain barrier, a protective membrane that controls the passage of substances from the blood into the central nervous system. Most researchers consider MS to be an autoimmune disease-one in which the body, through its immune system, launches a defensive attack against its own tissues. Immune factors converge in the nerve cells and trigger inflammation and an autoimmune attack on myelin and axons. Still, a number of disease patterns have been observed in MS patients, and some experts believe that MS may prove to be not a single disorder, but may represent several diseases with different causes.

treatment Herniated nucleus pulposus

The main treatment for a herniated disk is a short period of rest with pain and anti-inflammatory medications, followed by physical therapy. Most people who follow these treatments will recover and return to their normal activities. A small number of people need to have further treatment, which may include steroid injections or surgery. Other treatments include the use of nonsteroidal anti-inflammatory medications, lifestyle changes including physical therapy and the use of braces to support the spine. Steroid injections into the back in the area of the herniated disk can help control pain for several months. Such injections reduce swelling around the disk and relieve many symptoms. Spinal injections are usually done on an outpatient basis using x-ray or fluoroscopy to identify the area where the injection is needed. Surgery may be an option for the few patients whose symptoms persist despite other treatments. Surgeries include; a diskectomy that removes a protruding disk; a microdiskectomy that removes fragments of nucleated disk through a small opening; and chemonucleolysis that involves injecting an enzyme called chymopapain into the herniated disk to dissolve the protruding gelatinous substance.

symptoms of Meningitis

The most common symptoms of meningitis are headache and neck stiffness associated with fever, confusion or altered consciousness, and an inability to tolerate bright light (photophobia) or loud noises (phonophobia). Sometimes, especially in small children, only nonspecific symptoms may be present, such as irritability and drowsiness. If a rash is present, it may indicate a particular cause of meningitis; for instance, meningitis caused by meningococcus bacteria may be accompanied by a characteristic rash.

treatment of Multiple sclerosis

The three goals of drug therapy in the treatment of MS are management of acute episodes, prevention of disease progression, and treatment of chronic symptoms. Specific symptoms that may be treated include muscle spasticity, lack of co-ordination, tremor, fatigue, pain, bladder and bowel dysfunctions, sexual dysfunction and depression. Exacerbations (episodes of worsening symptoms) can be defined as temporary flare-ups, sometimes referred to as attacks or relapses. Most relapses show a degree of spontaneous recovery, but treatment is offered for those relapses that have a severe impact on function. Medications include beta interferons, glatiramer acetate, Tecfidera, Gilenya, Tysabri and more. For primary-progressive MS, ocrelizumab (Ocrevus) is the only FDA-approved disease-modifying therapy. It slows worsening of disability in people with this type of MS.

treatment for Acoustic neuroma

There are 3 treatment options available for AN: 1) Observation 2) Microsurgical removal (partial or total) 3) Stereotactic radiation therapy (radiosurgery) Observation: ANs are occasionally discovered incidentally while evaluating another problem or when the tumor is very small with subtle symptoms. Since ANs are benign tumors and produce symptoms due to pressure on surrounding structures, careful observation over a period of time may be appropriate for some patients. For instance, a small tumor diagnosed in an elderly patient may only require observation to study the growth rate of the tumor if acute symptoms are not present. If it appears that the tumor will not need to be treated during the patient's normal life expectancy, treatment and its potential risks and complications maybe avoided. In these patients, MRI is performed periodically to monitor growth of the tumor. If there is no growth, observation is continued. On the other hand, if the tumor shows increase in size, treatment may become necessary. Microsurgical removal: At the present time, the only treatment that can cure the patient is removal of the tumor by surgery. Within the last 2 decades, microsurgical techniques have been pioneered and refined. Use of the operating microscope, finely scaled surgical instruments, alternate cutting & tumor reducing tools, better anesthesia, have reduced the death rate extremely. In addition, the experience gained by trained surgeons in the delicate removal process of the tumor and minimizing contact with nerves and tissue adjacent to the tumor, have improved the overall results. Stereotactic Radiation Therapy (Radiosurgery): This is a technique based on the principle that a single relatively high dose of radiation delivered precisely to a small area will arrest or kill the tumor while minimizing injury to the surrounding nerves & brain tissue. The source of radiation is from either radioactive cobalt (called gamma ray) or a linear accelerator (LINAC). Radiation, even at relatively high doses such as those used in radiosurgery, does not kill or injure cells immediately. Some tumor cells die in weeks while others die more gradually over 6-18 months after radiation. This treatment usually arrests growth of the tumor and some tumors shrink, but they rarely disappear.

treatment for Glioma

Treatment for brain gliomas depends on the location, the cell type and the grade of malignancy. Often, treatment is a combined approach, using surgery, radiation therapy, and chemotherapy. The radiation therapy is in the form of external beam radiation or the stereotactic approach using radiosurgery. Spinal cord tumors can be treated by surgery and radiation. Temozolomide is a chemotherapeutic drug that is able to cross the blood-brain barrier effectively and is being used in therapy.

symptoms Acoustic neuroma

• Hearing loss • Ringing in the ears (tinnitus) • Dizziness (vertigo) • Difficulty in balance (imbalance or dysequilibrium) • Fullness or pressure in the ears • Facial numbness or paralysis (for very large tumors)